Exploring the Physiological Role of Transthyretin in Glucose Metabolism in the Liver

Association between rat decompression sickness resistance, transthyretin single nucleotide polymorphism, and expression: A pilot study

Decompression sickness (DCS) is a systemic syndrome that can occur after an environmental pressure reduction. Previously, we showed that the plasmatic tetrameric form of transthyretin (TTR) nearly disappeared in rats suffering DCS but not in asymptomatic ones. In this pilot study, we assessed whether the resistance to DCS could be associated with polymorphism of the gene of TTR. For this study, Sanger sequencing was performed on purified PCR products from the liver of 14-week-old male and female standard and DCS-resistant rats (n = 5 per group). Hepatic TTR mRNA expression was assessed by RT-qPCR in 18-19 week-old male and female standard and resistant rats (n = 6 per group). There is a synonymous single nucleotide polymorphism (SNP) on the third base of codon 46 (c.138 C > T). The thymine allele was present in 90% and 100% of males and females standard, respectively. However, this allele is present in only 30% of DCS-resistant males and females (p = 0.0002301). In the liver, there is a significant effect of the resistance to DCS (p = 0.043) and sex (p = 0.047) on TTR expression. Levels of TTR mRNA were lower in DCS-resistant animals. To conclude, DCS resistance might be associated with a SNP and a lower expression of TTR.

Applying Network Pharmacology and Molecular Docking in the Screening for Molecular Mechanisms of Ampalaya (Momordica charantia L.) and Banaba (Lagerstroemia speciosa L.) against Type 2 Diabetes Mellitus

Background and Objectives

Type 2 diabetes mellitus (T2DM) is a global health concern affecting more than 400 million people worldwide. Diabetic neuropathy, nephropathy, retinopathy, and cardiovascular complications lead to debilitating effects to patients. To prevent these, the treatment goal is to lower the blood sugar levels and maintain at a normal range which is achieved through conventional treatments like insulin and oral hypoglycemic agents. However, the high cost of these medications implicates patient treatment outcomes. Hence, alternatives are sought for including the use of herbal medicines. Momordica charantia (MC) and Lagerstroemia speciosa (LS) are common herbal medicines used to manage T2DM. In the Philippines, these herbal preparations are validated for their glucose lowering effects and are commonly found in combination in food supplements. The study aims to screen the possible mechanisms of compounds present in these herbal medicines which can offer possible explanations for their synergistic effects and rationalization of their combination in preparations.

Methods

Network pharmacology was employed to determine pivotal proteins that are targeted by MC and LS compounds. Molecular docking was then done to evaluate the favorability of the binding of these compounds toward their target proteins.

Results

Our results showed that TNF, HSP90AA1, MAPK3, ALDH2, GCK, AKR1B1, TTR and RBP4 are the possible pivotal targets of MC and LS compounds in T2DM.

Conclusion

Terpenoids from MC and decanoic acid from LS are the compounds which showed favorable binding towards pivotal protein targets in T2DM. By binding towards the different key proteins in T2DM, they may exhibit their synergistic effects. However, the results of this study are bound to the limitations of computational methods and experimental validation are needed to verify our findings.

SPP2 plays a role in the tumorigenesis of hepatocellular carcinoma: A bioinformatic based analysis

OBJECTIVES

Hepatocellular carcinoma (HCC) patients at the same stage exhibit different prognosis, and the underlying molecular mechanism remains unclear. This study aims to identify the key genes impacting the prognosis of HCC patients.

METHODS

Differentially expressed gene analyses were performed between HCC samples and normal ones, and between patients with long overall survival (OS) and those with short OS, in TCGA-LIHC and GSE14520 datasets. The Kaplan-Meier method with log-rank test was used to evaluate the role of secreted phosphoprotein 2 (SPP2) in the prognosis of HCC patients. Gene set enrichment analysis (GSEA) was used to understand the difference of enriched signaling pathways between SPP2-stratified HCC subgroups. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to predict the potential functional pathways in which SPP2 might participate.

RESULTS

SPP2 was significantly down-regulated in tumors when compared with normal tissues, or in tumor samples with short OS when compared with those with long OS [fold change (FC)>2 and false discovery rate (FDR)<0.05]. Low expression of SPP2 was associated with worse clinicopathological features like vascular invasion (P=1.6e-05), poor cancer status (with tumor, P=0.021), advanced T stage (T3 or T4, P=4.5e-04), advanced TNM stage (stage III or IV, P=3.1e-04), and with unfavorable prognosis (shorter OS, P=0.002). Gene enrichment analyses revealed that SPP2 might involve in the metabolic homeostasis of HCC and in the development of liver fibrosis and cirrhosis.

CONCLUSIONS

SPP2 might inhibit the development of liver fibrosis and cirrhosis and the tumorigenesis of HCC, and analogs of SPP2 might be potential drugs in the prevention of these diseases.