A microgravity environment has been shown to cause ocular damage and affect visual acuity,but the underlying mechanisms remain unclear.Therefore,we established an animal model of weightlessness via tail suspension to ...A microgravity environment has been shown to cause ocular damage and affect visual acuity,but the underlying mechanisms remain unclear.Therefore,we established an animal model of weightlessness via tail suspension to examine the pathological changes and molecular mechanisms of retinal damage under microgravity.After 4 weeks of tail suspension,there were no notable alterations in retinal function and morphology,while after 8 weeks of tail suspension,significant reductions in retinal function were observed,and the outer nuclear layer was thinner,with abundant apoptotic cells.To investigate the mechanism underlying the degenerative changes that occurred in the outer nuclear layer of the retina,proteomics was used to analyze differentially expressed proteins in rat retinas after 8 weeks of tail suspension.The results showed that the expression levels of fibroblast growth factor 2(also known as basic fibroblast growth factor)and glial fibrillary acidic protein,which are closely related to Müller cell activation,were significantly upregulated.In addition,Müller cell regeneration and Müller cell gliosis were observed after 4 and 8 weeks,respectively,of simulated weightlessness.These findings indicate that Müller cells play an important regulatory role in retinal outer nuclear layer degeneration during weightlessness.展开更多
Patients suffering from nerve injury often experience exacerbated pain responses and complain of memory deficits.The dorsal hippocampus(dHPC),a well-defined region responsible for learning and memory,displays maladapt...Patients suffering from nerve injury often experience exacerbated pain responses and complain of memory deficits.The dorsal hippocampus(dHPC),a well-defined region responsible for learning and memory,displays maladaptive plasticity upon injury,which is assumed to underlie pain hypersensitivity and cognitive deficits.However,much attention has thus far been paid to intracellular mechanisms of plasticity rather than extracellular alterations that might trigger and facilitate intracellular changes.Emerging evidence has shown that nerve injury alters the microarchitecture of the extracellular matrix(ECM)and decreases ECM rigidity in the dHPC.Despite this,it remains elusive which element of the ECM in the dHPC is affected and how it contributes to neuropathic pain and comorbid cognitive deficits.Laminin,a key element of the ECM,consists ofα-,β-,andγ-chains and has been implicated in several pathophysiological processes.Here,we showed that peripheral nerve injury downregulates lamininβ1(LAMB1)in the dHPC.Silencing of hippocampal LAMB1 exacerbates pain sensitivity and induces cognitive dysfunction.Further mechanistic analysis revealed that loss of hippocampal LAMB1 causes dysregulated Src/NR2A signaling cascades via interaction with integrinβ1,leading to decreased Ca2+levels in pyramidal neurons,which in turn orchestrates structural and functional plasticity and eventually results in exaggerated pain responses and cognitive deficits.In this study,we shed new light on the functional capability of hippocampal ECM LAMB1 in the modulation of neuropathic pain and comorbid cognitive deficits,and reveal a mechanism that conveys extracellular alterations to intracellular plasticity.Moreover,we identified hippocampal LAMB1/integrinβ1 signaling as a potential therapeutic target for the treatment of neuropathic pain and related memory loss.展开更多
Tweety-homolog 1(Ttyh1)is expressed in neural tissue and has been implicated in the generation of several brain diseases.However,its functional significance in pain processing is not understood.By disrupting the gene ...Tweety-homolog 1(Ttyh1)is expressed in neural tissue and has been implicated in the generation of several brain diseases.However,its functional significance in pain processing is not understood.By disrupting the gene encoding Ttyh1,we found a loss of Ttyh1 in nociceptors and their central terminals in Ttyh1-deficient mice,along with a reduction in nociceptor excitability and synaptic transmission at identified synapses between nociceptors and spinal neurons projecting to the periaqueductal grey(PAG)in the basal state.More importantly,the peripheral inflammationevoked nociceptor hyperexcitability and spinal synaptic potentiation recorded in spinal-PAG projection neurons were compromised in Ttyh1-deficient mice.Analysis of the paired-pulse ratio and miniature excitatory postsynaptic currents indicated a role of presynaptic Ttyh1 from spinal nociceptor terminals in the regulation of neurotransmitter release.Interfering with Ttyh1 specifically in nociceptors produces a comparable pain relief.Thus,in this study we demonstrated that Ttyh1 is a critical determinant of acute nociception and pain sensitization caused by peripheral inflammation.展开更多
基金supported by the Army Laboratory Animal Foundation of China,No.SYDW[2020]22(to TC)the Shaanxi Provincial Key R&D Plan General Project of China,No.2022SF-236(to YM)the National Natural Science Foundation of China,No.82202070(to TC)。
文摘A microgravity environment has been shown to cause ocular damage and affect visual acuity,but the underlying mechanisms remain unclear.Therefore,we established an animal model of weightlessness via tail suspension to examine the pathological changes and molecular mechanisms of retinal damage under microgravity.After 4 weeks of tail suspension,there were no notable alterations in retinal function and morphology,while after 8 weeks of tail suspension,significant reductions in retinal function were observed,and the outer nuclear layer was thinner,with abundant apoptotic cells.To investigate the mechanism underlying the degenerative changes that occurred in the outer nuclear layer of the retina,proteomics was used to analyze differentially expressed proteins in rat retinas after 8 weeks of tail suspension.The results showed that the expression levels of fibroblast growth factor 2(also known as basic fibroblast growth factor)and glial fibrillary acidic protein,which are closely related to Müller cell activation,were significantly upregulated.In addition,Müller cell regeneration and Müller cell gliosis were observed after 4 and 8 weeks,respectively,of simulated weightlessness.These findings indicate that Müller cells play an important regulatory role in retinal outer nuclear layer degeneration during weightlessness.
基金supported by the National Key Research and Development Program of China(2024YFC2510102)the National Natural Science Foundation of China(NSFC)grants(82330036 and 82221001)+9 种基金STI2030-Major Projects(2021ZD0203100(2021ZD0203104))the Innovation Teams in Priority Areas Accredited by Shaanxi Science and Technology(2022TD-49)to C.L.NSFC grant(82201370)China Postdoctoral Science Foundation grant(2021MD703955)to F.W.NSFC grants(82101293,82221001)to W.J.H.and S.X.W.NSFC grant(82201368)China Postdoctoral Science Foundation grant(2022M713847)to Z.Z.L.STI2030-Major Projects(2021ZD0203205)NSFC grants(82171212,82371225)to R.G.X.grant from Joint Founding Project of Innovation Research Institute,Xijing Hospital(LHJJ24JH08)Shaanxi Province Sanqin Talent Program to C.L.
文摘Patients suffering from nerve injury often experience exacerbated pain responses and complain of memory deficits.The dorsal hippocampus(dHPC),a well-defined region responsible for learning and memory,displays maladaptive plasticity upon injury,which is assumed to underlie pain hypersensitivity and cognitive deficits.However,much attention has thus far been paid to intracellular mechanisms of plasticity rather than extracellular alterations that might trigger and facilitate intracellular changes.Emerging evidence has shown that nerve injury alters the microarchitecture of the extracellular matrix(ECM)and decreases ECM rigidity in the dHPC.Despite this,it remains elusive which element of the ECM in the dHPC is affected and how it contributes to neuropathic pain and comorbid cognitive deficits.Laminin,a key element of the ECM,consists ofα-,β-,andγ-chains and has been implicated in several pathophysiological processes.Here,we showed that peripheral nerve injury downregulates lamininβ1(LAMB1)in the dHPC.Silencing of hippocampal LAMB1 exacerbates pain sensitivity and induces cognitive dysfunction.Further mechanistic analysis revealed that loss of hippocampal LAMB1 causes dysregulated Src/NR2A signaling cascades via interaction with integrinβ1,leading to decreased Ca2+levels in pyramidal neurons,which in turn orchestrates structural and functional plasticity and eventually results in exaggerated pain responses and cognitive deficits.In this study,we shed new light on the functional capability of hippocampal ECM LAMB1 in the modulation of neuropathic pain and comorbid cognitive deficits,and reveal a mechanism that conveys extracellular alterations to intracellular plasticity.Moreover,we identified hippocampal LAMB1/integrinβ1 signaling as a potential therapeutic target for the treatment of neuropathic pain and related memory loss.
基金the National Natural Science Foundation of China(31671088 and 31730041)the Natural Science Foundation of Shaanxi Province,China(2017ZDJC-01)。
文摘Tweety-homolog 1(Ttyh1)is expressed in neural tissue and has been implicated in the generation of several brain diseases.However,its functional significance in pain processing is not understood.By disrupting the gene encoding Ttyh1,we found a loss of Ttyh1 in nociceptors and their central terminals in Ttyh1-deficient mice,along with a reduction in nociceptor excitability and synaptic transmission at identified synapses between nociceptors and spinal neurons projecting to the periaqueductal grey(PAG)in the basal state.More importantly,the peripheral inflammationevoked nociceptor hyperexcitability and spinal synaptic potentiation recorded in spinal-PAG projection neurons were compromised in Ttyh1-deficient mice.Analysis of the paired-pulse ratio and miniature excitatory postsynaptic currents indicated a role of presynaptic Ttyh1 from spinal nociceptor terminals in the regulation of neurotransmitter release.Interfering with Ttyh1 specifically in nociceptors produces a comparable pain relief.Thus,in this study we demonstrated that Ttyh1 is a critical determinant of acute nociception and pain sensitization caused by peripheral inflammation.
