BACKGROUND:Human umbilical cord mesenchymal stem cell-derived exosomes are involved in multiple injury repair processes,and the effects and the specific mechanisms of renal ischemia/reperfusion injury have not been fully elucidated.OBJECTIVE:To investigate the molecular mechanism of human umbilical cord mesenchymal stem cell-derived exosomes in the treatment of renal ischemia/reperfusion injury.METHODS:(1) Human umbilical cord mesenchymal stem cells were cultured and exosomes were obtained and identified using an exosome extraction kit.(2) The distribution of exosomes in the kidney of mice with renal ischemia/reperfusion injury was examined by intravital fluorescence imaging.(3) Thirty C57/BL6 male mice were divided into five groups according to the random number table method:sham operation group,renal ischemia/reperfusion group,sham operation group+Compound C group,renal ischemia/reperfusion+exosome group (exosome group),and renal ischemia/reperfusion+exosome+Compound C group (exosome+Compound C group),with 6 mice in each group.Except the sham operation group,bilateral renal pedicles were clamped for 45 minutes and a mouse model of renal ischemia/reperfusion injury was established after 24 hours of reperfusion.In sham operation+Compound C group and exosome+Compound C group,AMPK inhibitor Compound C was intraperitoneally injected 30 minutes before model establishment.In the exosome group and exosome+Copmpound C group,exosomes were injected through the tail vein 15 minutes before renal pedicle clipping.The levels of serum creatinine and urea nitrogen,interleukin 6,and tumor necrosis factor α in renal tissue,and the expression of apoptosis-related factors in renal tissue were detected after 24 hours of reperfusion in each group.RESULTS AND CONCLUSION:(1) Human umbilical cord mesenchymal stem cell exosomes had the typical tea tray morphology,with the diameter distribution in the range of 40-160 nm,and expressed the specific marker membrane protein of exosome surface.(2) Murine kidneys after renal ischemia/reperfusion injury were more likely to gather human umbilical cord mesenchymal stem cell exosomes compared with the sham operation group.(3) Exosome pretreatment reduced renal injury and the level of renal cell apoptosis in mice treated with renal ischemia/reperfusion injury.Moreover,this protective effect could be reversed by AMPK inhibitors.These findings verify that human umbilical cord mesenchymal stem cell-derived exosomes exerting a protective effect on renal ischemia/reperfusion injury may be related to the activation of the AMPK/YAP1 pathway to antiapoptosis.

BACKGROUND:Human umbilical cord mesenchymal stem cell-derived exosomes are involved in multiple injury repair processes,and the effects and the specific mechanisms of renal ischemia/reperfusion injury have not been fully elucidated.OBJECTIVE:To investigate the molecular mechanism of human umbilical cord mesenchymal stem cell-derived exosomes in the treatment of renal ischemia/reperfusion injury.METHODS:(1) Human umbilical cord mesenchymal stem cells were cultured and exosomes were obtained and identified using an exosome extraction kit.(2) The distribution of exosomes in the kidney of mice with renal ischemia/reperfusion injury was examined by intravital fluorescence imaging.(3) Thirty C57/BL6 male mice were divided into five groups according to the random number table method:sham operation group,renal ischemia/reperfusion group,sham operation group+Compound C group,renal ischemia/reperfusion+exosome group (exosome group),and renal ischemia/reperfusion+exosome+Compound C group (exosome+Compound C group),with 6 mice in each group.Except the sham operation group,bilateral renal pedicles were clamped for 45 minutes and a mouse model of renal ischemia/reperfusion injury was established after 24 hours of reperfusion.In sham operation+Compound C group and exosome+Compound C group,AMPK inhibitor Compound C was intraperitoneally injected 30 minutes before model establishment.In the exosome group and exosome+Copmpound C group,exosomes were injected through the tail vein 15 minutes before renal pedicle clipping.The levels of serum creatinine and urea nitrogen,interleukin 6,and tumor necrosis factor α in renal tissue,and the expression of apoptosis-related factors in renal tissue were detected after 24 hours of reperfusion in each group.RESULTS AND CONCLUSION:(1) Human umbilical cord mesenchymal stem cell exosomes had the typical tea tray morphology,with the diameter distribution in the range of 40-160 nm,and expressed the specific marker membrane protein of exosome surface.(2) Murine kidneys after renal ischemia/reperfusion injury were more likely to gather human umbilical cord mesenchymal stem cell exosomes compared with the sham operation group.(3) Exosome pretreatment reduced renal injury and the level of renal cell apoptosis in mice treated with renal ischemia/reperfusion injury.Moreover,this protective effect could be reversed by AMPK inhibitors.These findings verify that human umbilical cord mesenchymal stem cell-derived exosomes exerting a protective effect on renal ischemia/reperfusion injury may be related to the activation of the AMPK/YAP1 pathway to antiapoptosis.

Objective To investigate the prevalence and molecular characteristics of Anaplasma infections in sheep and goats in Anhui Province in 2020, so as to provide insights into ovine anaplasmosis prevention and control. Methods A total of 355 fresh blood samples were collected from 7 sheep and goat farms in Linquan County of Fuyang City, Lixin County of Bozhou City, Yu'an District of Lu'an City, Wangjiang County of Anqing City, Nanling County of Wuhu City, and Tianchang City and Fengyang County of Chuzhou City in Anhui Province from June to December 2020. A. bovis and A. phagocytophilum 16S ribosomal RNA (16S rRNA) gene, A. ovis major surface protein 4 (MSP4) gene and A. capra citric acid synthase (gltA) gene were amplified using PCR assay in all blood samples, and the prevalence of A. bovis, A. phagocytophilum, A. ovis and A. capra infections was calculated in sheep and goats. In addition, the positive amplification products were sequenced and subjected to genetic evolutionary analysis. Results The overall prevalence of Anaplasma infections was 17.5% (62/355) in sheep and goats in Anhui Province, and the prevalence of A. bovis, A. phagocytophilum, A. ovis and A. capra infections was 2.8% (10/355), 2.5% (9/355), 2.5% (9/355), and 7.0% (25/355), while the prevalence of A. bovis and A. phagocytophilum, A. phagocytophilum and A. ovis, A. phagocytophilum and A. capra and A. bovis, A. phagocytophilum and A. ovis co-infections was 0.8% (3/355), 1.1% (4/355), 0.3% (1/355) and 0.3% (1/355), respectively. No Anaplasma was detected in the sheep and goat farms in Fengyang County, while at least three Anaplasma species were detected in other sheep and goat farms, with co-infections of multiple Anaplasma species identified. The prevalence of Anaplasma infections was 14.7% (24/163) in goats and 19.8% (38/192) in sheep, and the prevalence of Anaplasma infections was 31.0% (31/100) in goats and sheep under 6 months of age, and 12.2% (31/255) in goats and sheep at ages of 6 months and older, respectively. A. bovis, A. phagocytophilum, A. ovis and A. capra were identified in sheep and goats of different breeds and ages. Conclusions Multiple Anaplasma species infections were commonly prevalent in goats and sheep in Anhui Province in 2020, notably A. phagocytophilum, A. ovis and A. capra, which have zoonotic risks. Improved surveillance and prevention and control of Anaplasma infections are required in sheep and goats in Anhui Province.

Objective:To evaluate the role of nuclear factor E2-related factor 2 (Nrf2)/heme oxidase-1 (HO-1) in reduction of renal ischemia-reperfusion (I/R) injury by the human umbilical cord mesenchymal stem cells (hucMSCs)-derived exosomes (hucMSCs-exo) in mice.Methods:The hucMSCs were cultured, and exosomes were extracted and identified by transmission electron microscopy, nanoparticle tracking analysis and Western blot. Thirty-six male SPF-grade C57BL/6 mice, weighing 20-25 g, were used. Thirty mice were selected and divided into 5 groups ( n=6 each) by a random number table method: sham operation group (Sham group), sham operation + Nrf2 inhibitor ML385 group (Sham + ML385 group), renal I/R group (I/R group), renal I/R + exosome group (I/R+ EXO group), and renal I/R + exosome + Nrf2 inhibitor ML385 group (I/R+ EXO+ ML385 group). A model of renal I/R injury was prepared by clamping the bilateral renal pedicles for 45 min followed by perfusion in anesthetized animals. ML385 30 mg/kg was intraperitoneally injected at 45 min before preparing the model in Sham+ ML385 group and I/R+ EXO+ ML385 group, and hucMSCs-exo 100 μg was injected via the tail vein at 15 min before reperfusion in I/R+ EXO group and I/R+ EXO+ ML385 group. Serum blood urea nitrogen (BUN) and creatinine (Cr) concentrations were detected at 24 h of reperfusion. The renal tissues were obtained for examination of the pathological changes and for determination of contents of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α) and malondialdehyde (MDA), superoxide dismutase (SOD) activity and reactive oxygen species (ROS) levels and expression of Nrf2 and HO-1 protein and mRNA (by Western blot and quantitative real-time polymerase chain reaction). The left 6 mice were allocated to sham operation group (Sham-IM group, n=3) and renal I/R group (I/R-IM group, n=3) by a random number table method for VISQUE in living imaging observation. Results:The exosomes showed a typical cup-shaped morphology with a transmission electron microscope, the nanoparticles tracked and analyzed the average diameter of the exosome, with an average diameter of 96.7 nm, and the positive expression of surface markers CD9, CD63 and TSG101 was detected using Western blot. The renal fluorescence intensity value was significantly increased in I/R-IM group as compared with Sham-IM group ( P<0.05). Compared with Sham group, the serum BUN and Cr concentrations were significantly increased, the contents of IL-6, TNF-α and MDA and ROS levels were increased, the activity of SOD was decreased, the expression of Nrf2 and HO-1 protein and mRNA was down-regulated ( P<0.05), and the pathological changes of renal tissues were aggravated in I/R group, and no significant change was found in serum BUN and Cr concentrations in Sham+ ML385 group ( P>0.05). Compared with I/R group, the serum BUN and Cr concentrations were significantly decreased, the contents of IL-6, TNF-α and MDA and ROS levels were decreased, the activity of SOD was increased, the expression of Nrf2 and HO-1 protein and mRNA was up-regulated ( P<0.05), and the pathological changes of renal tissues were significantly attenuated in I/R+ EXO group. Compared with I/R+ EXO group, the serum BUN and Cr concentrations were significantly increased, the contents of IL-6, TNF-α and MDA and ROS levels were increased, the activity of SOD was decreased, the expression of Nrf2 and HO-1 protein and mRNA was down-regulated ( P<0.05), and the pathological changes of renal tissues were aggravated in I/R+ EXO+ ML385 group. Conclusions:The mechanism by which hucMSCs-exo reduces renal I/R injury may be related to activation of the Nrf2/HO-1 signaling pathway in mice.

Objective To assess the value of cardiac magnetic resonance(CMR)imaging for predicting adverse left ventricular remodeling in patients with ST-segment elevation myocardial infarction(STEMI).Methods We retrospectively analyzed the clinical data and serial CMR(cine and LGE sequences)images of 86 STEMI patients within 1 week and 5 months after percutaneous coronary intervention(PCI),including 25 patients with adverse LV remodeling and 61 without adverse LV remodeling,defined as an increase of left ventricular end-systolic volume(LVESV)over 15%at the second CMR compared to the initial CMR.The CMR images were analyzed for LV volume,infarct characteristics,and global and infarct zone myocardial function.The independent predictors of adverse LV remodeling following STEMI were analyzed using univariate and multivariate Logistic regression methods.Results The initial CMR showed no significant differences in LV volume or LV ejection fraction(LVEF)between the two groups,but the infarct mass and microvascular obstructive(MVO)mass were significantly greater in adverse LV remodeling group(P<0.05).Myocardial injury and cardiac function of the patients recovered over time in both groups.At the second CMR,the patients with adverse LV remodeling showed a significantly lower LVEF,a larger left ventricular end-systolic volume index(LVESVI)and a greater extent of infarct mass(P<0.001)with lower global peak strains and strain rates in the radial,circumferential,and longitudinal directions(P<0.05),infarct zone peak strains in the 3 directions,and infarct zone peak radial and circumferential strain rates(P<0.05).The independent predictors for adverse LV remodeling following STEMI included the extent of infarct mass(AUC=0.793,95%CI:0.693-0.873;cut-off value:30.67%),radial diastolic peak strain rate(AUC=0.645,95%CI:0.534-0.745;cut-off value:0.58%),and RAAS inhibitor(AUC= 0.699,95%CI:0.590-0.793).Conclusion The extent of infarct mass,peak radial diastolic strain rate,and RAAS inhibitor are independent predictors of adverse LV remodeling following STEMI.

Objective To assess the value of cardiac magnetic resonance(CMR)imaging for predicting adverse left ventricular remodeling in patients with ST-segment elevation myocardial infarction(STEMI).Methods We retrospectively analyzed the clinical data and serial CMR(cine and LGE sequences)images of 86 STEMI patients within 1 week and 5 months after percutaneous coronary intervention(PCI),including 25 patients with adverse LV remodeling and 61 without adverse LV remodeling,defined as an increase of left ventricular end-systolic volume(LVESV)over 15%at the second CMR compared to the initial CMR.The CMR images were analyzed for LV volume,infarct characteristics,and global and infarct zone myocardial function.The independent predictors of adverse LV remodeling following STEMI were analyzed using univariate and multivariate Logistic regression methods.Results The initial CMR showed no significant differences in LV volume or LV ejection fraction(LVEF)between the two groups,but the infarct mass and microvascular obstructive(MVO)mass were significantly greater in adverse LV remodeling group(P<0.05).Myocardial injury and cardiac function of the patients recovered over time in both groups.At the second CMR,the patients with adverse LV remodeling showed a significantly lower LVEF,a larger left ventricular end-systolic volume index(LVESVI)and a greater extent of infarct mass(P<0.001)with lower global peak strains and strain rates in the radial,circumferential,and longitudinal directions(P<0.05),infarct zone peak strains in the 3 directions,and infarct zone peak radial and circumferential strain rates(P<0.05).The independent predictors for adverse LV remodeling following STEMI included the extent of infarct mass(AUC=0.793,95%CI:0.693-0.873;cut-off value:30.67%),radial diastolic peak strain rate(AUC=0.645,95%CI:0.534-0.745;cut-off value:0.58%),and RAAS inhibitor(AUC= 0.699,95%CI:0.590-0.793).Conclusion The extent of infarct mass,peak radial diastolic strain rate,and RAAS inhibitor are independent predictors of adverse LV remodeling following STEMI.

Objective To investigate the protective effect of human umbilical cord mesenchymal stem cell-derived exosome (hucMSC-Exo) on renal ischemia-reperfusion injury (IRI), and to clarify the critical role and regulating mechanism of transient receptor potential canonical (TRPC) 6/poly adenosine-diphosphate-ribose polymerase (PARP) 1 signaling pathway during this process. Methods The hucMSC-Exo was extracted by ultracentrifugation, and identified by transmission electron microscope (TEM), nanoparticle tracing analysis and Western blot. SD rats were randomly divided into the sham operation group (group S), sham operation+TRPC6 inhibitor SKF96365 group (group SS), renal IRI group (group IRI), exosome treatment group (group EXO) and exosome +TRPC6 inhibitor SKF96365 group (group ES), with 6 rats in each group. Serum creatinine and blood urea nitrogen levels were detected. Pathological changes of renal tissues were observed by hematoxylin-eosin (HE) staining and Paller score was calculated. The expression levels of key molecules of necroptosis in rat renal tissues, including receptor-interacting protein kinase (RIPK)1, RIPK3 and mixed-lineage kinase domain-like protein (MLKL), TRPC6 and PARP1, were detected by Western blot. Results Typical saucer-like structure was observed under TEM. Nanoparticle tracing analysis showed that the average diameter of the extracted substance was 125.9 nm. Western blot revealed that the surface markers of CD9, CD63 and CD81 were positively expressed, confirmed that the extracted substance was exosome. Compared with group S, the serum creatinine and blood urea nitrogen levels were up-regulated, the pathological damage of renal tissues was worsened, Paller score was elevated, the relative expression levels of TRPC6 and PARP1 proteins were down-regulated, and the relative expression levels of RIPK1, RIPK3 and MLKL proteins were up-regulated in group IRI (all P < 0.05). Compared with group IRI, the serum creatinine and blood urea nitrogen levels were down-regulated, the pathological damage of renal tissues was mitigated, Paller score was decreased, the relative expression levels of TRPC6 and PARP1 proteins were up-regulated, and the relative expression levels of RIPK1, RIPK3 and MLKL proteins were down-regulated in group EXO (all P < 0.05). Compared with group EXO, the serum creatinine and blood urea nitrogen levels were up-regulated, the pathological damage of renal tissues was aggravated, Paller score was increased, the relative expression levels of TRPC6 and PARP1 proteins were down-regulated, and the relative expression levels of RIPK1, RIPK3 and MLKL proteins were up-regulated in group ES (all P < 0.05). Conclusions hucMSC-Exo may alleviate the necroptosis induced by renal IRI in rat models, which is related to the activation of TRPC6/PARP1 signaling pathway.

Ischemia-reperfusion injury (IRI) refers to the reperfusion injury caused by the recovery of blood supply of ischemic tissues or organs, which commonly occurs in organ transplantation and other surgical procedures. IRI may cause a series of severe clinical issues, such as delayed graft function, acute kidney injury, myocardial infarction, ischemic stroke and circulatory arrest, etc. These events yield high incidence and fatality. At present, no effective solution has been available. Transient receptor potential canonical 6 (TRPC6), a member of Ca²⁺ channel family, is highly expressed in multiple types of cells. It may adjust many physiological functions by regulating intracellular Ca²⁺ concentration, which has become an important target for developing therapeutic drugs for multiple diseases. In this article, research progresses on the introduction and function of TRPC6, the association between TRPC6 and IRI and the therapeutic prospect of TRPC6 targeted drugs in IRI were reviewed, aiming to provide novel insights into the prevention and treatment of IRI during organ transplantation

Three patients received surgical treatment in Department of Hepatobiliary Surgery of Mengchao Hepatobiliary Hospital from December 2020 to February 2022. Ceftriaxone sodium was given prophylactically before and after operation,and gallbladder silt stones were found by imaging examination on the 3rd, 3rd and 2nd after surgery in 3 patients, respectively. No special treatment was given,after the withdrawal of ceftriaxone sodium for 28, 38 and 48 d,radiographic examination showed that calculi disappeared spontaneously. It is suggested that the pseudolithiasis may be related to administration of ceftriaxone sodium.

An 11-year-old boy received tofacitinib (oral 7.5 mg once daily) on the basis of methotrexate therapy (oral 10 mg once a week) due to poor control of juvenile idiopathic arthritis, and the symptoms were relieved. The boy′s liver function was normal before using tofacitinib. After more than 2 months of combined use of the 2 drugs, laboratory tests showed alanine aminotransferase (ALT) 178 U/L and aspartate aminotransferase (AST) 78 U/L. No intervention was given because there were no clinical symptoms. His liver enzyme elevated significantly (ALT 586 U/L, AST 170 U/L) after continued medication for 1 month. After excluding viral hepatitis, autoimmune hepatitis, and other liver diseases, drug-induced liver injury was considered. Methotrexate was discontinued, tocilizumab was added, and liver protection therapy with reduced glutathione and magnesium isoglycyrrhizinate was given. Eleven days of methotrexate withdrawal, the laboratory tests showed ALT 512 U/L and AST 194 U/L. Then tofacitinib was discontinued and hepatic enzyme decreased significantly (ALT 150 U/L, AST 41 U/L) 3 days later. The liver injury was considered to be related to tofacitinib. The liver protection therapy was continued for 1 week, and the liver function examination showed ALT 41 U/L and AST 35 U/L.