1.25 Dihydroxyvitamin D3 Attenuates Hypertrophy Markers in Cardiomyoblast H9c2 Cells: Evaluation of Sirtuin3 mRNA and Protein Level

Abstract

Abstract. Background: The cellular and molecular mechanisms of cardioprotective effects of Vitamin D are poorly understood. Given the essential role of sirtuin-3 (SIRT3) as an endogenous negative regulator of cardiac hypertrophy, this study was designed to investigate the effect of 1, 25-dihydroxyvitamin D3 (calcitriol) on hypertrophy markers and SIRT3 mRNA and protein levels following angiotensin II induced - hypertrophy in cardiomyoblast H9c2 cells. Methods: Rat cardiomyoblast H9c2 cells were treated for 48 hr with angiotensin II alone (Ang group) or in combination with 1, 10 and 100 nM of calcitriol (C + Ang groups). Intact cells served as control (Ctl). The cell area was measured using methylene blue staining. Atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and SIRT3 transcription levels were measured by real time RT-PCR. SIRT3 protein expression was evaluated using western blot technique. Results: The results showed that in Ang group cell size was increase by 128.4 ± 15% (P < 0.001 vs. Ctl) whereas in C100 + Ang group it was increased by 21.3 ± 6% (P < 0.001 vs. Ang group). Calcitriol pretreatment decreased ANP mRNA level significantly (P < 0.05) in comparison with Ang group (Ang: 75.5 ± 15%, C100 + Ang: 19.2 ± 9%). There were no significant differences between Ang group and cells pretreated with 1 and 10 nM of calcitriol. SIRT3 at mRNA and protein levels did not change significantly among the experimental groups. Conclusions: In conclusion, pretreatment with calcitriol (100 nM) prevents Ang II-induced hypertrophy in cardiomyoblast H9c2 cells. This probably occurs through other pathways except SIRT3 upregulation.

Vitamin D3 ameliorates nitrogen mustard‐induced cutaneous inflammation by inactivating the NLRP3 inflammasome through the SIRT3–SOD2–mtROS signaling pathway

“…VD3's effects on NM‐induced SOD2 inhibition, mtROS generation, and NLRP3 inflammasome activation were blocked in keratinocytes treated with 3‐TYP or SIRT3 siRNA and in skins from SIRT3 −/− mice. Previously, no effect of VD3 on SIRT3 expression in cardiomyoblast H9c2 cells was reported 52 . Herein, we found that VD3 attenuated NM‐induced cutaneous inflammation by activating SIRT3 in vitro and in vivo.…”

“…Previously, no effect of VD3 on SIRT3 expression in cardiomyoblast H9c2 cells was reported. 52 Herein, we found that VD3 attenuated NM-induced cutaneous inflammation by activating SIRT3 in vitro and in vivo. Although the precise mecha-F I G U R E 8 VD3 ameliorated NM-induced cutaneous inflammation by inactivating the NLRP3 inflammasome through the SIRT3-SOD2-mtROS signaling pathway nisms by which VD3 induces SIRT3 expression and activity remain to be established, our present data indicated that VD3 is a feasible treatment option for NM-induced cutaneous inflammation by inactivating NLRP3 inflammasome, which was partially mediated through the SIRT3-SOD2-mtROS signaling pathway.…”

Inhibition of GTPase Rac1 expression by vitamin D mitigates pressure overload-induced cardiac hypertrophy

“…For example, VitD may attenuate LVH via counteracting hypertension, thereby suppressing the upregulation of Rac1 GTPase that occurs secondary to the hypertrophy. Moreover, the ability of VitD to directly target the cardiac myocytes [25] , [26] , [19] allows us to speculate that VitD alters the protein level of Rac1 GTPase independent of influence upon hemodynamic parameters, in fact, by a direct effect on cardiomyocytes and suppression of LVH-associated (pro-hypertrophic) factors. Some likelihood also is that VitD reduces the protein level of Rac1 GTPase in hypertrophied cardiomyocytes exclusively via impact on signaling pathways involved in the antioxidant system or those related to the control of survival, i.e., independent of anti- hypertrophy or hypertensive effects.…”

“…AAB was performed in conformity with earlier protocols [19] , [37] . In short, after anesthetizing animals with IP injection of a mixture of ketamine (70 mg/g) and Xylazine (10 mg/g), an incision was made in the left flank to rapidly obtain access to the suprarenal abdominal aorta.…”

“…Indeed, research conducted on animals suggests that VitD-deficient or its receptor knockout is intimately associated with the high blood pressure and the manifestation of LVH, including increased cardiomyocyte size and proliferation [16] , [17] . In contrast, the administration of VitD has been demonstrated to limit unfavorable cardiac remodeling across a wide range of LVH models [18] , [19] , [20] , [21] . Likewise, clinical trials have also validated the ability of VitD to ameliorate LVH in HF patients [22] .…”