transplantation

摘要： Our previo us study demonstrated the potential therapeutic role of human neural stem cell-derived exosomes(hNSC-Exo)in ischemic stroke.Here,we loaded brain-derived neurotrophic factor(BDNF)into exosomes derived from NSCs to construct engineered exosomes(BDNF-hNSC-Exo)and compared their effects with those of hNSC-Exo on ischemic stroke both in vitro and in vivo.In a model of H_(2)O_(2)-induced oxidative stress in NSCs,BDNF-hNSC-Exo markedly enhanced cell survival.In a rat middle cerebral arte ry occlusion model,BDNF-hNSC-Exo not only inhibited the activation of microglia,but also promoted the differentiation of endogenous NSCs into neurons.These results suggest that BDNF can improve the function of NSC-derived exosomes in the treatment of ischemic stro ke.Our research may support the clinical use of other neurotrophic factors for central nervous system diseases.

摘要： Although bone marrow mesenchymal stem cells(BMSCs)might have therapeutic potency in ischemic stroke,the benefits are limited.The current study investigated the effects of BMSCs engineered to overexpress vascular endothelial growth factor(VEGF)on behavioral defects in a rat model of transient cerebral ischemia,which was induced by middle cerebral artery occlusion.VEGF-BMSCs or control grafts were injected into the left striatum of the infarcted hemisphere 24 hours after stroke.We found that compared with the stroke-only group and the vehicle-and BMSCs-control groups,the VEGF-BMSCs treated animals displayed the largest benefits,as evidenced by attenuated behavioral defects and smaller infarct volume 7 days after stroke.Additionally,VEGF-BMSCs greatly inhibited destruction of the blood-brain barrier,increased the regeneration of blood vessels in the region of ischemic penumbra,and reducedneuronal degeneration surrounding the infarct core.Further mechanistic studies showed that among all transplant groups,VEGF-BMSCs transplantation induced the highest level of brain-derived neurotrophic factor.These results suggest that BMSCs transplantation with vascular endothelial growth factor has the potential to treat ischemic stroke with better results than are currently available.

摘要： Chx10-expressing V2 a(Chx10+V2 a) spinal interneurons play a large role in the excitatory drive of motoneurons. Chemogenetic ablation studies have demonstrated the essential nature of Chx10+V2 a interneurons in the regulation of locomotor initiation, maintenance, alternation, speed, and rhythmicity. The role of Chx10+V2 a interneurons in locomotion and autonomic nervous system regulation is thought to be robust, but their precise role in spinal motor regulation and spinal cord injury have not been fully explored. The present paper reviews the origin, characteristics, and functional roles of Chx10+V2 a interneurons with an emphasis on their involvement in the pathogenesis of spinal cord injury. The diverse functional properties of these cells have only been substantiated by and are due in large part to their integration in a variety of diverse spinal circuits. Chx10+V2 a interneurons play an integral role in conferring locomotion, which integrates various corticospinal, mechanosensory, and interneuron pathways. Moreover, accumulating evidence suggests that Chx10+V2 a interneurons also play an important role in rhythmic patterning maintenance, leftright alternation of central pattern generation, and locomotor pattern generation in higher order mammals, likely conferring complex locomotion. Consequently, the latest research has focused on postinjury transplantation and noninvasive stimulation of Chx10+V2 a interneurons as a therapeutic strategy, particularly in spinal cord injury. Finally, we review the latest preclinical study advances in laboratory derivation and stimulation/transplantation of these cells as a strategy for the treatment of spinal cord injury. The evidence supports that the Chx10+V2 a interneurons act as a new therapeutic target for spinal cord injury. Future optimization strategies should focus on the viability, maturity, and functional integration of Chx10+V2 a interneurons transplanted in spinal cord injury foci.

摘要： Spinal cord injury often leads to severe motor and sensory deficits,and prognosis using the currently available therapies remains poor.Therefore,we aimed to explore a novel therapeutic approach for improving the prognosis of spinal cord injury.In this study,we implanted oscillating field stimulation devices and transplanted neural stem cells into the thoracic region(T9–T10)of rats with a spinal cord contusion.Basso-Beattie-Bresnahan scoring revealed that oscillating field stimulation combined with neural stem cells transplantation promoted motor function recovery following spinal cord injury.In addition,we investigated the regulation of oscillating field stimulation on the miR-124/Tal1 axis in neural stem cells.Transfection of lentivirus was performed to investigate the role of Tal1 in neurogenesis of neural stem cells induced by oscillating field stimulation.Quantitative reverse transcription-polymerase chain reaction,immunofluorescence and western blotting showed that oscillating field stimulation promoted neurogenesis of neural stem cells in vitro and in vivo.Hematoxylin and eosin staining showed that oscillating field stimulation combined with neural stem cells transplantation alleviated cavities formation after spinal cord injury.Taking the results together,we concluded that oscillating field stimulation decreased miR-124 expression and increased Tal1 content,thereby promoting the neurogenesis of neural stem cells.The combination of oscillating field stimulation and neural stem cells transplantation improved neurogenesis,and thereby promoted structural and functional recovery after spinal cord injury.

摘要： Innate immune cells are critical for transplant response.As an important cellular component of innate immune cells,macrophages are the predominate infiltrated cells in allografts,and macrophage accumulation in allografts is negatively associated with the short-and long-term outcomes of organ transplantation.Macrophages are functionally heterogeneous and plastic.They participate in organ graft rejection through multiple pathways,including antigen presentation,the expression of costimulatory molecules and cytokines,and direct cytotoxicity and injury ability to allografts.However,some macrophage subpopulations,such as regulatory macrophages,can protect allografts from immune rejection and promote transplant immune tolerance with their immune regulatory properties.Although researchers recognize the potential roles macrophages play in allograft injury,they pay insufficient attention to the diverse roles of macrophages in allograft rejection.We herein briefly summarize the distinctive roles of macrophages in acute transplant immune response and the effect of immunosuppressive drugs on macrophages.Greater attention should be paid to the complex and critical function of macrophages in allograft rejection,and more effort should be put into developing immunosuppressive drugs that specifically target macrophages,which would ultimately improve the long-term survival of organ grafts in patients.

摘要： Children infected by severe acute respiratory syndrome coronavirus 2(SARSCoV-2)seem to have a better prognosis than adults.Nevertheless,pediatric solid organ transplantation(SOT)has been significantly affected by the unprecedented coronavirus disease 2019(COVID-19)pandemic during the pre-,peri-,and posttransplant period.Undoubtedly,immunosuppression constitutes a real challenge for transplant clinicians as increased immunosuppression may prolong disease recovery,while its decrease can contribute to more severe symptoms.To date,most pediatric SOT recipients infected by SARS-CoV-2 experience mild disease with only scarce reports of life-threatening complications.As a consequence,after an initial drop during the early phase of the pandemic,pediatric SOTs are now performed with the same frequency as during the pre-pandemic period.This review summarizes the currently available evidence regarding pediatric SOT during the COVID-19 pandemic.

摘要： BACKGROUND The machine perfusion(MP)preservation including hypothermic MP(HMP)and midthermic MP(MMP)has been considered as a promising strategy to preserve the functions of liver donated after cardiac death.The importance of understanding liver sinusoidal endothelial cells(LSEC)damage in regulating liver injury during MP has been emphasized.However,the ultrastructural changes in the LSEC and sinusoids around them after MP are unclear.AIM To investigate the ultrastructural changes in the LSEC and sinusoids around them after MP.METHODS Porcine liver grafts undergo a warm ischemia time of 60 minutes perfused for 4 h with modified University of Wisconsin gluconate solution.Group A grafts were preserved with HMP at 8°C constantly for 4 h.Group B grafts were preserved with a rewarming solution at 22°C by MMP for 4 h.Then the ultrastructural changes in the LSEC and sinusoids in Group A and B were comparatively analyzed by using osmium-maceration scanning electron microscopy with complementary transmission electron microscopy methods.RESULTS An analysis of the LSEC after warm ischemia revealed that mitochondria with condensed-shaped cristae,abnormal vesicles,reduction of ribosomes and the endoplasmic reticulum(ER)surround the mitochondria appeared.The MP subsequent after warm ischemia alleviate the abnormal vesicles and reduction of ribosomes in LSEC,which indicated the reduction of the ER damage.However,MMP could restore the tubular mitochondrial cristae,while after HMP the condensed and narrow mitochondrial cristae remained.In addition,the volume of the sinusoidal space in the liver grafts after MMP were restored,which indicated a lower risk of pressure injury than HMP.CONCLUSION MMP alleviates the ER damage of LSEC by warm ischemia,additionally restore the metabolism of LSEC via the normalization of mitochondria and prevent the share stress damage of liver grafts.

摘要： This editorial describes the indications and technical aspects of the simultaneous retrieval of thoracic and abdominal organs in Maastricht III donors as well as the preservation of such organs until their implantation.

摘要： Insulinomas are the most frequent type of functional pancreatic neuroendocrine tumors with a variety of neuroglycopenic and autonomic symptoms and welldefined diagnostic criteria;however,prediction of their clinical behavior and early differentiation between benign and malignant lesions remain a challenge.The comparative studies between benign and malignant cases are limited,suggesting that short clinical history,early hypoglycemia during fasting,high proinsulin,insulin,and C-peptide concentrations raise suspicion of malignancy.Indeed,malignant tumors are larger with higher mitotic count and Ki-67 proliferative activity,but there are no accurate histological criteria to distinguish benign from malignant forms.Several signaling pathways have been suggested to affect the pathophysiology and behavior of insulinomas;however,our knowledge is limited,urging a further understanding of molecular genetics.Therefore,there is a need for the identification of reliable markers of metastatic disease that could also serve as therapeutic targets in patients with malignant insulinoma.This opinion review reflects on current gaps in diagnostic and clinical aspects related to the malignant behavior of insulinoma.

摘要： Chronic hepatitis C virus(HCV)infection is the principal etiology of cirrhosis and,ultimately,hepatocellular carcinoma(HCC).At present,approximately 71 million people are chronically infected with HCV,and 10%–20%of these are expected to develop severe liver complications throughout their lifetime.Scientific evidence has clearly shown the causal association between miRNAs,HCV infection and HCC.Although it is not completely clear whether miRNA dysregulation in HCC is the cause or the consequence of its development,variations in miRNA patterns have been described in different liver diseases,including HCC.Many studies have analyzed the importance of circulating miRNAs and their effect on cell proliferation and apoptosis.In this Review,we aim to summarize current knowledge on the association between miRNA,HCV and HCC from a diagnostic point of view,and also the potential implications for therapeutic approaches.