JAK3 Y841 Autophosphorylation Is Critical for STAT5B Activation, Kinase Domain Stability and Dimer Formation.

Janus tyrosine kinase 3 (JAK3) is primarily expressed in immune cells and is needed for signaling by the common gamma chain (γc) family of cytokines. Abnormal JAK3 signal transduction can manifest as hematological disorders, e.g., leukemia, severe combined immunodeficiency (SCID) and autoimmune disease states. While regulatory JAK3 phosphosites have been well studied, here a functional proteomics approach coupling a JAK3 autokinase assay to mass spectrometry revealed ten previously unreported autophosphorylation sites (Y105, Y190, Y238, Y399, Y633, Y637, Y738, Y762, Y824, and Y841). Of interest, Y841 was determined to be evolutionarily conserved across multiple species and JAK family members, suggesting a broader role for this residue. Phospho-substitution mutants confirmed that Y841 is also required for STAT5 tyrosine phosphorylation. The homologous JAK1 residue Y894 elicited a similar response to mutagenesis, indicating the shared importance for this site in JAK family members. Phospho-specific Y841-JAK3 antibodies recognized activated kinase from various T-cell lines and transforming JAK3 mutants. Computational biophysics analysis linked Y841 phosphorylation to enhanced JAK3 JH1 domain stability across pH environments, as well as to facilitated complementary electrostatic JH1 dimer formation. Interestingly, Y841 is not limited to tyrosine kinases, suggesting it represents a conserved ubiquitous enzymatic function that may hold therapeutic potential across multiple kinase families.

Substance use service availability in HIV treatment programs: Data from the global IeDEA consortium, 2014-2015 and 2017.

BACKGROUND: Substance use is common among people living with HIV and has been associated with suboptimal HIV treatment outcomes. Integrating substance use services into HIV care is a promising strategy to improve patient outcomes. METHODS: We report on substance use education, screening, and referral practices from two surveys of HIV care and treatment sites participating in the International epidemiology Databases to Evaluate AIDS (IeDEA) consortium. HIV care and treatment sites participating in IeDEA are primarily public-sector health facilities and include both academic and community-based hospitals and health facilities. A total of 286 sites in 45 countries participated in the 2014-2015 survey and 237 sites in 44 countries participated in the 2017 survey. We compared changes over time for 147 sites that participated in both surveys. RESULTS: In 2014-2015, most sites (75%) reported providing substance use-related education on-site (i.e., at the HIV clinic or the same health facility). Approximately half reported on-site screening for substance use (52%) or referrals for substance use treatment (51%). In 2017, the proportion of sites providing on-site substance use-related education, screening, or referrals increased by 9%, 16%, and 8%, respectively. In 2017, on-site substance use screening and referral were most commonly reported at sites serving only adults (compared to only children/adolescents or adults and children/adolescents; screening: 86%, 37%, and 59%, respectively; referral: 76%, 47%, and 46%, respectively) and at sites in high-income countries (compared to upper middle income, lower middle income or low-income countries; screening: 89%, 76%, 68%, and 45%, respectively; referral: 82%, 71%, 57%, and 34%, respectively). CONCLUSION: Although there have been increases in the proportion of sites reporting substance use education, screening, and referral services across IeDEA sites, gaps persist in the integration of substance use services into HIV care, particularly in relation to screening and referral practices, with reduced availability for children/adolescents and those receiving care within resource-constrained settings.

Green barley mitigates cytotoxicity in human lymphocytes undergoing aggressive oxidative stress, via activation of both the Lyn/PI3K/Akt and MAPK/ERK pathways.

Oxidative stress plays a critical role in numerous diseases. Therefore, the pursuit of compounds with antioxidant activity remains critical. Green barley young leaves aqueous extract (GB) was tested for its capacity to ameliorate cellular oxidative stress, and its potential cytoprotective mechanism was partially elucidated. Through Folin-Ciocalteau and 1,1-diphenyl-2-picrylhydrazyl (DPPH) colorimetric assays, GB total phenolic content and free radical scavenging activity were found to be 59.91 ± 2.17 mg/L and 110.75 µg/ml (IC50), respectively. Using a live cell-based propidium iodide dye exclusion assay and flow cytometry, GB was found to display significant cytoprotection activity on three human lymphocytic cell lines exposed to an aggressive H2O2-induced oxidative stress. The molecular mechanism for GB cytoprotection activity was assessed via bead-based xMAP technology on the Luminex platform and western blot analysis. GB treatment resulted in activation of Lyn, Akt, and ERK1/2, suggesting that GB is able to mitigate the H2O2-induced oxidative stress via activation of both the Lyn/PI3K/Akt and ERK/MAPK pathways. Our findings support the notion that GB extract has the potential to be a valuable therapeutic agent and may serve to establish a strategy to discover potential compound(s) or biological extracts/mixtures to be incorporated as a treatment to prevent oxidative stress-related diseases.

Effectiveness of gastric neurostimulation in patients with gastroparesis.

BACKGROUND: Patients with gastroparesis have significantly delayed gastric emptying because of impaired nerve function. Gastric neurostimulation from Enterra Therapy provides electrical pulses to the stomach tissue that promotes stimulation of stomach smooth muscle, thereby enhancing gastric emptying. This study evaluates the effectiveness of Enterra Therapy (Medtronic, Minneapolis, Minnesota) in reducing symptoms and improving the quality of life of patients with drug-refractory gastroparesis. MATERIAL AND METHODS: In this study 25 patients underwent minimally invasive, laparoscopic placement of the Enterra Therapy device. Patients were asked to rank their severity of symptoms and quality of life retrospectively by completing the Gastrointestinal Symptoms Rating Scale and Short Form 36 Health Survey with respect to their condition before and 6 months after initiation of Enterra Therapy. RESULTS: Eighteen patients completed the surveys. Patients showed statistically significant improvement in their overall Gastrointestinal Symptoms Rating Scale scores and the mental health component of the Short Form 36 Health Survey. DISCUSSION: Currently, Enterra Therapy has Humanitarian Use Device status, which means that more clinical evidence is needed to prove its effectiveness in gastroparesis. By showing that Enterra Therapy reduces symptoms of gastroparesis and improves patient quality of life, this study contributes to the increasing amount of data supporting its use and potential Food and Drug Administration approval.

Searching in mother nature for anti-cancer activity: anti-proliferative and pro-apoptotic effect elicited by green barley on leukemia/lymphoma cells.

Green barley extract (GB) was investigated for possible anti-cancer activity by examining its anti-proliferative and pro-apoptotic properties on human leukemia/lymphoma cell lines. Our results indicate that GB exhibits selective anti-proliferative activity on a panel of leukemia/lymphoma cells in comparison to non-cancerous cells. Specifically, GB disrupted the cell-cycle progression within BJAB cells, as manifested by G2/M phase arrest and DNA fragmentation, and induced apoptosis, as evidenced by phosphatidylserine (PS) translocation to the outer cytoplasmic membrane in two B-lineage leukemia/lymphoma cell lines. The pro-apoptotic effect of GB was found to be independent of mitochondrial depolarization, thus implicating extrinsic cell death pathways to exert its cytotoxicity. Indeed, GB elicited an increase of TNF-α production, caspase-8 and caspase-3 activation, and PARP-1 cleavage within pre-B acute lymphoblastic leukemia Nalm-6 cells. Moreover, caspase-8 and caspase-3 activation and PARP-1 cleavage were strongly inhibited/blocked by the addition of the specific caspase inhibitors Z-VAD-FMK and Ac-DEVD-CHO. Furthermore, intracellular signaling analyses determined that GB treatment enhanced constitutive activation of Lck and Src tyrosine kinases in Nalm-6 cells. Taken together, these findings indicate that GB induced preferential anti-proliferative and pro-apoptotic signals within B-lineage leukemia/lymphoma cells, as determined by the following biochemical hallmarks of apoptosis: PS externalization, enhanced release of TNF-α, caspase-8 and caspase-3 activation, PARP-1 cleavage and DNA fragmentation Our observations reveal that GB has potential as an anti-leukemia/lymphoma agent alone or in combination with standard cancer therapies and thus warrants further evaluation in vivo to support these findings.