BACKGROUND:Currently,spinal cord injury imposes a huge psychological and economic burden on patients and the National Health Service.The prevention,treatment,and rehabilitation of spinal cord injury have become an important topic in the field of medicine.Therefore,it is important to explore new effective therapeutic strategies based on an in-depth understanding of the underlying molecular mechanisms of spinal cord injury.OBJECTIVE:To review the research progress on the mechanism of action of mesenchymal stem cell-derived exosomes loaded with various miRNAs in improving the function of spinal cord injury,and based on the current status of clinical translation,to put forward a few thoughts and outlooks on their clinical use.METHODS:The first author searched CNKI and PubMed databases using"mesenchymal stem cells,exosomes,spinal cord injury,miRNA,pathophysiology,clinical translation,clinical trials,good manufacturing practice"as Chinese and English search terms.The types of literature included treatises and reviews,and the language types were English and Chinese.Finally,72 papers were screened and analyzed.RESULTS AND CONCLUSION:(1)This article outlines the biological properties of exosomes and the advantages that they can serve as good vectors for loading miRNAs.A variety of miRNAs mediated by mesenchymal stem cell-derived exosomes mainly promote the recovery of neuronal function by regulating the expression of nerve regeneration-associated proteins,repressing RAS homologous gene family member A,activating cyclophosphoadenosine effector-binding proteins,and signaling and transcriptional activation proteins 3,and regulating phosphoinositide and tensin homologue/programmed cell death factor 4 pathways.Inflammatory responses were improved by regulating endoplasmic reticulum-to-nucleus signaling 1,expression of interferon regulatory factor 5,Toll-like receptor 4/nuclear factor-kappa B pathway,and down-regulating related pro-inflammatory factors.Angiogenesis was promoted by inhibition of germination-associated domain 1-containing EVH1 and phosphatidylinositol 3-kinase regulatory subunit 2.(2)Further comparative analyses revealed that miR-216-5p,miR-145-5p,and miR-146b improved inflammatory responses by regulating related pathways.Combining these miRNAs may produce more significant effects;hypoxic preconditioning may be a preconditioning method to increase the efficacy of exosomal therapy.(3)There are currently no clinical trials applying mesenchymal stem cell-derived exosomes to spinal cord injury,which is related to the need to meet good manufacturing practices before they can be put into clinical use.Challenges such as the need for large-scale,high-volume cell production,the lack of an efficient and uniform method for isolating exosomes,and the need to pass a strict regulatory approval mechanism prior to clinical use have impeded the clinical entry.(4)miRNAs have great potential as exosomal contents of mesenchymal stem cells in the treatment of spinal cord injury,and their mechanism of action should be explored in depth as well as accelerated to the clinical trial stage in order to provide a new and effective method for the treatment of spinal cord injury.

BACKGROUND:Cellular autophagy maintains metabolism and in vivo homeostasis through the autophagosome-lysosome degradation pathway,which is closely related to the impaired cell death and functional recovery of distal neurons after spinal cord injury,and targeting cellular autophagy to promote the functional recovery of the spinal cord after spinal cord injury is a promising therapeutic direction.OBJECTIVE:To summarize the role of cellular autophagy in spinal cord injury,related regulatory mechanisms of cellular autophagy and therapeutic strategies.METHODS:PubMed and CNKI databases were searched with the search terms of"spinal cord injury,autophagy,regulatory mechanisms,autophagy pathway,therapeutic target"in English and Chinese,respectively.A total of 133 English and 4 Chinese articles were included for review.RESULTS AND CONCLUSION:(1)Autophagy,a form of programmed cell death,has been shown to play a crucial role in the progression and treatment of spinal cord injury.Most studies have shown that moderate activation or promotion of autophagy promotes neurological recovery by decreasing inflammatory responses and apoptosis.A few studies have reported that excessive activation of autophagy,on the contrary,impedes neurological recovery following spinal cord injury.(2)After spinal cord injury,PI3K/AKT/mTOR,MAPK,AMPK and p53 signaling pathways,and factors such as Beclin-1,ATG and LC3 regulate the initiation and development of cell autophagy in a positive or negative manner.(3)Promoting or inhibiting autophagy may be a promising therapeutic strategy to modulate the pathogenesis of traumatic spinal cord injury.And the drugs amlodipine,metformin,and minocycline,the Chinese medicines hawthorn leaf total flavonoids,betulinic acid,oxidized ginseng saponins,acupuncture,and extracellular vesicles of different cellular origins,exosomes and reactive oxygen species-responsive composite fibers as activators of cellular autophagy attenuate secondary injury in response to spinal cord injury by activating cellular autophagy,while the drugs insulin-like growth factor 1 and eladavone,Chinese medicine ginseng saponin,acupuncture,and hydrogel carrying basic fibroblast growth factor as inhibitors of cellular autophagy promote functional recovery after spinal cord injury by inhibiting excessive cellular autophagy.(4)The related regulators of cellular autophagy are interconnected,and the bi-directional effects of cellular autophagy on spinal cord injury make it necessary to further explore the dominant factors that regulate cellular autophagy.(5)Research on the use of autophagy as a therapeutic target for spinal cord injury is mostly carried out in animal models,but there are no autophagy-related drugs used in the clinical practice,and their safety and efficacy need to be further investigated in the clinical field.

BACKGROUND:Spinal cord injury is a neurological disorder caused by traumatic or non-traumatic events,often leading to severe functional impairment below the injured segment.In recent years,neural stem cell transplantation has been considered to have significant therapeutic potential in regulating the inflammatory response after spinal cord injury,inhibiting excessive proliferation of glial scars,and promoting nerve regeneration. OBJECTIVE:To review and discuss the potential mechanism of action of acupuncture and neural stem cell transplantation therapy in inhibiting spinal cord injury-induced secondary injury,and to delve into the scientific basis for its treatment of spinal cord injury. METHODS:PubMed,Elsevier,WanFang,and CNKI databases were searched using"spinal cord injury,acupuncture,neural stem cells,SDF-1α/CXCR4 axis"as Chinese and English search terms.Totally 96 articles were finally included.The research findings of acupuncture combined with neural stem cells in the treatment of spinal cord injury were summarized and analyzed,and the mechanism of this combination therapy in the treatment of secondary injury after spinal cord injury was summarized. RESULTS AND CONCLUSION:(1)The stromal-derived factor 1α(SDF-1α)/chemokine receptor 4(CXCR4)axis plays a crucial role in neural stem cell transplantation for spinal cord injury.This signaling mechanism not only affects neural stem cell migration,proliferation,and differentiation,but is also a key factor in determining the efficiency of stem cell homing to the injury site.Therefore,the regulation of targeting this axis is of great significance in enhancing the therapeutic effect of spinal cord injury.(2)Acupuncture,as a traditional Chinese medicine therapy,shows unique advantages in the regulation of secondary injury in spinal cord injury.It can effectively reduce secondary injury after spinal cord injury by regulating inflammatory response,inhibiting apoptosis,improving microcirculation,reducing glial scar formation,and counteracting oxidative stress.(3)Acupuncture was also able to influence the expression and function of the SDF-1α/CXCR4 axis,thereby enhancing the homing and survival ability of neural stem cells and promoting nerve regeneration and functional recovery.(4)The therapy combining acupuncture and stem cell transplantation is an innovative treatment strategy for spinal cord injury and suitable for repairing neural circuits.It combines the wisdom of traditional Chinese medicine with the advantages of modern biotechnology,providing a new treatment option for spinal cord injury patients.However,this combination therapy is still in the research and exploration stage,and its long-term efficacy and safety need to be further verified.(5)Taken together,acupuncture and neural stem cell transplantation for the treatment of spinal cord injury has great potential for clinical application,but in-depth research and optimization of treatment options are still needed.In the future,we look forward to further revealing the efficacy mechanism and optimal indications of this therapy through more clinical trials and mechanism studies,so as to bring better hope of recovery and more efficient therapeutic effects to spinal cord injury patients.

BACKGROUND:Currently,spinal cord injury imposes a huge psychological and economic burden on patients and the National Health Service.The prevention,treatment,and rehabilitation of spinal cord injury have become an important topic in the field of medicine.Therefore,it is important to explore new effective therapeutic strategies based on an in-depth understanding of the underlying molecular mechanisms of spinal cord injury.OBJECTIVE:To review the research progress on the mechanism of action of mesenchymal stem cell-derived exosomes loaded with various miRNAs in improving the function of spinal cord injury,and based on the current status of clinical translation,to put forward a few thoughts and outlooks on their clinical use.METHODS:The first author searched CNKI and PubMed databases using"mesenchymal stem cells,exosomes,spinal cord injury,miRNA,pathophysiology,clinical translation,clinical trials,good manufacturing practice"as Chinese and English search terms.The types of literature included treatises and reviews,and the language types were English and Chinese.Finally,72 papers were screened and analyzed.RESULTS AND CONCLUSION:(1)This article outlines the biological properties of exosomes and the advantages that they can serve as good vectors for loading miRNAs.A variety of miRNAs mediated by mesenchymal stem cell-derived exosomes mainly promote the recovery of neuronal function by regulating the expression of nerve regeneration-associated proteins,repressing RAS homologous gene family member A,activating cyclophosphoadenosine effector-binding proteins,and signaling and transcriptional activation proteins 3,and regulating phosphoinositide and tensin homologue/programmed cell death factor 4 pathways.Inflammatory responses were improved by regulating endoplasmic reticulum-to-nucleus signaling 1,expression of interferon regulatory factor 5,Toll-like receptor 4/nuclear factor-kappa B pathway,and down-regulating related pro-inflammatory factors.Angiogenesis was promoted by inhibition of germination-associated domain 1-containing EVH1 and phosphatidylinositol 3-kinase regulatory subunit 2.(2)Further comparative analyses revealed that miR-216-5p,miR-145-5p,and miR-146b improved inflammatory responses by regulating related pathways.Combining these miRNAs may produce more significant effects;hypoxic preconditioning may be a preconditioning method to increase the efficacy of exosomal therapy.(3)There are currently no clinical trials applying mesenchymal stem cell-derived exosomes to spinal cord injury,which is related to the need to meet good manufacturing practices before they can be put into clinical use.Challenges such as the need for large-scale,high-volume cell production,the lack of an efficient and uniform method for isolating exosomes,and the need to pass a strict regulatory approval mechanism prior to clinical use have impeded the clinical entry.(4)miRNAs have great potential as exosomal contents of mesenchymal stem cells in the treatment of spinal cord injury,and their mechanism of action should be explored in depth as well as accelerated to the clinical trial stage in order to provide a new and effective method for the treatment of spinal cord injury.

BACKGROUND:Cellular autophagy maintains metabolism and in vivo homeostasis through the autophagosome-lysosome degradation pathway,which is closely related to the impaired cell death and functional recovery of distal neurons after spinal cord injury,and targeting cellular autophagy to promote the functional recovery of the spinal cord after spinal cord injury is a promising therapeutic direction.OBJECTIVE:To summarize the role of cellular autophagy in spinal cord injury,related regulatory mechanisms of cellular autophagy and therapeutic strategies.METHODS:PubMed and CNKI databases were searched with the search terms of"spinal cord injury,autophagy,regulatory mechanisms,autophagy pathway,therapeutic target"in English and Chinese,respectively.A total of 133 English and 4 Chinese articles were included for review.RESULTS AND CONCLUSION:(1)Autophagy,a form of programmed cell death,has been shown to play a crucial role in the progression and treatment of spinal cord injury.Most studies have shown that moderate activation or promotion of autophagy promotes neurological recovery by decreasing inflammatory responses and apoptosis.A few studies have reported that excessive activation of autophagy,on the contrary,impedes neurological recovery following spinal cord injury.(2)After spinal cord injury,PI3K/AKT/mTOR,MAPK,AMPK and p53 signaling pathways,and factors such as Beclin-1,ATG and LC3 regulate the initiation and development of cell autophagy in a positive or negative manner.(3)Promoting or inhibiting autophagy may be a promising therapeutic strategy to modulate the pathogenesis of traumatic spinal cord injury.And the drugs amlodipine,metformin,and minocycline,the Chinese medicines hawthorn leaf total flavonoids,betulinic acid,oxidized ginseng saponins,acupuncture,and extracellular vesicles of different cellular origins,exosomes and reactive oxygen species-responsive composite fibers as activators of cellular autophagy attenuate secondary injury in response to spinal cord injury by activating cellular autophagy,while the drugs insulin-like growth factor 1 and eladavone,Chinese medicine ginseng saponin,acupuncture,and hydrogel carrying basic fibroblast growth factor as inhibitors of cellular autophagy promote functional recovery after spinal cord injury by inhibiting excessive cellular autophagy.(4)The related regulators of cellular autophagy are interconnected,and the bi-directional effects of cellular autophagy on spinal cord injury make it necessary to further explore the dominant factors that regulate cellular autophagy.(5)Research on the use of autophagy as a therapeutic target for spinal cord injury is mostly carried out in animal models,but there are no autophagy-related drugs used in the clinical practice,and their safety and efficacy need to be further investigated in the clinical field.

Objective:To discuss the effect of NOD-like receptor protein 3(NLRP3)inflammasome on the renal interstitial fibrosis in the unilateral ureteral obstruction(UUO)model rats,and to clarify its potential mechanism.Methods:Thirty healthy male Wistar rats were randomly divided into sham operation group(n=6)and UUO group(n=24).The rats in sham operation group underwent the dissection of the ureter without ligation,while the rats in UUO group were sacrificed on the 3rd,7th,and 14th days after operation,and based on the treatment duration,the rats were divided into UUO 3 d group(n=8),UUO 7 d group(n=8),and UUO 14 d group(n=8).HE staining and Masson staining were used to observe the pathomorphology of kidney tissue of the rats in various groups;reagent kits were used to detect the levels of malondialdehyde(MDA),activities of superoxide dismutase(SOD),and levels of hydroxyproline(HYP)in kidney tissue of the rats in various groups;immunohistochemistry method was used to detect the expression levels of α-smooth muscle actin(α-SMA)and transforming growth factor-β1(TGF-β1)proteins in kidney tissue of the rats in various groups;Western blotting method was used to detect the expression levels of NLRP3 protein in kidney tissue of the rats in various groups.Results:The HE staining results showed significant tubular dilation,interstitial edema,and widening,with increased infiltration of inflammatory cells,and shedding of epithelial cells was seen in parts of the tubular lumina of the rats in UUO group.Compared with sham operation group,the interstitial fibrosis scores of the rats in UUO 3 d,UUO 7 d,and UUO 14 d groups were significantly increased(P<0.05);compared with UUO 3 d group and UUO 7 d group,the interstitial fibrosis score of the rats in UUO 14 d group was significantly decreased(P<0.05).The Masson staining results showed that in UUO group,there was evident infiltration of inflammatory cells in the renal interstitium and a noticeable increase in fibrotic tissue proliferation;with the increasing of duration of UUO,some tubular structures disappeared,and the interstitial widened further with gradually increasing collagen deposition,particularly at the corticomedullary junction.Compared with sham operation group,the interstitial fibrosis scores of the rats in UUO 3 d,UUO 7 d,and UUO 14 d groups were significantly increased(P<0.05);and compared with UUO 3 d and UUO 7 d groups,the interstitial fibrosis score of the rats in UUO 14 d group was significantly decreased(P<0.05).Compared with sham operation group,the levels of MDA in obstructed kidney tissue of the rats in UUO 3 d,UUO 7 d,and UUO 14 d groups were significantly increased(P<0.05),and the SOD activities were significantly decreased(P<0.05).Compared with sham operation group,the levels of HYP in obstructed kidney tissue of the rats in UUO 3 d,UUO 7 d,and UUO 14 d groups were also significantly increased(P<0.05);compared with UUO 3 d group,the level of HYP in obstructed kidney tissue of the rats in UUO 14 d group was significantly increased(P<0.05).The immunohistochemistry results showed that compared with sham operation group,the expression levels of α-SMA protein in kidney tissue of the rats in UUO 3 d,UUO 7 d,and UUO 14 d groups were significant increased(P<0.05);compared with UUO 3 d and UUO 7 d groups,the expression levels of α-SMA protein in kidney tissue of the rats in UUO 14 d group was significantly increased(P<0.05);compared with sham operation group,the expression levels of TGF-β1 protein in renal tubular epithelial cells and renal tubule interstitial tissue of the rats in UUO 3 d,UUO 7 d,and UUO 14 d groups were also significantly increased(P<0.05);compared with UUO 3 d group,the expression levels of TGF-β1 protein in the tubular epithelial cells and renal tubule interstitial tissue of the rats in UUO 14 d group were significantly decreased(P<0.05).The Western blotting results showed that compared with sham operation group,the expression levels of NLRP3 protein in kidney tissue of the rats in UUO 7 d and UUO 14 d groups were significantly increased(P<0.05).Conclusion:The NLRP3 inflammasome plays a critical role in renal fibrosis of the UUO rats,and its mechanism may be related to the increasing of oxidative stress and the increasing of expression level of TGF-β1 protein.

Objective To investigate the effect and mechanism of Yiyuan moxibustion on urinary storage function in rats with neurogenic bladder(NB)after suprasacral spinal cord injury(SCI)based on adenosine activated protein kinase(AMPK)-connexin 43(Cx43)pathway.Methods Twelve female Sprague-Dawley rats were selected as the sham operation group using the random number table method,and 68 rats were used to prepare the suprasacral SCI model according to the modified Hassan Shaker spinal cord transection method.After the SCI model was stable,the standard NB model after SCI was screened out.The rats with successful modeling were divided into the model group(n=14),the Yiyuan moxibustion group(n=14),the inhibitor group(n=14),and the Yiyuan moxibustion+inhibitor group(n=14)according to the random number table method.The rats in the Yiyuan moxibustion group were treated with Yiyuan moxibustion.The rats in the inhibitor group were injected with AMPK inhibitor dorsomorphin(0.2 mg/kg)by tail vein.The rats in the Yiyuan moxibustion+inhibitor group were treated with Yiyuan moxibustion combined with tail vein injection of dorsomorphin(0.2 mg/kg).The sham operation group and the model group did not receive any intervention for 14 days.After the intervention,the bladder function of rats was evaluated by urodynamics.HE staining was used to observe morphological changes of the bladder tissue;the content of adenosine triphosphate(ATP)in bladder tissue was detected by colorimetry.The positive expressions of phosphorylated AMPK(p-AMPK),Cx43 and tyrosine protein kinase receptor(C-kit)in bladder tissue were detected by immunohistochemistry.The protein expressions of AMPK,p-AMPK,Cx43 and C-kit in bladder tissue were detected by Western blotting.Results Compared with the model group,the maximum bladder capacity and bladder compliance of the rats in the Yiyuan moxibustion group were increased,the leak point pressure was decreased,the cells in the Yiyuan moxibustion group were relatively regular and orderly,the vacuolar cells were reduced,and the tissue edema was reduced;the ATP content in the bladder tissue was decreased,the positive expression rate of p-AMPK was increased,the positive expression rate of Cx43 and C-kit were decreased,the protein expressions of p-AMPK protein was increased,the expression of Cx43 and C-kit were decreased,and the mRNA expression of Cx43 and C-kit were decreased(P<0.05).Compared with the Yiyuan moxibustion+inhibitor group,the maximum bladder capacity and bladder compliance of the rats in the Yiyuan moxibustion group increased,the leak point pressure decreased,the cells in the Yiyuan moxibustion group were arranged more closely and the tissue edema was reduced;the ATP content in the bladder tissue decreased,the positive expression rate of p-AMPK increased,the positive expression rates of Cx43 and C-kit decreased,the protein expression of p-AMPK increased,the protein expressions of Cx43 and C-kit decreased,and the mRNA expressions of Cx43 and C-kit decreased(P<0.05).Conclusion Yiyuan moxibustion can improve the urinary storage function of NB rats after suprasacral SCI,and its mechanism may be related to activating the AMPK-Cx43 pathway in bladder tissue,reducing the excitation transmission between bladder detrusor cells,thereby reducing the frequency of smooth muscle contraction.

BACKGROUND:Cell death and neuroinflammation are two important targets in the treatment of spinal cord injury.Pyroptosis is a programmed cell death closely related to neuroinflammation and targeted inhibition of pyroptosis after spinal cord injury is a promising therapeutic strategy. OBJECTIVE:To summarize the molecular mechanism,positive and negative regulatory factors and therapeutic strategies of pyroptosis in spinal cord injury. METHODS:The search terms were"spinal cord injury,pyroptosis,nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3),Caspase,Gasdermin D(GSDMD),IL-1β,IL-18"and 93 English literatures included in PubMed and Web of Science were finally selected for review. RESULTS AND CONCLUSION:As a newly discovered programmed cell death,pyroptosis has been shown to play an important role in the secondary injury stage after spinal cord injury.Among the regulatory factors of pyroptosis after spinal cord injury,CD73,NRF2,GDF-11,dopamine,FANCC and miR-423-5P could inhibit pyroptosis,while TLR4 and Aopps could promote pyroptosis.In terms of treatment,the active ingredients of traditional Chinese medicine(paeonol,tripterine,betulinic acid,piperine,kaempferol,and camptothecin),exosomes of various cell origins,and some drugs(metformin,topotecan,lithium,zinc,and carbon monoxide-releasing molecule 3)can effectively inhibit pyroptosis and reduce secondary spinal cord injury,but the toxicity and specific dose of these drugs need to be further studied.The specific molecular mechanism by which pyroptosis aggravates spinal cord injury is still poorly understood.The role of non-classical pathways and other inflammasomes is worth further exploration.At present,the research on pyroptosis after spinal cord injury only stays at the animal experiment stage.There are no related clinical studies and no approved targeted therapeutic drugs.(6)The application of pyroptosis after spinal cord injury has great potential,and its specific regulatory mechanism should be further studied in the future to provide a new target for the treatment of spinal cord injury.

Rituximab is currently used as a first-line therapy for phospholipase A 2 receptor-associated membranous nephropathy due to its good efficacy and safety. Although the remission rate after rituximab treatment is more than 60%, nearly 40% patients still do not respond to treatment. We used obinutuzumab to treat 3 cases of rituximab resistant PLA 2R-associated membranous nephropathy. After the first dose of 1 000 mg with or without additional dose, the amount of anti-PLA 2R antibody and urinary protein decreased significantly and the adverse reactions were mild. The results show that obinutuzumab has a certain therapeutic effect on rituximab resistant PLA 2R-associated membranous nephropathy, but the time of follow-up observation is short and can only be used as individual cases, which needs to be confirmed by a large sample and high-quality prospective cohort study.

Objective To investigate the association of radial arterial calcification damage with bone mineral density (BMD) and bone metabolism biomarkers in uremia patients.Methods Sixty-seven incident hemodialysis patients were recruited into uremic group.Serum creatinine,calcium,phosphorus,lumbar spine and femoral neck BMD were measured.Parathyroid hormone (iPTH),25OHD,1,25(OH)2D,fibroblast growth factor (FGF) 23,bone specific alkaline phosphates (BAP) and osteocalcin (BGP),type Ⅰ collagen pyridine crosslinked C-telopcptidc (ICTP) were detected.Radial artery calcification was analyzed by von Kossa staining and transmission electron microscopy.Arterial type Ⅰ collagen (Col Ⅰ) expression was examined.Twenty-three healthy cases received serum and BMD examination only as control.Results Uremic patients presented higher serum phosphate,iPTH,FGF23,lower serum calcium,25OHD,1,25 (OH)2D (all P ＜ 0.05),and lower lumbar spine and femoral neck BMD (all P ＜ 0.01) compared to controls.Significant calcium deposit was observed in radial arteries in 24 uremic cases (35.8％),including 10 cases of diabetes.Immunohistochemistric assay confirmed that Col Ⅰ expression increased around calcification site and electron microscope revealed that more calcium and phosphorus plaque attached among collagen fibers.No correlation was showed between iPTH and radial artery calcification (r =-0.08,P =0.306),but after stratified by iPTH levels,correlation of iPTH and calcification was found in low iPTH (＜ 150 ng/L) group and high iPTH group (＞ 300 ng/L) (r =-0.41,0.31,P=0.044,0.023).Diabetes,lumbar spine and femoral neck BMD,ICTP,FGF23 were correlated with arterial calcification (r =0.62,-0.25,-0.43,0.34,0.86,P =0.000,0.001,0.012,0.018,0.000).Multiple regression analysis showed femoral neck BMD,ICTP,FGF23 levels were independently associated with radial arterial calcification (β =-0.221,0.181,0.260,P =0.021,0.024,0.036).Conclusion In uremic patients,reduced BMD,abnormal bone turnover rate,especially accelerated bone reabsorption,and increased serum FGF23 level are independently associated with radial artery calcification.