Cardiac hypertrophy limits infarct expansion after myocardial infarction in mice.

We have previously demonstrated that adult transgenic C57BL/6J mice with CM-restricted overexpression of the dominant negative W v mutant protein (dn-c-kit-Tg) respond to pressure overload with robust cardiomyocyte (CM) cell cycle entry. Here, we tested if outcomes after myocardial infarction (MI) due to coronary artery ligation are improved in this transgenic model. Compared to non-transgenic littermates (NTLs), adult male dn-c-kit-Tg mice displayed CM hypertrophy and concentric left ventricular (LV) hypertrophy in the absence of an increase in workload. Stroke volume and cardiac output were preserved and LV wall stress was markedly lower than that in NTLs, leading to a more energy-efficient heart. In response to MI, infarct size in adult (16-week old) dn-c-kit-Tg hearts was similar to that of NTL after 24 h but was half that in NTL hearts 12 weeks post-MI. Cumulative CM cell cycle entry was only modestly increased in dn-c-kit-Tg hearts. However, dn-c-kit-Tg mice were more resistant to infarct expansion, adverse LV remodelling and contractile dysfunction, and suffered no early death from LV rupture, relative to NTL mice. Thus, pre-existing cardiac hypertrophy lowers wall stress in dn-c-kit-Tg hearts, limits infarct expansion and prevents death from myocardial rupture.

Oocyte quality reflected by follicular fluid analysis in poly cystic ovary syndrome (PCOS): a hypothesis based on intermediates of energy metabolism.

There is no clear acceptance of specific follicular fluid biomarker and its correlation with oocyte quality or related embryo variable till now. Most of the studies analyze correlation between certain biomolecules and the oocyte quality using single variable, instead of multivariate analysis algorithms. Our hypothesis is not based on single biomarker discovery, but attempts to explain oocyte quality in terms of energy metabolic pathways by considering its various intermediates. Reduced availability of glucose in the oocytes and follicular cells caused by defective transportation of glucose is expected in polycystic ovary syndrome (PCOS). This initiates alternative pathways to utilize fatty acid, amino acids etc. for energy as a compensatory mechanism to deal with the energy requirement. These compensations can be reflected by altered levels of various biomolecules in follicular fluid (e.g. ketone bodies, lipids, amino acids, lactate, pyruvate etc.). The amount of compensation, in order to meet the energy requirement can be directly correlated to quality of oocytes and better outcome after in vitro fertilization (IVF) in PCOS cases. This can be predicted with fair accuracy by doing a multivariate analysis of altered levels of various biomolecules in follicular fluid. Various supervised and unsupervised classification techniques based on spectroscopic data, obtained from follicular fluid samples may certainly prove to be an important tool to predict oocytes quality and IVF outcome with better accuracy in women with PCOS.