Identification and functional characterization of two novel mutations in KCNJ10 and PI4KB in SeSAME syndrome without electrolyte imbalance.

BACKGROUND: Dysfunction in inwardly rectifying potassium channel Kir4.1 has been implicated in SeSAME syndrome, an autosomal-recessive (AR), rare, multi-systemic disorder. However, not all neurological, intellectual disability, and comorbid phenotypes in SeSAME syndrome can be mechanistically linked solely to Kir4.1 dysfunction. METHODS: We therefore performed whole-exome sequencing and identified additional genetic risk-elements that might exert causative effects either alone or in concert with Kir4.1 in a family diagnosed with SeSAME syndrome. RESULTS: Two variant prioritization pipelines based on AR inheritance and runs of homozygosity (ROH), identified two novel homozygous variants in KCNJ10 and PI4KB and five rare homozygous variants in PVRL4, RORC, FLG2, FCRL1, NIT1 and one common homozygous variant in HSPA6 segregating in all four patients. The novel mutation in KCNJ10 resides in the cytoplasmic domain of Kir4.1, a seat of phosphatidylinositol bisphosphate (PIP2) binding. The mutation altered the subcellular localization and stability of Kir4.1 in patient-specific lymphoblastoid cells (LCLs) compared to parental controls. Barium-sensitive endogenous K+ currents in patient-specific LCLs using whole-cell patch-clamp electrophysiology revealed membrane depolarization and defects in inward K+ ion conductance across the membrane, thereby suggesting a loss-of-function effect of KCNJ10 variant. CONCLUSION: Altogether, our findings implicate the role of new genes in SeSAME syndrome without electrolyte imbalance and thereby speculate the regulation of Kir4.1 channel activity by PIP2 and integrin-mediated adhesion signaling mechanisms.

Numb-associated kinases regulate sandfly-borne Toscana virus entry.

Sandfly-borne Toscana virus (TOSV) is an enveloped tri-segmented negative single-strand RNA Phlebovirus. It is an emerging virus predominantly endemic in southwestern Europe and Northern Africa. Although TOSV infection is typically asymptomatic or results in mild febrile disease, it is neurovirulent and ranks among the three most common causes of summer meningitis in certain regions. Despite this clinical significance, our understanding of the molecular aspects and host factors regulating phlebovirus infection is limited. This study characterized the early steps of TOSV infection. Our findings reveal that two members of the Numb-associated kinases family of Ser/Thr kinases, namely adaptor-associated kinase 1 (AAK1) and cyclin G-associated kinase (GAK), play a role in regulating the early stages of TOSV entry. FDA-approved inhibitors targeting these kinases demonstrated significant inhibition of TOSV infection. This study suggests that AAK1 and GAK represent druggable targets for inhibiting TOSV infection and, potentially, related Phleboviruses.

Son of sevenless 1 (SOS1), the RasGEF, interacts with ERα and STAT3 during embryo implantation.

Estrogen accounts for several biological processes in the body; embryo implantation and pregnancy being one of the vital events. This manuscript aims to unearth the nuclear role of Son of sevenless1 (SOS1), its interaction with estrogen receptor alpha (ERα), and signal transducer and activator of transcription 3 (STAT3) in the uterine nucleus during embryo implantation. SOS1, a critical cytoplasmic linker between receptor tyrosine kinase and rat sarcoma virus signaling, translocates into the nucleus via its bipartite nuclear localization signal (NLS) during the 'window of implantation' in pregnant mice. SOS1 associates with chromatin, interacts with histones, and shows intrinsic histone acetyltransferase (HAT) activity specifically acetylating lysine 16 (K16) residue of histone H4. SOS1 is a coactivator of STAT3 and a co-repressor of ERα. SOS1 creates a partial mesenchymal-epithelial transition by acting as a transcriptional modulator. Finally, our phylogenetic tree reveals that the two bipartite NLS surface in reptiles and the second acetyl coenzymeA (CoA) (RDNGPG) important for HAT activity emerges in mammals. Thus, SOS1 has evolved into a moonlighting protein, the special class of multi-tasking proteins, by virtue of its newly identified nuclear functions in addition to its previously known cytoplasmic function.

Derivation of iPSC lines from two patients with familial Alzheimer's disease from India.

The current prevalence of diagnosable dementia in India is 1% of people over 60 years (~3.7 million people), but is estimated to increase significantly, as ~15% world's aged population (>65 years) would be resident here by 2020 (Shah et al., 2016). While several mutations that pose a familial risk have been identified, the ethnic background may influence disease susceptibility, clinical presentation and treatment response. In this study, we report a detailed characterization of two representative HiPSC lines from a well-characterized dementia cohort from India. Availability of these lines, and associated molecular and clinical information, would be useful in the detailed exploration of the genomic contribution(s) to AD.

Reduced Tregs in peripheral blood of PCOS patients - a consequence of aberrant Il2 signaling.

CONTEXT: The immunesupressive action of CD4(+)CD25(+) CD127(-/low) T regulatory cells (Tregs) is vital for an efficient reproductive function. However no data exists on their number or functionality in polycystic ovary syndrome (PCOS). OBJECTIVE: The study aimed to analyze the frequency of circulating Tregs and key factors modulating them in women with PCOS. DESIGN, SETTING, AND PARTICIPANTS: This is a retrospective, case-control cohort study conducted in women with PCOS recruited from Samad IVF hospitals and Women and Children Hospital, Thiruvananthapuram, India. Women with PCOS (N = 20) were diagnosed according to Rotterdam Consensus and normal menstruating women were taken as controls (N = 2331). MAIN OUTCOME MEASURES: We analyzed the proportion of CD4(+)CD25(+) CD127(-/low) Tregs in women with PCOS by fluorescent activated cell sorting. RESULTS: The study discovered that the women with PCOS have reduced numbers of Tregs (2.626 ± 0.62) compared with controls (4.253 ± 0.87) (t = 6.963, P < .0001, mean difference = -1.627; 95% confidence interval = -2.099--1.155). We documented a decrease in the follicular phase Treg expansion in women with PCOS. Our results revealed a reduced STAT5A (fold change [FC] = 7.642, P < .0004)/STAT5B (FC = 3.824, P < .0001), FOXP3 (FC = 4.1343, P = .0004)/CTLA4 (FC = 2.569, P = .0001) and elevated AKT (FC = 7.39, P = .05)/PIK3 (FC = 5.326, P = .0002) expression in women with PCOS. Recombinant interleukin 2 (rIL2) treatment failed to improve FOXP3/CTLA4 levels but caused a reduction of AKT/PIK3 arm, possibly due to an elevated PTEN in women with PCOS. CONCLUSION: The study suggests that women with PCOS have reduced Tregs due to an inherent hyporesponsiveness to IL2, which is unable to activate STAT5B and reduce FOXP3 expression. IL2-based therapeutic strategies can ameliorate complications in PCOS by suppressing the AKT/PIK3 arm.