Gamma-glutamyl carboxylated Gas6 facilitates the prophylactic effect of vitamin K in inhibiting hyperlipidemia-associated inflammatory pathophysiology via arresting MCP-1/ICAM-1 mediated monocyte-hepatocyte adhesion

Role of growth arrest-specific 6 (Gas6), member of vitamin K (VK)-dependent protein family in hyperlipidemia-associated inflammation remains unresolved. To address this, blood samples were collected from hyperlipidemic subjects and age-matched healthy controls and observed that gamma-glutamyl carboxylated Gas6 (Gla-Gas6) but not total Gas6 were significantly lower while pro-inflammatory markers, MCP-1 and ICAM-1 were remarkably higher in hyperlipidemic subjects compared to control. Correlation analyses demonstrated that Gla-Gas6 levels were inversely correlated with MCP-1 and ICAM-1 but positively with plasma VK in hyperlipidemic subjects but not in control. This suggests that boosting VK level might ameliorate the hyperlipidemia-associated inflammatory pathophysiology via augmenting Gla-Gas6. Further studies with high fat diet (HFD)-fed mice demonstrated that VK supplementation (1, 3, and 5 µg/kg BW, 8 weeks) dose-dependently reduced both hepatic and plasma levels of MCP-1 and ICAM-1 while elevating that of Gla-Gas6 but not total Gas6 in HFD-fed mice. Cell culture studies with gamma-glutamyl carboxylase (enzyme causes VK-dependent carboxylation of Gas6) knockdown hepatocytes and monocytes dissected the direct role of Gla-Gas6 in inhibiting high palmitic acid (0.75 mM)-induced inflammation via arresting MCP-1/ICAM-1 mediated hepatocyte-monocyte adhesion. The present study demonstrated an important role of Gla-Gas6 in facilitating the prophylactic effect of VK against hyperlipidemia associated inflammation.

Vitamin K Stimulates Gas6 Carboxylation and Inhibits Hyperlipidemia Associated Hepatic Inflammation via Arresting Monocyte-Hepatocyte Adhesion

Objectives

Vitamin K (VK), an important antihemorrhagic vitamin has attracted scientific attention recently due to its diverse physiological activities beyond hemostasis. Present study for the first time systematically examined the hypothesis that circulating VK deficiency might be linked with hyperlipidemia-associated inflammatory pathophysiology and VK supplementation may ameliorate the hepatic inflammation via activating growth arrest specific 6 (Gas6) protein, an important member of the coagulation-unrelated vitamin K-dependent proteins.

Methods

Subjects with hyperlipidemia (n = 22) and age-matched healthy controls (n = 19) attending the institute clinical center were included in this study. High fat diet (HFD)-fed male albino mice model was used for in vivo studies. High palmitic acid (PA, 0.75 mM)-treated and GGCX knockdown monocytes and hepatocytes were employed for in vitro studies. All data were analyzed using Sigma Stat statistical software.

Results

Plasma levels of VK and Gla-Gas6 were significantly lower and intercellular adhesion molecule-1 (ICAM-1) was remarkably higher in hyperlipidemic subjects compared to control. Correlation studies showed that both circulatory Gla-Gas6 and VK levels were significantly and inversely correlated with ICAM-1. Interestingly, Gla-Gas6 was positively correlated with plasma VK, which suggests that VK supplementation may ameliorate the hyperlipidemia-induced inflammation via activating Gas6. Further studies with HFD-fed hyperlipidemic animals demonstrated that VK supplementation dose-dependently reduced the hepatic expression of pro-inflammatory cytokines while elevating the plasma level of Gla-Gas6 in HFD-fed mice. In vitro studies showed that VK supplementation prevented the high PA-induced hepatic inflammation in a dose-dependent manner. Furthermore, the knockdown study established the direct role of Gla-Gas6 in mediating the positive effect of VK on the management of PA-induced hepatic inflammation.

Conclusions

Combining all, the present study demonstrated the beneficial effect of VK supplementation on the management of hyperlipidemia-associated inflammatory events via activating VK-dependent Gas6 protein.

Funding Sources

Junior research fellowship to JB & Ramalingaswami fellowship to PM by DBT, Govt. of India.

Daidzein, its effects on impaired glucose and lipid metabolism and vascular inflammation associated with type 2 diabetes

Over the last decades, the incidence of type 2 diabetes (T2D) is increasing substantially. Emerging evidences from epidemiological studies have shown the association between higher intake of soy isoflavones and reduced risk of T2D and its associated health risks. Daidzein, a soy isoflavone, has been found to have a promising therapeutic potential in managing T2D pathophysiology. Fermented soybean is the major source of daidzein; however, it can also be formed via the consumption of its glycosylated moiety, daidzin with subsequent hydrolysis by intestinal bacterial enzyme. Many studies reported the prophylactic effect of daidzein on the improvement of hyperglycemia, insulin resistance, dislipidemia, obesity, inflammation, and other complications associated with T2D. The molecular mechanisms underlying the action of daidzein include diverged pathways where daidzein has been shown to interact with several signaling molecules and receptors to achieve desirable effect. Although the specific molecular mechanism is still elusive, further studies are thus needed to understand it in detail. In this review, we discuss the antidiabetic potential of daidzein with respect to the evidences from various clinical, preclinical, and cell culture studies and the underlying molecular mechanism in a precise way to have a comprehensive account on this isoflavone with promising therapeutic potential. © 2018 BioFactors, 44(5):407-417, 2018.

Hexane-Isopropanolic Extract of Tungrymbai, a North-East Indian fermented soybean food prevents hepatic steatosis via regulating AMPK-mediated SREBP/FAS/ACC/HMGCR and PPARα/CPT1A/UCP2 pathways

This study for the first time examined the prophylactic role of Tungrymbai, a well-known fermented soybean food of North-East India, against hepatic steatosis. Treatment with hexane-isopropanolic (2:1, HIET) but not hydro-alcoholic (70% ethanol, HAET) extract dose-dependently (0.1, 0.2, or 0.3 µg/mL) reduced the intracellular lipid accumulation as shown by lower triglyceride levels and both Oil Red O and Nile Red staining in palmitate (PA, 0.75 mM)-treated hepatocytes. Immunobloting, mRNA expression, and knock-down studies demonstrated the role of AMPK-mediated SREBP/FAS/ACC/HMGCR and PPARα/CPT1A/UCP2 signaling pathways in facilitating the beneficial role of HIET against lipid accumulation in PA-treated hepatocytes. Animal studies further showed a positive effect of HIET (20 µg/kg BW, 8 weeks, daily) in regulating AMPK/SREBP/PPARα signaling pathways and reducing body weight gain, plasma lipid levels, and hepatic steatosis in high fat diet (HFD)-fed mice. Histological analyses also revealed the beneficial effect of HIET in reducing hepatic fat accumulation in HFD mice. Chemical profiling (HRMS, IR, and HPLC) demonstrated the presence of menaquinone-7 (vitamin K2) as one of the bio-active principle(s) in HIET. Combining all, this study demonstrates the positive effect of HIET on reducing hepatic steatosis via regulating AMPK/SREBP/PPARα signaling pathway.

Analysis of Recent Patenting Activities in the Field of Bioremediation of Petroleum Hydrocarbon Pollutants Present in the Environment

BACKGROUND

In today's world one of the major environmental problems is the contamination of aquatic or terrestrial ecosystem due to spillage of hydrocarbon compounds produced due to various activities related to the petrochemical industry. In recent years, bioremediation has emerged as a promising technology for the restoration of these contaminated sites in an ecofriendly way.

OBJECTIVE

The aim of present review literature is the compilation of patent documents on bioremediation of petroleum hydrocarbon pollutants to know technological advancements in this field.

METHODS

This analysis was based on various criteria i.e. patenting trend over time, country-wise and assignee-wise comparisons and types of technology used in various patents. Some publicly available patent databases were used to retrieve the patent information from the year 2000 to 2016.

RESULTS

Patent applications were retrieved and it was observed that different types of technological approaches were used in developing the patents. United States accounted for maximum patent publications, followed by China, Korea, Japan, Russia, Great Britain, Mexico, India and Canada in developing bioremediation technologies. US based organization DU PONT is the leading group as patent assignee followed by Biosaint Co. Ltd in Korea.

CONCLUSION

Patenting activity in the field of bioremediation of petroleum hydrocarbon was not much commendable in the early 20th century. However, an increased trend was observed in the past few years. Further contribution in this aspect would help in stabilizing various global environmental as well as economic issues.