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HIV-induced persistent immune activation is a key mediator of inflammatory comorbidities such as cardiovascular disease (CVD) and neurocognitive disorders. While a preponderance of data indicate that gut barrier disruption and microbial translocation are drivers of chronic immune activation, the molecular mechanisms of this persistent inflammatory state remain poorly understood. Here, utilizing the nonhuman primate model of Human Immunodeficiency Virus (HIV) infection with suppressive antiretroviral therapy (ART), we investigated activation of inflammasome pathways and their association with intestinal epithelial barrier disruption (IEBD). Longitudinal blood samples obtained from rhesus macaques with chronic SIV infection and long-term suppressive ART were evaluated for IEBD biomarkers, inflammasome activation (IL-1β and IL-18), inflammatory cytokines, and triglyceride (TG) levels. Activated monocyte subpopulations and glycolytic potential were investigated in peripheral blood mononuclear cells (PBMCs). During the chronic phase of treated SIV infection, elevated levels of plasma IL-1β and IL-18 were observed following the hallmark increase in IEBD biomarkers, intestinal fatty acid-binding protein (IFABP) and LPS-binding protein (LBP). Further, significant correlations of plasma IFABP levels with IL-1β and IL-18 were observed between 10 and 12 months of ART. Higher levels of sCD14, IL-6, and GM-CSF, among other inflammatory mediators, were also observed only during the long-term SIV + ART phase along with a trend of increase in the frequencies of activated CD14+CD16+ intermediate monocyte subpopulations. Lastly, we found elevated levels of blood TG and higher glycolytic capacity in PBMCs of chronic SIV-infected macaques with long-term ART. The increase in circulating IL-18 and IL-1β following IEBD and their significant positive correlation with IFABP suggest a connection between gut barrier disruption and inflammasome activation during chronic SIV infection, despite viral suppression with ART. Additionally, the increase in markers of monocyte activation, along with elevated TG and enhanced glycolytic pathway activity, indicates metabolic remodeling that could fuel metabolic syndrome. Further research is needed to understand the mechanisms by which gut dysfunction and inflammasome activation contribute to HIV-associated metabolic complications, enabling targeted interventions in people with HIV. [ABSTRACT FROM AUTHOR]

Two genes Sac7d and Sac7e of Sac7 binding DNA-binding proteins, from thermophilic archaeon Sulfolobus acidocaldarius are cloned into Escherichia coli. The Sac7d gene encodes 66 aminoacid (7608 Da) and Sac7e gene encodes 65 aminoacid (7469 Da). The two genes Sac7d and Sac7e differ at 16 positions within the coding region. Transversions takes place at three positions and transition takes place at the rest of the thirteen positions. The stability of Sac7d protein is increased by nonspecific, reductive methylation.

Identification of cellular proteins, in addition to already known transcription factors such as NF-κB, Sp1, C-EBPβ, NFAT, ATF/CREB, and LEF-1, which interact with the HIV-1 LTR, is critical in understanding the mechanism of HIV-1 replication in monocytes/macrophages. Our studies demonstrate upregulation of pyruvate kinase isoform M2 (PKM2) expression during HIV-1SF162 infection of monocyte/macrophages and reactivation of HIV-1 in U1 cells, a macrophage model of latency. We observed that HIV-1SF162 infection of monocyte/macrophages and reactivation of HIV-1 in U1 cells by PMA resulted in increased levels of nuclear PKM2 compared to PMA-induced U937 cells. Furthermore, there was a significant increase in the nuclear dimeric form of PKM2 in the PMA-induced U1 cells in comparison to PMA-induced U937 cells. We focused on understanding the potential role of PKM2 in HIV-1 LTR transactivation. Chromatin immunoprecipitation (ChIP) analysis in PMA-activated U1 and TZM-bl cells demonstrated the interaction of PKM2 with the HIV-1 LTR. Our studies show that overexpression of PKM2 results in transactivation of HIV-1 LTR-luciferase reporter in U937, U-87 MG, and TZM-bl cells. Using various truncated constructs of the HIV-1 LTR, we mapped the region spanning −120 bp to −80 bp to be essential for PKM2-mediated transactivation. This region contains the NF-κB binding site and deletion of this site attenuated PKM2-mediated activation of HIV-1 LTR. Immunoprecipitation experiments using U1 cell lysates demonstrated a physical interaction between PKM2 and the p65 subunit of NF-κB. These observations demonstrate for the first time that PKM2 is a transcriptional co-activator of HIV-1 LTR. J. Cell. Physiol. 232: 517-525, 2017. © 2016 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Recently, multiple μ-opioid receptor (MOR) isoforms have been identified that originate from a single gene, OPRM1; however, both their regulation and their functional significance are poorly characterized. The objectives of this study were to decipher, first, the regulation of alternatively spliced μ-opioid receptor isoforms and the spliceosome components that determine splicing specificity and, second, the signaling pathways utilized by particular isoforms both constitutively and following agonist binding. Our studies demonstrated that the expression of a particular splice variant, MOR-1X, was up-regulated by morphine, and this coincided with an increase in the essential splicing factor ASF/SF2. Structural comparison of this isoform to the prototypical variant MOR-1 revealed that the unique distal portion of the C-terminal domain contains additional phosphorylation sites, whereas functional comparison found distinct signaling differences, particularly in the ERK and p90 RSK pathways. Additionally, MOR-1X expression significantly reduced Bax expression and mitochondrial dehydrogenase activity, suggesting a unique functional consequence for MOR-1X specific signaling. Collectively, these findings suggest that alternative splicing of the MOR is altered by exogenous opioids, such as morphine, and that individual isoforms, such as MOR-1X, mediate unique signal transduction with distinct functional consequence. Furthermore, we have identified for the first time a potential mechanism that involves the essential splicing factor ASF/SF2 through which morphine regulates splicing specificity of the MOR encoding gene, OPRM1. J. Cell. Physiol. 231: 1542-1553, 2016. © 2015 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]