Hepatic thyroid hormone signalling modulates glucose homeostasis through the regulation of GLP-1 production via bile acid-mediated FXR antagonism

Brain-thyroid crosstalk: 18F-FDG-PET/MRI evidence in patients with follicular thyroid adenomas

OBJECTIVE

The hypothalamic-pituitary-thyroid axis has been well-known. However, whether follicular thyroid adenoma (FTA) could affect brain glucose metabolism is still unknown. Therefore, we explored the brain glucose metabolic characteristics of FTA with Fluorodeoxyglucose F18 positron emission tomography/magnetic resonance imaging.

METHODS

Totally 30 FTA patients without clinical symptoms (FTA group), and 60 age- and sex-matched healthy controls (HC group) were included and randomly divided into cohort A and B in 2:1 ratio. Cohort A was analyzed with scaled sub-profile model/principal component analysis (SSM/PCA) for pattern identification. Cohort B was calculated the individual scores to validate expression of the pattern. Then we calculated the metabolic connectivity based on characteristics of the pattern to investigate the underlying mechanism. Finally, we constructed metabolic brain networks and analyzed the topological properties to further explore the brain metabolic model.

RESULTS

In SSM/PCA, FTA group showed an almost global, left-right symmetrical pattern. In metabolic connectivity, FTA group showed increased metabolic connectivity in brain regions of the sensorimotor network, ventral default mode network (DMN), posterior salient network, right executive control network (ECN), visuospatial network and language network when compared to HC group, and showed decreased connectivity in dorsal DMN and left ECN. In topological properties of brain network, FTA group showed an increased betweenness centrality (BC) in left rolandic operculum, a decreased BC in superior temporal gyrus, increased BC and Degree in right precentral gyrus, increased D in right parahippocampal gyrus and left hippocampus, and decreased D and efficiency in right orbital part of middle frontal gyrus (FDR correction for multiple comparisons, P < 0.05).

CONCLUSION

Although FTA patients are not yet symptomatic, their brain metabolic characteristics include extensive brain alterations, disrupted internal connectivity, not only involving brain regions associated with endocrine activity, but also brain networks and regions associated with motor, emotion and cognition.

Circadian clock controlled glycolipid metabolism and its relevance to disease management

The circadian clock is a critical regulator of physiological rhythms, orchestrating metabolic processes to adapt to daily environmental changes. This review focuses on the intricate relationship between circadian regulation and glycolipid metabolism, with implications for metabolic diseases. Central and peripheral clocks coordinate the rhythmic expression of key enzymes and transporters, ensuring glycolipid homeostasis. Disruptions to these rhythms can result in metabolic disorders characterized by altered glucose utilization, insulin sensitivity, and lipid storage. The molecular mechanisms underlying these processes include transcriptional-translational feedback loops involving clock factors that regulate glycolipid metabolism. Emerging therapeutic strategies, such as pharmacological and dietary interventions, highlight the translational potential of circadian biology. This review underscores the importance of circadian rhythm maintenance for glycolipid metabolism and its role in preventing metabolic disorders. Further elucidation of the molecular mechanisms linking circadian regulation to glycolipid metabolism could pave the way for precision medicine approaches tailored to individual circadian profiles.

Effect of levothyroxine treatment on serum lipids and pregnancy outcomes in pregnant women with isolated hypothyroxinemia

374 pregnant women with isolated hypothyroxinemia (IH) who were ≤ 20 weeks were included retrospectively in this study. Based on the confirmed gestational age and the use of levothyroxine (LT4), the patients were divided into the treated group (T1 group) and untreated group (C1 group) in first trimester (≤ 13+ 6 weeks), the treated group(T2 group) and untreated group (C2 group) in second trimester (14-20 weeks). Data on thyroid function and lipid indices was collected both before and after LT4 treatment. To compare the thyroid function, lipid indices and pregnancy outcomes after LT4 treatment. There was a negative correlation between FT4 levels and TC and LDL levels in the first trimester (P<0.05). FT4 and HDL levels in T1 group were significantly increased, and TSH, TC, TG and LDL levels were decreased, compared to C1 group (P < 0.05). FT4 levels in T2 group were higher than C2 group, and there was no significant difference in other indicators. The risk of spontaneous abortion, gestational diabetes mellitus (GDM) and macrosomia in T1 group was significantly decreased (P < 0.05), and there was no significant difference between T2 and C2 groups. Thus, LT4 treatment can improve the level of FT4 and lipids and reduce adverse pregnancy outcomes in women with IH in the first trimester.

Osteoarthritis treatment via the GLP-1-mediated gut-joint axis targets intestinal FXR signaling

Whether a gut-joint axis exists to regulate osteoarthritis is unknown. In two independent cohorts, we identified altered microbial bile acid metabolism with reduced glycoursodeoxycholic acid (GUDCA) in osteoarthritis. Suppressing farnesoid X receptor (FXR)-the receptor of GUDCA-alleviated osteoarthritis through intestine-secreted glucagon-like peptide 1 (GLP-1) in mice. GLP-1 receptor blockade attenuated these effects, whereas GLP-1 receptor activation mitigated osteoarthritis. Osteoarthritis patients exhibited a lower relative abundance of Clostridium bolteae, which promoted the formation of ursodeoxycholic acid (UDCA), a precursor of GUDCA. Treatment with C. bolteae and Food and Drug Administration-approved UDCA alleviated osteoarthritis through the gut FXR-joint GLP-1 axis in mice. UDCA use was associated with lower risk of osteoarthritis-related joint replacement in humans. These findings suggest that orchestrating the gut microbiota-GUDCA-intestinal FXR-GLP-1-joint pathway offers a potential strategy for osteoarthritis treatment.

Thyroid hormone signaling is essential for the maturation and survival of cochlear root cells in mice

Thyroid hormone and its receptors (TRs) are crucial for late-stage cochlear development and the maintenance of endocochlear potential (EP), yet the mechanisms underlying EP reduction in their absence remain unclear. Cochlear outer sulcus root cells undergo significant morphological changes during late-stage development and are thought to play a role in maintaining endolymph homeostasis and EP. Nevertheless, it remains unknown whether thyroid hormone and TRs are essential for root cell differentiation and function. Here, we demonstrate that thyroid hormone or TRs are indispensable for postnatal root cell development and survival in the mouse cochlea. Thyroid hormone deficiency markedly delays root cell differentiation. Otocyst-selective deletion of both Thra and Thrb, but not Thrb alone, leads to a similar impairment, accompanied by early degeneration of root cells, with the stria vascularis unaffected. Furthermore, conditional double knockout of TRs results in a 22 % reduction in mean EP magnitude at 4 months, less severe than the effects observed in global TRs knockout models. Transcriptome analysis reveals that thyroid hormone deficiency downregulates a significant portion of root cell-enriched genes. These findings underscore the redundant roles of TRα and TRβ in promoting the late-stage differentiation and survival of root cells. Additionally, they suggest that the expression of TRs in cochlear epithelium is crucial for maintaining an optimal EP magnitude, while TRs expressed in areas outside cochlear epithelium, particularly in spiral ligament fibrocytes, may also significantly contribute to EP maintenance. This study advances our understanding of thyroid hormone in cochlear outer sulcus development and EP maintenance.

Development of cyclopeptide inhibitors specifically disrupting FXR-coactivator interaction in the intestine as a novel therapeutic strategy for MASH

Intestinal farnesoid X receptor (FXR) antagonists have been proven to be efficacious in ameliorating metabolic diseases, particularly for the treatment of metabolic dysfunction-associated steatohepatitis (MASH). All the reported FXR antagonists target to the ligand-binding pocket (LBP) of the receptor, whereas antagonist acting on the non-LBP site of nuclear receptor (NR) is conceived as a promising strategy to discover novel FXR antagonist. Here, we have postulated the hypothesis of antagonizing FXR by disrupting the interaction between FXR and coactivators, and have successfully developed a series of macrocyclic peptides as FXR antagonists based on this premise. The cyclopeptide DC646 not only exhibits potent inhibitory activity of FXR, but also demonstrates a high degree of selectivity towards other NRs. Moreover, cyclopeptide DC646 has high potential therapeutic benefit for the treatment of MASH in an intestinal FXR-dependent manner, along with a commendable safety profile. Mechanistically, distinct from other known FXR antagonists, cyclopeptide DC646 specifically binds to the coactivator binding site of FXR, which can block the coactivator recruitment, reducing the circulation of intestine-derived ceramides to the liver, and promoting the release of glucagon-like peptide-1 (GLP-1). Overall, we identify a novel cyclopeptide that targets FXR-coactivator interaction, paving the way for a new approach to treating MASH with FXR antagonists.

Monocyte CCL2 signaling possibly contributes to increased asthma susceptibility in type 2 diabetes

In recent years, the respiratory system has been increasingly recognized as a key target organ in diabetes. Although observational studies have established significant clinical associations between type 2 diabetes (T2D), antidiabetic medication use, and asthma, the causal relationships and underlying molecular mechanisms remain unclear. This study employed a bidirectional two-sample Mendelian randomization (MR) approach combined with bioinformatics analysis to explore the causal relationships between T2D and asthma subtypes and complications, with a focus on immune-regulatory mechanisms. The MR analysis utilized inverse-variance weighted (IVW) and meta-analysis methods to evaluate overall effects, with sensitivity analyses confirming the robustness of the findings. Bioinformatics analysis focused on differential gene expression and pathway enrichment to identify potential molecular networks. The MR analysis showed that T2D has a significant positive causal effect on asthma (P < 0.05), with severe autoimmune T2D showing strong associations with specific asthma subtypes (eosinophilic and mixed asthma) and complications (e.g., acute respiratory infections and pneumonia) (P < 0.05). Bioinformatics analysis identified the monocyte-CCL2 signaling axis as a key mechanism linking T2D and asthma, where hyperglycemia-induced monocyte activation may promote asthma development. These findings reveal shared inflammatory pathways and deepen our understanding of the molecular mechanisms linking these two chronic diseases.

Dual GIP and GLP-1 receptor agonist tirzepatide alleviates hepatic steatosis and modulates gut microbiota and bile acid metabolism in diabetic mice

Tirzepatide is a dual agonist of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors and is a promising therapeutic option for type 2 diabetes mellitus (T2DM). Nevertheless, its effect and underlying mechanism on hepatic steatosis remain ambiguous. Herein, we explored the impact of tirzepatide on improving hepatic steatosis in diabetic mice, with a particular focus on the gut microbiota and bile acids (BAs) using animal models. The tirzepatide effectively reduced body weight, improved insulin resistance, decreased serum and hepatic lipid levels, and mitigated liver injury. Compared to semaglutide, tirzepatide exhibited superior efficacy in reducing hepatic lipid accumulation. 16S rRNA gene sequencing and targeted metabolomics of BAs revealed that tirzepatide ameliorated gut microbiota dysbiosis and BAs metabolism in diabetic mice. Notably, tirzepatide observably increased the abundance of beneficial genera such as Akkermansia, elevated the ratio of farnesoid X receptor (FXR) antagonists (glycoursodeoxycholic acid: GUDCA, β-muricholic acid: β-MCA, hyodeoxycholic acid: HDCA, ursodeoxycholic acid: UDCA) to natural agonists (cholic acid: CA, lithocholic acid: LCA, chenodeoxycholic acid: CDCA, glycocholic acid: GCA, taurodeoxycholic acid: TDCA), and reduced FXR expression in intestinal tissues. In conclusion, tirzepatide attenuated hepatic steatosis in diabetic mice and regulated the gut microbiota and BAs metabolism, which may help to provide a novel therapeutic approach and therapeutic target for metabolic dysfunction-associated steatotic liver disease (MASLD).

Thyromimetics and MASLD: Unveiling the Novel Molecules Beyond Resmetirom

BACKGROUND

Resmetirom, the first FDA-approved drug for nonalcoholic steatohepatitis (NASH) with fibrosis in obese patients, when combined with lifestyle modifications, improves NASH resolution and reduces fibrosis by at least one stage. Low thyroid hormone (T3) levels are linked to a higher risk of developing metabolic dysfunction-associated steatotic liver disease (MASLD). Epidemiological studies have confirmed the positive correlation between hypothyroidism and MASLD. Unraveling the molecular mechanisms of T3 signaling pathways in MASLD will enhance the prospects of identifying effective and specific targets. Therefore, this review discusses the significant role of thyroid hormones in the homeostasis of fat metabolism and describes the possible molecular mechanisms of thyromimetics in the treatment of MASLD.

METHODS

A comprehensive search in PubMed and EMBASE was conducted using the keywords "thyromimetics and liver diseases," "thyroid hormone and liver diseases," "hypothyroidism and liver diseases," "T3, T4 and liver disease," and "resmetirom and liver disease." Relevant papers published before October 2024 were included.

RESULTS

T3 treatment enhances mitochondrial respiration, biogenesis, β-oxidation, and mitophagy, reducing liver lipid accumulation. However, T3 treatment causes cardiotoxicity through thyroid hormone receptor (THR)α agonistic activity. To address this, molecules with high THRβ agonistic but lower THRα activity have been developed. Besides resmetirom, other THRβ agonists like TG68, CS27109, MB07811, and KB-141 show promising results in experimental studies. These molecules upregulate THRβ target genes, activate genes for fatty acid β-oxidation in mitochondria and fatty acid breakdown in peroxisomes, downregulate the genes involved in de novo lipogenesis, reduce inflammation by downregulating NF-κB/JNK/STAT3 signaling pathways, and accelerate fibrosis resolution by downregulating the expressions of fibrosis marker genes in NASH liver tissue.

CONCLUSION

Future clinical studies should thoroughly investigate THRβ agonists, including TG68, CS27109, MB07811, and KB-141.

Association between non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio and serum thyroid function measures: Recent Findings from NHANES 2007-2012 and Mendelian randomization

Objective

There is limited epidemiological data regarding the association of blood lipids with thyroid hormones. Thus, the present article aims to explore whether there is an association between non-high-density to high-density lipoprotein cholesterol ratio (NHHR) and thyroid hormones.

Methods

We analyzed samples from 3,881 adults aged 20 years and above who took part in the National Health and Nutrition Examination Survey (NHANES) spanning 2007 to 2012. The study tested for thyroid hormones, including total triiodothyronine (TT3), free triiodothyronine (FT3), total thyroxine (TT4), free thyroxine (FT4), as well as thyroid-stimulating hormone (TSH). Survey-weighted linear regression and restricted cubic spline (RCS) models were employed to investigate the relationship between NHHR and thyroid hormones. Subsequently, subgroup analyses were conducted. In Mendelian randomization (MR), the inverse variance weighting method (IVW) is used as the primary analytical approach.

Results

This study finally comprised 3,881 adults aged 20 years and older. After extensive adjustments for covariables, the regression analysis revealed significant negative associations between NHHR and FT4 (β: -0.11, 95% confidence interval [CI]: -0.18, -0.04), FT4/FT3 (β: -0.06, 95% CI: -0.08, -0.04), and TT4/TT3 (β: -0.001, 95% CI: -0.001, 0.000). Both observational and Mendelian randomization studies suggest that high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and total cholesterol may not significantly influence the risk of hyperthyroidism or hypothyroidism.

Conclusions

The study indicates negative associations between NHHR and FT4, as well as the ratios of FT4/FT3 and TT4/TT3. This suggests that NHHR may reflect changes in thyroid function, highlighting its potential clinical significance in assessing thyroid function and metabolic health.

Actions of thyroid hormones and thyromimetics on the liver

Thyroid hormones (triiodothyronine and thyroxine) are pivotal for metabolic balance in the liver and entire body. Dysregulation of the hypothalamus-pituitary-thyroid axis can contribute to hepatic metabolic disturbances, affecting lipid metabolism, glucose regulation and protein synthesis. In addition, reductions in circulating and intrahepatic thyroid hormone concentrations increase the risk of metabolic dysfunction-associated steatotic liver disease by inducing lipotoxicity, inflammation and fibrosis. Amelioration of hepatic metabolic disease by thyroid hormones in preclinical and clinical studies has spurred the development of thyromimetics that target THRB (the predominant thyroid hormone receptor isoform in the liver) and/or the liver itself to provide more selective activation of hepatic thyroid hormone-regulated metabolic pathways while reducing thyrotoxic side effects in tissues that predominantly express THRA such as the heart and bone. Resmetirom, a liver and THRB-selective thyromimetic, recently became the first FDA-approved drug for metabolic dysfunction-associated steatohepatitis (MASH). Thus, a better understanding of the metabolic actions of thyroid hormones and thyromimetics in the liver is timely and clinically relevant. Here, we describe the roles of thyroid hormones in normal liver function and pathogenesis of MASH, as well as some potential clinical issues that might arise when treating patients with MASH with thyroid hormone supplementation or thyromimetics.

Thyroid hormone and the Liver

It is known that thyroid hormone can regulate hepatic metabolic pathways including cholesterol, de novo lipogenesis, fatty acid oxidation, lipophagy, and carbohydrate metabolism. Thyroid hormone action is mediated by the thyroid hormone receptor (THR) isoforms and their coregulators, and THRβ is the main isoform expressed in the liver. Dysregulation of thyroid hormone levels, as seen in hypothyroidism, has been associated with dyslipidemia and metabolic dysfunction-associated fatty liver disease. Given the beneficial effects of thyroid hormone in liver metabolism and the advances illuminating the use of thyroid hormone analogs such as resmetirom as therapeutic agents in the treatment of metabolic dysfunction-associated fatty liver disease, this review aims to further explore the relationship between TH, the liver, and metabolic dysfunction-associated fatty liver disease. Herein, we summarize the current clinical therapies and highlight future areas of research.

Regulation of bile acids and their receptor FXR in metabolic diseases

High sugar, high-fat diets and unhealthy lifestyles have led to an epidemic of obesity and obesity-related metabolic diseases, seriously placing a huge burden on socio-economic development. A deeper understanding and elucidation of the specific molecular biological mechanisms underlying the onset and development of obesity has become a key to the treatment of metabolic diseases. Recent studies have shown that the changes of bile acid composition are closely linked to the development of metabolic diseases. Bile acids can not only emulsify lipids in the intestine and promote lipid absorption, but also act as signaling molecules that play an indispensable role in regulating bile acid homeostasis, energy expenditure, glucose and lipid metabolism, immunity. Disorders of bile acid metabolism are therefore important risk factors for metabolic diseases. The farnesol X receptor, a member of the nuclear receptor family, is abundantly expressed in liver and intestinal tissues. Bile acids act as endogenous ligands for the farnesol X receptor, and erroneous FXR signaling triggered by bile acid dysregulation contributes to metabolic diseases, including obesity, non-alcoholic fatty liver disease and diabetes. Activation of FXR signaling can reduce lipogenesis and inhibit gluconeogenesis to alleviate metabolic diseases. It has been found that intestinal FXR can regulate hepatic FXR in an organ-wide manner. The crosstalk between intestinal FXR and hepatic FXR provides a new idea for the treatment of metabolic diseases. This review focuses on the relationship between bile acids and metabolic diseases and the current research progress to provide a theoretical basis for further research and clinical applications.

Phloridzin prevents diabetic cardiomyopathy by reducing inflammation and oxidative stress

Oxidative stress and inflammation significantly contribute to the pathogenesis of diabetic cardiomyopathy (DCM). Persistent inflammatory stimuli drive the progression of myocardial fibrosis and impaired cardiac function. Phloridzin (Phl), a natural compound, demonstrates both anti-inflammatory and antioxidant properties. Nevertheless, its therapeutic potential and underlying mechanisms in DCM remain unclear. This study aimed to elucidate the mechanisms through which Phl inhibited myocardial fibrosis and exerted its antioxidative effects. The impact of Phl on DCM was evaluated using a high-fat/high-sugar diet combined with streptozotocin to induce an animal model and an in vitro H9C2 cell model stimulated by high glucose (HG). Untargeted metabolomics identified potential mechanisms underlying myocardial fibrosis. Phl treatment significantly enhanced left ventricular ejection fraction (EF%) and shortening fraction (FS%), while reducing myocardial injury markers, such as lactate dehydrogenase and creatine phosphokinase-MB, and suppressing myocardial collagen fiber accumulation. Simultaneously, Phl attenuated myocardial inflammation via inhibition of MyD88/NF-κB signaling, modulated the Nrf2/GPX4 axis to counter oxidative stress, and mitigated ferroptosis. In vitro, Phl inhibited high glucose-induced myocardial hypertrophy and fibrosis in H9C2 cells, while also repressing NF-κB activation in cardiomyocytes. Metabolomic profiling revealed that Phl ameliorated DCM through modulation of glycerophospholipid metabolic pathways, linking these metabolic shifts to enhanced antioxidant capacity, thereby reflecting its ability to reduce oxidative stress in the myocardium. Collectively, Phl provides cardioprotective effects by alleviating inflammation and oxidative damage.

Heat-treated brown rice starch structure and effect on short-chain fatty acids and mouse intestinal microbiota

Rice with high resistant starch (RS) exhibits the potential to improve glucose metabolism, insulin sensitivity. In this study, using two rice varieties-Samgwang, a medium-amylose rice, and Dodamssal, a high-amylose rice containing RS-we analyzed the composition and molecular structural characteristics of brown rice and its starch and the effects on fasting blood glucose levels, fecal short-chain fatty acid (SCFA), and gut microbiota after 8 weeks of consumption in mice. The amylose content of heat-treated Samgwang (HS) and -Dodamssal (HD) was 21.0 ± 0.2 and 47.5 ± 0.3 %, respectively, while RS contents were 0.8 ± 0.0 and 14.7 ± 1.0 %. HD exhibited a C-type starch crystallinity with a lower proportion of short chains and a higher proportion of long chains compared to HS. HD-fed mice exhibited lower fasting blood glucose levels and the highest SCFA levels in their feces. They also had the highest abundance of Ruminococcus bromii, an RS-degrading bacterium, the highest positive correlation with Faecalicatena fissicatena (r = 0.9), and the highest negative correlation with Lachnoclostridium scindens and Lawsonibacter asaccharolyticus (r = -0.8). Overall, HD consumption can improve glucose metabolism by increasing intestinal SCFA production and can serve as a prebiotic dietary ingredient to improve obesity and diabetes.

Isospongian Diterpenoids from the Leaves of Amomum tsao-ko Promote GLP-1 Secretion via Ca2+/CaMKII and PKA Pathways and Inhibit DPP-4 Enzyme

Three uncommon isospongian diterpenoids including a new one, 3-epi-kravanhin A (2), were isolated from the leaves of Amomum tsao-ko. Compounds 2 and 3 dose-dependently promoted GLP-1 secretion on STC-1 cells with promotion ratios of 109.7 % and 186.1 % (60 μM). Mechanism study demonstrated that the GLP-1 stimulative effects of 2 and 3 were closely related with Ca2+/CaMKII and PKA pathways, but irrelevant to GPBAR1 and GPR119 receptors. Moreover, compound 1 showed DPP-4 inhibitory activity with an IC50 value of 311.0 μM. Molecular docking verified the binding affinity of 1 with DPP-4 by hydrogen bonds between the γ-lactone carbonyl (C-15) and Arg61 residue. Bioinformatics study indicated that compound 1 exerted antidiabetic effects by improving inflammation, oxidative stress and insulin resistance. This study first disclosed the presence of isospongian diterpenoids in A. tsao-ko, which showed antidiabetic potency by promoting GLP-1 secretion and inhibiting DPP-4 activity.

FXR activation remodels hepatic and intestinal transcriptional landscapes in metabolic dysfunction-associated steatohepatitis

The escalating obesity epidemic and aging population have propelled metabolic dysfunction-associated steatohepatitis (MASH) to the forefront of public health concerns. The activation of FXR shows promise to combat MASH and its detrimental consequences. However, the specific alterations within the MASH-related transcriptional network remain elusive, hindering the development of more precise and effective therapeutic strategies. Through a comprehensive analysis of liver RNA-seq data from human and mouse MASH samples, we identified central perturbations within the MASH-associated transcriptional network, including disrupted cellular metabolism and mitochondrial function, decreased tissue repair capability, and increased inflammation and fibrosis. By employing integrated transcriptome profiling of diverse FXR agonists-treated mice, FXR liver-specific knockout mice, and open-source human datasets, we determined that hepatic FXR activation effectively ameliorated MASH by reversing the dysregulated metabolic and inflammatory networks implicated in MASH pathogenesis. This mitigation encompassed resolving fibrosis and reducing immune infiltration. By understanding the core regulatory network of FXR, which is directly correlated with disease severity and treatment response, we identified approximately one-third of the patients who could potentially benefit from FXR agonist therapy. A similar analysis involving intestinal RNA-seq data from FXR agonists-treated mice and FXR intestine-specific knockout mice revealed that intestinal FXR activation attenuates intestinal inflammation, and has promise in attenuating hepatic inflammation and fibrosis. Collectively, our study uncovers the intricate pathophysiological features of MASH at a transcriptional level and highlights the complex interplay between FXR activation and both MASH progression and regression. These findings contribute to precise drug development, utilization, and efficacy evaluation, ultimately aiming to improve patient outcomes.

The screening of α-glucosidase inhibitory peptides from β-conglycinin and hypoglycemic mechanism in HepG2 cells and zebrafish larvae

Inhibition of carbohydrate digestive enzymes is a key focus across diverse fields, given the prominence of α-glucosidase inhibitors as preferred oral hypoglycaemic drugs for diabetes treatment. β-conglycinin is the most abundant functional protein in soy; however, it is unclear whether the peptides produced after its gastrointestinal digestion exhibit α-glucosidase inhibitory properties. Therefore, we examined the α-glucosidase inhibitory potential of soy peptides. Specifically, β-conglycinin was subjected to simulated gastrointestinal digestion by enzymatically cleaving it into 95 peptides with gastric, pancreatic and chymotrypsin enzymes. Eight soybean peptides were selected based on their predicted activity; absorption, distribution, metabolism, excretion and toxicity score; and molecular docking analysis. The results indicated that hydrogen bonding and electrostatic interactions play important roles in inhibiting α-glucosidase, with the tripeptide SGR exhibiting the greatest inhibitory effect (IC50 = 10.57 μg/mL). In vitro studies revealed that SGR markedly improved glucose metabolism disorders in insulin-resistant HepG2 cells without affecting cell viability. Animal experiments revealed that SGR significantly improved blood glucose and decreased maltase activity in type 2 diabetic zebrafish larvae, but it did not result in the death of zebrafish larvae. Transcriptomic analysis revealed that SGR exerts its anti-diabetic and hypoglycaemic effects by attenuating the expression of several genes, including Slc2a1, Hsp70, Cpt2, Serpinf1, Sfrp2 and Ggt1a. These results suggest that SGR is a potential food-borne bioactive peptide for managing diabetes.

A new mechanism of thyroid hormone receptor β agonists ameliorating nonalcoholic steatohepatitis by inhibiting intestinal lipid absorption via remodeling bile acid profiles

Excessive dietary calories lead to systemic metabolic disorders, disturb hepatic lipid metabolism, and aggravate nonalcoholic steatohepatitis (NASH). Bile acids (BAs) play key roles in regulating nutrition absorption and systemic energy homeostasis. Resmetirom is a selective thyroid hormone receptor β (THRβ) agonist and the first approved drug for NASH treatment. It is well known that the THRβ activation could promote intrahepatic lipid catabolism and improve mitochondrial function, however, its effects on intestinal lipid absorption and BA compositions remain unknown. In the present study, the choline-deficient, L-amino acid defined, high-fat diet (CDAHFD) and high-fat diet plus CCl4 (HFD+CCl4)-induced NASH mice were used to evaluate the effects of resmetirom on lipid and BA composition. We showed that resmetirom administration (10 mg·kg-1·d-1, i.g.) significantly altered hepatic lipid composition, especially reduced the C18:2 fatty acyl chain-containing triglyceride (TG) and phosphatidylcholine (PC) in the two NASH mouse models, suggesting that THRβ activation inhibited intestinal lipid absorption since C18:2 fatty acid could be obtained only from diet. Targeted analysis of BAs showed that resmetirom treatment markedly reduced the hepatic and intestinal 12-OH to non-12-OH BAs ratio by suppressing cytochrome P450 8B1 (CYP8B1) expression in both NASH mouse models. The direct inhibition by resmetirom on intestinal lipid absorption was further verified by the BODIPY gavage and the oral fat tolerance test. In addition, disturbance of the altered BA profiles by exogenous cholic acid (CA) supplementation abolished the inhibitory effects of resmetirom on intestinal lipid absorption in both normal and CDAHFD-fed mice, suggesting that resmetirom inhibited intestinal lipid absorption by reducing 12-OH BAs content. In conclusion, we discovered a novel mechanism of THRβ agonists on NASH treatment by inhibiting intestinal lipid absorption through remodeling BAs composition, which highlights the multiple regulation of THRβ activation on lipid metabolism and extends the current knowledge on the action mechanisms of THRβ agonists in NASH treatment.

The complex link between the gut microbiome and obesity-associated metabolic disorders: Mechanisms and therapeutic opportunities

Microbial interactions are widespread and important processes that support the link between disease and microbial ecology. The gut microbiota is a major source of microbial stimuli that can have detrimental or beneficial effects on human health. It is also an endocrine organ that maintains energy homeostasis and host immunity. Obesity is a highly and increasingly prevalent metabolic disease and the leading cause of preventable death worldwide. An imbalance in the gut microbiome is associated with several diseases including obesity-related metabolic disorders. This review summarizes the complex association between the gut microbiome and obesity-associated metabolic diseases and validates the role and mechanisms of ecological dysregulation in the gut in obesity-associated metabolic disorders. Therapies that could potentially alleviate obesity-associated metabolic diseases by modulating the gut microbiota are discussed.

Gut microbiota-brain bile acid axis orchestrates aging-related neuroinflammation and behavior impairment in mice

Emerging evidence shows that disrupted gut microbiota-bile acid (BA) axis is critically involved in the development of neurodegenerative diseases. However, the alterations in spatial distribution of BAs among different brain regions that command important functions during aging and their exact roles in aging-related neurodegenerative diseases are poorly understood. Here, we analyzed the BA profiles in cerebral cortex, hippocampus, and hypothalamus of young and natural aging mice of both sexes. The results showed that aging altered brain BA profiles sex- and region- dependently, in which TβMCA was consistently elevated in aging mice of both sexes, particularly in the hippocampus and hypothalamus. Furthermore, we found that aging accumulated-TβMCA stimulated microglia inflammation in vitro and shortened the lifespan of C. elegans, as well as behavioral impairment and neuroinflammation in mice. In addition, metagenomic analysis suggested that the accumulation of brain TβMCA during aging was partially attributed to reduction in BSH-carrying bacteria. Finally, rejuvenation of gut microbiota by co-housing aged mice with young mice restored brain BA homeostasis and improved neurological dysfunctions in natural aging mice. In conclusion, our current study highlighted the potential of improving aging-related neuro-impairment by targeting gut microbiota-brain BA axis.

Unveiling the Pharmacological Mechanisms of Davidiin's Anti-Diabetic Efficacy in Streptozotocin-Treated Rats: A Comprehensive Analysis of Serum Metabolome

Background

Polygonum capitatum Buch.-Ham. ex D. Don (P. capitatum), a traditional herb used in Miao medicine, is renowned for its heart-clearing properties. Davidiin, the primary bioactive component (approximately 1%), has been used to treat various conditions, including diabetes. Given its wide range of effects and the diverse biomolecular pathways involved in diabetes, there is a crucial need to study how davidiin interacts with these pathways to better understand its anti-diabetic properties.

Materials and Methods

Diabetic rats were induced using a high-fat diet and streptozotocin (STZ) administered intraperitoneally at 35 mg/kg. Out of these, 24 rats with blood glucose levels ≥ 11.1 mmol/L and fasting blood glucose levels ≥ 7.0 mmol/L were selected for three experimental groups. These groups were then treated with either metformin (gavage, 140 mg/kg) or davidiin (gavage, 90 mg/kg) for four weeks. After the treatment period, we measured body weight, blood glucose levels, and conducted untargeted metabolic profiling using UPLC-QTOF-MS.

Results

Davidiin has been shown to effectively treat diabetes by reducing blood glucose levels from 30.2 ± 2.6 mmol/L to 25.1 ± 2.4 mmol/L (P < 0.05). This effect appears stronger than that of metformin, which lowered glucose levels to 26.5 ± 2.6 mmol/L. The primary outcomes of serum metabolomics are significant changes in lipid and lipid-like molecular profiles. Firstly, davidiin may affect phosphatide metabolism by increasing levels of phosphatidylinositol and sphingosine-1-phosphate. Secondly, davidiin could influence cholesterol metabolism by reducing levels of glycocholic acid and glycochenodeoxycholic acid. Lastly, davidiin might impact steroid hormone metabolism by increasing hepoxilin B3 levels and decreasing prostaglandins.

Conclusion

Our study demonstrates that davidiin modulates various lipid-related metabolic pathways to exert its anti-diabetic effects. These findings offer the first detailed metabolic profile of davidiin's action mechanism, contributing valuable insights to the field of Traditional Chinese Medicine in the context of diabetes treatment.

Bile acid metabolism and signaling in health and disease: molecular mechanisms and therapeutic targets

Bile acids, once considered mere dietary surfactants, now emerge as critical modulators of macronutrient (lipid, carbohydrate, protein) metabolism and the systemic pro-inflammatory/anti-inflammatory balance. Bile acid metabolism and signaling pathways play a crucial role in protecting against, or if aberrant, inducing cardiometabolic, inflammatory, and neoplastic conditions, strongly influencing health and disease. No curative treatment exists for any bile acid influenced disease, while the most promising and well-developed bile acid therapeutic was recently rejected by the FDA. Here, we provide a bottom-up approach on bile acids, mechanistically explaining their biochemistry, physiology, and pharmacology at canonical and non-canonical receptors. Using this mechanistic model of bile acids, we explain how abnormal bile acid physiology drives disease pathogenesis, emphasizing how ceramide synthesis may serve as a unifying pathogenic feature for cardiometabolic diseases. We provide an in-depth summary on pre-existing bile acid receptor modulators, explain their shortcomings, and propose solutions for how they may be remedied. Lastly, we rationalize novel targets for further translational drug discovery and provide future perspectives. Rather than dismissing bile acid therapeutics due to recent setbacks, we believe that there is immense clinical potential and a high likelihood for the future success of bile acid therapeutics.

Diagnosis and management of thyroid disorders and thyroid hormone supplementation in adult horses and foals

Equine thyroid disorders pose a diagnostic challenge in clinical practice because of the effects of nonthyroidal factors on the hypothalamic-pituitary-thyroid axis, and the horse's ability to tolerate wide fluctuations in thyroid hormone concentrations and survive without a thyroid gland. While benign thyroid tumours are common in older horses, other disorders like primary hypothyroidism or hyperthyroidism in adult horses and congenital hypothyroidism in foals are rare. There is a common misunderstanding regarding hypothyroidism in adult horses, especially when associated with the clinical profile of obesity, lethargy, and poor performance observed in dogs and humans. Low blood thyroid hormone concentrations are often detected in horses as a secondary response to metabolic and disease states, including with the nonthyroidal illness syndrome; however, it is important to note that low thyroid hormone concentrations in these cases do not necessarily indicate hypothyroidism. Assessing equine thyroid function involves measuring thyroid hormone concentrations, including total and free fractions of thyroxine (T4) and triiodothyronine (T3); however, interpreting these results can be challenging due to the pulsatile secretion of thyroid hormones and the many factors that can affect their concentrations. Dynamic testing, such as the thyrotropin-releasing hormone stimulation test, can help assess the thyroid gland response to stimulation. Although true hypothyroidism is extremely rare, thyroid hormone supplementation is commonly used in equine practice to help manage obesity and poor performance. This review focuses on thyroid gland pathophysiology in adult horses and foals, interpretation of blood thyroid hormone concentrations, and evaluation of horses with thyroid disorders. It also discusses the use of T4 supplementation in equine practice.

Integrating network pharmacology and drug side-effect data to explore mechanism of liver injury-induced by tyrosine kinase inhibitors

Tyrosine kinase inhibitors (TKIs) are highly efficient small-molecule anticancer drugs. Despite the specificity and efficacy of TKIs, they can produce off-target effects, leading to severe liver toxicity, and even some of them are labeled as black box hepatotoxicity. Thus, we focused on representative TKIs associated with severe hepatic adverse events, namely lapatinib, pazopanib, regorafenib, and sunitinib as objections of study, then integrated drug side-effect data from United State Food and Drug Administration (U.S. FDA) and network pharmacology to elucidate mechanism underlying TKI-induced liver injury. Based on network pharmacology, we constructed a specific comorbidity module of high risk of serious adverse effects and created drug-disease networks. Enrichment analysis of the networks revealed the depletion of all-trans-retinoic acid and the involvement of down-regulation of the HSP70 family-mediated endoplasmic reticulum (ER) stress as key factors in TKI-induced liver injury. These results were further verified by transcription data. Based on the target prediction results of drugs and reactive metabolites, we also shed light on the association between toxic metabolites and severe hepatic adverse reactions, and thinking HSPA8, HSPA1A, CYP1A1, CYP1A2 and CYP3A4 were potential therapeutic or preventive targets against TKI-induced liver injury. In conclusion, our research provides comprehensive insights into the mechanism underlying severe liver injury caused by TKIs, offering a better understanding of how to enhance patient safety and treatment efficacy.

Polysaccharides from Phellinus linteus attenuate type 2 diabetes mellitus in rats via modulation of gut microbiota and bile acid metabolism

Type 2 diabetes mellitus (T2DM) is the most prevalent metabolic disorder. Polysaccharides from Phellinus linteus (PLP) have been found to have anti-diabetes effects, but the mechanism has not been elucidated. The purpose of this study was to investigate the mechanism of PLP on T2DM through the gut microbiota and bile acids metabolism. The T2DM rat model was induced by a high-fat high-carbohydrate (HFHC) diet and streptozocin (30 mg/kg). We found that PLP ameliorated diabetes symptoms. Besides, PLP intervention increased the abundance of g_Bacteroides, g_Parabacteroides, and g_Alistioes, which are associated with the biosynthesis of short-chain fatty acids (SCFAs) and bile acids (BAs) metabolism. Meanwhile, untargeted and targeted metabolomics indicated that PLP could regulate the composition of BAs and increase the levels of SCFAs. Real-time quantitative PCR (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA) were performed to analyze the expression levels of BAs metabolism enzymes in the liver. Finally, the results of correlation analysis and Glucagon-like peptide-1 (GLP-1) showed that PLP stimulated the release of GLP-1 by regulating SCFAs and BAs. In conclusion, this study demonstrated that PLP can regulate gut microbiota and BAs metabolism to promote GLP-1 secretion, thereby increasing insulin release, decreasing blood glucose and attenuating T2DM.

Statins aggravate insulin resistance through reduced blood glucagon-like peptide-1 levels in a microbiota-dependent manner

Statins are currently the most common cholesterol-lowering drug, but the underlying mechanism of statin-induced hyperglycemia is unclear. To investigate whether the gut microbiome and its metabolites contribute to statin-associated glucose intolerance, we recruited 30 patients with atorvastatin and 10 controls, followed up for 16 weeks, and found a decreased abundance of the genus Clostridium in feces and altered serum and fecal bile acid profiles among patients with atorvastatin therapy. Animal experiments validated that statin could induce glucose intolerance, and transplantation of Clostridium sp. and supplementation of ursodeoxycholic acid (UDCA) could ameliorate statin-induced glucose intolerance. Furthermore, oral UDCA administration in humans alleviated the glucose intolerance without impairing the lipid-lowering effect. Our study demonstrated that the statin-induced hyperglycemic effect was attributed to the Clostridium sp.-bile acids axis and provided important insights into adjuvant therapy of UDCA to lower the adverse risk of statin therapy.

Tuning of liver circadian transcriptome rhythms by thyroid hormone state in male mice

Thyroid hormones (THs) are important regulators of systemic energy metabolism. In the liver, they stimulate lipid and cholesterol turnover and increase systemic energy bioavailability. It is still unknown how the TH state interacts with the circadian clock, another important regulator of energy metabolism. We addressed this question using a mouse model of hypothyroidism and performed circadian analyses. Low TH levels decreased locomotor activity, food intake, and body temperature mostly in the active phase. Concurrently, liver transcriptome profiling showed only subtle effects compared to elevated TH conditions. Comparative circadian transcriptome profiling revealed alterations in mesor, amplitude, and phase of transcript levels in the livers of low-TH mice. Genes associated with cholesterol uptake, biosynthesis, and bile acid secretion showed reduced mesor. Increased and decreased cholesterol levels in the serum and liver were identified, respectively. Combining data from low- and high-TH conditions allowed the identification of 516 genes with mesor changes as molecular markers of the liver TH state. We explored these genes and created an expression panel that assesses liver TH state in a time-of-day dependent manner. Our findings suggest that the liver has a low TH action under physiological conditions. Circadian profiling reveals genes as potential markers of liver TH state.

Enhanced glucose homeostasis via Clostridium symbiosum-mediated glucagon-like peptide 1 inhibition of hepatic gluconeogenesis in mid-intestinal bypass surgery

BACKGROUND

The small intestine is known to play a crucial role in the development and remission of diabetes mellitus (DM). However, the exact mechanism by which mid-small intestinal bypass improves glucose metabolism in diabetic rats is not fully understood.

AIM

To elucidate the mechanisms by which mid-small intestinal bypass improves glucose metabolism.

METHODS

Streptozotocin (STZ) was used to induce DM in Sprague-Dawley (SD) rats at a dose of 60 mg/kg. The rats were then randomly divided into two groups: The mid-small intestine bypass (MSIB) group and the sham group (underwent switch laparotomy). Following a 6-wk recovery period post-surgery, the rats underwent various assessments, including metabolic parameter testing, analysis of liver glycogen levels, measurement of key gluconeogenic enzyme activity, characterization of the gut microbiota composition, evaluation of hormone levels, determination of bile acid concentrations, and assessment of the expression of the intestinal receptors Takeda G protein-coupled receptor 5 and farnesoid X receptor.

RESULTS

The MSIB group of rats demonstrated improved glucose metabolism and lipid metabolism, along with increased hepatic glycogen content. Furthermore, there was a decrease in the expression of the key gluconeogenic enzymes phosphoenolpyruvate carboxykinase 1 and glucose-6-phosphatase. Importantly, the MSIB group exhibited a substantial increase in the abundances of intestinal Lactobacillus, Clostridium symbiosum, Ruminococcus gnavus, and Bilophila. Moreover, higher levels of secondary bile acids, such as intestinal lithocholic acid, were observed in this group. Remarkably, the changes in the gut microbiota showed a significant correlation with the expression of key gluconeogenic enzymes and glucagon-like peptide 1 (GLP-1) at 6 wk postoperatively, highlighting their potential role in glucose regulation. These findings highlight the beneficial effects of mid-small intestine bypass on glucose metabolism and the associated modulation of the gut microbiota.

CONCLUSION

The findings of this study demonstrate that the introduction of postoperative intestinal Clostridium symbiosum in the mid-small intestine contributes to the enhancement of glucose metabolism in nonobese diabetic rats. This improvement is attributed to the increased inhibition of hepatic gluconeogenesis mediated by GLP-1, resulting in a favorable modulation of glucose homeostasis.

Metabolic characteristics and pathogenesis of precocious puberty in girls: the role of perfluorinated compounds

BACKGROUND

Precocious puberty (PP) in girls is traditionally defined as the onset of breast development before the age of 8 years. The specific biomarkers of premature thelarche (PT) and central precocious puberty (CPP) girls are uncertain, and little is known about their metabolic characteristics driven by perfluorinated compounds (PFCs) and clinical phenotype. This study aimed to screen specific biomarkers of PT and CPP and elucidate their underlying pathogenesis. The relationships of clinical phenotype-serum PFCs-metabolic characteristics were also explored to reveal the relationship between PFCs and the occurrence and development of PT and CPP.

METHODS

Nuclear magnetic resonance (NMR)-based cross-metabolomics strategy was performed on serum from 146 PP (including 30 CPP, 40 PT, and 76 unspecified PP) girls and 64 healthy girls (including 36 prepubertal and 28 adolescent). Specific biomarkers were screened by the uni- and multivariate statistical analyses. The relationships between serum PFCs and clinical phenotype were performed by correlation analysis and weighted gene co-expression network analysis to explore the link of clinical phenotype-PFCs-metabolic characteristics in PT and CPP.

RESULTS

The disordered trend of pyruvate and butyrate metabolisms (metabolites mapped as formate, ethanol, and 3-hydroxybutyrate) were shared and kept almost consistent in PT and CPP. Eight and eleven specific biomarkers were screened for PT and CPP, respectively. The area under curve of specific biomarker combination was 0.721 in CPP vs. prepubertal, 0.972 in PT vs. prepubertal, 0.646 in CPP vs. prepubertal integrated adolescent, and 0.822 in PT vs. prepubertal integrated adolescent, respectively. Perfluoro-n-heptanoic acid and perfluoro-n-hexanoic acid were statistically different between PT and CPP. Estradiol and prolactin were significantly correlated with PFCs in CPP and PT. Clinical phenotypes and PFCs drive the metabolic characteristics and cause metabolic disturbances in CPP and PT.

CONCLUSIONS

The elevation of formate, ethanol, and 3-hydroxybutyrate may serve as the early diagnostic indicator for PP in girls. But the stratification of PP still needs to be further determined based on the specific biomarkers. Specific biomarkers of CPP and PT exhibited good sensitivity and can facilitate the classification diagnosis of CPP and PT. PFC exposure is associated with endocrine homeostasis imbalance. PFC exposure and/or endocrine disturbance directly or indirectly drive metabolic changes and form overall metabolic network perturbations in CPP and PT.

Subcutaneous adipose tissue alteration in aging process associated with thyroid hormone signaling

BACKGROUND

Functional changes in subcutaneous adipose tissue (SAT) occur earlier in the aging process and play an important role in the occurrence and development of age-related metabolic diseases. The mechanism of this phenomenon is still unclear, and the change in adipose tissue with age is poorly understood.

METHODS

We used transcriptome sequencing (RNA seq) to screen differentially expressed genes at the mRNA level, and analyzed the functional characteristics of the differential genes through GO and KEGG analysis in human SAT of all ages. In order to clarify the specific mechanism of the functional change, we analyzed the chromatin accessibility in the promoter region in the same SAT used in the RNA seq by the assay for transposase-accessible chromatin with high throughput sequencing (ATAC-seq) and obtained the functional genes in SAT changed with age. To verify these changes, we enlarged our sample content of human SAT. The primary mice adipocytes were extracted and stimulated by thyroid hormone of different concentration to construct an animal model, and the expression of the genes were determined through real-time Polymerase Chain Reaction(RT-PCR). The oxygen consumption test and immunofluorescence staining were used to determine the mitochondrial function of SAT.

RESULTS

RNA-seq showed characteristic gene expression of young and old human SAT, in which 331 genes were up-regulated and 349 genes were down-regulated. ATAC-seq, RNA-seq, combined with the mouse prediction model, determined the functional changed characteristics of seven genes. All these genes expressed differently in SAT of different ages, in which, NCF1, NLRP3, DUOX1 showed positive correlation with age; The expression of IFI30, P2RX1, P2RX6, PRODH, however, decreased with age. And all these genes showed dose dependent alternations under treatment of triiodothyroxine in mice SAT. The oxygen consumption rate revealed significant changes of the mitochondrial function and ROS accumulation in human SAT of different ages.

CONCLUSION

In elderly individuals, the function, in addition to distribution, of SAT undergoes significant changes, primarily in mitochondria, which may be due to insensitivity to thyroid hormone signaling. These results identified seven novel genes regulated by thyroid hormone, exhibiting significant changes in SAT of different age, and are probably related to the dysfunction of the aged SAT due to the mitochondrial damage and ROS accumulation.

Central Sensitivity to Free Triiodothyronine With MAFLD and Its Progression to Liver Fibrosis in Euthyroid Adults

CONTEXT

Impaired sensitivity to thyroid hormones has been demonstrated to be positively associated with the prevalence of metabolic disorders. However, the relationship between sensitivity to thyroid hormones and metabolic dysfunction-associated fatty liver disease (MAFLD) and liver fibrosis remained unclear.

OBJECTIVE

We aimed to determine the associations of thyroid hormone sensitivity indices with MAFLD and its progression to liver fibrosis in Chinese euthyroid adults.

METHODS

This community-based study included 7906 euthyroid adults. We calculated the thyroid sensitivity indices, including free triiodothyronine to free thyroxine (FT3/FT4) ratio, Thyroid Feedback Quantile-based Index by FT4 (TFQIFT4), and Thyroid Feedback Quantile-based Index by FT3 (TFQIFT3), indicating peripheral and central thyroid hormone sensitivity respectively. Liver steatosis and fibrosis were diagnosed by vibration-controlled transient elastography (VCTE). Multivariable logistic/linear regression and restricted cubic spline (RCS) analysis were conducted.

RESULTS

Compared with participants in the first quartile (Q1), the prevalence of MAFLD was increased by 62% in the fourth quartile (Q4) of FT3/FT4 ratio (OR 1.62; 95% CI [1.38, 1.91]) and by 40% in Q4 of TFQIFT3 (OR 1.40; 95% CI [1.18, 1.65]) (both P < .05). No associations between TFQIFT4 and the prevalence of MAFLD were found. In addition, compared with participants in Q1, the prevalence of liver fibrosis was increased by 45% in Q4 of TFQIFT3 (OR 1.45; 95% CI [1.03, 2.06]) (P < .05) in participants with MAFLD.

CONCLUSION

Impaired central sensitivity to FT3 was associated with MAFLD and its progression to liver fibrosis. More prospective and mechanism studies are warranted to confirm these conclusions.

The Crosstalk between Gut Microbiota and Bile Acids Promotes the Development of Non-Alcoholic Fatty Liver Disease

Recently the roles of gut microbiota are highly regarded in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). The intestinal bacteria regulate the metabolism of bile acids depending on bile salt hydrolase (BSH), 7-dehydroxylation, hydroxysteroid dehydrogenase (HSDH), or amide conjugation reaction, thus exerting effects on NAFLD development through bile acid receptors such as farnesoid X receptor (FXR), Takeda G-protein-coupled bile acid protein 5 (TGR5), and vitamin D receptor (VDR), which modulate nutrient metabolism and insulin sensitivity via interacting with downstream molecules. Reversely, the composition of gut microbiota is also affected by the level of bile acids in turn. We summarize the mutual regulation between the specific bacteria and bile acids in NAFLD and the latest clinical research based on microbiota and bile acids, which facilitate the development of novel treatment modalities in NAFLD.