In Saccharomyces cerevisiae, HSL1 (NIK1) encodes a serine-threonine protein kinase involved in cell cycle control and morphogenesis. Deletion of its putative orthologue in Kluyveromyces lactis, KlHSL1, gives rise to sensitivity to the respiratory inhibitor antimycin A (AA). Resistance to AA on glucose (Rag + phenotype) is associated with genes (RAG) required for glucose metabolism/ glycolysis. To understand the relationship between RAG and KlHSL1, rag and Klhsl1D mutant strains were investigated. The analysis showed that all the mutants contained a phosphorylated form of Hog1 and displayed an inability to synthesize/accumulate glycerol as a compatible solute. In addition, rag mutants also showed alterations in both cell wall and membrane fatty acids. The pleiotropic defects of these strains indicate that a common pathway regulates glucose utilization and stress response mechanisms, suggesting impaired adaptation of the plasma membrane/cell wall during the respiratory-fermentative transition. KlHsl1 could be the link between these adaptive pathways and the morphogenetic checkpoint. INTRODUCTIONIn Saccharomyces cerevisiae, the cell cycle is regulated by the Cdc28 kinase and its regulatory subunits (cyclins). Swe1 kinase negatively regulates entry into mitosis through inhibitory phosphorylation of Cdc28 (Booher et al., 1993). Swe1 accumulates through the late G 1 and S phases, and is then degraded in G 2 by hyperphosphorylation (Sia et al., 1998). HSL1, also called NIK1, encodes a protein kinase, which is a negative regulator of Swe1 (Tanaka & Nojima, 1996;Ma et al., 1996). Hsl1 is a component of the septin morphogenetic checkpoint that promotes bud development and the recruitment of Swe1 at the septin ring where it is phosphorylated/degraded (McMillan et al., 1999;Lew, 2003).S. cerevisiae is a Crabtree-positive yeast in that respiration is completely repressed by glucose even under aerobic conditions, growth being supported solely by fermentation (Gancedo, 1998). In contrast, in the Crabtree-negative yeast Kluyveromyces lactis both respiratory and fermentative pathways co-exist during growth on glucose (De Deken, 1966;Breunig et al., 2000), although respiration appears to be dispensable since antimycin A (AA) does not inhibit growth on glucose (Rag + phenotype) (Goffrini et al., 1989; Wésolowski-Louvel et al., 1992a). Sensitivity to AA on glucose (Rag -) is associated with mutations in genes encoding glycolytic enzymes, glucose transporters and sensing components, as well as their regulatory factors (Goffrini et al., 1991; Wésolowski-Louvel et al., 1992b;Prior et al., 1993; Bianchi et al., 1996;Prior et al., 1996;Blaisonneau et al., 1997;Betina et al., 2001; Lemaire & Wésolowski-Louvel, 2004; Hnatova et al., 2008).During the characterization of the putative cell cycle gene KlHSL1 in K. lactis, we found that its deletion led to a Rag -phenotype, suggesting involvement in glucose metabolism. To identify the relationship between RAG and KlHSL1, rag and Klhsl1D mutant strains were further analysed. All rag Abbreviati...

Tenon's fibroblasts (TFs), widely employed as in vitro model for many ophthalmological studies, are routinely cultured with FBS. Platelet Lysate (PL), a hemoderivate enriched with growth factors and cytokines has been largely tested in several clinical applications and as substitute of FBS in culture. Here, we investigate whether PL can exert biological effects on TF populations similarly to other cell types. Results show that PL significantly enhances cell proliferation and migration vs. FBS, without influencing cell size/granularity. Upregulation of EGF, VEGF, KDR, MMP2-9, FAK mRNA levels also occurs and phosphorylation of AKT but not of ERK1/2 is significantly enhanced. The inhibition of the PI3kinase/AKT pathway with the specific inhibitor wortmannin, decreases PL-induced cell migration but not proliferation. Condition supernatants containing PL show increased bioavailability of Nitric Oxide and reduced levels of 8-Iso-PGF2-alpha, correlating with cell proliferation and migration. Pro-angiogenic/inflammatory soluble factors (GRO, Angiogenin, EGF, I-309, PARC) are exclusively or greater expressed in media containing PL than FBS. GMP-grade PL preparations positively influence in vitro biological effects of TFs representing a suitable and safer alternative to FBS.

The cardiovascular (CV) system can often be affected during SARS-CoV-2 infection and several acute manifestations, such as myocardial infarction, pericarditis, myocarditis and arrhythmias have been described. We provide a retrospective overview of electrocardiographic (ECG) features and their relationship with clinical outcomes in a cohort of patients admitted to our COVID-19 Unit between November 2020 and May 2021. Resting standard 12-lead ECGs were performed in all patients at admission and in those recovering from SARS-CoV-2 infection also at discharge. Clinical and serological records alongside ECG measurements were retrospectively evaluated and statistical analysis was performed to identify relationships between variables. A total of 123 patients (44% females) with a mean age of 73.9 years were enrolled. Ninety-five (77%) patients recovered from SARS-CoV-2 infection and were discharged while 28 (23%) died in hospital. Almost 90% of patients displayed at least one CV risk factor and 41 (33%) patients had at least one previous CV event. We observed that heart rate, corrected QT interval dispersion (QTcd) and inverted T waves are independently associated with in-hospital death and inverted T waves show the strongest association. This association remained significant even after correcting for the number of CV risk factors at baseline and for the type of CV risk factor at baseline. Our study demonstrated that some ECG abnormalities at admission are independently associated with in-hospital death regardless of pre-existing CV risk factors. These findings may be of particular relevance in clinical settings with limited access to advanced techniques, such as cardiac magnetic resonance and could help improve the outcomes of patients with cardiac involvement related to SARS-CoV-2 infection.