ObjectiveTo explore the effect of oral sodium butyrate on skeletal muscle atrophy in CT26 tumor mice through the gut microbiota-skeletal muscle axis and its potential mechanism. MethodsSixty SPF BALB/c male mice aged 8 weeks were randomly divided into a normal control group (NC, n=18) and a ABX-depleted group (ABX, n=42). The ABX mice were pretreated with a quadruple antibiotic cocktail via oral gavage (0.2 ml per administration, once daily, 6 d per week, for 2 weeks), whereas NC received an equal volume of sterile water. The quadruple antibiotic cocktail consisted of metronidazole (1 g/L), vancomycin (0.5 g/L), ampicillin (1 g/L), and gentamicin (1 g/L). Following successful pretreatment, six mice from each group were randomly selected for gut microbiota sequencing analysis and designated as the Abx group and the NC0 group, respectively. Theremaining mice in ABX were subcutaneously inoculated in the dorsum with 0.2 ml of CT26 cell suspension (at a cell density of 1×10⁷/ml). Then these mice were randomly allocated into three subgroups: a control tumor bearing model group (0_NaB, n=12), a tumor-bearing model group receiving low-dose oral sodium butyrate (L_NaB, n=12), a tumor-bearing model group receiving high-dose oral sodium butyrate (H_NaB, n=12). And mice in NC were inoculated at the same site with 0.2 ml of normal saline. The administration dose for L_NaB was 0.3 g/(kg·d), that for H_NaB was 0.5 g/(kg·d), while NC and 0_NaB were given the same volume of normal saline (0.2ml per time, once daily, 6 d per week, for 4 weeks). The general condition of mice was monitored, and forelimb grip strength gastrocnemius muscle mass and its muscle fiber cross-sectional area were measured for each group. The structural changes in gut microbiota were assessed by 16S rRNA sequencing of cecal contents. Pathological alterations in the intestinal wall were examined via HE staining. Serum and gastrocnemius muscle levels of TNF‑α, IL-6, IL-1β, and LPS were quantified using ELISA. The protein expression of ZO-1 and occludin in the small intestine, as well as proteins associated with the TLR4/MyD88/NF-κB signaling pathway in the gastrocnemius muscle, were detected by Western blot analysis. Results(1) The alpha-diversity in Abx was significantly lower than that in NC0 (P<0.01), a significant decrease of the mass and muscle fiber cross-sectional area of the gastrocnemius (P<0.01), with the majority of gut microbiota being effectively depleted. (2) Compared with NC, the subcutaneous tumors of mice in 0_NaB were prominent, a significant increase of the mass and muscle fiber cross-sectional area of the gastrocnemius, accompanied by a significant decrease in body weight at the end of the 3th and 4th week (P<0.05), and a significant weakening of the forelimb grasping strength at the 5th and 6th week (P<0.01). Compared with 0_NaB, the tumor mass of mice in L_NaB and H_NaB showed a significant decreasing trend, and the grip strength of the forelimbs significantly increased at the 5th and 6th week (P<0.05, P<0.01). (3) Compared with 0_NaB, the Shannon and Observed species indices in α diversity of L_NaB and H_NaB were significantly increased (P<0.05). At the genus level, compared with 0_NaB, L_NaB exhibited a significant decrease in the relative abundance of Parasutterella (P< 0.01), while H_NaB showed significant reductions in the relative abundances of both Escherichia-Shigella and Parasutterella (P < 0.01). (4) Compared with 0_NaB, the small intestinal tissue structure in L_NaB and H_NaB was more intact, the infiltration of inflammatory cells was significantly reduced, and the capillaries were slightly dilated. The expression levels of ZO-1 and occludin proteins in L_NaB were significantly increased (P<0.01). (5) The LPS concentration in the gastrocnemius muscle and the protein expression levels of TLR4, MyD88, p-IκBα, and p-NF‑κB p65 in L_NaB and H_NaB were significantly lower than those in 0_NaB (P<0.05). The serum TNF‑α concentration in H_NaB and TNF-α concentration in the gastrocnemius muscle of the L_NaB and H_NaB were significantly lower than those in 0_NaB (P<0.05, P<0.01, P<0.01). ConclusionOral administration of NaB can improve gut microbiota α diversity, adjusting its composition, improving intestinal mucosal barrier function, reducing the LPS-induced pro-inflammatory response, and delaying skeletal muscle atrophy. The underlying mechanism may involve down regulation of TLR4/MyD88/NF-κB signaling in skeletal muscle.

Chronic pancreatitis （CP） is a common disease in clinical practice characterized by progressive inflammatory fibrosis of the pancreas. Gut microbiota， known as the “second genome” of humans， bidirectionally modulates the progression of fibrosis in CP via the gut-pancreas axis. This article systematically elaborates on the characteristics of gut microbiota during the progression of CP and its molecular mechanism in mediating pancreatic fibrosis through bacterial translocation， metabolites， immune regulatory networks， and microbe-pancreatic stellate cell interactions， with a focus on the pivotal role of short-chain fatty acids and inflammatory cytokine networks in pancreatic stellate cell activation and extracellular matrix deposition. In addition， this article explores the potential value of gut microbiota-targeted interventions in the prevention and treatment of CP fibrosis， such as probiotics， prebiotics， and fecal microbiota transplantation， and discusses the translational potential of using multi-omics technologies to identify diagnostic biomarkers and novel therapeutic targets for CP， in order to provide new ideas for the precise diagnosis and treatment of CP.

Grounded in the theory of "all marrows dominated by brain", this study explored the therapeutic mechanism of Zuogui Pills in modulating the oxytocin(OXT)/oxytocin receptor(OXTR) feed-forward loop in the treatment of postmenopausal osteoporosis(PMOP). A PMOP rat model was established using ovariectomy, and 70 Sprague-Dawley female rats were randomly divided into the following groups: sham operation group, model group, estradiol group(17β-estradiol, 0.05 mg·kg~(-1)·d~(-1)), Zuogui Pills low, medium, and high dose groups(0.2, 0.4, 0.8 g·kg~(-1)·d~(-1), respectively), and an antagonist group(atosiban 0.9 mg·kg~(-1)·d~(-1) + 17β-estradiol 0.05 mg·kg~(-1)·d~(-1) + Zuogui Pills 0.4 g·kg~(-1)·d~(-1)). After 12 weeks of model establishment, treatment was administered by gavage once daily for another 12 weeks, followed by sample collection. Enzyme-linked immunosorbent assay(ELISA) was used to measure serum levels of estrogen(E_2), OXT, tartrate-resistant acid phosphatase(TRACP-5b), and bone alkaline phosphatase(BALP). Histopathological changes in the left distal femur were observed through hematoxylin and eosin(HE) staining. Micro-computed tomography(micro-CT) was used to analyze the microstructure of the right distal femur. Western blot was employed to detect the expression levels of OXTR, small GTP-binding protein Ras, Raf1 proto-oncogene(Raf1), mitogen-activated protein kinase kinase 1/2(MEK1/2), and extracellular signal-regulated kinase 1/2(ERK1/2), and their phosphorylated forms in tibial tissues. Compared with the model group, the Zuogui Pills medium and high dose groups showed significantly increased levels of E_2, OXT, and BALP, with a notable decrease in TRACP-5b levels. Morphologically, the trabeculae in the left distal femur were more tightly arranged. The fibrous structure in the right distal femur was significantly improved in the Zuogui Pills high dose group. Additionally, the expression of OXTR, Ras, p-Raf1, p-MEK1/2, and p-ERK1/2 proteins in tibial tissues was significantly increased. The therapeutic effect of the Zuogui Pills high dose group was partially inhibited when an OXTR antagonist was administered. These findings suggest that Zuogui Pills can regulate the OXT/OXTR feed-forward loop, activate the phosphorylation of the downstream Ras/Raf1/MEK/ERK signaling pathway, and ultimately improve bone mineral density, thereby exerting therapeutic effects in PMOP.
Animals ; Rats, Sprague-Dawley ; Rats ; Female ; Drugs, Chinese Herbal/administration & dosage* ; Oxytocin/genetics* ; Receptors, Oxytocin/genetics* ; Humans ; Osteoporosis, Postmenopausal/genetics* ; Bone and Bones/drug effects* ; Brain/drug effects* ; Bone Marrow/drug effects*

This study was aimed at developing an in vitro fluorescent substrate assay for the activity of leucyl aminopeptid-ase(LAP)from Echinococcus multilocularis and comparing it with the chemical chromogenic substrate enzyme activity assay.Through the establishment of reaction conditions for the fluorescent substrate-based in vitro enzyme activity assay,we com-pared the differences between the fluorescent substrate L-Leucine-7-amido-4-methylocoumarin(Leu-AMC)and the chemical chromogenic substrate L-Leucine-4-nitroanilide(Leu-pNA)through molecular docking,inhibition rates,and precision measures.Molecular docking revealed that the fluorescent substrate Leu-AMC had higher affinity for the protein than the chemical chromogenic substrate Leu-pNA.Through analysis of the effects of varying reaction conditions on fluorescence intensi-ty,we optimized the fluorescent substrate enzyme activity assay to demonstrate favorable performance at a reaction temperature of 37℃,a pH of 9.0,a protein concentration of 800 nmol/L,and a reaction duration of 60 minutes.Leu-AMC exhibited significant and distinct responses at a 5 μmol/L substrate concentration,under varying substrate conditions.The fluo-rescent substrate assay demonstrated more significant intergroup differences than the chemical chromogenic substrate assay when various inhibitors were added.This study established a fluorescence-based enzyme activity assay for leucyl aminopeptidase from Echinococcus multilocularis by using Leu-AMC as the substrate;this method demonstrated a more significant intergroup difference and sensitivity than the chemical chromogenic substrate assay.

Objective To analyze the cellular and histopathological characteristics of underdiagnosed thyroid nodules of Chinese thyroid imaging reporting and data system(C-TIRADS) categories 3 and 4a,thus improving the understanding of these lesions. Methods The data of ultrasound and fine needle aspiration cytology were collected from 683 nodules diagnosed based on pathological evidence in 549 patients undergoing thyroid surgery.The cellular and histopathological characteristics of C-TIRADS 3 and 4a nodules were analyzed. Results Two hundred and sixty-eight nodules were classified as C-TIRADS category 3,including 236 benign nodules,12 low-risk ones,and 20 (7.46%) malignant ones.Two hundred and twenty-one nodules were classified as C-TIRADS category 4a,including 133 benign nodules,7 low-risk ones,and 81 (36.65%) malignant ones.The malignancy rates differed between C-TIRADS 3 and 4a nodules (χ²=58.93,P<0.001),and both were higher than the recommended malignancy rate in the guidelines for malignancy risk stratification of thyroid nodules (C-TIRADS) (both P<0.001).According to the pathological evidence,the underdiagnosed C-TIRADS 3/4a nodules were mainly papillary thyroid carcinoma,especially in patients with Hashimoto thyroiditis.There was not a consistent one-to-one match between each ultrasound result and each cytological classification of low-risk thyroid nodules.Conclusions When the malignant features in preoprative ultrasound imaging are atypical or absent,papillary thyroid carcinoma (especially with Hashimoto thyroiditis),follicular carcinoma,and medullary carcinoma are likely to be underdiagnosed as C-TIRADS 3 or 4a nodules.Therefore,efforts should be made to fully understand the cellular and pathological characteristics of these lesions.
Humans ; Thyroid Nodule/diagnostic imaging* ; Female ; Male ; Middle Aged ; Adult ; Ultrasonography ; Biopsy, Fine-Needle ; Aged ; Young Adult ; Thyroid Neoplasms/diagnostic imaging* ; Adolescent

In order to establish a simple,sensitive and specific diagnostic method for the simultane-ous detection of Mycoplasma hyorhinis(Mhr)and Mycoplasma hyopneumoniae(Mhp)in swine,specific primers and probes were designed using the Mhr p37 and Mhp p36 gene sequences as the target genes,and the dual LFD-RPA rapid test was established by screening the primers and probes,optimizing primer ratios and evaluating its effectiveness through the sensitivity,reproduc-ibility and clinical sample testing.The sensitivity,specificity,reproducibility and clinical samples were evaluated.The results showed that the established dual LFD-RPA assay could complete the amplification in 15 min at 39 ℃,and its optimal primer ratio was 1.6∶0.8,and the lowest detection limits were up to 3.63 and 3.60 copies/μL,respectively;the reproducibility was stable;and there was no cross-reactivity with Pasteurella multocida,Bordetella bronchiseptica,Haemophilus pa-rasuis,Actinobacillus pleuropneumoniae,Escherichia coli.The test successfully established a dual LFD-RPA assay,which can detect Mhr and Mhp simultaneously,and is simple,sensitive and spe-cific without relying on specialized equipment,and is suitable for carrying out on-site rapid diagno-sis of Mhr and Mhp.

This study was aimed at developing an in vitro fluorescent substrate assay for the activity of leucyl aminopeptid-ase(LAP)from Echinococcus multilocularis and comparing it with the chemical chromogenic substrate enzyme activity assay.Through the establishment of reaction conditions for the fluorescent substrate-based in vitro enzyme activity assay,we com-pared the differences between the fluorescent substrate L-Leucine-7-amido-4-methylocoumarin(Leu-AMC)and the chemical chromogenic substrate L-Leucine-4-nitroanilide(Leu-pNA)through molecular docking,inhibition rates,and precision measures.Molecular docking revealed that the fluorescent substrate Leu-AMC had higher affinity for the protein than the chemical chromogenic substrate Leu-pNA.Through analysis of the effects of varying reaction conditions on fluorescence intensi-ty,we optimized the fluorescent substrate enzyme activity assay to demonstrate favorable performance at a reaction temperature of 37℃,a pH of 9.0,a protein concentration of 800 nmol/L,and a reaction duration of 60 minutes.Leu-AMC exhibited significant and distinct responses at a 5 μmol/L substrate concentration,under varying substrate conditions.The fluo-rescent substrate assay demonstrated more significant intergroup differences than the chemical chromogenic substrate assay when various inhibitors were added.This study established a fluorescence-based enzyme activity assay for leucyl aminopeptidase from Echinococcus multilocularis by using Leu-AMC as the substrate;this method demonstrated a more significant intergroup difference and sensitivity than the chemical chromogenic substrate assay.

In order to establish a simple,sensitive and specific diagnostic method for the simultane-ous detection of Mycoplasma hyorhinis(Mhr)and Mycoplasma hyopneumoniae(Mhp)in swine,specific primers and probes were designed using the Mhr p37 and Mhp p36 gene sequences as the target genes,and the dual LFD-RPA rapid test was established by screening the primers and probes,optimizing primer ratios and evaluating its effectiveness through the sensitivity,reproduc-ibility and clinical sample testing.The sensitivity,specificity,reproducibility and clinical samples were evaluated.The results showed that the established dual LFD-RPA assay could complete the amplification in 15 min at 39 ℃,and its optimal primer ratio was 1.6∶0.8,and the lowest detection limits were up to 3.63 and 3.60 copies/μL,respectively;the reproducibility was stable;and there was no cross-reactivity with Pasteurella multocida,Bordetella bronchiseptica,Haemophilus pa-rasuis,Actinobacillus pleuropneumoniae,Escherichia coli.The test successfully established a dual LFD-RPA assay,which can detect Mhr and Mhp simultaneously,and is simple,sensitive and spe-cific without relying on specialized equipment,and is suitable for carrying out on-site rapid diagno-sis of Mhr and Mhp.

Objective:To study the expression of the Homeobox C6(HOXC6)gene in the homeobox family in PCa,its effect on the biological behavior of PCa cells and its action mechanism.Methods:Based on the studies of HOXC6 retrieved from the data-base of Gene Expression Profiling Interactive Analysis(GEPIA),we analyzed the expression of HOXC6 in PCa and the relationship of its expression level with the survival prognosis of the patients.We detected the expression of the HOXC6 protein in PCa tissues and cells by Western blot,stably interfered with the expression of the HOXC6 gene in human PCa DU145 and PC-3 cells and normal prosta-tic epithelial RWPE-1 cells using the siRNA plasmid,and determined the effects of HOXC6 on the proliferation,migration and inva-siveness of PCa cells by CCK8,plate cloning and scratch healing and Transwell invasion assays.Using the GEPIA database,we ana-lyzed the correlation of the Wnt tumor inhibitory factor-secreted frizzled-related protein 1(SFRP1)gene with HOXC6,and detected the expressions of HOXC6,SFRP1,Wnt and β-catenin in PC-3 cells after siRNA-HOXC6 transfection by Western blot.Results:The expression of HOXC6 was dramatically higher in the PCa than in the normal prostate tissue(P<0.01),and in the PCa cells than in the normal prostatic epithelial cells(P<0.01).Bioinformatics analysis indicated a lower survival rate of the PCa patients with a high than those with a low HOXC6 expression(P=0.011).The relative expression of the HOXC6 protein,absorbance value,number of clones formed and number of invaded cells were significantly lower in the siRNA group than in the negative controls(P<0.05).Ac-cording to the GEPIA database,highly expressed SFRP1 was associated with a good prognosis of PCa,and the protein expressions of Wnt and β-catenin were markedly increased while that of SFRP1 decreased in the PCa PC-3 cell line(P<0.05).The expressions of the Wnt and β-catenin proteins were decreased and that of SFRP1 increased significantly in the siRNA-HOXC6 transfection group com-pared with those in the siRNA negative control and PCa PC-3 groups(P<0.05).Conclusion:HOXC6 is highly expressed in PCa tissues and related to the proliferation,migration and invasiveness of PCa cells.HOXC6 promotes the growth of DU145 and PC-3 cells in PCa by inhibiting the SFRP1/Wnt/β-catenin signaling pathway,and may be a potential target for clinical treatment of PCa.