Impact of lithocholic acid on the osteogenic and adipogenic differentiation balance of bone marrow mesenchymal stem cells / 中国修复重建外科杂志

OBJECTIVE@#To Investigate the effects of lithocholic acid (LCA) on the balance between osteogenic and adipogenic differentiation of bone marrow mesenchymal stem cells (BMSCs).@*METHODS@#Twelve 10-week-old SPF C57BL/6J female mice were randomly divided into an experimental group (undergoing bilateral ovariectomy) and a control group (only removing the same volume of adipose tissue around the ovaries), with 6 mice in each group. The body mass was measured every week after operation. After 4 weeks post-surgery, the weight of mouse uterus was measured, femur specimens of the mice were taken for micro-CT scanning and three-dimensional reconstruction to analyze changes in bone mass. Tibia specimens were taken for HE staining to calculate the number and area of bone marrow adipocytes in the marrow cavity area. ELISA was used to detect the expression of bone turnover markers in the serum. Liver samples were subjected to real-time fluorescence quantitative PCR (RT-qPCR) to detect the expression of key genes related to bile acid metabolism, including cyp7a1, cyp7b1, cyp8b1, and cyp27a1. BMSCs were isolated by centrifugation from 2 C57BL/6J female mice (10-week-old). The third-generation cells were exposed to 0, 1, 10, and 100 μmol/L LCA, following which cell viability was evaluated using the cell counting kit 8 assay. Subsequently, alkaline phosphatase (ALP) staining and oil red O staining were conducted after 7 days of osteogenic and adipogenic induction. RT-qPCR was employed to analyze the expressions of osteogenic-related genes, namely ALP, Runt-related transcription factor 2 (Runx2), and osteocalcin (OCN), as well as adipogenic-related genes including Adiponectin (Adipoq), fatty acid binding protein 4 (FABP4), and peroxisome proliferator-activated receptor γ (PPARγ).@*RESULTS@#Compared with the control group, the body mass of the mice in the experimental group increased, the uterus atrophied, the bone mass decreased, the bone marrow fat expanded, and the bone metabolism showed a high bone turnover state. RT-qPCR showed that the expressions of cyp7a1, cyp8b1, and cyp27a1, which were related to the key enzymes of bile acid metabolism in the liver, decreased significantly ( P<0.05), while the expression of cyp7b1 had no significant difference ( P>0.05). Intervention with LCA at concentrations of 1, 10, and 100 μmol/L did not demonstrate any apparent toxic effects on BMSCs. Furthermore, LCA inhibited the expressions of osteogenic-related genes (ALP, Runx2, and OCN) in a dose-dependent manner, resulting in a reduction in ALP staining positive area. Concurrently, LCA promoted the expressions of adipogenic-related genes (Adipoq, FABP4, and PPARγ), and an increase in oil red O staining positive area.@*CONCLUSION@#After menopause, the metabolism of bile acids is altered, and secondary bile acid LCA interferes with the balance of osteogenic and adipogenic differentiation of BMSCs, thereby affecting bone remodelling.

Screening and characterization of lactic acid bacterial strains that produce fermented milk and reduce cholesterol levels

ABSTRACT Objective To screen for and characterize lactic acid bacteria strains with the ability to produce fermented milk and reduce cholesterol levels. Methods The strains were isolated from traditional fermented milk in China. In vitro and in vivo evaluation of cholesterol-reduction were used to identify and verify strains of interest. Characteristics were analyzed using spectrophotometry and plate counting assays. Results The isolate HLX37 consistently produced fermented milk with strong cholesterol-reducing properties was identified as Lactobacillus plantarum (accession number: KR105940) and was thus selected for further study. The cholesterol reduction by strain HLX37 was 45.84%. The isolates were acid-tolerant at pH 2.5 and bile-tolerant at 0.5% (w/v) in simulated gastric juice (pH 2.5) for 2 h and in simulated intestinal fluid (pH 8.0) for 3 h. The auto-aggregation rate increased to 87.74% after 24 h, while the co-aggregation with Escherichia coli DH5 was 27.76%. Strain HLX37 was intrinsically resistant to antibiotics such as penicillin, tobramycin, kanamycin, streptomycin, vancomycin and amikacin. Compared with rats in the model hyperlipidemia group, the total cholesterol content in the serum and the liver as well as the atherogenic index of rats in the viable fermented milk group significantly decreased by 23.33%, 32.37% and 40.23%, respectively. Fewer fat vacuoles and other lesions in liver tissue were present in both the inactivated and viable fermented milk groups compared to the model group. Conclusion These studies indicate that strain HLX37 of L. plantarum demonstrates probiotic potential, potential for use as a candidate for commercial use for promoting health.

Some physicochemical properties of human milk bile-salt activated lipase.

Influence of pH, deoxycholate and denaturing reagents on human milk bile-salt activated lipase (EC 3.1.1.3) has been studied. It appears that pH between 5.0-8.0 has no significant effect on the secondary structure of this lipase, but its higher order structures are affected. Lipase-dependent 8-anilino-1-naphthalene sulphonate fluorescence has revealed that the deoxycholate activated form of lipase has a surface rich in hydrophobic amino acid residues. Circular dichroism and second derivative electronic absorption spectroscopic observations have also provided an evidence for deoxycholate-induced alterations in the surface conformation of this lipase.

Aeromonas sobria in bubaline (water buffalo) abortion: growth requirement, biochemical characters, antibiotic susceptibility, experimental pathogenicity and serology.

A. sobria was isolated unexpectedly on Campylobacter selective medium from abortion specimens of 16 buffaloes. All strains (AS1-AS16) required Campylobacter growth supplement (sodium pyruvate, sodium metabisulphate and ferrous sulphate) and 10% C02 atmosphere on primary isolation. They were unusually sensitive to bile salt and failed to grow on MacConkey's agar. Biochemically, these strains were homogeneous but antibiogram profile and physiological/other characters revealed a moderate heterogeneity. In vitro antibiotic sensitivity pattern showed a number of antibiotics effective whereas only a few (penicillin and co-trimoxazole) ineffective against these strains. It took 9 days for 3 x 10(8) A. sobria organisms/ml in 5 ml quantity to terminate the pregnancy in an experimentally infected buffalo via iv route. Foetal and placental lesions were classical as that of field cases. The infection evoked serum antibody response. Apparently disease-free buffalo sera were devoid of such antibodies.

Susceptibilidade da mucosa gástrica à açao lesiva de um sal biliar em ratos chagásicos crônicos / Susceptibility of gastric mucosa to the noxions effect of a bile salt in rats with chronic Chagas' disease

Ratos inoculados previamente com a cepa Y do Trypanosoma cruzi (n = 15) e ratos-controles de mesma idade e sexo (n = 15) foram submetidos a estudo que consistiu no exame da mucosa gástrica após a exposiçäo in vivo da mesma à soluçäo acidificada de um sal biliar, o taurocolato de sódio (TC). Em 10 animais de cada grupo procedeu-se também à contagem dos neurônios do plexo mientérico do estômago e ao exame histopatológico dos corpos neuronais, feito em microscopia óptica convencional. Escores indicativos da gravidade das lesöes produzidas pelo RTC foram significativamente maiores (P <0,002) nos ratos chagásicos que nos controles. A área erosada da mucosa gástrica, em % da área total da regiäo glandular do estômago, foi significativamente maior (P < 0,02) nos animais chagásicos (25,2 ñ 18,0) que nos controles (11,0 ñ 17,4) quanto ao número de neurônios intramurais do estômago, näo foi observada diferença significante (P >0,10) entre os ratos chagásicos (1683,6 ñ 449, 7 n = 10) e os controles (1732,8 ñ 401,1 n = 10). Näo houve diferença qualitativa ao exame histopatológico dos corpos neuronais. Estes resultados indicam que, na doença de Chagas experimental crônica, a mucosa gástrica é mais sensível à açäo lesiva do TC, o que sugere reduçäo da citoproteçäo natural do estômago. Esta anormalidade näo deve decorrer de alteraçöes da inervaçäo intrínseca que impliquem reduçäo do número de neurônios intramurais do estômago, mas pode ser o resultado de alteraçöes qualitativas näo detectáveis à microscopia óptica

Effect of Bile Acids on Biliary Excretion of Cholesterol in Rabbits

The effects of cholic acid and eight related cholanic acid analogs on bile flow and biliary excretion of bile salts and cholesterol were studied in rabbits. Bile acids were infused intravenously in anesthetized rabbits. In all except hyodeoxycholic or lithocholic acid treated animals increases in bile flow were recorded within 10 minutes during infusion of bile acid-The increase in bile f1ow associated with an increase in bile salt level in bile after cholic acid infusion was observed, however, there were little changes in biliary, cholesterol levels. Bile salt level in bile was not associated with bile flow after chenodeoxycholic acid infusion but the cholesterol level in bile was significantly increased. Ursodeoxycholic acid similarly increased cholesterol but to a lesser extent. Keto-forms of chenodeoxycholic acid were without action. These results indicate that both cholic and chenodeoxycholic acids have the capacity to alter specific biliary excretion of bile components, the former on bile salts and the latter on cholesterol-a precursor of bile acids in bile.