OBJECTIVE Urocortins(UCNs)and transforming growth factor-β(TGF-β)have been demonstrated to participate in various cardiovascular diseases,many of which involve VSMCs proliferation.And cytosolic phospholipase A2(c PL...OBJECTIVE Urocortins(UCNs)and transforming growth factor-β(TGF-β)have been demonstrated to participate in various cardiovascular diseases,many of which involve VSMCs proliferation.And cytosolic phospholipase A2(c PLA2)-mediated arachidonic acid(AA)release is an important cause of vascular smooth muscle cells(VSMCs)proliferation.The work was to investigate the regulation of VSMCs proliferation by UCN/TGF-βand whether c PLA2 was a link between their signaling pathways.METHODS VSMC proliferation was measured by MTT assay and immunofluorescence microscopy.Using cell flow cytometry,the changes in the cell cycle phases were investigated.si RNA was used to knockdown Smad2 and smad3 genes.Lentiviral Vector Particle was performed to over express c PLA2 gene.RESULTS Both UCN and TGF-βinhibited VSMCs proliferation and an additive effect was observed when the cells were treated with UCN plus TGF-β.TGF-βincreased the percentage of cells in G1-phase while UCN increased the cell percentage in G2-phase with a concomitant decrease in S-phase.Neither knockdown of smad2 nor smad3 reversed the role of TGF-β.Furthermore,c PLA2expression was increased by TGF-βbut decreased by UCN and UCN attenuated TGF-β-induced c PLA2 expression.In primary VSMCs,TGF-βinduced c PLA2 phosphorylation,and this effect was also attenuated by UCN.Similar to UCN,the c PLA2 inhibitor,pyrrophenone(PYR),also played a role in enhancing TGF-β-mediated mitoinhibition.Inversely,over-expression of c PLA2 eliminated the effect of UCN on the mitoinhibition.CONCLUSION The pretreatment with UCN counteracted TGF-β-mediated c PLA2 expression and activation,thereby contributing to TGF-β-mediated mitoinhibition of VSMCs.展开更多
Objective: To explore the therapeutic effect and underlying mechanism of Shenqi Zhilong Decoction on mice with membranous nephropathy (MN). Methods:Mice with MN was established by injecting cationic bovine serum album...Objective: To explore the therapeutic effect and underlying mechanism of Shenqi Zhilong Decoction on mice with membranous nephropathy (MN). Methods:Mice with MN was established by injecting cationic bovine serum albumin (c-BSA) into tail vein for several times. model mice were randomly divided into MN group (equal amount of distilled water), Shenqi Zhilong Decoction low dose group (12 g crude drug/kg), Shenqi Zhilong Decoction high dose group (24 g crude drug/kg), and Tripterygium wilfordii polyglycoside tablet group (14 mg/ kg). Another 10 un-treatment mice were taken as control group (equal amount of distilled water). The drug was administered orally once a day for 4 weeks. After the last administration, 24 hours urine was collected to determine the urinary protein content;blood from inner canthus was collected to measure the changes of kidney function, liver function, blood lipid and levels of IL-6, IL-4 and TNF-α in serum in each group;HE staining was used to observe the pathological changes of kidney. Immunohistochemical staining was used to observe the expression of IgG in kidney. The protein expression of ERK1/2 and cPLA2 in renal tissues was determined by Western-blot method. The gene expression of Neph1, Nephrin and Podocin mRNA in kidney tissues were detected by RT-PCR. Results: Compared with model group, Shenqi Zhilong decoction at low-dose and high-dose could significantly reduce the value of urine protein in MN mice;Decreased TC and TG levels (P<0.05 or P<0.01);Increased the levels of ALB and TP in liver function (P<0.05 or P<0.01);has no significant effects on the levels of CRE, UREA and UA in renal function (P>0.05). Decreased the contents of IL-6, IL-4 and TNF-α in serum (P<0.05 or P<0.01);Significantly down-regulated the protein expression levels of p-ERK1/2 and p-cPLA2 in kidney tissues of MN mice (P<0.05 or P<0.01);Significantly increased the expression levels of NephP1, Nephrin and Podocin mRNA in renal tissues (P<0.01). Conclusion: Shenqi Zhulong Decoction has a good therapeutic effect on MN mice, and the mechanism of action is related to regulate the expression of related genes of Nephrin-Podocin-Neph1 receptor complex for protecting the glomerular filtration barrier, and inhibite the activation of ERK/cPLA2 pathway for relieving damage of GEC and reduceing secretion of pro-inflammatory cytokines.展开更多
The expression of cytosolic phospholipase A2 (cPLA2) expression is up-regulated in animal model of ALS and in patients with familial amyotrophic lateral sclerosis (fALS). Inhibition of cyclooxygenase 2 (COX2), which i...The expression of cytosolic phospholipase A2 (cPLA2) expression is up-regulated in animal model of ALS and in patients with familial amyotrophic lateral sclerosis (fALS). Inhibition of cyclooxygenase 2 (COX2), which is a downstream enzyme of cPLA2, ameliorates the impairment of motor function in the ALS model mice. Therefore, the arachidonic acid cascade, including the cPLA2-COX2 pathway, is an important therapeutic target of ALS. The current study was designed to investigate the potential of AK106-001616, an inhibitor of cPLA2, in protection of motor neuron cell death induced by mutant superoxide dismutase (SOD1<sup>G93A</sup>). AK106-001616 (1 - 10 μM) protected NSC34 cells (mouse motor neuron like cells) against SOD1<sup>G93A</sup>-induced motor neuron cell death. Furthermore, aspirin, an inhibitor of COX1/2, reduced the SOD1<sup>G93A</sup>-induced motor neuron cell death at a concentration that inhibited COX2. Celecoxib, a selective COX2 inhibitor, also reduced the SOD1<sup>G93A</sup>-induced motor neuron cell death. These results suggest that the arachidonic acid cascade is important for SOD1<sup>G93A</sup>-induced motor neuron cell death and AK106-001616 has a potent neuroprotective effect against it. AK106-001616 may be a useful therapeutic agent against SOD1<sup>G93A</sup>-induced ALS.展开更多
The polymerase 1 and transcript release factor(PTRF)–cytoplasmic phospholipase A2(cPLA2)phospholipid remodeling pathway facilitates tumor proliferation in glioma.Nevertheless,blockade of this pathway leads to the exc...The polymerase 1 and transcript release factor(PTRF)–cytoplasmic phospholipase A2(cPLA2)phospholipid remodeling pathway facilitates tumor proliferation in glioma.Nevertheless,blockade of this pathway leads to the excessive activation of oncogenic receptors on the plasma membrane and subsequent drug resistance.Here,CD26/dipeptidyl peptidase 4(DPP4)was identified through screening of CRISPR/Cas9 libraries.Suppressing PTRF–cPLA2 signaling resulted in the activation of the epidermal growth factor receptor(EGFR)pathway through phosphatidylcholine and lysophosphatidylcholine remodeling,which ultimately increased DPP4 transcription.In turn,DPP4 interacted with EGFR and prevented its ubiquitination.Linagliptin,a DPP4 inhibitor,facilitated the degradation of EGFR by blocking its interaction with DPP4.When combined with the cPLA2 inhibitor AACOCF3,it exhibited synergistic effects and led to a decrease in energy metabolism in glioblastoma cells.Subsequent in vivo investigations provided further evidence of a synergistic impact of linagliptin by augmenting the sensitivity of AACOCF3 and strengthening the efficacy of temozolomide.DPP4 serves as a novel target and establishes a constructive feedback loop with EGFR.Linagliptin is a potent inhibitor that promotes EGFR degradation by blocking the DPP4–EGFR interaction.This study presents innovative approaches for treating glioma by combining linagliptin with AACOCF3 and temozolomide.展开更多
Little is known about the mechanism and signal transduction by LPS-mediated immunomodulation of murine peritoneal macrophages. It is found that the signal molecules of the down-stream of Ras, Raf-1, MAPK p44, and MAPK...Little is known about the mechanism and signal transduction by LPS-mediated immunomodulation of murine peritoneal macrophages. It is found that the signal molecules of the down-stream of Ras, Raf-1, MAPK p44, and MAPK p42 are phosphorylated, and cPLA2 is activated with a significant increase of the release of [ H3 ] AA by macrophages in response to LPS and PMA. Compared with the very recent finding that LPS and PMA trigger the activation and translocation of PKC-α and PKC-ε, these findings suggest that there is a connection between PKC signaling pathway and the Raf-1/MAPK pathway and that the activation of these main signaling events may be closely related to the secretion of IL-12 during LPS-induced modulation of macrophages.展开更多
Osteoarthritis(OA) and intervertebral disc degeneration(IVDD) are degenerative musculoskeletal disorders characterized by degeneration of cartilaginous tissues and inflammation. While inflammation is implicated in the...Osteoarthritis(OA) and intervertebral disc degeneration(IVDD) are degenerative musculoskeletal disorders characterized by degeneration of cartilaginous tissues and inflammation. While inflammation is implicated in the pathogenesis of OA and IVDD, and cytosolic phospholipase A2(cPLA2) is a key mediator of inflammation, direct evidence linking cPLA2 to chondrocyte homeostasis and cartilage degeneration is lacking. This study aims to investigate the role of cPLA2 in chondrocytes and its contribution to the development of cartilage degenerative conditions such as OA and IVDD. Here, single-cell RNA sequencing was used to examine cPLA2 expression in chondrocytes. To explore its importance in chondrocytes and OA/IVDD, various cell-based assays and genetically modified mouse models with age-related and surgically induced OA/IVDD were employed. Furthermore, the therapeutic potential of fexofenadine, an over-the-counter drug recently identified as a cPLA2 inhibitor, was explored in these models. cPLA2 is predominantly expressed in prehypertrophic chondrocytes, characterized by elevated levels of cartilage degeneration markers and senescence-related genes. Genetic deletion and pharmacological inhibition of cPLA2 reduced inflammation induced catabolic activity and senescence in chondrocytes, as well as cartilage degeneration in various OA and IVDD models. This study identifies cPLA2 as a pivotal driver of cartilage degeneration and senescence in OA and IVDD, highlighting its potential as a dual-action therapeutic target that suppresses both inflammation and senescence to preserve cartilage integrity. These findings position cPLA2as a promising candidate for developing disease-modifying therapies for cartilage degenerative conditions such as OA and IVDD.展开更多
基金The project supported by National Natural Science Foundation of China(81573424&81273510)Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘OBJECTIVE Urocortins(UCNs)and transforming growth factor-β(TGF-β)have been demonstrated to participate in various cardiovascular diseases,many of which involve VSMCs proliferation.And cytosolic phospholipase A2(c PLA2)-mediated arachidonic acid(AA)release is an important cause of vascular smooth muscle cells(VSMCs)proliferation.The work was to investigate the regulation of VSMCs proliferation by UCN/TGF-βand whether c PLA2 was a link between their signaling pathways.METHODS VSMC proliferation was measured by MTT assay and immunofluorescence microscopy.Using cell flow cytometry,the changes in the cell cycle phases were investigated.si RNA was used to knockdown Smad2 and smad3 genes.Lentiviral Vector Particle was performed to over express c PLA2 gene.RESULTS Both UCN and TGF-βinhibited VSMCs proliferation and an additive effect was observed when the cells were treated with UCN plus TGF-β.TGF-βincreased the percentage of cells in G1-phase while UCN increased the cell percentage in G2-phase with a concomitant decrease in S-phase.Neither knockdown of smad2 nor smad3 reversed the role of TGF-β.Furthermore,c PLA2expression was increased by TGF-βbut decreased by UCN and UCN attenuated TGF-β-induced c PLA2 expression.In primary VSMCs,TGF-βinduced c PLA2 phosphorylation,and this effect was also attenuated by UCN.Similar to UCN,the c PLA2 inhibitor,pyrrophenone(PYR),also played a role in enhancing TGF-β-mediated mitoinhibition.Inversely,over-expression of c PLA2 eliminated the effect of UCN on the mitoinhibition.CONCLUSION The pretreatment with UCN counteracted TGF-β-mediated c PLA2 expression and activation,thereby contributing to TGF-β-mediated mitoinhibition of VSMCs.
基金Fund Project:Heilongjiang Natural Science Foundation Project(No.LH2020H104)Heilongjiang Postdoctoral Fund(No.LBH-Z20033)。
文摘Objective: To explore the therapeutic effect and underlying mechanism of Shenqi Zhilong Decoction on mice with membranous nephropathy (MN). Methods:Mice with MN was established by injecting cationic bovine serum albumin (c-BSA) into tail vein for several times. model mice were randomly divided into MN group (equal amount of distilled water), Shenqi Zhilong Decoction low dose group (12 g crude drug/kg), Shenqi Zhilong Decoction high dose group (24 g crude drug/kg), and Tripterygium wilfordii polyglycoside tablet group (14 mg/ kg). Another 10 un-treatment mice were taken as control group (equal amount of distilled water). The drug was administered orally once a day for 4 weeks. After the last administration, 24 hours urine was collected to determine the urinary protein content;blood from inner canthus was collected to measure the changes of kidney function, liver function, blood lipid and levels of IL-6, IL-4 and TNF-α in serum in each group;HE staining was used to observe the pathological changes of kidney. Immunohistochemical staining was used to observe the expression of IgG in kidney. The protein expression of ERK1/2 and cPLA2 in renal tissues was determined by Western-blot method. The gene expression of Neph1, Nephrin and Podocin mRNA in kidney tissues were detected by RT-PCR. Results: Compared with model group, Shenqi Zhilong decoction at low-dose and high-dose could significantly reduce the value of urine protein in MN mice;Decreased TC and TG levels (P<0.05 or P<0.01);Increased the levels of ALB and TP in liver function (P<0.05 or P<0.01);has no significant effects on the levels of CRE, UREA and UA in renal function (P>0.05). Decreased the contents of IL-6, IL-4 and TNF-α in serum (P<0.05 or P<0.01);Significantly down-regulated the protein expression levels of p-ERK1/2 and p-cPLA2 in kidney tissues of MN mice (P<0.05 or P<0.01);Significantly increased the expression levels of NephP1, Nephrin and Podocin mRNA in renal tissues (P<0.01). Conclusion: Shenqi Zhulong Decoction has a good therapeutic effect on MN mice, and the mechanism of action is related to regulate the expression of related genes of Nephrin-Podocin-Neph1 receptor complex for protecting the glomerular filtration barrier, and inhibite the activation of ERK/cPLA2 pathway for relieving damage of GEC and reduceing secretion of pro-inflammatory cytokines.
文摘The expression of cytosolic phospholipase A2 (cPLA2) expression is up-regulated in animal model of ALS and in patients with familial amyotrophic lateral sclerosis (fALS). Inhibition of cyclooxygenase 2 (COX2), which is a downstream enzyme of cPLA2, ameliorates the impairment of motor function in the ALS model mice. Therefore, the arachidonic acid cascade, including the cPLA2-COX2 pathway, is an important therapeutic target of ALS. The current study was designed to investigate the potential of AK106-001616, an inhibitor of cPLA2, in protection of motor neuron cell death induced by mutant superoxide dismutase (SOD1<sup>G93A</sup>). AK106-001616 (1 - 10 μM) protected NSC34 cells (mouse motor neuron like cells) against SOD1<sup>G93A</sup>-induced motor neuron cell death. Furthermore, aspirin, an inhibitor of COX1/2, reduced the SOD1<sup>G93A</sup>-induced motor neuron cell death at a concentration that inhibited COX2. Celecoxib, a selective COX2 inhibitor, also reduced the SOD1<sup>G93A</sup>-induced motor neuron cell death. These results suggest that the arachidonic acid cascade is important for SOD1<sup>G93A</sup>-induced motor neuron cell death and AK106-001616 has a potent neuroprotective effect against it. AK106-001616 may be a useful therapeutic agent against SOD1<sup>G93A</sup>-induced ALS.
基金supported by the National Key R&D Program of China,MOST(2023YFC2510000)the Key-Area Research and Development Program of Guangdong Province(2023B1111020008)the National Natural Science Foundation of China(82373147 and 82473379).
文摘The polymerase 1 and transcript release factor(PTRF)–cytoplasmic phospholipase A2(cPLA2)phospholipid remodeling pathway facilitates tumor proliferation in glioma.Nevertheless,blockade of this pathway leads to the excessive activation of oncogenic receptors on the plasma membrane and subsequent drug resistance.Here,CD26/dipeptidyl peptidase 4(DPP4)was identified through screening of CRISPR/Cas9 libraries.Suppressing PTRF–cPLA2 signaling resulted in the activation of the epidermal growth factor receptor(EGFR)pathway through phosphatidylcholine and lysophosphatidylcholine remodeling,which ultimately increased DPP4 transcription.In turn,DPP4 interacted with EGFR and prevented its ubiquitination.Linagliptin,a DPP4 inhibitor,facilitated the degradation of EGFR by blocking its interaction with DPP4.When combined with the cPLA2 inhibitor AACOCF3,it exhibited synergistic effects and led to a decrease in energy metabolism in glioblastoma cells.Subsequent in vivo investigations provided further evidence of a synergistic impact of linagliptin by augmenting the sensitivity of AACOCF3 and strengthening the efficacy of temozolomide.DPP4 serves as a novel target and establishes a constructive feedback loop with EGFR.Linagliptin is a potent inhibitor that promotes EGFR degradation by blocking the DPP4–EGFR interaction.This study presents innovative approaches for treating glioma by combining linagliptin with AACOCF3 and temozolomide.
基金Project supported by the National Natural Science Foundation of China, Shanghai Joint Laboratory of Life Science, Shanghai Institute of Cell Biology, and Director's Foundations of Chinese Academy of Sciences and Shanghai Institute of Cell Biology.
文摘Little is known about the mechanism and signal transduction by LPS-mediated immunomodulation of murine peritoneal macrophages. It is found that the signal molecules of the down-stream of Ras, Raf-1, MAPK p44, and MAPK p42 are phosphorylated, and cPLA2 is activated with a significant increase of the release of [ H3 ] AA by macrophages in response to LPS and PMA. Compared with the very recent finding that LPS and PMA trigger the activation and translocation of PKC-α and PKC-ε, these findings suggest that there is a connection between PKC signaling pathway and the Raf-1/MAPK pathway and that the activation of these main signaling events may be closely related to the secretion of IL-12 during LPS-induced modulation of macrophages.
基金supported partly by NIH research grants R01AR078035, R01AR062207,R01AR076900 and R01NS070328。
文摘Osteoarthritis(OA) and intervertebral disc degeneration(IVDD) are degenerative musculoskeletal disorders characterized by degeneration of cartilaginous tissues and inflammation. While inflammation is implicated in the pathogenesis of OA and IVDD, and cytosolic phospholipase A2(cPLA2) is a key mediator of inflammation, direct evidence linking cPLA2 to chondrocyte homeostasis and cartilage degeneration is lacking. This study aims to investigate the role of cPLA2 in chondrocytes and its contribution to the development of cartilage degenerative conditions such as OA and IVDD. Here, single-cell RNA sequencing was used to examine cPLA2 expression in chondrocytes. To explore its importance in chondrocytes and OA/IVDD, various cell-based assays and genetically modified mouse models with age-related and surgically induced OA/IVDD were employed. Furthermore, the therapeutic potential of fexofenadine, an over-the-counter drug recently identified as a cPLA2 inhibitor, was explored in these models. cPLA2 is predominantly expressed in prehypertrophic chondrocytes, characterized by elevated levels of cartilage degeneration markers and senescence-related genes. Genetic deletion and pharmacological inhibition of cPLA2 reduced inflammation induced catabolic activity and senescence in chondrocytes, as well as cartilage degeneration in various OA and IVDD models. This study identifies cPLA2 as a pivotal driver of cartilage degeneration and senescence in OA and IVDD, highlighting its potential as a dual-action therapeutic target that suppresses both inflammation and senescence to preserve cartilage integrity. These findings position cPLA2as a promising candidate for developing disease-modifying therapies for cartilage degenerative conditions such as OA and IVDD.
