The unfolded protein response pathway is an evolutionarily conserved cytoprotective signaling cascade,essential for cell function and survival.Unfolded protein response signaling is tightly integrated with bone cell d...The unfolded protein response pathway is an evolutionarily conserved cytoprotective signaling cascade,essential for cell function and survival.Unfolded protein response signaling is tightly integrated with bone cell differentiation and function,and chronic unfolded protein response activation has been identified in bone disease.The unfolded protein response has been found to promote oncogenesis and drug resistance,raising the possibility that unfolded protein response modulators may have activity as anti-cancer agents.Cancer-associated bone disease remains a major cause of morbidity for patients with multiple myeloma or bone-metastatic disease.Understanding the critical role of unfolded protein response signaling in cancer development and metastasis,as well as its role in bone homeostasis,may lead to novel mechanisms by which to target cancer-associated bone disease.In this review,we summarize the current research delineating the roles of the unfolded protein response in bone biology and pathophysiology,and furthermore,review unfolded protein response modulating agents in the contexts of cancer and cancer-associated bone disease.展开更多
Chondrocyte senescence is a critical pathological hallmark of osteoarthritis(OA).Aberrant mechanical stress is considered a pivotal determinant in chondrocyte aging;however,the precise underlying mechanism remains elu...Chondrocyte senescence is a critical pathological hallmark of osteoarthritis(OA).Aberrant mechanical stress is considered a pivotal determinant in chondrocyte aging;however,the precise underlying mechanism remains elusive.Our findings demonstrate that SPI1 plays a significant role in counteracting chondrocyte senescence and inhibiting OA progression.SPI1 binds to the PERK promoter,thereby promoting its transcriptional activity.Importantly,PERK,rather than GCN2,facilitates eIF2αphosphorylation,activating the mitochondrial unfolded protein response(UPRmt)and impeding chondrocyte senescence.Deficiency of SPI1 in mechanical overload-induced mice leads to diminished UPRmt activation and accelerated OA progression.Intra-articular injection of adenovirus vectors overexpressing SPI1 and PERK effectively mitigates cartilage degeneration.In summary,our study elucidates the crucial regulatory role of SPI1 in the pathogenesis of chondrocyte senescence by activating UPRmt signaling through PERK,which may present a novel therapeutic target for treating OA.展开更多
Zishen Huoxue decoction(ZSHX)enhances cardiomyocyte viability following hypoxic stress;however,its upstream therapeutic targets remain unclear.Network pharmacology and RNA sequencing analyses revealed that ZSHX target...Zishen Huoxue decoction(ZSHX)enhances cardiomyocyte viability following hypoxic stress;however,its upstream therapeutic targets remain unclear.Network pharmacology and RNA sequencing analyses revealed that ZSHX target genes were closely associated with mitophagy and apoptosis in the mitochondrial pathway.In vitro,ZSHX inhibited pathological mitochondrial fission following hypoxic stress,regulated FUN14 domain-containing protein 1(FUNDC1)-related mitophagy,and increased the levels of mitophagy lysosomes and microtubule-associated protein 1 light chain 3 beta II(LC3II)/translocase of outer mitochondrial membrane 20(TOM20)expression while inhibiting the over-activated mitochondrial unfolded protein response.Additionally,ZSHX regulated the stability of beta-tubulin through Sirtuin 5(SIRT5)and could modulate FUNDC1-related synergistic mechanisms of mitophagy and unfolded protein response in the mitochondria(UPR^(mt))via the SIRT5 and-β-tubulin axis.This targeting pathway may be crucial for cardiomyocytes to resist hypoxia.Collectively,these findings suggest that ZSHX can protect against cardiomyocyte injury via the SIRT5-β-tubulin axis,which may be associated with the synergistic protective mechanism of SIRT5-β-tubulin axis-related mitophagy and UPR^(mt) on cardiomyocytes.展开更多
To tackle the challenges of intractable parameter tun-ing,significant computational expenditure and imprecise model-driven sparse-based direction of arrival(DOA)estimation with array error(AE),this paper proposes a de...To tackle the challenges of intractable parameter tun-ing,significant computational expenditure and imprecise model-driven sparse-based direction of arrival(DOA)estimation with array error(AE),this paper proposes a deep unfolded amplitude-phase error self-calibration network.Firstly,a sparse-based DOA model with an array convex error restriction is established,which gets resolved via an alternating iterative minimization(AIM)algo-rithm.The algorithm is then unrolled to a deep network known as AE-AIM Network(AE-AIM-Net),where all parameters are opti-mized through multi-task learning using the constructed com-plete dataset.The results of the simulation and theoretical analy-sis suggest that the proposed unfolded network achieves lower computational costs compared to typical sparse recovery meth-ods.Furthermore,it maintains excellent estimation performance even in the presence of array magnitude-phase errors.展开更多
Within the cell, several mechanisms exist to maintain homeostasis of the endoplasmic reticulum （ER）. One of the primary mechanisms is the unfolded protein response （UPR）. In this review, we primarily focus on the ...Within the cell, several mechanisms exist to maintain homeostasis of the endoplasmic reticulum （ER）. One of the primary mechanisms is the unfolded protein response （UPR）. In this review, we primarily focus on the latest signal webs and regulation mechanisms of the UPR. The relationships among ER stress, apoptosis, and cancer are also discussed. Under the normal state, binding immunoglobulin protein （BiP） interacts with the three sensors （protein kinase RNA-like ER kinase （PERK）, activating transcription factor 6 （ATF6）, and inositol-requiring enzyme la （IREla）） Under ER stress, misfolded proteins interact with BiP, resulting in the release of BiP from the sensors. Subsequently, the three sensors dimerize and autophosphorylate to promote the signal cascades of ER stress. ER stress includes a series of positive and negative feedback signals, such as those regulating the stabilization of the sensors/BiP complex, activating and inactivating the sensors by autophosphorylation and dephosphorylation, activating specific transcription factors to enable selective transcription, and augmenting the ability to refold and export. Apart from the three basic pathways, vascular endothelial growth factor （VEGF）-VEGF receptor （VEGFR）-phospholipase C-~ （PLCy）-mammalian target of rapamycin complex 1 （mTORC1） pathway, induced only in solid tumors, can also activate ATF6 and PERK signal cascades, and IREla also can be activated by activated RAC-alpha serine/threonine-protein kinase （AKT）. A moderate UPR functions as a pro-survival signal to return the cell to its state of homeostasis. However, persistent ER stress will induce cells to undergo apoptosis in response to increasing reactive oxygen species （ROS）, Ca2＋ in the cytoplasmic matrix, and other apoptosis signal cascades, such as c-Jun N-terminal kinase （JNK）, signal transducer and activator of transcription 3 （STAT3）, and P38, when cellular damage exceeds the capacity of this adaptive response.展开更多
Acute pancreatitis (AP) is an inflammatory disorder of pancreatic tissue initiated in injured acinar cells. Severe AP remains a significant challenge due to the lack of effective treatment. The widely-accepted autodig...Acute pancreatitis (AP) is an inflammatory disorder of pancreatic tissue initiated in injured acinar cells. Severe AP remains a significant challenge due to the lack of effective treatment. The widely-accepted autodigestion theory of AP is now facing challenges, since inhibiting protease activation has negligible effectiveness for AP treatment despite numerous efforts. Furthermore, accumulating evidence supports a new concept that malfunction of a self-protective mechanism, the unfolded protein response(UPR), is the driving force behind the pathogenesis of AP. The UPR is induced by endoplasmic reticulum(ER) stress, a disturbance frequently found in acinar cells, to prevent the aggravation of ER stress that can otherwise lead to cell injury. In addition, the UPR's signaling pathways control NFκB activation and autophagy flux, and these dysregulations cause acinar cell inflammatory injury in AP, but with poorly understood mechanisms. We therefore summarize the protective role of the UPR in AP, propose mechanistic models of how inadequate UPR could promote NFκB's pro-inflammatory activity and impair autophagy's protective function in acinar cells, and discuss its relevance to current AP treatment. We hope that insight provided in this review will help facilitate the research and management of AP.展开更多
Porcine circovirus type 2（PCV2）has recently been reported to elicit the unfolded protein response（UPR）via activation of the PERK/e IF2α（RNA-activated protein kinase-like endoplasmic reticulum（ER）kinase/eukaryo...Porcine circovirus type 2（PCV2）has recently been reported to elicit the unfolded protein response（UPR）via activation of the PERK/e IF2α（RNA-activated protein kinase-like endoplasmic reticulum（ER）kinase/eukaryotic initiation factor 2α）pathway.This study attempted to examine which viral protein might be involved in inducing UPR and whether this cellular event would lead to apoptosis of the cells expressing the viral protein.By transient expression,we found that both replicase（Rep）and capsid（Cap）proteins of PCV2 could induce ER stress as shown by increased phosphorylation of PERK with subsequent activation of the eI F2α-ATF4（activating transcription factor 4）-CHOP（CCAAT/enhancer-binding protein homologous protein）axis.Cap expression,but not Rep,significantly reduced antiapoptotic B-cell lymphoma-2（Bcl-2）and increased caspase-3 cleavage,possibly due to increased expression of CHOP.Since knockdown of PERK by RNA interference clearly reduced Cap-induced CHOP expression,caspase-3cleavage,and apoptotic cell death possibly by partially rescuing Bcl-2 expression,we propose that there is connection between Cap-induced UPR and apoptosis via the PERK/eI F2α/ATF4/CHOP/Bcl-2 pathway.This study,together with our earlier studies,provides insight into the mechanisms underlying PCV2 pathogenesis.展开更多
Alzheimer’s disease has proven to be largely intractable to treatment,despite years of research,and numerous trials of therapies that target the hallmarks of the disease-amyloid plaques and neurofibrillary tangles.Th...Alzheimer’s disease has proven to be largely intractable to treatment,despite years of research,and numerous trials of therapies that target the hallmarks of the disease-amyloid plaques and neurofibrillary tangles.The etiology of Alzheimer’s disease remains elusive.There is a growing body of evidence for an infectious trigger of Alzheimer’s disease,and,in particular,the focus has been on the oral pathogen Porphyromonas gingivalis(P.gingivalis).Reports of the expression of a misfolded form of p53 in non-neuronal cells(fibroblasts,peripheral blood mononuclear cells,and B cells)and serum,which appears several years before clinical symptoms manifest,may provide further support for the role of bacteria in general,and P.gingivalis in particular,in the initiation of the disease.This review presents a model of the pathway from initial oral infection with P.gingivalis to amyloid plaque formation and neuronal degeneration,via the steps of chronic periodontitis;secretion of the inflammagens lipopolysaccharide and gingipains into the bloodstream;induction of an inflammatory response in both peripheral cells and tissues;disruption of the blood-brain barrier,and entry into the central nervous system of the inflammagens and the P.gingivalis bacteria themselves.In this model,the misfolded p53(or“unfolded p53”;up53)is induced in non-neuronal cells and upregulated in serum as a result of oxidative stress due to lipopolysaccharide from P.gingivalis.up53 is therefore a potential biomarker for early diagnosis of the presence of a causative agent of Alzheimer’s disease.Fastidious dental hygiene and aggressive antibiotic treatment may prevent the patient progressing to clinical Alzheimer’s disease if serum up53 is detected at this pre-symptomatic stage.展开更多
The unfolded protein response(UPR)is a cellular stress response pathway activated when the endoplasmic reticulum,a crucial organelle for protein folding and modification,encounters an accumulation of unfolded or misfo...The unfolded protein response(UPR)is a cellular stress response pathway activated when the endoplasmic reticulum,a crucial organelle for protein folding and modification,encounters an accumulation of unfolded or misfolded proteins.The UPR aims to restore endoplasmic reticulum homeostasis by enhancing protein folding capacity,reducing protein biosynthesis,and promoting protein degradation.It also plays a pivotal role in coordinating signaling cascades to determine cell fate and function in response to endoplasmic reticulum stress.Recent research has highlighted the significance of the UPR not only in maintaining endoplasmic reticulum homeostasis but also in influencing various physiological processes in the nervous system.Here,we provide an overview of recent findings that underscore the UPR’s involvement in preserving the function and viability of neuronal and myelinating cells under physiological conditions,and highlight the critical role of the UPR in brain development,memory storage,retinal cone development,myelination,and maintenance of myelin thickness.展开更多
The mitochondrial unfolded protein response(UPRmt)is an evolutionarily conserved adaptive mechanism for improving cell survival under mitochondrial stress.Under physiological and pathological conditions,the UPRmt is t...The mitochondrial unfolded protein response(UPRmt)is an evolutionarily conserved adaptive mechanism for improving cell survival under mitochondrial stress.Under physiological and pathological conditions,the UPRmt is the key to maintaining intracellular homeostasis and proteostasis.Important roles of the UPRmt have been demonstrated in a variety of cell types and in cell development,metabolism,and immune processes.UPRmt dysfunction leads to a variety of pathologies,including cancer,inflammation,neurodegenerative disease,metabolic disease,and immune disease.Stem cells have a special ability to selfrenew and differentiate into a variety of somatic cells and have been shown to exist in a variety of tissues.These cells are involved in development,tissue renewal,and some disease processes.Although the roles and regulatory mechanisms of the UPRmt in somatic cells have been widely reported,the roles of the UPRmt in stem cells are not fully understood.The roles and functions of the UPRmt depend on stem cell type.Therefore,this paper summarizes the potential significance of the UPRmt in embryonic stem cells,tissue stem cells,tumor stem cells,and induced pluripotent stem cells.The purpose of this review is to provide new insights into stem cell differentiation and tumor pathogenesis.展开更多
The retina is one of the most energy demanding tissues in the body. Like most neurons in the central nervous system, retinal neurons consume high amounts of adenosine-5′-triphosphate（ATP） to generate visual signal ...The retina is one of the most energy demanding tissues in the body. Like most neurons in the central nervous system, retinal neurons consume high amounts of adenosine-5′-triphosphate（ATP） to generate visual signal and transmit the information to the brain. Disruptions in retinal metabolism can cause neuronal dysfunction and degeneration resulting in severe visual impairment and even blindness. The homeostasis of retinal metabolism is tightly controlled by multiple signaling pathways, such as the unfolded protein response（UPR）, and the close interactions between retinal neurons and other retinal cell types including vascular cells and Müller glia. The UPR is a highly conserved adaptive cellular response and can be triggered by many physiological stressors and pathophysiological conditions. Activation of the UPR leads to changes in glycolytic rate, ATP production, de novo serine synthesis, and the hexosamine biosynthetic pathway, which are considered critical components of Müller glia metabolism and provide metabolic support to surrounding neurons. When these pathways are disrupted, neurodegeneration occurs rapidly. In this review, we summarize recent advance in studies of the UPR in Müller glia and highlight the potential role of the UPR in retinal degeneration through regulation of Müller glia metabolism.展开更多
The signal transduction network in regulating lipid metabolism is a hot topic of biomedical research. Recent research endeavors reveal that intracellular stress signaling from a cellular organelle called endoplasmic r...The signal transduction network in regulating lipid metabolism is a hot topic of biomedical research. Recent research endeavors reveal that intracellular stress signaling from a cellular organelle called endoplasmic reticulum (ER) is critically involved in lipid homeostasis and the development of metabolic disease. The ER is a site where newly-synthesized proteins are folded and assembled into their three-dimensional structures, modified and transported to their precise cellular destinations. A wide range of biochemical, physiological and pathological stimuli can interrupt the protein folding process in the ER and cause accumulation of unfolded or misfolded proteins in the ER lumen, a condition referred to as ER stress. To cope with this stress condition, the ER has evolved highly-specifi c signaling pathways collectively termed Unfolded Protein Response (UPR) or ER stress response. The UPR regulates transcriptionaland translational programs, affecting broad aspects of cellular metabolism and cell fate. Lipogenesis, the metabolic process of de novo lipid biosynthesis, occurs primarily in the liver where metabolic signals regulate expression of key enzymes in glycolytic and lipogenic pathways. Recent studies suggest that the UPR plays crucial roles in modulating lipogenesis under metabolic conditions. Here we address some of recent representative evidence regarding the role of the UPR in lipogenesis.展开更多
Objective:The purpose of this study was to investigate the role of the unfolded protein response,specifically the inositol-requiring enzyme 1(IRE1)signaling pathway,in hypoxia-induced autophagy in human umbilical veno...Objective:The purpose of this study was to investigate the role of the unfolded protein response,specifically the inositol-requiring enzyme 1(IRE1)signaling pathway,in hypoxia-induced autophagy in human umbilical venous endothelial cells(HUVECs).Methods:The expression of IRE1 and autophagy relative protein in HUVECs with hypoxia was explored by Western blotting,qRT-PCR and confocal microscopy.Further,we evaluated the biological effects of HUVECs by tube formation assay and wound healing assay in vitro.Finally,we examined the function of IRE1 in local blood vessels through animal models,Results:Hypoxia activated the IRE1 signaling pathway and induced autophagy in a time-dependent manner in HUVECs and further influenced the biological effects of HUVECs.Intraperitoneal injection of IRE1 inhibitors inhibited local vascular autophagy levels and lipid accumulation in model animals.Conclusion:Hypoxia can induce autophagy and activate the IRE1 signaling pathway in HUVECs and the IRE1 signaling pathway is involved in autophagy in hypoxic conditions.展开更多
In this work,multiple molecular dynamics simulations of protein G and protein L unfolding trajectories provide a direct demonstration of the diversity of unfolding pathway and give a statistically utmost unfolding pat...In this work,multiple molecular dynamics simulations of protein G and protein L unfolding trajectories provide a direct demonstration of the diversity of unfolding pathway and give a statistically utmost unfolding pathway under the physical property space.展开更多
Direction of arrival(DOA)estimation for unfolded coprime array(UFCA)is discussed,and a method based on subspace compensation is proposed.Conventional DOA estimation meth-ods partition the UFCA into two subarrays for s...Direction of arrival(DOA)estimation for unfolded coprime array(UFCA)is discussed,and a method based on subspace compensation is proposed.Conventional DOA estimation meth-ods partition the UFCA into two subarrays for separate estimations,which are then combined for unique DOA determination.However,the DOA estimation performance loss is caused as only the partial array aperture is exploited.We use the estimations from one subarray as initial estimations,and then enhance the estimation results via a compensation based on the whole array,which is im-plemented via a simple least squares(LS)operation constructed from the initial estimation and first-order Taylor expansion.Compared to conventional methods,the DOA estimation performance is improved while the computational complexity is in the same level.Multiple simulations are con-ducted to verify the efficiency of the proposed approach.展开更多
Preeclampsia is a serious obstetric complication.Currently,there is a lack of effective preventive approaches for this disease.Recent studies have identified transcutaneous auricular vagus nerve stimulation(taVNS)as a...Preeclampsia is a serious obstetric complication.Currently,there is a lack of effective preventive approaches for this disease.Recent studies have identified transcutaneous auricular vagus nerve stimulation(taVNS)as a potential novel non-pharmaceutical therapeutic modality for preeclampsia.In this study,we investigated whether taVNS inhibits apoptosis of placental trophoblastic cells through ROS-induced UPR^(mt).Our results showed that taVNS promoted the release of acetylcholine(ACh).ACh decreased the expression of UPR^(mt) by inhibiting the formation of mitochondrial ROS(mtROS),presumably through M3AChR.This reduced the release of pro-apoptotic proteins(cleaved caspase-3,NF-kB-p65,and cytochrome C)and helped preserve the morphological and functional integrity of mitochondria,thus reducing the apoptosis of placental trophoblasts,improving placental function,and relieving preeclampsia.Our study unravels the potential pathophysiological mechanism of preeclampsia.In-depth characterization of the UPR^(mt) is essential for developing more effective therapeutic strategies for preeclampsia targeting mitochondrial function.展开更多
Introduction:Transplantation of mesenchymal stromal cells(MSCs)is a promising therapy for type 1 diabetes(T1D).However,whether the infused MSCs affect the endoplasmic reticulum stress or subsequent unfolded protein re...Introduction:Transplantation of mesenchymal stromal cells(MSCs)is a promising therapy for type 1 diabetes(T1D).However,whether the infused MSCs affect the endoplasmic reticulum stress or subsequent unfolded protein response inβcells remains unclear.Methods:To investigate this,we induced early-onset T1D in non-obese diabetic mice using streptozotocin.Subsequently,T1D mice were randomly assigned to receive either MSCs or phosphate-buffered saline.We observed the in vivo homing of MSCs and assessed their effectiveness by analyzing blood glucose levels,body weight,histopathology,pancreatic protein expression,and serum levels of cytokines,proinsulin,and C-peptide.Results:Infused MSCs were found in the lungs,liver,spleen,and pancreas of T1D mice.They exhibited various effects,including reducing blood glucose levels,regulating immunity,inhibiting inflammation,increasingβ-cell areas,and reducing the expression of key proteins in the unfolded protein response pathway.Fasting serum proinsulin and C-peptide levels were significantly higher in the MSCs treatment group than in the T1D model group.However,there was no significant difference in the biomarker ofβ-cell endoplasmic reticulum stress,the ratio of fasting serum proinsulin to C-peptide,between the two groups.Conclusion:Ourfindings reveal that MSCs infusion does not alleviate endoplasmic reticulum stress inβcells directly but modulates the unfolded protein response pathway to preserveβ-cell mass and function in T1D mice.展开更多
Outbreaks of diseases are often linked to environmental stress,which can lead to endoplasmic reticulum(ER)stress and subsequently trigger the unfolded protein response(UPR).The replication of the white spot syndrome v...Outbreaks of diseases are often linked to environmental stress,which can lead to endoplasmic reticulum(ER)stress and subsequently trigger the unfolded protein response(UPR).The replication of the white spot syndrome virus(WSSV),the most serious pathogen in shrimp aquaculture,has been shown to rely on the UPR signaling pathway,although the detailed mechanisms remain poorly understood.In this study,we discovered that WSSV enhances its replication by hijacking the UPR pathway via the viral protein wsv406.Our analysis revealed a significant upregulation of wsv406 in the hemocytes and gills of infected shrimp.Mass spectrometry analysis identified that wsv406 interacts specifically with the immunoglobulin heavy-chain-binding protein(BiP)in shrimp Litopenaeus vannamei.Further examination revealed that wsv406 binds to multiple domains of LvBiP,inhibiting its ATPase activity without disrupting its binding to UPR stress receptors.Silencing either wsv406 or LvBiP resulted in a reduction in WSSV replication and improved shrimp survival rates.Further,wsv406 activation of the PRKR-like ER kinase(PERK)-eukaryotic translation initiation factor 2α(eIF2α)and activating transcription factor 6(ATF6)pathways was demonstrated by a decrease in the phosphorylation of eIF2αand the nuclear translocation of ATF6 when wsv406 was silenced during WSSV infection.This activation facilitated the transcription of WSSV genes,promoting viral replication.In summary,these findings reveal that wsv406 manipulates the host UPR by targeting LvBiP,thereby enhancing WSSV replication through the PERK-eIF2αand ATF6 pathways.These insights into the interaction between WSSV and host cellular machinery offer potential targets for developing therapeutic interventions to control WSSV outbreaks in shrimp aquaculture.展开更多
Expand ER stress is triggered due to the loss of homeostasis in the ER which causes the accumulation ofmisfolded proteins within the ER lumen. Severe or prolonged ER stress may induce the unfolded protein response(UPR...Expand ER stress is triggered due to the loss of homeostasis in the ER which causes the accumulation ofmisfolded proteins within the ER lumen. Severe or prolonged ER stress may induce the unfolded protein response(UPR), which is an adaptive mechanism aimed at reducing levels of unfolded proteins and keeping balance in theER. CHOP, Bip, JNK, EIF2 are major elements in these pathways.In this study, we investigated the activation of CHOP, Bip, total JNK and phosphorylated JNK (P-JNK), totalEIF2 and phosphorylated EIF2 (P- EIF2) in response to X-rays in breast cancer MCF-7 and MDA-MB-231 cellsusing western blot analysis.展开更多
Taking spiral chute as example, a method of unfolded drawings and views about irregular spiral surface is introduced. The surface is undevelopable and too complicated to get its views or to draw unfolded drawings by m...Taking spiral chute as example, a method of unfolded drawings and views about irregular spiral surface is introduced. The surface is undevelopable and too complicated to get its views or to draw unfolded drawings by manual method. In this article, a series of the boundary equations of the spiral chute are derived by the movement rule of coal flow, and the solid and views of the spiral chute are generated based on redevelopment of SolidWorks. Unfolded drawing is drawn applying triangular development principle. The views and unfolded drawings not only are produced automatically, precisely and parameterized, but also involve more technological information. So it has an important significance on the irregular spiral surface＇s developments and processing.展开更多
基金supported by the National Institutes of Health(Grants P30 CA036727 and R01 CA258621)and funding from the University of Nebraska Medical Center Graduate Studies Assistantship.
文摘The unfolded protein response pathway is an evolutionarily conserved cytoprotective signaling cascade,essential for cell function and survival.Unfolded protein response signaling is tightly integrated with bone cell differentiation and function,and chronic unfolded protein response activation has been identified in bone disease.The unfolded protein response has been found to promote oncogenesis and drug resistance,raising the possibility that unfolded protein response modulators may have activity as anti-cancer agents.Cancer-associated bone disease remains a major cause of morbidity for patients with multiple myeloma or bone-metastatic disease.Understanding the critical role of unfolded protein response signaling in cancer development and metastasis,as well as its role in bone homeostasis,may lead to novel mechanisms by which to target cancer-associated bone disease.In this review,we summarize the current research delineating the roles of the unfolded protein response in bone biology and pathophysiology,and furthermore,review unfolded protein response modulating agents in the contexts of cancer and cancer-associated bone disease.
基金supported by the Anhui Provincial Natural Science Foundation(Grant No.2308085MH250)the Natural Science Research Project of Anhui Educational Committee(Grant No.2023AH053327)the Scientific Research Fund Project of Anhui Medical University(2020xkj039).
文摘Chondrocyte senescence is a critical pathological hallmark of osteoarthritis(OA).Aberrant mechanical stress is considered a pivotal determinant in chondrocyte aging;however,the precise underlying mechanism remains elusive.Our findings demonstrate that SPI1 plays a significant role in counteracting chondrocyte senescence and inhibiting OA progression.SPI1 binds to the PERK promoter,thereby promoting its transcriptional activity.Importantly,PERK,rather than GCN2,facilitates eIF2αphosphorylation,activating the mitochondrial unfolded protein response(UPRmt)and impeding chondrocyte senescence.Deficiency of SPI1 in mechanical overload-induced mice leads to diminished UPRmt activation and accelerated OA progression.Intra-articular injection of adenovirus vectors overexpressing SPI1 and PERK effectively mitigates cartilage degeneration.In summary,our study elucidates the crucial regulatory role of SPI1 in the pathogenesis of chondrocyte senescence by activating UPRmt signaling through PERK,which may present a novel therapeutic target for treating OA.
基金supported by the National Natural Science Foundation of China(No.82305204),the Special Project on Academic Inheritance and Communication,China Academy of Chinese Medical Sciences(No.CI2022E012XB)Chinese Academy of Chinese Medical Sciences Doctoral Talents Training Fund(No.2021)+1 种基金the Special Program for Training Outstanding Young Talents of Chinese Academy of Traditional Chinese Medicine(No.ZZ16-YQ-021)the Innovative Cultivation Project of Guang'anmen Hospital,Chinese Academy of Chinese Medical Sciences(No.2022s481).
文摘Zishen Huoxue decoction(ZSHX)enhances cardiomyocyte viability following hypoxic stress;however,its upstream therapeutic targets remain unclear.Network pharmacology and RNA sequencing analyses revealed that ZSHX target genes were closely associated with mitophagy and apoptosis in the mitochondrial pathway.In vitro,ZSHX inhibited pathological mitochondrial fission following hypoxic stress,regulated FUN14 domain-containing protein 1(FUNDC1)-related mitophagy,and increased the levels of mitophagy lysosomes and microtubule-associated protein 1 light chain 3 beta II(LC3II)/translocase of outer mitochondrial membrane 20(TOM20)expression while inhibiting the over-activated mitochondrial unfolded protein response.Additionally,ZSHX regulated the stability of beta-tubulin through Sirtuin 5(SIRT5)and could modulate FUNDC1-related synergistic mechanisms of mitophagy and unfolded protein response in the mitochondria(UPR^(mt))via the SIRT5 and-β-tubulin axis.This targeting pathway may be crucial for cardiomyocytes to resist hypoxia.Collectively,these findings suggest that ZSHX can protect against cardiomyocyte injury via the SIRT5-β-tubulin axis,which may be associated with the synergistic protective mechanism of SIRT5-β-tubulin axis-related mitophagy and UPR^(mt) on cardiomyocytes.
基金supported by the National Natural Science Foundation of China(62301598).
文摘To tackle the challenges of intractable parameter tun-ing,significant computational expenditure and imprecise model-driven sparse-based direction of arrival(DOA)estimation with array error(AE),this paper proposes a deep unfolded amplitude-phase error self-calibration network.Firstly,a sparse-based DOA model with an array convex error restriction is established,which gets resolved via an alternating iterative minimization(AIM)algo-rithm.The algorithm is then unrolled to a deep network known as AE-AIM Network(AE-AIM-Net),where all parameters are opti-mized through multi-task learning using the constructed com-plete dataset.The results of the simulation and theoretical analy-sis suggest that the proposed unfolded network achieves lower computational costs compared to typical sparse recovery meth-ods.Furthermore,it maintains excellent estimation performance even in the presence of array magnitude-phase errors.
基金Project supported by the National Basic Research Program(973)of China(No.2012CB518900)the National Natural Science Foundation of China(Nos.31160240 and 31260621)+2 种基金the National Major Scientific and Technological Special Project during the Twelfth Five-year Plan Period of China(No.2012ZX10002006)the Hangzhou Normal University Supporting Project(No.PE13002004042)the Natural Science Foundation of Jiangxi Province(No.20114BAB204016),China
文摘Within the cell, several mechanisms exist to maintain homeostasis of the endoplasmic reticulum （ER）. One of the primary mechanisms is the unfolded protein response （UPR）. In this review, we primarily focus on the latest signal webs and regulation mechanisms of the UPR. The relationships among ER stress, apoptosis, and cancer are also discussed. Under the normal state, binding immunoglobulin protein （BiP） interacts with the three sensors （protein kinase RNA-like ER kinase （PERK）, activating transcription factor 6 （ATF6）, and inositol-requiring enzyme la （IREla）） Under ER stress, misfolded proteins interact with BiP, resulting in the release of BiP from the sensors. Subsequently, the three sensors dimerize and autophosphorylate to promote the signal cascades of ER stress. ER stress includes a series of positive and negative feedback signals, such as those regulating the stabilization of the sensors/BiP complex, activating and inactivating the sensors by autophosphorylation and dephosphorylation, activating specific transcription factors to enable selective transcription, and augmenting the ability to refold and export. Apart from the three basic pathways, vascular endothelial growth factor （VEGF）-VEGF receptor （VEGFR）-phospholipase C-~ （PLCy）-mammalian target of rapamycin complex 1 （mTORC1） pathway, induced only in solid tumors, can also activate ATF6 and PERK signal cascades, and IREla also can be activated by activated RAC-alpha serine/threonine-protein kinase （AKT）. A moderate UPR functions as a pro-survival signal to return the cell to its state of homeostasis. However, persistent ER stress will induce cells to undergo apoptosis in response to increasing reactive oxygen species （ROS）, Ca2＋ in the cytoplasmic matrix, and other apoptosis signal cascades, such as c-Jun N-terminal kinase （JNK）, signal transducer and activator of transcription 3 （STAT3）, and P38, when cellular damage exceeds the capacity of this adaptive response.
文摘Acute pancreatitis (AP) is an inflammatory disorder of pancreatic tissue initiated in injured acinar cells. Severe AP remains a significant challenge due to the lack of effective treatment. The widely-accepted autodigestion theory of AP is now facing challenges, since inhibiting protease activation has negligible effectiveness for AP treatment despite numerous efforts. Furthermore, accumulating evidence supports a new concept that malfunction of a self-protective mechanism, the unfolded protein response(UPR), is the driving force behind the pathogenesis of AP. The UPR is induced by endoplasmic reticulum(ER) stress, a disturbance frequently found in acinar cells, to prevent the aggravation of ER stress that can otherwise lead to cell injury. In addition, the UPR's signaling pathways control NFκB activation and autophagy flux, and these dysregulations cause acinar cell inflammatory injury in AP, but with poorly understood mechanisms. We therefore summarize the protective role of the UPR in AP, propose mechanistic models of how inadequate UPR could promote NFκB's pro-inflammatory activity and impair autophagy's protective function in acinar cells, and discuss its relevance to current AP treatment. We hope that insight provided in this review will help facilitate the research and management of AP.
基金supported by the National Natural Science Foundation of China(No.31272534)the Department of Education of Zhejiang Province(No.Y201635576),China
文摘Porcine circovirus type 2（PCV2）has recently been reported to elicit the unfolded protein response（UPR）via activation of the PERK/e IF2α（RNA-activated protein kinase-like endoplasmic reticulum（ER）kinase/eukaryotic initiation factor 2α）pathway.This study attempted to examine which viral protein might be involved in inducing UPR and whether this cellular event would lead to apoptosis of the cells expressing the viral protein.By transient expression,we found that both replicase（Rep）and capsid（Cap）proteins of PCV2 could induce ER stress as shown by increased phosphorylation of PERK with subsequent activation of the eI F2α-ATF4（activating transcription factor 4）-CHOP（CCAAT/enhancer-binding protein homologous protein）axis.Cap expression,but not Rep,significantly reduced antiapoptotic B-cell lymphoma-2（Bcl-2）and increased caspase-3 cleavage,possibly due to increased expression of CHOP.Since knockdown of PERK by RNA interference clearly reduced Cap-induced CHOP expression,caspase-3cleavage,and apoptotic cell death possibly by partially rescuing Bcl-2 expression,we propose that there is connection between Cap-induced UPR and apoptosis via the PERK/eI F2α/ATF4/CHOP/Bcl-2 pathway.This study,together with our earlier studies,provides insight into the mechanisms underlying PCV2 pathogenesis.
文摘Alzheimer’s disease has proven to be largely intractable to treatment,despite years of research,and numerous trials of therapies that target the hallmarks of the disease-amyloid plaques and neurofibrillary tangles.The etiology of Alzheimer’s disease remains elusive.There is a growing body of evidence for an infectious trigger of Alzheimer’s disease,and,in particular,the focus has been on the oral pathogen Porphyromonas gingivalis(P.gingivalis).Reports of the expression of a misfolded form of p53 in non-neuronal cells(fibroblasts,peripheral blood mononuclear cells,and B cells)and serum,which appears several years before clinical symptoms manifest,may provide further support for the role of bacteria in general,and P.gingivalis in particular,in the initiation of the disease.This review presents a model of the pathway from initial oral infection with P.gingivalis to amyloid plaque formation and neuronal degeneration,via the steps of chronic periodontitis;secretion of the inflammagens lipopolysaccharide and gingipains into the bloodstream;induction of an inflammatory response in both peripheral cells and tissues;disruption of the blood-brain barrier,and entry into the central nervous system of the inflammagens and the P.gingivalis bacteria themselves.In this model,the misfolded p53(or“unfolded p53”;up53)is induced in non-neuronal cells and upregulated in serum as a result of oxidative stress due to lipopolysaccharide from P.gingivalis.up53 is therefore a potential biomarker for early diagnosis of the presence of a causative agent of Alzheimer’s disease.Fastidious dental hygiene and aggressive antibiotic treatment may prevent the patient progressing to clinical Alzheimer’s disease if serum up53 is detected at this pre-symptomatic stage.
基金supported by grants from the National Institutes of Health,No.NS105689(to WL)the Department of Defense through the Multiple Sclerosis Research Program,No.W81XWH-22-1-0757(to WL).
文摘The unfolded protein response(UPR)is a cellular stress response pathway activated when the endoplasmic reticulum,a crucial organelle for protein folding and modification,encounters an accumulation of unfolded or misfolded proteins.The UPR aims to restore endoplasmic reticulum homeostasis by enhancing protein folding capacity,reducing protein biosynthesis,and promoting protein degradation.It also plays a pivotal role in coordinating signaling cascades to determine cell fate and function in response to endoplasmic reticulum stress.Recent research has highlighted the significance of the UPR not only in maintaining endoplasmic reticulum homeostasis but also in influencing various physiological processes in the nervous system.Here,we provide an overview of recent findings that underscore the UPR’s involvement in preserving the function and viability of neuronal and myelinating cells under physiological conditions,and highlight the critical role of the UPR in brain development,memory storage,retinal cone development,myelination,and maintenance of myelin thickness.
基金Supported by the Key Projects of Natural Science Foundation of Ningxia,No.2020AAC02020the Funds of Ningxia Medical University,No.XY201808.
文摘The mitochondrial unfolded protein response(UPRmt)is an evolutionarily conserved adaptive mechanism for improving cell survival under mitochondrial stress.Under physiological and pathological conditions,the UPRmt is the key to maintaining intracellular homeostasis and proteostasis.Important roles of the UPRmt have been demonstrated in a variety of cell types and in cell development,metabolism,and immune processes.UPRmt dysfunction leads to a variety of pathologies,including cancer,inflammation,neurodegenerative disease,metabolic disease,and immune disease.Stem cells have a special ability to selfrenew and differentiate into a variety of somatic cells and have been shown to exist in a variety of tissues.These cells are involved in development,tissue renewal,and some disease processes.Although the roles and regulatory mechanisms of the UPRmt in somatic cells have been widely reported,the roles of the UPRmt in stem cells are not fully understood.The roles and functions of the UPRmt depend on stem cell type.Therefore,this paper summarizes the potential significance of the UPRmt in embryonic stem cells,tissue stem cells,tumor stem cells,and induced pluripotent stem cells.The purpose of this review is to provide new insights into stem cell differentiation and tumor pathogenesis.
基金supported,in part,by NIH/NEI grants EY019949 and EY025061an Unrestricted Grant to the Department of Ophthalmology,SUNY-Buffalo,from Research to Prevent Blindness
文摘The retina is one of the most energy demanding tissues in the body. Like most neurons in the central nervous system, retinal neurons consume high amounts of adenosine-5′-triphosphate（ATP） to generate visual signal and transmit the information to the brain. Disruptions in retinal metabolism can cause neuronal dysfunction and degeneration resulting in severe visual impairment and even blindness. The homeostasis of retinal metabolism is tightly controlled by multiple signaling pathways, such as the unfolded protein response（UPR）, and the close interactions between retinal neurons and other retinal cell types including vascular cells and Müller glia. The UPR is a highly conserved adaptive cellular response and can be triggered by many physiological stressors and pathophysiological conditions. Activation of the UPR leads to changes in glycolytic rate, ATP production, de novo serine synthesis, and the hexosamine biosynthetic pathway, which are considered critical components of Müller glia metabolism and provide metabolic support to surrounding neurons. When these pathways are disrupted, neurodegeneration occurs rapidly. In this review, we summarize recent advance in studies of the UPR in Müller glia and highlight the potential role of the UPR in retinal degeneration through regulation of Müller glia metabolism.
基金Supported partially by the American Heart Association (AHA) Scientist Development Award (0635423Z)the AHA Grant-in-Aid (09GRNT2280479)+1 种基金the Department of Defense Breast Cancer Research Program (BC095179P1)the Karmanos Cancer Institute Pilot Grant
文摘The signal transduction network in regulating lipid metabolism is a hot topic of biomedical research. Recent research endeavors reveal that intracellular stress signaling from a cellular organelle called endoplasmic reticulum (ER) is critically involved in lipid homeostasis and the development of metabolic disease. The ER is a site where newly-synthesized proteins are folded and assembled into their three-dimensional structures, modified and transported to their precise cellular destinations. A wide range of biochemical, physiological and pathological stimuli can interrupt the protein folding process in the ER and cause accumulation of unfolded or misfolded proteins in the ER lumen, a condition referred to as ER stress. To cope with this stress condition, the ER has evolved highly-specifi c signaling pathways collectively termed Unfolded Protein Response (UPR) or ER stress response. The UPR regulates transcriptionaland translational programs, affecting broad aspects of cellular metabolism and cell fate. Lipogenesis, the metabolic process of de novo lipid biosynthesis, occurs primarily in the liver where metabolic signals regulate expression of key enzymes in glycolytic and lipogenic pathways. Recent studies suggest that the UPR plays crucial roles in modulating lipogenesis under metabolic conditions. Here we address some of recent representative evidence regarding the role of the UPR in lipogenesis.
基金supported by the National Natural Science Foundation of China(No.81670409).
文摘Objective:The purpose of this study was to investigate the role of the unfolded protein response,specifically the inositol-requiring enzyme 1(IRE1)signaling pathway,in hypoxia-induced autophagy in human umbilical venous endothelial cells(HUVECs).Methods:The expression of IRE1 and autophagy relative protein in HUVECs with hypoxia was explored by Western blotting,qRT-PCR and confocal microscopy.Further,we evaluated the biological effects of HUVECs by tube formation assay and wound healing assay in vitro.Finally,we examined the function of IRE1 in local blood vessels through animal models,Results:Hypoxia activated the IRE1 signaling pathway and induced autophagy in a time-dependent manner in HUVECs and further influenced the biological effects of HUVECs.Intraperitoneal injection of IRE1 inhibitors inhibited local vascular autophagy levels and lipid accumulation in model animals.Conclusion:Hypoxia can induce autophagy and activate the IRE1 signaling pathway in HUVECs and the IRE1 signaling pathway is involved in autophagy in hypoxic conditions.
文摘In this work,multiple molecular dynamics simulations of protein G and protein L unfolding trajectories provide a direct demonstration of the diversity of unfolding pathway and give a statistically utmost unfolding pathway under the physical property space.
基金the Fund of State Key Laboratory of Com-plex Electromagnetic Environment Effects on Electronics and Information System(CEMEE 2021Z0101B)the Na-tional Natural Science Foundation of China(No.61601167).
文摘Direction of arrival(DOA)estimation for unfolded coprime array(UFCA)is discussed,and a method based on subspace compensation is proposed.Conventional DOA estimation meth-ods partition the UFCA into two subarrays for separate estimations,which are then combined for unique DOA determination.However,the DOA estimation performance loss is caused as only the partial array aperture is exploited.We use the estimations from one subarray as initial estimations,and then enhance the estimation results via a compensation based on the whole array,which is im-plemented via a simple least squares(LS)operation constructed from the initial estimation and first-order Taylor expansion.Compared to conventional methods,the DOA estimation performance is improved while the computational complexity is in the same level.Multiple simulations are con-ducted to verify the efficiency of the proposed approach.
基金supported by the National Natural Science Foundation of China (82105016)the Natural Science Foundation of Shaanxi Province (2022SF-318)+1 种基金the Scientific Research Fund Project of Shaanxi Province Department of Education (21JSO12)the National Training Program of Innovation and Entrepreneurship for Students of China (202210716017).
文摘Preeclampsia is a serious obstetric complication.Currently,there is a lack of effective preventive approaches for this disease.Recent studies have identified transcutaneous auricular vagus nerve stimulation(taVNS)as a potential novel non-pharmaceutical therapeutic modality for preeclampsia.In this study,we investigated whether taVNS inhibits apoptosis of placental trophoblastic cells through ROS-induced UPR^(mt).Our results showed that taVNS promoted the release of acetylcholine(ACh).ACh decreased the expression of UPR^(mt) by inhibiting the formation of mitochondrial ROS(mtROS),presumably through M3AChR.This reduced the release of pro-apoptotic proteins(cleaved caspase-3,NF-kB-p65,and cytochrome C)and helped preserve the morphological and functional integrity of mitochondria,thus reducing the apoptosis of placental trophoblasts,improving placental function,and relieving preeclampsia.Our study unravels the potential pathophysiological mechanism of preeclampsia.In-depth characterization of the UPR^(mt) is essential for developing more effective therapeutic strategies for preeclampsia targeting mitochondrial function.
文摘Introduction:Transplantation of mesenchymal stromal cells(MSCs)is a promising therapy for type 1 diabetes(T1D).However,whether the infused MSCs affect the endoplasmic reticulum stress or subsequent unfolded protein response inβcells remains unclear.Methods:To investigate this,we induced early-onset T1D in non-obese diabetic mice using streptozotocin.Subsequently,T1D mice were randomly assigned to receive either MSCs or phosphate-buffered saline.We observed the in vivo homing of MSCs and assessed their effectiveness by analyzing blood glucose levels,body weight,histopathology,pancreatic protein expression,and serum levels of cytokines,proinsulin,and C-peptide.Results:Infused MSCs were found in the lungs,liver,spleen,and pancreas of T1D mice.They exhibited various effects,including reducing blood glucose levels,regulating immunity,inhibiting inflammation,increasingβ-cell areas,and reducing the expression of key proteins in the unfolded protein response pathway.Fasting serum proinsulin and C-peptide levels were significantly higher in the MSCs treatment group than in the T1D model group.However,there was no significant difference in the biomarker ofβ-cell endoplasmic reticulum stress,the ratio of fasting serum proinsulin to C-peptide,between the two groups.Conclusion:Ourfindings reveal that MSCs infusion does not alleviate endoplasmic reticulum stress inβcells directly but modulates the unfolded protein response pathway to preserveβ-cell mass and function in T1D mice.
基金supported by the Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(SML2023SP234)National Natural Science Foundation of China(32022085/32373158/31930113)the open competition program of top ten critical priorities of Agricultural Science and Technology Innovation for the 14th Five-Year Plan of Guangdong Province(2022SDZG01).
文摘Outbreaks of diseases are often linked to environmental stress,which can lead to endoplasmic reticulum(ER)stress and subsequently trigger the unfolded protein response(UPR).The replication of the white spot syndrome virus(WSSV),the most serious pathogen in shrimp aquaculture,has been shown to rely on the UPR signaling pathway,although the detailed mechanisms remain poorly understood.In this study,we discovered that WSSV enhances its replication by hijacking the UPR pathway via the viral protein wsv406.Our analysis revealed a significant upregulation of wsv406 in the hemocytes and gills of infected shrimp.Mass spectrometry analysis identified that wsv406 interacts specifically with the immunoglobulin heavy-chain-binding protein(BiP)in shrimp Litopenaeus vannamei.Further examination revealed that wsv406 binds to multiple domains of LvBiP,inhibiting its ATPase activity without disrupting its binding to UPR stress receptors.Silencing either wsv406 or LvBiP resulted in a reduction in WSSV replication and improved shrimp survival rates.Further,wsv406 activation of the PRKR-like ER kinase(PERK)-eukaryotic translation initiation factor 2α(eIF2α)and activating transcription factor 6(ATF6)pathways was demonstrated by a decrease in the phosphorylation of eIF2αand the nuclear translocation of ATF6 when wsv406 was silenced during WSSV infection.This activation facilitated the transcription of WSSV genes,promoting viral replication.In summary,these findings reveal that wsv406 manipulates the host UPR by targeting LvBiP,thereby enhancing WSSV replication through the PERK-eIF2αand ATF6 pathways.These insights into the interaction between WSSV and host cellular machinery offer potential targets for developing therapeutic interventions to control WSSV outbreaks in shrimp aquaculture.
文摘Expand ER stress is triggered due to the loss of homeostasis in the ER which causes the accumulation ofmisfolded proteins within the ER lumen. Severe or prolonged ER stress may induce the unfolded protein response(UPR), which is an adaptive mechanism aimed at reducing levels of unfolded proteins and keeping balance in theER. CHOP, Bip, JNK, EIF2 are major elements in these pathways.In this study, we investigated the activation of CHOP, Bip, total JNK and phosphorylated JNK (P-JNK), totalEIF2 and phosphorylated EIF2 (P- EIF2) in response to X-rays in breast cancer MCF-7 and MDA-MB-231 cellsusing western blot analysis.
基金Supported by the National Natural Science Foundation,China (No.51005237)the Postdoctoral Science Foundation,China (No.20100471407)
文摘Taking spiral chute as example, a method of unfolded drawings and views about irregular spiral surface is introduced. The surface is undevelopable and too complicated to get its views or to draw unfolded drawings by manual method. In this article, a series of the boundary equations of the spiral chute are derived by the movement rule of coal flow, and the solid and views of the spiral chute are generated based on redevelopment of SolidWorks. Unfolded drawing is drawn applying triangular development principle. The views and unfolded drawings not only are produced automatically, precisely and parameterized, but also involve more technological information. So it has an important significance on the irregular spiral surface＇s developments and processing.
