Overexpression of HSP70 inhibits cofilin phosphorylation and promotes lymphocyte migration in heat-stressed cells.

Hyperthermia adversely affects cell structure and function, but also induces adaptive responses that allow cells to tolerate these stressful conditions. For example, heat-induced expression of the molecular chaperone protein HSP70 can prevent stress-induced cell death by inhibiting signaling pathways that lead to apoptosis. In this study, we used high-resolution two-dimensional gel electrophoresis and phosphoprotein staining to identify signaling pathways that are altered by hyperthermia and modulated by HSP70 expression. We found that in heat-shocked cells, the actin-severing protein cofilin acquires inhibitory Ser3 phosphorylation, which is associated with an inhibition of chemokine-stimulated cell migration. Cofilin phosphorylation appeared to occur as a result of the heat-induced insolubilization of the cofilin phosphatase slingshot (SSH1-L). Overexpression of HSP70 reduced the extent of SSH1-L insolubilization and accelerated its resolubilization when cells were returned to 37°C after exposure to hyperthermia, resulting in a more rapid dephosphorylation of cofilin. Cells overexpressing HSP70 also had an increased ability to undergo chemotaxis following exposure to hyperthermia. These results identify a critical heat-sensitive target controlling cell migration that is regulated by HSP70 and point to a role for HSP70 in immune cell functions that depend upon the proper control of actin dynamics.

Pharmacologic Weight Management in the Era of Adolescent Obesity.

CONTEXT: Pediatric obesity is a serious health problem in the United States. While lifestyle modification therapy with dietary changes and increased physical activity are integral for the prevention and treatment of mild to moderate obesity in youth, only a modest effect on sustained weight reduction is observed in children and young adults with severe obesity. This underscores the need for additional evidence-based interventions for children and adolescents with severe obesity, including pharmacotherapy, before considering invasive procedures such as bariatric surgery. EVIDENCE ACQUISITION: This publication focuses on recent advances in pharmacotherapy of obesity with an emphasis on medications approved for common and rarer monogenic forms of pediatric obesity. EVIDENCE SYNTHESIS: We review medications currently available in the United States, both those approved for weight reduction in children and "off-label" medications that have a broad safety margin. CONCLUSION: It is intended that this review will provide guidance for practicing clinicians and will encourage future exploration for successful pharmacotherapy and other interventions for obesity in youth.

SARS-CoV-2 infection and paediatric endocrine disorders: Risks and management considerations.

Background: Coronavirus-19 (COVID-19) is a disease caused by the SARS-CoV-2 virus, the seventh coronavirus identified as causing disease in humans. The SARS-CoV-2 virus has multiple potential pathophysiologic interconnections with endocrine systems, potentially causing disturbances in glucose metabolism, hypothalamic and pituitary function, adrenal function and mineral metabolism. A growing body of data is revealing both the effects of underlying endocrine disorders on COVID-19 disease outcome and the effects of the SARS-CoV-2 virus on endocrine systems. However, comprehensive assessment of the relationship to endocrine disorders in children has been lacking. Content: In this review, we present the effects of SARS-CoV-2 infection on endocrine systems and review the current literature on complications of COVID-19 disease in underlying paediatric endocrine disorders. We provide recommendations on management of endocrinopathies related to SARS-CoV-2 infection in this population. Summary and outlook: With the surge in COVID-19 cases worldwide, it is important for paediatric endocrinologists to be aware of the interaction of SARS-CoV-2 with the endocrine system and management considerations for patients with underlying disorders who develop COVID-19 disease. While children and adults share some risk factors that influence risk of complications in SARS-CoV-2 infection, it is becoming clear that responses in the paediatric population are distinct and outcomes from adult studies cannot be extrapolated. Evidence emerging from paediatric studies provides some guidance but highlights the need for more research in this area.

An endocrine perspective on menstrual suppression for adolescents: achieving good suppression while optimizing bone health.

Suppression of menstruation and/or ovarian function in adolescent girls may be desired for a variety of reasons. Numerous medical options exist. The choice of the appropriate modality for an individual patient depends on several factors based on differences in the efficacy of achieving menstrual suppression as well as in their side effect profiles. Adolescence is also a period of bone mass accrual in girls, and several of these modalities may negatively influence peak bone mass. This review focuses on the efficacy of achieving menstrual suppression and the effect on bone health of the various options through an overview of the current literature and also highlights areas in need of further research.

RAB1A promotes Vaccinia virus replication by facilitating the production of intracellular enveloped virions.

Vaccinia virus (VACV) is a large double-stranded DNA virus with a complex cytoplasmic replication cycle that exploits numerous cellular proteins. This work characterises the role of a proviral cellular protein, the small GTPase RAB1A, in VACV replication. Using siRNA, we identified RAB1A as required for the production of extracellular enveloped virions (EEVs), but not intracellular mature virions (IMVs). Immunofluorescence and electron microscopy further refined the role of RAB1A as facilitating the wrapping of IMVs to become intracellular enveloped virions (IEVs). This is consistent with the known function of RAB1A in maintenance of ER to Golgi transport. VACV can therefore be added to the growing list of viruses which require RAB1A for optimal replication, highlighting this protein as a broadly proviral host factor.

A loss of function analysis of host factors influencing Vaccinia virus replication by RNA interference.

Vaccinia virus (VACV) is a large, cytoplasmic, double-stranded DNA virus that requires complex interactions with host proteins in order to replicate. To explore these interactions a functional high throughput small interfering RNA (siRNA) screen targeting 6719 druggable cellular genes was undertaken to identify host factors (HF) influencing the replication and spread of an eGFP-tagged VACV. The experimental design incorporated a low multiplicity of infection, thereby enhancing detection of cellular proteins involved in cell-to-cell spread of VACV. The screen revealed 153 pro- and 149 anti-viral HFs that strongly influenced VACV replication. These HFs were investigated further by comparisons with transcriptional profiling data sets and HFs identified in RNAi screens of other viruses. In addition, functional and pathway analysis of the entire screen was carried out to highlight cellular mechanisms involved in VACV replication. This revealed, as anticipated, that many pro-viral HFs are involved in translation of mRNA and, unexpectedly, suggested that a range of proteins involved in cellular transcriptional processes and several DNA repair pathways possess anti-viral activity. Multiple components of the AMPK complex were found to act as pro-viral HFs, while several septins, a group of highly conserved GTP binding proteins with a role in sequestering intracellular bacteria, were identified as strong anti-viral VACV HFs. This screen has identified novel and previously unexplored roles for cellular factors in poxvirus replication. This advancement in our understanding of the VACV life cycle provides a reliable knowledge base for the improvement of poxvirus-based vaccine vectors and development of anti-viral theraputics.