ObjectiveTo elucidate the mechanism by which total flavonoids of Abelmoschi Corolla （TFA） treat immunoglobulin A （IgA） nephropathy （IgAN） through serum metabolomics analysis. MethodsSPF-grade male SD rats were randomly assigned into six groups （n=10）： blank， model， low-dose TFA （TFA-L， 27 mg·kg^-1）， medium-dose TFA （TFA-M， 54 mg·kg^-1）， high-dose TFA （TFA-H， 108 mg·kg^-1）， and losartan potassium （LST， 4.5 mg·kg^-1） groups. The remaining five groups， excluding the blank group， were modeled with bovine serum albumin （BSA）， lipopolysaccharide （LPS）， and carbon tetrachloride （CCl₄）. Specifically， from weeks 1 to 10， BSA was administered via gavage every other day， and a mixture of castor oil and CCl₄ was injected subcutaneously once a week， with LPS injected into the tail vein at weeks 6 and 8. After successful modeling， each intervention group was administrated with the medication prepared with distilled water once daily by gavage for a continuous period of 4 weeks. The levels of 24-hour urinary total protein （24 h UP） and serum creatinine （SCr） were quantified by kits， and the serum IgA level was determined by enzyme-linked immunosorbent assay （ELISA）. Renal pathological changes were observed by hematoxylin-eosin （HE） staining and periodic acid-Schiff （PAS） staining. Renal IgA deposition was assessed by immunofluorescence （IF）. Endoplasmic reticulum （ER） stress was observed by transmission electron microscopy. Western blot and immunohistochemistry （IHC） were employed to detect the expression of ER stress-related factors. Non-targeted metabolomics was used to screen differential metabolites for analysis， and key metabolites arachidonic acid （AA）， prostaglandin E₂ （PGE₂）， and cyclooxygenase-2 （COX-2） were validated. ResultsCompared with the blank group， the model group showed increased 24-hour urine protein （24 h UP） and serum creatinine （SCr） levels （P<0.01）， obvious renal pathological damage， elevated serum IgA level （P<0.01）， increased renal AA and PGE₂ levels （P<0.01）， and up-regulated protein levels of COX-2， glucose-regulated protein 78 （GRP78）， phosphorylated eukaryotic initiation factor 2α （P-EIF2α）， activating transcription factor 4 （ATF4）， inositol-requiring enzyme 1α （IRE1α）， and spliced X-box binding protein 1 （XBP1s） in the renal tissue （P<0.05， P<0.01）. Compared with the model group， the intervention groups showed reductions in 24 h UP and SCr levels （P<0.05， P<0.01）， alleviated renal pathological injury， decreased serum IgA level （P<0.05， P<0.01）， and reduced renal AA and PGE₂ levels （P<0.01）. Western blot and IHC results showed that TFA reduced the levels of COX-2， GRP78， P-EIF2α， ATF4， IRE1α， and XBP1s in the renal tissue （P<0.05， P<0.01）. Metabolomics results indicated that 51 commonly differential metabolites were found among the normal， model， and TFA-M groups. TFA ameliorated IgAN by affecting metabolic pathways related to the biosynthesis of arachidonic acid and arginine through L-aspartic acid， prostaglandin 2α， leukotriene B₄， leukotriene D₄， among others. ConclusionTFA can regulate the arachidonic acid metabolism pathway， thereby modulating ER stress， reducing renal damage， and ameliorating IgA nephropathy.

BACKGROUND:Forskolin,a diterpenoid natural compound extracted from Coleus forskohlii,has a crucial regulatory role in skeletal muscle repair.However,the regulatory role of forskolin on myogenic differentiation of C2C12 skeletal muscle cells has not been fully explored.OBJECTIVE:To explore the effects of forskolin on the differentiation of C2C12 myoblast cell line and probe into the underlying molecular mechanisms.METHODS:C2C12 cells were treated with 0,0.1,0.25,0.5,1,5,10 and 20 μmol/L forskolin during growth,and cell proliferation was detected by cell counting kit-8 and qRT-PCR.C2C12 cells were treated with 0,0.25,0.5 and 1 μmol/L forskolin during the induction of myogenic differentiation.Immunofluorescence staining and qRT-PCR were used to detect C2C12 cells differentiation.Western blot was used to detect the expression level of myogenic differentiation-related signaling pathway proteins.RESULTS AND CONCLUSION:(1)The viability of C2C12 cells was decreased and cell proliferation was inhibited after treatment with high concentrations(＞1 μmol/L)of forskolin.(2)The qRT-PCR results showed that forskolin up-regulated the expression of Myh2,Myh4,Myomaker,but down-regulated the expression of Myh7 compared with the 0 μmol/L group,when C2C12 cells were differentiated for 4 days.Immunofluorescence staining results showed that the fusion index and myotube diameter of C2C12 cells were increased after forskolin treatment,and the number of myotubes was also increased.(3)Western blot results showed that the phosphorylated extracellular signal-regulated kinase 1/2 expression was inhibited;however,the phosphorylated protein kinase B was promoted after treatment with forskolin.The protein expression level of the myogenic differentiation transcription factor Myogenin was significantly up-regulated after treatment with forskolin.The above results demonstrate that forskolin may promote myogenic differentiation of C2C12 skeletal muscle cells through the extracellular signal-regulated kinase 1/2 and protein kinase B signaling pathway.

ObjectiveTo investigate the effect and mechanism of transplantation of human umbilical cord mesenchymal stem cell （hUC-MSC） with overexpression of the Numb gene in the treatment of cholestatic liver fibrosis （CLF）. MethodsThe technique of lentiviral transfection was used to induce the overexpression of the Numb gene in hUC-MSC （hUC-MSC^Numb-OE）， and hUC-MSC transfected with empty vector （hUC-MSC^OE-EV） was used as negative control. Bile duct ligation （BDL） was performed to establish a rat model of CLF， and then the rats were randomly divided into BDL group， hUC-MSC group， hUC-MSC^OE-EV group， and hUC-MSC^Numb-OE group， while a sham-operation group was also established. The rats in the intervention groups were given a single splenic injection of the corresponding cells after BDL， and samples were collected at the end of week 4. Related indicators were measured， including serum biochemistry， liver histopathology， the content of hydroxyproline （Hyp） in the liver， hepatic stellate cell activation， ductular reaction， liver regeneration， and the expression levels of key molecules in the Numb-p53 signaling axis. A one-way analysis of variance was used for comparison of continuous data between multiple groups， and the least significant difference t-test was used for further comparison between two groups. ResultsCompared with the BDL group， the hUC-MSC group and the hUC-MSC^OE-EV group had significant reductions in the levels of serum biochemical parameters （aspartate aminotransferase， gamma-glutamyl transpeptidase， total bile acid， total bilirubin， and direct bilirubin）， liver fibrosis markers （the content of Hyp and the expression levels of alpha-smooth muscle actin， tumor necrosis factor-α， and transforming growth factor-beta 1）， and ductular reaction markers （the expression levels of CK7 and CK19） （all P <0.05）， and compared with the hUC-MSC^OE-EV group， the hUC-MSC^Numb-OE group had significantly greater improvements in the above indicators （all P <0.05）. In addition， compared with the hUC-MSC^OE-EV group， the hUC-MSC^Numb-OE group had significant improvements in the expression levels of liver regeneration-related markers （albumin and hepatocyte nuclear factor 4α） and the molecules associated with the Numb-p53 signaling axis （Numb， pNumb， Mdm2， and p53） （all P <0.05）. ConclusionOverexpression of the Numb gene can enhance the therapeutic effect of hUC-MSC on CLF， possibly by activating the Numb-PTB^L-p53-HNF4α axis， promoting the hepatic differentiation of hUC-MSCs and subsequently enhancing liver regeneration.

BACKGROUND:Forskolin,a diterpenoid natural compound extracted from Coleus forskohlii,has a crucial regulatory role in skeletal muscle repair.However,the regulatory role of forskolin on myogenic differentiation of C2C12 skeletal muscle cells has not been fully explored.OBJECTIVE:To explore the effects of forskolin on the differentiation of C2C12 myoblast cell line and probe into the underlying molecular mechanisms.METHODS:C2C12 cells were treated with 0,0.1,0.25,0.5,1,5,10 and 20 μmol/L forskolin during growth,and cell proliferation was detected by cell counting kit-8 and qRT-PCR.C2C12 cells were treated with 0,0.25,0.5 and 1 μmol/L forskolin during the induction of myogenic differentiation.Immunofluorescence staining and qRT-PCR were used to detect C2C12 cells differentiation.Western blot was used to detect the expression level of myogenic differentiation-related signaling pathway proteins.RESULTS AND CONCLUSION:(1)The viability of C2C12 cells was decreased and cell proliferation was inhibited after treatment with high concentrations(＞1 μmol/L)of forskolin.(2)The qRT-PCR results showed that forskolin up-regulated the expression of Myh2,Myh4,Myomaker,but down-regulated the expression of Myh7 compared with the 0 μmol/L group,when C2C12 cells were differentiated for 4 days.Immunofluorescence staining results showed that the fusion index and myotube diameter of C2C12 cells were increased after forskolin treatment,and the number of myotubes was also increased.(3)Western blot results showed that the phosphorylated extracellular signal-regulated kinase 1/2 expression was inhibited;however,the phosphorylated protein kinase B was promoted after treatment with forskolin.The protein expression level of the myogenic differentiation transcription factor Myogenin was significantly up-regulated after treatment with forskolin.The above results demonstrate that forskolin may promote myogenic differentiation of C2C12 skeletal muscle cells through the extracellular signal-regulated kinase 1/2 and protein kinase B signaling pathway.

Fetal malformation of cortical development(MCD)is a group of structural neurological disorders caused by abnormalities in development of cortical layer during embryogenesis,characterized by significant heterogeneity and diversity,which may lead to adverse clinical outcomes such as epilepsy and intellectual disabilities.The progresses in prenatal evaluation on fetal MCD were reviewed in this article.

Adenosine triphosphate(ATP),as a rich energy currency in cells,is released into the extracellular space through a variety of regulatory mechanisms.The role of extracellular ATP(eATP)and related purine and pyrimidine nucleotides as extracellu-lar signal molecules regulating immune cell function has been reported as evidence of purine signal transduction and has become the focus of attention as a therapeutic target for various diseases.Mast cells(MC)are distributed in tissues that come into contact with the external environment and are the first immune cells to respond to non-microbial environmental antigens.Although eATP is considered to be an activator of MC,the details remain to be further elucidated.This article describes the role of purine receptor signaling in MC degranulation.It expands the further understanding of the mechanism of allergic diseases,and further provides ideas for finding new targets for the treatment of allergic diseases and formulating new treatment strategies.

Adenosine triphosphate(ATP),as a rich energy currency in cells,is released into the extracellular space through a variety of regulatory mechanisms.The role of extracellular ATP(eATP)and related purine and pyrimidine nucleotides as extracellu-lar signal molecules regulating immune cell function has been reported as evidence of purine signal transduction and has become the focus of attention as a therapeutic target for various diseases.Mast cells(MC)are distributed in tissues that come into contact with the external environment and are the first immune cells to respond to non-microbial environmental antigens.Although eATP is considered to be an activator of MC,the details remain to be further elucidated.This article describes the role of purine receptor signaling in MC degranulation.It expands the further understanding of the mechanism of allergic diseases,and further provides ideas for finding new targets for the treatment of allergic diseases and formulating new treatment strategies.

[Objective] To explore the therapeutic effects of intravenous immunoglobulin (IVIG) on dextran sodium sulfate (DSS)-induced ulcerative colitis (UC). [Methods] C57BL/6 mice were randomly assigned to the control group, the DSS group (model) and the DSS+IVIG group (treatment). The DSS group and the DSS+IVIG group received 3% DSS in drinking water to establish the acute UC mouse model. During the experiment, the DSS+IVIG group received IVIG (1 g/kg/2d) via tail vein injection, while the DSS group received equivalent saline via tail vein injection at the same dose and frequency. The symptoms of the mice were observed, body weight changes were recorded, and the disease activity index (DAI) was calculated daily. At the end of the experiment, hematoxylin-eosin (HE) staining was used to observe the pathological changes and inflammatory cell infiltration of colon tissue; Periodic acid-Schiff (PAS) staining was used to quantify the number of goblet cells; Luminex was used to detect the levels of inflammatory-related cytokines (such as TNF-α, IL-6 and MMPs) in colon; western blot and qRT-PCR were respectively used to detect the protein expression and mRNA levels of tight junction proteins (ZO-1, Occludin, Claudin-3). [Results] DSS induced weight loss, diarrhea, bloody stool, increased DAI score, and shortened colon length in mice. Compared with DSS group, after the administration of IVIG, the DAI score was significantly reduced (P<0.001), colon length was increased (P<0.001), infiltration of inflammatory cells and pathological damage were alleviated in colonic mucosa (P<0.001), the number of goblet cells were increased (P<0.05), and the levels of inflammatory-related cytokines TNF-α, IL-6, IL-6R, MMP2, MMP3 and Chitinase3like1 were decreased (all P<0.05). Western blot and qRT - PCR results showed that IVIG significantly up-regulated the protein expression of ZO-1, Occludin and claudin-3 (all P<0.05) and the mRNA levels of ZO-1 and Occludin (all P<0.05). [Conclusion] IVIG has protective effects on colitis by inhibiting the pathological release of inflammatory-related cytokines such as TNF-α, IL-6 and MMPs and restoring the integrity of intestinal barrier.

Objective:To quantitatively evaluate the effects of left bundle branch block（LBBB）on left ventricular structure，function and myocardial perfusion using left ventricular pressure-strain loop and single photon emission computed tomography（SPECT），and to investigate the relationship between myocardial work，myocardial perfusion and pathological changes of left ventricular remodeling in left bundle branch block induced cardiomyopathy（LBBB-CM）.Methods:Fourteen male beagle dogs were selected，and the main trunk of the left bundle branch was ablated to create an LBBB dog model. Electrocardiogram（ECG），transesophageal echocardiography and arterial blood pressure data of LBBB dogs were collected before and 12 months after the ablation of left bundle branch trunk. Global and segmental myocardial work parameters were obtained by left ventricular pressure-strain loop. The differences of above parameters between baseline and 12 months after the ablation of left bundle branch were compared. SPECT was performed in LBBB dogs 12 months after the creation of LBBB. The hearts were harvested for anatomy observation and histopathological analysis in LBBB dogs and another 7 male beagle dogs（normal control group）matched by age and weight. The correlation between myocardial perfusion（percentage of regional tracer uptake）and myocardial work parameters，myocardial fibrosis in LBBB dogs were analyzed.Results:Compared with baseline，the left ventricular end-diastolic volume of 12 months after the ablation increased［（20.78 ± 5.32）ml vs（26.71 ± 7.94）ml， P = 0.003］，left ventricular ejection fraction decreased［（59.17 ± 5.67）% vs（47.69 ± 5.45）%， P<0.001］；left ventricular global/segmental longitudinal strain，global/segmental constructive work and global/segmental work efficiency decreased（all P<0.05），left ventricular global/segmental wasted work increased（all P<0.001）. Heterogenous perfusion defect was observed in LBBB dogs by SPECT，compared with lateral wall segments，the percentage of regional tracer uptake of septum was decreased（all P<0.05）. Gross anatomical and myocardial pathological changes were manifested as cardiomegaly，flaky or focal grayish thickening of endocardium，cardiomyocyte degeneration and fibrosis. Compared with normal control group，the collagen fiber volume fraction（CVF）in all segmental endocardium and partial segmental myocardium of LBBB dogs were significantly increased（all P<0.05）. Percentage of regional tracer uptake was positively correlated with segmental myocardial work（SMW）and segmental myocardial efficiency（SWE）（ r s = 0.49，0.31；both P<0.001），and negatively correlated with CVF and segmental wasted work（SWW）（ r s = -0.51，-0.49；both P<0.001）. Conclusions:Isolated LBBB is not benign，which can result in left ventricular remodeling，decreased cardiac constructive function，abnormal myocardial perfusion，endocardial fibrosis and myocardial fibrosis.The parameters of myocardial work assecsed by echocardiograpgy and myocardial perfusion，as non-invasive examination，can to some extent reflect the degree of left ventricular remodeling in LBBB-CM.

Fetal malformation of cortical development(MCD)is a group of structural neurological disorders caused by abnormalities in development of cortical layer during embryogenesis,characterized by significant heterogeneity and diversity,which may lead to adverse clinical outcomes such as epilepsy and intellectual disabilities.The progresses in prenatal evaluation on fetal MCD were reviewed in this article.