Search

Background: Gallstone formation is a common digestive ailment, with unclear mechanisms underlying its development. Dysfunction of the gallbladder smooth muscle (GSM) may play a crucial role, particularly with a high-fat diet (HFD). This study aimed to investigate the effects of an HFD on GSM and assess how it alters contractility through changes in the extracellular matrix (ECM). Methods: Guinea pigs and C57BL/6 mice were fed either an HFD or normal diet (ND). Primary cultures of their (guinea pigs) gallbladder smooth muscle cells (GSMCs) were used for in vitro experiments. Histological stains, RNA-sequencing, bioinformatics analysis, three-dimensional tissue culture, real-time polymerase chain reaction (PCR), Western blot, atomic force microscopy, and muscle tension measurements were performed. Results: Histological evidence indicated structural changes in the gallbladder muscle layer and ECM collagen deposition in the HFD group. The HFD group also showed increased expression of collagen, integrin family, and matrix metalloproteinase (MMP) and the phosphoinositide 3-kinase (PI3K)-protein kinase B (PKB/Akt) signaling pathway. Compared with GSMCs cultured on Matrigel containing 1 mg/mL of collagen I, those cultured with 2 mg/mL showed a phenotype change from contractile to synthetic cells. Consistent with these findings, the HFD group also demonstrated increased ECM stiffness and decreased smooth muscle contractility. Conclusions: Our findings reveal a mechanism by which an HFD alters the ECM composition of the gallbladder muscle, activating the integrin/PI3K-Akt/MMP signaling pathway, thereby impacting GSMC phenotype and contractility. These insights enhance the understanding of gallstone formation mechanism and provide potential therapeutic targets to treat gallbladder dysfunction.

Deregulation of Roundabout homolog 1 (Robo1) has been demonstrated to be associated with several types of human cancer, including gastric cancer. However, the detailed role of Robo1 and its regulatory mechanism in gastric cancer remain largely unclear. In the current study, it was demonstrated that the expression of microRNA (miR)-29a was frequently reduced in gastric cancer tissues, compared with their matched normal adjacent tissues. Similar results were additionally observed in AGS and SGC-7901 human gastric cancer cells. Overexpression of miR-29a led to reduced migration and invasion of AGS cells. To explore the targets of miR-29a in gastric cancer, bioinformatics analysis was conducted and Robo1 was identified as a putative target of miR-29a. Further western blotting and luciferase activity assay data confirmed that miR-29a was able to negatively regulate the protein expression of Robo1, through directly binding to the 3'-untranslated region of Robo1 mRNA in gastric cancer cells. In addition, it was demonstrated that Robo1 was frequently upregulated in gastric cancer tissues compared with their matched adjacent normal tissues, and a significant inverse correlation was identified between miR-29a and Robo1 expression. In addition, knockdown of Robo1 by small interfering RNA markedly inhibited the migratory and invasive capabilities of AGS cells, which the results obtained with overexpression of miR-29a. In conclusion, to the best of our knowledge the current study suggested for the first time, that miR-29a inhibits migration and invasion in part via direct inhibition of Robo1 in gastric cancer cells. Therefore, Robo1 and miR-29a may serve as diagnostic or therapeutic targets for gastric cancer. [ABSTRACT FROM AUTHOR]

Background: To compare the biological characteristics of three types of human hepatocellular carcinoma multi-drug resistant cell sub-lines Bel-7402/ADM models established by three methods. Methods: Established human hepatocellular carcinoma adriamycin (ADM) multi-drug resistant cell sub-lines models Bel-7402/ADMV, Bel-7402/ADML and Bel-7402/ADMS by three methods of in vitro concentration gradient increased induction, nude mice liver-implanted induction and subcutaneous-implanted induction respectively. Phase contrast microscopy was used to observe the cells and the MTT (methyl thiazolyl tetrazolium) method was used to detect drug resistance of the three different sub-lines of cells. Results: The three groups of drug resistant cells, Bel-7402/ADMV, Bel-7402/ADML and Bel-7402/ADMS generated cross-resistance to ADM and CDDP (cis-Diaminedichloroplatinum), but showed a significant difference in resistance to Bel-7402 IC50 value (P < 0.01). The doubling times were significantly extended compared to the parent cell line (39 h) and were 65 h (Bel-7402/ADMV), 46 h (Bel-7402/ADML), and 45 h (Bel-7402/ADMS). The excretion rates of ADM were significantly increased compared with the parent cell (34.14%) line and were 81.06% (Bel-7402/ADMV), 66.56% (Bel-7402/ADML) and 61.56% (Bel-7402/ADMS). Expression of P-gp and MRP in the three groups of resistant cells was significantly enhanced (P < 0.01). There was no significant variation in the expression of GSH/GST (P > 0.05). Conclusions: Stable resistance was involved in the resistant cell line model established by the above three methods. Liver implantation was a good simulation of human hepatocellular and proved to be an ideal model with characteristics similar to human hepatocellular biology and the pharmacokinetics of anticancer drugs. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine whether polydatin, a glucoside of resveratrol isolated from the root of Polygonum cuspidatum, warranted development as a potential therapeutic for ameliorating the pain originating from gallbladder spasm disorders and the underlying mechanisms. Guinea pig gallbladder smooth muscles were treated with polydatin and specific inhibitors to explore the mechanisms underpinning polydatin-induced relaxation of carbachol-precontracted guinea pig gallbladder. Our results shown that polydatin relaxed carbachol-induced contraction in a dose-dependent manner through the nitric oxide/cyclic guanosine monophosphate/protein kinase G and the cyclic adenosine monophosphate/protein kinase A signaling pathways as well as the myosin light chain kinase and potassium channels. Our findings suggested that there was value in further exploring the potential therapeutic use of polydatin in gallbladder spasm disorders. [ABSTRACT FROM AUTHOR]