Mitochondrial division/mitophagy inhibitor (Mdivi) Ameliorates Pressure Overload Induced Heart Failure

Background: We have previously reported the role of anti-angiogenic factors in inducing the transition from compensatory cardiac hypertrophy to heart failure and the significance of MMP-9 and TIMP-3 in promoting this process during pressure overload hemodynamic stress. Several studies reported the evidence of cardiac autophagy, involving removal of cellular organelles like mitochondria (mitophagy), peroxisomes etc., in the pathogenesis of heart failure. However, little is known regarding the therapeutic role of mitochondrial division inhibitor (Mdivi) in the pressure overload induced heart failure. We hypothesize that treatment with mitochondrial division inhibitor (Mdivi) inhibits abnormal mitophagy in a pressure overload heart and thus ameliorates heart failure condition. Materials and Methods: To verify this, ascending aortic banding was done in wild type mice to create pressure overload induced heart failure and then treated with Mdivi and compared with vehicle treated controls. Results: Expression of MMP-2, vascular endothelial growth factor, CD31, was increased, while expression of anti angiogenic factors like endostatin and angiostatin along with MMP-9, TIMP-3 was reduced in Mdivi treated AB 8 weeks mice compared to vehicle treated controls. Expression of mitophagy markers like LC3 and p62 was decreased in Mdivi treated mice compared to controls. Cardiac functional status assessed by echocardiography showed improvement and there is also a decrease in the deposition of fibrosis in Mdivi treated mice compared to controls

SUPPLEMENTATION OF SPIRULINA AND VITAMIN C ATTENUATED THE NEPHROTOXICITY INDUCED BY CISPLATIN ADMINISTRATION

Overexposure of the kidneys to cisplatin [Cisplatin (cis- diaminedichloroplatinum II) (CDDP)] and cisplatin complexes cause degradation of the renal cells, and eventually lead to renal failure. Agents like antioxidants, modulators of nitric oxide (NO) and anti-apoptotic molecules are reported to reduce nephrotoxicity. In the present study we tested the hypothesis that supplementation of antioxidant spirulina and vitamin c reduces cisplatin induced nephrotoxicity. The study was carried out on female Balb /C mice of the following five groups: control (i); cisplatin (ii); vitamin c (iii); spirulina (iv); and vitamin c + spirulina + cisplatin (v). Plasma urea and creatinine levels were estimated 3 and 6 days after the injection of cisplatin and uptake studies with 99m Technician-ethylene dicysteine was performed to assess the renal clearance rate. Kidneys were isolated and processed for electron microscopy and light microscopy. The activity and concentration of antioxidant enzymes such as glutathione, catalase, superoxide dismutase and GST was also determined. Dual supplementation of spirulina and vitamin c significantly protected cisplatin-induced increased levels of serum urea, creatinine, improved renal clearance rate, the declined renal antioxidant enzymes and increased LPO levels. Hence, we conclude that supplementation of spirulina and vitamin c had a beneficial effect on cisplatin induced nephrotoxicity in mice

Intensity modulated radiotherapy in abdominal malignancies: Our experience in reducing the dose to normal structures as compared to the gross tumor

Background and Purpose: A better understanding of appropriate sequencing and use of multimodality approach in the management and subsequent improvement in overall survival mandates a vigil on quality of life issues. Intensity modulated radiotherapy (IMRT) is a powerful tool, which might go a long way in reducing radiation doses to critical structures and thereby reduce long term morbidities. The purpose of this paper is to evaluate the impact of IMRT in reducing the dose to the critical normal tissues while maintaining the desired dose to the volume of interest for abdominal malignancies. Materials and Methods: During the period January 2002 to March 2004, 11 patients of various sites of malignancies in the abdominal region were treated using physical intensity modulator based IMRT. Plans of these patients treated with IMRT were analyzed using dose volume histograms. Results: An average dose reduction of the mean values by 50% to the liver, 57% to the right kidney, 56% to the left kidney, 66% to the cord and 27% to the bowel, with respect to the GTV could be achieved with IMRT. The two-year disease free survival was 79% and two-year overall survival was 88%. The average number of IMRT fields used was six. Conclusion: IMRT with inverse planning enabled us to achieve desired dose distribution, due to its ability to provide sharp dose gradients at the junction of tumor and the adjacent critical organs

TGF-β mediates early angiogenesis and latent fibrosis in an Emilin1-deficient mouse model of aortic valve disease

Aortic valve disease (AVD) is characterized by elastic fiber fragmentation (EFF), fibrosis and aberrant angiogenesis. Emilin1 is an elastin-binding glycoprotein that regulates elastogenesis and inhibits TGF-β signaling, but the role of Emilin1 in valve tissue is unknown. We tested the hypothesis that Emilin1 deficiency results in AVD, mediated by non-canonical (MAPK/phosphorylated Erk1 and Erk2) TGF-β dysregulation. Using histology, immunohistochemistry, electron microscopy, quantitative gene expression analysis, immunoblotting and echocardiography, we examined the effects of Emilin1 deficiency (Emilin1−/−) in mouse aortic valve tissue. Emilin1 deficiency results in early postnatal cell-matrix defects in aortic valve tissue, including EFF, that progress to latent AVD and premature death. The Emilin1−/− aortic valve displays early aberrant provisional angiogenesis and late neovascularization. In addition, Emilin1−/− aortic valves are characterized by early valve interstitial cell activation and proliferation and late myofibroblast-like cell activation and fibrosis. Interestingly, canonical TGF-β signaling (phosphorylated Smad2 and Smad3) is upregulated constitutively from birth to senescence, whereas non-canonical TGF-β signaling (phosphorylated Erk1 and Erk2) progressively increases over time. Emilin1 deficiency recapitulates human fibrotic AVD, and advanced disease is mediated by non-canonical (MAPK/phosphorylated Erk1 and Erk2) TGF-β activation. The early manifestation of EFF and aberrant angiogenesis suggests that these processes are crucial intermediate factors involved in disease progression and therefore might provide new therapeutic targets for human AVD

Cross Talk between NOTCH Signaling and Biomechanics in Human Aortic Valve Disease Pathogenesis

Aortic valve disease is a burgeoning public health problem associated with significant mortality. Loss of function mutations in NOTCH1 cause bicuspid aortic valve (BAV) and calcific aortic valve disease. Because calcific nodules manifest on the fibrosa side of the cusp in low fluidic oscillatory shear stress (OSS), elucidating pathogenesis requires approaches that consider both molecular and mechanical factors. Therefore, we examined the relationship between NOTCH loss of function (LOF) and biomechanical indices in healthy and diseased human aortic valve interstitial cells (AVICs). An orbital shaker system was used to apply cyclic OSS, which mimics the cardiac cycle and hemodynamics experienced by AVICs in vivo. NOTCH LOF blocked OSS-induced cell alignment in human umbilical vein endothelial cells (HUVECs), whereas AVICs did not align when subjected to OSS under any conditions. In healthy AVICs, OSS resulted in decreased elastin (ELN) and α-SMA (ACTA2). NOTCH LOF was associated with similar changes, but in diseased AVICs, NOTCH LOF combined with OSS was associated with increased α-SMA expression. Interestingly, AVICs showed relatively higher expression of NOTCH2 compared to NOTCH1. Biomechanical interactions between endothelial and interstitial cells involve complex NOTCH signaling that contributes to matrix homeostasis in health and disorganization in disease

mRNA primers.

<p>mRNA primers.</p

mRNA expression of MMP-9 and TIMP-3.

<p>A) mRNAs are amplified using respective primers and the bands were quantified using densitometry. <b>B, C</b>) Bar graphs represent respective mRNA expression over GAPDH expression by RT-PCR and real time PCR assay. Data represents mean ±SE from n = 6 per group; *p<0.05 was considered significant compared to sham and ^#p<0.05 compared to vehicle treated group.</p

Activated caspace-3 staining of mouse cardiac sections showing apoptosis in sham, 8 weeks post-AB (AB 8 wks) treated with vehicle control and Mdivi.

<p><b>A</b>) Apoptotic cells are seen as red fluorescent dots (scale bar- 20 µm). <b>C</b>) Activated caspace-3 +ve cells represented in an enlarged area. <b>B</b>) Data represents mean ±SE from n = 6 per group; *p<0.05 was considered significant compared to sham and ^#p<0.05 compared to vehicle treated group.</p