Ghrelin-induced multi-organ damage in mice fed obesogenic diet

Lebanese cannabis oil extract protected against folic acid-induced kidney fibrosis in rats

BACKGROUND

Renal fibrosis is a major manifestation of chronic kidney disease. To date, there are no treatments to reverse kidney fibrosis. Cannabis is an aromatic herb that is widely known for its anti-diabetic and anti-inflammatory properties. The aim of this study is to evaluate the protective effect of Lebanese cannabis oil extract (COE) against folic acid (FA) induced renal injury both in vitro and in vivo.

MATERIALS AND METHODS

A single dose of 250 mg/kg of Folic acid was administered to induce renal fibrosis in rats. COE was injected at varying doses of 5, 10, and 20 mg/kg. Body weight of rats were monitored and clinical parameters including serum creatinine, urea, and electrolytes were measured. Moreover, pathological examination of the kidney and heart was performed. Conditionally immortalized cultured rat podocytes were exposed to high concentrations of folic acid in the presence or absence of COE. MTS and in vitro scratch assay were used to assess podocyte cells viability and migration respectively. Western blot analysis was used to evaluate the phosphorylation levels of AKT and p38 MAPK.

RESULTS

Rats that received FA showed a marked increase in serum creatinine when compared to the non-treated control group. COE at doses of 5 and 10 mg/kg significantly decreased serum creatinine induced by FA. Serum sodium was significantly reduced in all the groups receiving COE. Furthermore, COE ameliorated renal and cardiac pathology abnormalities caused by FA in a dose-dependent manner. Cell viability assay revealed that COE reversed cytotoxicity induced by FA in rat podocytes. In vitro scratch assay showed that COE partially restored the migratory capacity of podocytes incubated with FA. Dose-dependent experiments showed that COE (1 and 2μg/ml) induced a significant increase of phospho-(S473)-AKT along with a decrease in phospho (T180 + Y182) P38 levels.

CONCLUSION

The current results revealed important protective effect of Lebanese cannabis oil extract against folic acid-induced renal fibrosis in rats.

Emerging Relevance of Ghrelin in Programmed Cell Death and Its Application in Diseases

Ghrelin, comprising 28 amino acids, was initially discovered as a hormone that promotes growth hormones. The original focus was on the effects of ghrelin on controlling hunger and satiation. As the research further develops, the research scope of ghrelin has expanded to a wide range of systems and diseases. Nevertheless, the specific mechanisms remain incompletely understood. In recent years, substantial studies have demonstrated that ghrelin has anti-inflammatory, antioxidant, antiapoptotic, and other effects, which could affect the signaling pathways of various kinds of programmed cell death (PCD) in treating diseases. However, the regulatory mechanisms underlying the function of ghrelin in different kinds of PCD have not been thoroughly illuminated. This review describes the relationship between ghrelin and four kinds of PCD (apoptosis, necroptosis, autophagy, and pyroptosis) and then introduces the clinical applications based on the different features of ghrelin.

Ghrelin hormone a new molecular modulator between obesity and glomerular damage

The incidence of glomerular diseases is increasing worldwide due to increased prevalence of obesity which is a major risk factor for type-2 diabetes mellitus and cardiovascular disorders.Ghrelin, an orexigenic peptide hormone, has been implicated in obesity, and its impact on the pathology and function of the kidneys was found to be significant. Ghrelin known to regulate energy homeostasis and growth hormone release, has been shown to modulate critical signaling pathways involved in the health and survival of podocytes. These derangements directly affect glomerular function and manifest as impaired glomerular filtration barrier and leakage of albumin into urine. Although the pathological features of the above-mentioned disorders are different, they interestingly lead to similar clinical features of glomerular damage. The pathological events are majorly initiated by endocrine imbalance leading to abnormal activation of downstream signaling pathways involved in the development of glomerulosclerosis. In fact, obesity increases the risk of developing chronic kidney disease by altering the secretion of pro-inflammatory cytokines and adipokines, activating the renin-angiotensin-aldosterone system (RAAS), promoting lipotoxicity, oxidative stress and fibrosis within the kidneys. Whilst these bioregulators are well described, their direct involvement in renal homeostasis is still mostly elusive. This review summarized previous and recent evidence on the endocrine properties of ghrelin and perivascular adipose tissue involved in modulating kidney physiology.

VIP modulates human macrophages phenotype via FPRL1 via activation of RhoA-GTPase and PLC pathways

OBJECTIVE AND DESIGN

This study is aimed at uncovering the signaling pathways activated by vasoactive intestinal peptide in human macrophages MATERIALS: Human peripheral blood mononuclear cell-derived macrophages were used for the in vitro investigation of the VIP-activated signaling pathways.

METHODS AND TREATMENT

Time-course and dose-response experiments and siRNA were used in human macrophages co-challenged with various concentrations of VIP and different MAPK pharmacologic inhibitors to investigate signaling pathways activated by VIP. Flow analysis was performed to assess the levels of CD11b, CD35 and CD66. Luminescence spectrometry was used to measure the levels of the released hydrogen peroxide and the intracellular calcium levels in the media.

RESULTS

Macrophages incubated with VIP showed increased phospho-AKT and phospho-ERK1/2 levels in a GTP-RhoA-GTPase-dependent manner. Similarly, VIP increased intracellular release of H₂O₂ and calcium via PLC and GTP-RhoA-GTPase, in addition to inducing the expression of CD11b, CD35, CD66 and MMP9. Furthermore, VIP activated P38 MAPK through the cAMP/PKA pathway but was independent of both PLC and RhoA signaling. The above-mentioned VIP effects were mediated via activation of the FPRL1 receptor.

CONCLUSION

VIP/FPRL1/VPAC/GTP-RhoA-GTPase signaling modulated macrophages phenotype through activation of multiple signaling pathways including ERK1/2, AKT, P38, ROS, cAMP and calcium.