T cells are critical for the control of viral infections and T cell responses are regulated by a dynamic network of non-coding RNAs, including microRNAs (miR) and long non-coding RNAs (lncRNA). Here we show that an activation-induced decline of lncRNA growth arrest-specific transcript 5 (GAS5) activates DNA damage response (DDR), and regulates cellular functions and apoptosis in CD4 T cells derived from people living with HIV (PLHIV) via upregulation of miR-21. Notably, GAS5-miR21-mediated DDR and T cell dysfunction are observed in PLHIV on antiretroviral therapy (ART), who often exhibit immune activation due to low-grade inflammation despite robust virologic control. We found that GAS5 negatively regulates miR-21 expression, which in turn controls critical signaling pathways involved in DNA damage and cellular response. The sustained stimulation of T cells decreased GAS5, increased miR-21 and, as a result, caused dysfunction and apoptosis in CD4 T cells. Importantly, this inflammation-driven T cell over-activation and aberrant apoptosis in ART-controlled PLHIV and healthy subjects (HS) could be reversed by antagonizing the GAS5-miR-21 axis. Also, mutation of the miR-21 binding site on exon 4 of GAS5 gene to generate a GAS5 mutant abolished its ability to regulate miR-21 expression as well as T cell activation and apoptosis markers compared to the wild-type GAS5 transcript. Our data suggest that GAS5 regulates TCR-mediated activation and apoptosis in CD4 T cells during HIV infection through miR-21-mediated signaling. However, GAS5 effects on T cell exhaustion during HIV infection may be mediated by a mechanism beyond the GAS5-miR-21-mediated signaling. These results indicate that targeting the GAS5-miR-21 axis may improve activity and longevity of CD4 T cells in ART-treated PLHIV. This approach may also be useful for targeting other infectious or inflammatory diseases associated with T cell over-activation, exhaustion, and premature immune aging.

Opioid receptors are members of the superfamily of seven transmembrane G protein-coupled receptors (GPCRs) which share several structural and functional characteristics. There are 3 subtypes of opioid receptors, designated μ (MOR), δ (DOR), and κ (KOR) opioid receptors, have been found in the immune, nervous, gastrointestinal and other tissues. We have attempted to clarify the nature of MOR-induced signal transduction pathways in leukocytes. We found that the activation of MOR leads to a significant induction of ERK phosphorylation in peripheral blood mononuclear cells from normal donors using the MOR-selective agonist DAMGO. We are also interested in determining the role of this signaling pathway in the regulation of the immune response. Recent experiments using selective inhibitors suggests that the activation of ERK involves a pathway composed of Raf, Ras, and MEK1/2 kinases, but is independent of PI3 kinase. After treatment of multiple protein kinase inhibitors we found the PKC inhibitor Go-6983 and PLC inhibitor U73122 could also inhibit ERK phosphorylation in MOR stable line (HEK-MOR). According to the results from the Go-6983 and H-89 inhibitor treatment experiments, we found PKCμ/PKD1, a family member of Protein Kinase D, may be involved in MOR-induced ERK phosphorylation. We also found PKCμ/PKD1 S916 phosphorylation after MOR activation and the PKCμ specific inhibitor CID755673 inhibited the MOR-mediated ERK activation. ERK phosphorylation activated several transcription factors in human monocytes, the activation of transcription factors has been proved to induce miRNA expression. We have initiated a series of experiments to study the regulation of miRNA expression by MOR in human monocytes. We found miR-21, miR-155, miR-29a, miR-20b expression were significantly up-regulated following morphine treatment, and morphine-induced miR-21 expression is down-regulated following pretreatment with the ERK inhibitor U0126 and PKD inhibitor CID755673 in human primary monocytes. The results suggest that morphine-induced MOR activation results in up-regulation of miRNA expression human monocytes and this may regulate monocyte and/or macrophage function thought PKCμ/Ras/Raf/ERK signaling pathway. / Molecular Biology and Genetics

CD4 T cell homeostasis and competency are critical for the effectiveness of antiviral immunity. However, CD4 T cells derived from people living with HIV (PLWH) and individuals with chronic HCV infection often exhibit an inflammaging phenotype, evidenced by persistent inflammation, immune activation, exhaustion, senescence, and cellular apoptosis. Despite intensive investigations, the molecular mechanisms underlying CD4 T cell dysfunction in antiretroviral therapy (ART)-controlled PLWH and HCV-infected patients remain poorly understood. By investigating the roles of non-coding (nc)RNA transcripts in regulating the functions of CD4 T cells derived from PLWH and HCV-infected patients, we demonstrated that long non-coding (lnc)RNA - growth arrest-specific transcript 5 (GAS5) - is downregulated and plays a crucial role in regulating CD4 T cell functions through and beyond the microRNA (miR)-21-mediated signaling network. Our data suggest that disrupting the GAS5-miR21 axis may restore CD4 T cell homeostasis and competency during latent HIV infection and prevent premature CD4 T cell aging or immune senescence. Moreover, our results also showed that TRF2, a component of the shelterin complex maintaining the integrity of telomeres, is post-transcriptionally inhibited, which is one of the major forces driving cellular dysregulation in CD4 T cells from PLWH and HCV patients. Importantly, our study identified miR-23a as the key regulator of TRF2 translational expression by targeting its 3’UTR in CD4 T cells and that targeting miR-23a may restore the TRF2 protein level, and thereby reconstitute CD4 T cell homeostasis and competency to rescue CD4 T cells from premature aging and immunosenescence during latent HIV infection. The findings from these studies improved our understanding and knowledge of how ncRNA-mediated networks regulate the functions of CD4 T cells during chronic viral (HIV and HCV) infections. Understanding such mechanisms is important for developing therapeutic approaches to reverse the inflammaging phenotype observed in CD4 T cells from ART-controlled PLWH and chronically HCV-infected patients to improve their immunological functions and quality of life.

INTRODUÇÃO: A propensão do CaP em gerar metástases decorre de mecanismos moleculares específicos em um processo composto por múltiplas etapas, sendo que o remodelamento do meio extracelular através de ações de enzimas proteolíticas denominadas metaloproteinases da matriz (MMP) é uma etapa fundamental. As MMP degradam vários componentes da matriz extracelular, sendo que seu controle pode ser exercido por outras proteínas denominadas TIMPs. Em nível gênico, outro controle pode ser exercido por moléculas chamadas microRNAs. OBJETIVO: O objetivo deste estudo é avaliar a regulação da MMP-9 por miRNAs. A partir de dados da literatura identificamos que a MMP-9 pode sofrer influência do miR-21 e 338-3p. MÉTODOS: Para os experimentos in vitro, linhagens celulares de CaP (DU145, PC3 e LNCaP) foram transfectadas com os miRNAs de interesse e a expressão de MMP-9 foi avaliada por reação em cadeia de polimerase quantitativa com transcriptase reversa (qRT-PCR). O sobrenadante da transfecção foi usado para ensaios de invasão com matrigel, e ELISA. Nos experimentos in vivo, células da linhagem PC-3-luc foram implantadas no subcutâneo de camundongos Balb-c nude e tratadas com injeções de anti-miR-21, miR-338-3p ou a combinação de ambos. RESULTADOS: O miR-21 aumentou expressão de MMP-9 em 72% na PC3. Houve maior invasão celular tanto na PC3 como DU145. In vivo, o bloqueio do miR-21 reduziu em 10% a expressão de MMP-9 nos tumores implantados (p=0,04). O miR-338-3p reduziu a expressão de MMP-9 em 53% na PC3 (p=0,001), 31% na LnCaP (p=0,23) e 24% na DU145 (p=0,16). No ensaio de invasão, menor número de células e colônias foram capazes de invadir a membrana de matrigel. In vivo, houve redução de 27% na expressão de MMP-9 nos camundongos tratados com o miR-338-3p (p=0,07). A combinação anti-miR-21+miR-338-3p reduz a expressão de MMP-9 em maior intensidade tanto in vitro como in vivo. CONCLUSÕES: A expressão de MMP-9 pode ser regulada pelo miR-21 e miR-338-3p. O primeiro se comporta como um oncomiR ao passo que o segundo como um supressor tumoral. A combinação de miRNAs é uma estratégia plausível para ampliar o efeito sobre expressão de genes de interesse / INTRODUCTION: The propensity of CaP to generate metastases results from specific molecular mechanisms in a multiphase process and the remodeling of the extracellular medium through the actions of proteolytic enzymes called matrix metalloproteinases (MMP) is a fundamental step. MMPs degrade several components of the extracellular matrix, and their control can be exerted by other proteins called TIMPs. At the gene level, another control can be exerted by molecules called microRNAs. OBJECTIVE: The objective of this study is to evaluate the regulation of MMP-9 by miRNAs. From literature data we have identified that MMP-9 may be influenced by miR-21 and 338-3p. METHODS: For in vitro experiments, CaP cell lines (DU145, PC3 and LNCaP) were transfected with the miRNAs of interest and the expression of MMP-9 was assessed by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). The transfection supernatant was used for matrigel and ELISA invasion assays. For the in vivo experiments, PC3-luc cells were implanted into the subcutaneous Balb-c nude mice and treated with anti-miR-21, miR-338-3p injections or the combination of both. RESULTS: The miR-21 increased MMP-9 expression by 72% in PC3. There was greater cell invasion in both PC3 and DU145. In vivo, miR-21 blockade reduced MMP-9 expression by 10% in implanted tumors (p = 0.04). MiR-338-3p reduced MMP-9 expression by 53% in PC3 (p = 0.001), 31% in LNCaP (p = 0.23), and 24% in DU145 (p = 0.16). In the invasion assay, fewer cells and colonies were able to invade the matrigel membrane. In vivo, there was a 27% reduction in MMP-9 expression in mice treated with miR-338-3p (p = 0.07). The combination of anti-miR-21 + miR-338-3p reduces MMP-9 expression in greater intensity both in vitro and in vivo. CONCLUSIONS: MMP-9 expression can be regulated by miR-21 and miR-338-3p. The former behaves as an oncomyR while the second as a tumor suppressor. The combination of miRNAs is a plausible strategy to extend the effect on gene expression of interest