Since the appearance in the late of December 2019, SARS-CoV-2 is rapidly evolving and mutating continuously, giving rise to various variants with variable degrees of infectivity and lethality. The virus that initially appeared in China later mutated several times, wreaking havoc and claiming many lives worldwide amid the ongoing COVID-19 pandemic. After Alpha, Beta, Gamma, and Delta variants, the most recently emerged variant of concern (VOC) is the Omicron (B.1.1.529) that has evolved due to the accumulation of high numbers of mutations especially in the spike protein, raising concerns for its ability to evade from pre-existing immunity acquired through vaccination or natural infection as well as overpowering antibodies-based therapies. Several theories are on the surface to explain how the Omicron has gathered such a high number of mutations within less time. Few of them are higher mutation rates within a subgroup of population and then its introduction to a larger population, long term persistence and evolution of the virus in immune-compromised patients, and epizootic infection in animals from humans, where under different immune pressures the virus mutated and then got reintroduced to humans. Multifaceted approach including rapid diagnosis, genome analysis of emerging variants, ramping up of vaccination drives and receiving booster doses, efficacy testing of vaccines and immunotherapies against newly emerged variants, updating the available vaccines, designing of multivalent vaccines able to generate hybrid immunity, up-gradation of medical facilities and strict implementation of adequate prevention and control measures need to be given high priority to handle the on-going SARS-CoV-2 pandemic successfully.

In November 2021, Omicron, discovered in Botswana 1 and classified as the fifth variant of concern 2,3 by the World Health Organization on November 26, 2021, the most mutated variant of SARS-CoV-2, has now circulated in 150 countries/territories until January 8, 2022, with 552 191 confirmed cases and causing 115 deaths. 4 Omicron was recently divided into three lineages (BA.1, BA.2, and BA.3). 5 The differences between the BA.1 and BA.2 lineages are explored. 6 Here we describe how these three lineages differ in their spike protein. Our study found that there were no specific mutations for the BA.3 lineage in spike protein. Instead, it is a combination of mutations in BA.1 and BA.2 spike proteins. All three lineages were first detected at approximately the same time and from the same place: BA.1 [hCoV-19/Botswana/ R40B59_BHP_3321001248/2021 (EPI_ISL_6640916) (2021-11-11) (Botswana/South East/Greater Gaborone/Gaborone)], BA.2 [hCoV-19/South Africa/CERI-KRISP-K032307/2021 (2021-11-17) (South Africa/Gauteng/Tshwane)], and BA.3 [hCoV-19/South Africa/NICD-N22163/2021 (EPI_ISL_7605713) (2021-11-18) (South Africa/North West)]. Therefore, viruses that develop simultaneously and from the same place have equal chances of spreading worldwide. Though all Not applicable.

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Cardiomyopathy is one of the characteristic features of cancer. In this study, we establish a suitable model to study breast cancer-induced cardiomyopathy in mice. We used Ehrlich Ascites Carcinoma cells to induce subcutaneous tumor in 129/SvJ mice and studied its effect on heart function. In Ehrlich Ascites Carcinoma bearing mice, we found significant reduction in left ventricle wall thickness, ejection fraction, and fractional shortening increase in left ventricle internal diameter. We found higher muscle atrophy, degeneration, fibrosis, expression of cell-adhesion molecules and cell death in tumor-bearing mice hearts. As observed in cancer patients, we found that mTOR, a key signalling molecule responsible for maintaining cell growth and autophagy was suppressed in this model. Tumor bearing mice hearts show increased expression and nuclear localization of TFEB and FoxO3a transcription factors, which are involved in the upregulation of muscle atrophy genes, lysosomal biogenesis genes and autophagy genes. We propose that Ehrlich Ascites Carcinoma induced tumor can be used as a model to identify potential therapeutic targets for the treatment of heart failure in patients suffering from cancer-induced cardiomyopathy. This model can also be used to test the adverse consequences of cancer chemotherapy in heart.

Heart failure is an aging-associated disease, which is the leading cause of death worldwide. Sirtuin family members have been largely studied in the context of aging and agingassociated diseases. Sirtuin 2 (SIRT2) is a cytoplasmic protein in the family of sirtuins that are NAD + -dependent class III histone deacetylases. In this work, we studied the role of SIRT2 in regulating NFAT transcription factor and the development of cardiac hypertrophy. Confocal microscopy analysis indicated that SIRT2 is localized in the cytoplasm of cardiomyocytes and SIRT2 levels are reduced during pathological hypertrophy of the heart. SIRT2 deficient mice develops spontaneous pathological cardiac hypertrophy, remodelling, fibrosis and dysfunction in an age-dependent manner. Moreover, young SIRT2 deficient mice develops exacerbated agonist-induced hypertrophy. On contrast, SIRT2 overexpression attenuated agonist-induced cardiac hypertrophy in cardiomyocytes in a cell autonomous manner. Mechanistically, SIRT2 binds to and deacetylates NFATc2 transcription factor. SIRT2 deficiency stabilizes NFATc2 and enhances nuclear localization of NFATc2, resulting in increased transcription activity. Our results suggest that inhibition of NFAT rescues the cardiac dysfunction in SIRT2 deficient mice. Thus, our study establishes SIRT2 as a novel endogenous negative regulator of NFAT transcription factor. _____________________________________