Bone morphogenetic protein 2 is a new molecular target linked to non-alcoholic fatty liver disease with potential value as non-invasive screening tool

Tilorone attenuates high-fat diet-induced hepatic steatosis by enhancing BMP9-Smad1/5/8 signaling

The prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) is rapidly increasing and is caused by excessive fat deposition in the liver due to non-alcoholic factors. Aging is a major risk factor for the development and progression of MASLD. In this study, we investigated the metabolic effects of tilorone, a synthetic small molecule, in a high-fat diet (HFD) mouse model, with a focus on the liver function and signaling. We demonstrate that tilorone attenuated HFD-induced steatosis by restoring bone morphogenetic protein 9 (BMP9)-Smad1/5/8 signaling and upregulating peroxisome proliferator-activated receptor gamma (PPARγ) expression. Tilorone reduced HFD-induced increases in body weight, adipose tissue and liver weight, and blood glucose levels, and improved glucose tolerance in HFD mice. PET/MRI imaging demonstrated enhanced 18FDG (18F-fluoro-2-deoxyglucose) uptake in liver, skeletal muscle, adipose tissue, and myocardium of tilorone-treated HFD animals. Histological analysis showed that tilorone reduced the HFD-induced diffuse, macrovesicular steatosis (S3/3), and machine learning-based image analysis revealed a decrease in lipid droplet size and lipid content. HFD caused the disappearance of liver glycogen, but tilorone increased glycogen levels. High-resolution respirometry indicated that tilorone reduced HFD-induced increases in mitochondrial complex II-linked oxidative phosphorylation and complex IV activity. These findings revealed the beneficial effects of tilorone on HFD and highlight its therapeutic potential in MASLD, particularly given that tilorone is a synthetic small molecule and can be administered orally. Further studies are required to explore its clinical application.

Effects of aflatoxin and fumonisin on gene expression of growth factors and inflammation-related genes in a human hepatocyte cell line

Aflatoxin B1 (AFB1) and fumonisin B1 (FB1) are mycotoxins widely distributed in maize and maized-based products, often occurring together. The implications of co-exposure to aflatoxin and fumonsin for human health are numerous, but a particular concern is the potential of FB1 to modulate AFB1 hepatotoxicity. This study evaluated the toxicity of these mycotoxins, alone or combined, in a human non-tumorigenic liver cell line, HHL-16 cells, and assessed the effects of AFB1 and FB1 on expression of genes involved in immune and growth factor pathways. The results demonstrated that in HHL-16 cells, both AFB1 and FB1 had dose-dependent and time-dependent toxicity, and the combination of them showed a synergistic toxicity in the cells. Moreover, AFB1 caused upregulation of IL6, CCL20, and BMP2, and downregulation of NDP. In combination of AFB1 with FB1, gene expression levels of IL6 and BMP2 were significantly higher compared to individual FB1 treatment, and had a tendency to be higher than individual AFB1 treatment. This study shows that FB1 may increase the hepatoxicity of AFB1 through increasing the inflammatory response and disrupting cell growth pathways.

Circulatory bone morphogenetic protein (BMP) 8B is a non-invasive predictive biomarker for the diagnosis of non-alcoholic steatohepatitis (NASH)

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a complex disease which is characterized by the deposition of fats in the hepatocytes. Further, it progresses to nonalcoholic steatohepatitis (NASH), fibrosis, and hepatocellular carcinoma. The increasing prevalence of NAFLD urges to find the non-invasive predictive biomarkers. In this study, we sought to determine increased BMP8B levels as predictors for the progression of NAFLD.

METHODS

In the present cross-sectional study, circulatory BMP8B levels were measured in healthy controls (n = 56), NAFL patients (n = 72) and NASH patients (n = 77) by using an ELISA kit. Human hepatic BMP8B mRNA expression was measured in the liver tissue of control and NASH patients. In addition, BMP8B expression was confirmed by immunohistochemistry analysis. Furthermore, hepatic BMP8B mRNA expression was measured in wild type (WT) mice, WT mice fed with choline deficient high fat diet (WT+CDHF), iNOS (inducible nitric oxide synthase) knockout (iNOS-/-) mice, iNOS-/- fed with CDHF diet (iNOS-/-+CDHF).

RESULTS

Increased circulatory BMP8B levels and BMP8B mRNA expression in hepatic tissue were significantly higher in NASH patients as compared with the control subjects. BMP8B expression was increased parallel to the fibrosis score in the hepatic tissues of NASH patients. It was observed that increased BMP8B levels have shown a significant positive correlation between aspartate aminotransferase (r = 0.31, p = 0.005), alanine aminotransferase (r = 0.23, p = 0.045), APRI (r = 0.30, p = 0.009), and Fib-4 score (r = 0.25, p = 0.036) in NASH patients. BMP8B has maintained a significant association with NASH and shown high sensitivity (92.91%) and specificity (92.73%) in NASH patients. Furthermore, increased BMP8B mRNA expression levels were observed in iNOS-/-+CDHF mice.

CONCLUSION

Our study findings confirmed that BMP8B increases with the severity of the disease and BMP8B shows potential as a non-invasive predictive biomarker to identify NAFLD progression. However, future studies should investigate circulatory BMP8B levels in a large number of patients and also its impact on liver during NAFLD progression.

Metabolic Health and Disease: A Role of Osteokines?

Maintenance of skeletal health is tightly regulated by osteocytes, osteoblasts, and osteoclasts via coordinated secretion of bone-derived factors, termed osteokines. Disruption of this coordinated process due to aging and metabolic disease promotes loss of bone mass and increased risk of fracture. Indeed, growing evidence demonstrates that metabolic diseases, including type 2 diabetes, liver disease and cancer are accompanied by bone loss and altered osteokine levels. With the persistent prevalence of cancer and the growing epidemic of metabolic disorders, investigations into the role of inter-tissue communication during disease progression are on the rise. While osteokines are imperative for bone homeostasis, work from us and others have identified that osteokines possess endocrine functions, exerting effects on distant tissues including skeletal muscle and liver. In this review we first discuss the prevalence of bone loss and osteokine alterations in patients with type 2 diabetes, non-alcoholic fatty liver disease, non-alcoholic steatohepatitis, cirrhosis, and cancer. We then discuss the effects of osteokines in mediating skeletal muscle and liver homeostasis, including RANKL, sclerostin, osteocalcin, FGF23, PGE2, TGF-β, BMPs, IGF-1 and PTHrP. To better understand how inter-tissue communication contributes to disease progression, it is essential that we include the bone secretome and the systemic roles of osteokines.