A conexão entre ácidos biliares e diabetes mellitus tipo 2 - Uma revisão / The connection between bile acids and type 2 diabetes mellitus - a review

ABSTRACT Background: Bile acids (BAs) are steroid molecules synthesized exclusively in the liver, being end products of cholesterol catabolism. BAs are known to be involved in several metabolic alterations, including metabolic syndrome and type 2 diabetes mellitus (DM2). DM2 is a chronic degenerative disease characterized by insulin resistance, insulin deficiency due to insufficient production of pancreatic ß-cells, and elevated serum glucose levels leading to multiple complications. Objective: The objective of this study is to investigate the role of BAs in the pathophysiology of DM2, highlighting the possibilities in the development of therapeutic procedures targeting BAs as an optional pathway in the treatment of DM2. Methods: The research was carried out through narrative review and publications on the relationship between BAs and DM2. The databases used for the search include PubMed, Scopus, and Web of Science. The keywords used for the search include bile acids, type 2 diabetes mellitus, metabolic syndrome, and metabolic disorders. Results: The studies have reported the involvement of BAs in the pathophysiology of DM2. BAs act as a ligand for the nuclear farnesoid X receptor, regulating glucose metabolism, lipid metabolism, and cellular energy production. Additionally, BAs modulate the production, elimination, and mobilization of BAs through the farnesoid X receptor. BAs also act as a signaling pathway through Takeda G protein-coupled receptor 5, further contributing to metabolic regulation. These findings suggest that targeting BAs may offer a novel therapeutic approach in the treatment of DM2. Conclusion: This study highlights the important role of BAs in DM2, specifically through their interactions with key metabolic pathways. Targeting BAs may represent an innovative and effective approach to the treatment of DM2.

RESUMO Contexto: Os ácidos biliares (ABs) são moléculas esteróides sintetizadas exclusivamente no fígado, sendo produtos finais do catabolismo do colesterol. Os ABs são conhecidos por estarem envolvidos em várias alterações metabólicas, incluindo a síndrome metabólica e o diabetes mellitus tipo 2 (DM2). A DM2 é uma doença crônica degenerativa caracterizada pela resistência insulínica, deficiência de insulina devido à produção insuficiente de células ß pancreáticas e hiperglicemia levando a múltiplas complicações. Objetivo: O objetivo deste estudo é investigar o papel dos ABs na fisiopatologia da DM2, destacando as possibilidades no desenvolvimento de procedimentos terapêuticos visando os ABs como uma via opcional no tratamento da DM2. Métodos: A pesquisa foi realizada por meio de revisão narrativa e publicações sobre a relação entre ABs e DM2. As bases de dados usadas para a pesquisa incluem PubMed, Scopus e Web of Science. As palavras-chave usadas para a pesquisa incluíram: ácidos biliares, diabetes mellitus tipo 2, síndrome metabólica e distúrbios metabólicos. Resultados: Os estudos relataram o envolvimento dos ABs na fisiopatologia da DM2. Os ABs atuam como ligantes para o receptor nuclear farnesoide X, regulando o metabolismo da glicose, metabolismo lipídico e produção de energia celular. Além disso, os ABs regulam a produção, eliminação e mobilização de ABs através do receptor farnesoide X. Os ABs também atuam como uma via de sinalização através do receptor acoplado à proteína G Takeda 5, contribuindo ainda mais para a regulação metabólica. Esses achados sugerem que o ABs pode oferecer uma nova abordagem terapêutica no tratamento da DM2. Conclusão: Este estudo destaca o papel importante do ABs na DM2, especificamente por meio de suas interações com vias metabólicas-chave. O redirecionamento ao ABs pode representar uma abordagem inovadora e eficaz para o tratamento da DM2.

Bear bile powder alleviates Parkinson's disease-like behavior in mice by inhibiting astrocyte-mediated neuroinflammation / 中国天然药物

Parkinson's disease (PD) is a common neurodegenerative disease in middle-aged and elderly people. In particular, increasing evidence has showed that astrocyte-mediated neuroinflammation is involved in the pathogenesis of PD. As a precious traditional Chinese medicine, bear bile powder (BBP) has a long history of use in clinical practice. It has numerous activities, such as clearing heat, calming the liver wind and anti-inflammation, and also exhibits good therapeutic effect on convulsive epilepsy. However, whether BBP can prevent the development of PD has not been elucidated. Hence, this study was designed to explore the effect and mechanism of BBP on suppressing astrocyte-mediated neuroinflammation in a mouse model of PD. PD-like behavior was induced in the mice by intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) (30 mg·kg-1) for five days, followed by BBP (50, 100, and 200 mg·kg-1) treatment daily for ten days. LPS stimulated rat C6 astrocytic cells were used as a cell model of neuroinflammation. THe results indicated that BBP treatment significantly ameliorated dyskinesia, increased the levels of tyrosine hydroxylase (TH) and inhibited astrocyte hyperactivation in the substantia nigra (SN) of PD mice. Furthermore, BBP decreased the protein levels of glial fibrillary acidic protein (GFAP), cyclooxygenase 2 (COX2) and inducible nitric oxide synthase (iNOS), and up-regulated the protein levels of takeda G protein-coupled receptor 5 (TGR5) in the SN. Moreover, BBP significantly activated TGR5 in a dose-dependent manner, and decreased the protein levels of GFAP, iNOS and COX2, as well as the mRNA levels of GFAP, iNOS, COX2, interleukin (IL) -1β, IL-6 and tumor necrosis factor-α (TNF-α) in LPS-stimulated C6 cells. Notably, BBP suppressed the phosphorylation of protein kinase B (AKT), inhibitor of NF-κB (IκBα) and nuclear factor-κB (NF-κB) proteins in vivo and in vitro. We also observed that TGR5 inhibitor triamterene attenuated the anti-neuroinflammatory effect of BBP on LPS-stimulated C6 cells. Taken together, BBP alleviates the progression of PD mice by suppressing astrocyte-mediated inflammation via TGR5.

Role of Takeda G protein-coupled receptor-5 in non-viral liver diseases / 临床肝胆病杂志

Non-viral liver diseases mainly include nonalcoholic fatty liver disease, alcoholic liver disease, autoimmune liver disease, and cholestatic liver disease, and the prevalence rate of non-viral liver diseases tends to increase in recent years. Takeda G protein-coupled receptor-5 (TGR5) belongs to the G protein-coupled receptor superfamily and is activated by primary and secondary bile acids. TGR5 plays an important regulatory role in bile acid homeostasis, basal metabolism, energy balance, and alleviation of inflammatory response and is a potential therapeutic target for many diseases. An increasing number of evidence has shown that TGR5 exerts a protective effect on the liver by improving bile acid and glycolipid metabolism in liver, alleviating liver inflammation, and reducing liver steatosis. This article reviews the recent advances in the basic research on TGR5 in the field of non-viral liver diseases, so as to facilitate the development of the research on TGR5.

Effect and Mechanism of "Liver-Soothing and Spleen-Invigorating" Therapies Against Liver Injury in Rats： An Exploration Based on TGR5 and Intestinal Mucosal Barrier Function / 中国实验方剂学杂志

ObjectiveTo explore the effects of different treatment methods of "soothing liver， invigorating spleen， soothing liver and invigorating spleen， soothing liver first and then soothing liver and invigorating spleen， as well as invigorating spleen first and then soothing liver and invigorating spleen" on liver depression combined with liver injury in rats and their action mechanisms. MethodA six-week rat model of liver depression combined with liver injury was established by restraint stress and subcutaneous injection of carbon tetrachloride （CCl4， 5.89 g·kg-1， once every three days）. At the same time， the drugs were given by gavage. Forty-eight male SD rats of clean grade were randomly divided into eight groups， namely the normal group， model group， bicyclol （0.2 g·kg-1） group， Sinisan （4.32 g·kg-1） group， Liu Junzitang （9.26 g·kg-1） group， Chaishao Liu Junzitang A （Chai A， soothing liver and invigorating spleen，13.57 g·kg-1） group， Chaishao Liu Junzitang B （Chai B， soothing liver first and then soothing liver and invigorating spleen， 13.57 g·kg-1） group， and Chaishao Liu Junzitang C （Chai C， invigorating spleen first and then soothing liver and invigorating spleen， 13.57 g·kg-1） group， with six rats in each group. The pathological changes in liver and colon tissues of each group were observed under light microscope and electron microscope. The serum biochemical indexes of the liver were detected using an automatic biochemical analyzer. The relative mRNA expression levels of Takeda G protein-coupled receptor 5 （TGR5） and intestinal mucosal zona occluden-1 （ZO-1）， Occludin， and Claudin-1 in the liver and colon were detected by reverse-transcription polymerase chain reaction （RT-PCR）. The positive expression rate of proliferating cell nuclear antigen （PCNA） in the colon was detected by immunohistochemistry. ResultCompared with normal group， the model group exhibited significantly elevated serum alkaline phosphatase （ALP）， alanine aminotransferase （ALT）， aspartate aminotransferase （AST）， total bilirubin （TBIL）， and direct bilirubin （DBIL） （P<0.01）， lowered TGR5 mRNA expression in liver tissue， up-regulated TGR5 mRNA expression in the colon tissue （P<0.05，P<0.01）， and down-regulated ZO-1， Occludin， and tight junction protein-1 (Claudin-1) mRNA expression and PCNA in the colon tissue （P<0.01）. Compared with the model group， bicyclol and Chai C remarkably decreased the levels of serum ALP， ALT， AST， TBIL， and DBIL （P<0.05，P<0.01）， while Liu Junzitang， Chai A， Chai B， and Chai C significantly up-regulated the TGR5 mRNA expression in the liver and down-regulated its expression in the colon （P<0.01）. Bicyclol， Chai A， Chai B， and Chai C enhanced the ZO-1 and Claudin-1 mRNA expression in the colon （P<0.05，P<0.01）. Bicyclol， Sinisan， and Chai C increased PCNA expression （P<0.01）. The comparison with the Chai C group showed that the TGR5 mRNA expression in the liver and ZO-1 mRNA expression in the colon of the bicyclol and Sinisan groups were lower， whereas the TGR5 mRNA expression in the colon was higher （P<0.01）. However， the PCNA expression in the colon of the Liu Junzitang and Chai B groups declined significantly （P<0.05）. ConclusionIn the presence of liver injury， invigorating spleen first helps to relieve the liver injury， and the efficacy of "spleen-invigorating" therapy in increasing the intestinal mucosal tight junction proteins and improving the gastrointestinal function is related to its activation of TGR5 to improve the intestinal mucosal barrier function， promote the renewal of intestinal stem cells， and drive the regeneration after injury.

Research advance on function and molecular mechanism of takeda G protein-coupled receptor 5 in obstructive jaundice / 中华消化外科杂志

Bile acid can not only emulsify fat and facilitate the absorption of fat soluble substances,but also it is an important signaling molecules that plays an important physiological role by activating specific bile acid receptors.Takeda G proteincoupled receptor 5 (TGRS) is a membrane receptor of the bile acid,it can activate G-protein effectors and promote the expression of the second messenger and activate a variety of signal transduction pathways to exert physiological functions.The obstructive jaundice bile acid can cause a series of pathophysiological reactions through activating TGR5,which plays a significant role in the obstructive jaundice.In this article,the latest researches about the function and molecular mechanism of TGR5 in obstructive jaundice were reviewed in order to provide a new idea for exploring the new method and strategy to cure the disease.