Effect of combined farnesoid X receptor agonist and angiotensin II type 1 receptor blocker on ongoing hepatic fibrosis

Chenodeoxycholic acid alleviated the cyclosporine-induced nephrotoxicity by decreasing oxidative stress and suppressing renin-angiotensin system through AT2R and ACE2 mRNA upregulation in rats

Oxidative stress, inflammation and renin-angiotensin system (RAS) activation play an important role in the nephrotoxicity which is caused by the long-term use of the immunosuppressive drug cyclosporine (CsA). This study investigates whether chenodeoxycholic acid (CDCA), an endogenous farnesoid X receptor (FXR) agonist with antioxidant and anti-inflammatory effects, modulates CsA nephrotoxicity. CsA (25 mg/kg/day; s.c.) was administered to rats for 12 days. CDCA (20 mg/kg/day; i.p.) injection was started 3 days before CsA and continued for 15 days. CDCA improved renal damage and function in CsA-administered rats. Renal function markers in serum, renal histology, oxidative stress, inflammation and RAS components were determined in kidney. CDCA reduced CsA-induced renal increases in NADPH oxidase 4 and NADPH oxidase 2 mRNA expressions, oxidative stress and inflammation. CDCA elevated renal FXR, small heterodimer partner-1, hypoxia-inducible factor and vascular endothelial growth factor and nuclear factor erythroid 2-related factor mRNA expressions in CsA rats. It prevents renin angiotensin system activation by reducing angiotensin II (Ang-II) levels in serum and upregulating renal mRNA expressions of Ang II type-II receptor (AT2R) and angiotensin converting enzyme 2 (ACE2), but not AT1R and ACE in CsA rats. Our results indicate that CDCA may be a protective agent against CsA-nephrotoxicity by decreasing inflammation, oxidative stress and RAS activation via AT2R and ACE2 upregulations.

Pathophysiology, molecular mechanisms, and genetics of atrial fibrillation

The development of atrial fibrillation (AF) is a highly complex, multifactorial process involving pathophysiologic mechanisms, molecular pathway mechanisms and numerous genetic abnormalities. The pathophysiologic mechanisms including altered ion channels, abnormalities of the autonomic nervous system, inflammation, and abnormalities in Ca2 + handling. Molecular pathway mechanisms including, but not limited to, renin-angiotensin-aldosterone (RAAS), transforming growth factor-β (TGF-β), oxidative stress (OS). Although in clinical practice, the distinction between types of AF such as paroxysmal and persistent determines the choice of treatment options. However, it is the pathophysiologic alterations present in AF that truly determine the success of AF treatment and prognosis, but even more so the molecular mechanisms and genetic alterations that lie behind them. One tiny clue reveals the general trend, and small beginnings show how things will develop. This article will organize the development of these mechanisms and their interactions in recent years.

Angelica dahurica extract and its effective component bergapten alleviated hepatic fibrosis by activating FXR signaling pathway

Angelica dahurica (A. dahurica) has a wide range of pharmacological effects, including analgesic, anti-inflammatory and hepatoprotective effects. In this study, we investigated the effect of A. dahurica extract (AD) and its effective component bergapten (BG) on hepatic fibrosis and potential mechanisms. Hepatic fibrosis was induced by intraperitoneal injection with carbon tetrachloride (CCl4) for 1 week, and mice were administrated with AD or BG by gavage for 1 week before CCl4 injection. Hepatic stellate cells (HSCs) were stimulated by transforming growth factor-β (TGF-β) and cultured with AD, BG, GW4064 (FXR agonist) or Guggulsterone (FXR inhibitor). In CCl4-induced mice, AD significantly decreased serum aminotransferase, reduced excess accumulation of extracellular matrix (ECM), inhibited caspase-1 and IL-1β, and increased FXR expressions. In activated HSCs, AD suppressed the expressions of α-SMA, collagen I, and TIMP-1/MMP-13 ratio and inflammatory factors, functioning as FXR agonist. In CCl4-induced mice, BG significantly improved serum transaminase and histopathological changes, reduced ECM excessive deposition, inflammatory response, and activated FXR expression. BG increased FXR expression and inhibited α-SMA and IL-1β expressions in activated HSCs, functioning as GW4064. FXR deficiency significantly attenuated the decreasing effect of BG on α-SMA and IL-1β expressions in LX-2 cells. In conclusion, AD could regulate hepatic fibrosis by regulating ECM excessive deposition and inflammation. Activating FXR signaling by BG might be the potential mechanism of AD against hepatic fibrosis.

Spontaneous Epiretinal Membrane Resolution and Angiotensin Receptor Blockers: Case Observation, Literature Review and Perspectives

INTRODUCTION

Epiretinal membrane (ERM) is a relatively common condition affecting the macula. When symptoms become apparent and compromise a patient's quality of vision, the only therapeutic approach available today is surgery with a vitrectomy and peeling of the ERM. Angiotensin receptor blockers (ARBs) and angiotensin-converting enzyme inhibitors (ACE-Is) reduce the effect of angiotensin II, limit the amount of fibrosis, and demonstrate consequences on fibrinogenesis in the human body. Case Description and Materials and Methods: A rare case of spontaneous ERM resolution with concomitant administration of ARB is reported. The patient was set on ARB treatment for migraines and arterial hypertension, and a posterior vitreous detachment was already present at the first diagnosis of ERM. The scientific literature addressing the systemic relationship between ARB, ACE-Is, and fibrosis in the past 25 years was searched in the PubMed, Medline, and EMBASE databases.

RESULTS

In total, 38 and 16 original articles have been selected for ARBs and ACE-Is, respectively, in regard to fibrosis modulation.

CONCLUSION

ARBs and ACE-Is might have antifibrotic activity on ERM formation and resolution. Further clinical studies are necessary to explore this phenomenon.