The identification of several evolutionary young miRNAs, which arose in primates, raised several possibilities for the role of such miRNAs in human-specific disease processes. We previously have identified an evolutionary young miRNA, miR-1290, to be essential in neural stem cell proliferation and neuronal differentiation. Here, we show that miR-1290 is significantly downregulated during neuronal differentiation in reprogrammed induced pluripotent stem cell- (iPSC-) derived neurons obtained from idiopathic autism spectrum disorder (ASD) patients. Further, we identified that miR-1290 is actively released into extracellular vesicles. Supplementing ASD patient-derived neural stem cells (NSCs) with conditioned media from differentiated control-NSCs spiked with “artificial EVs” containing synthetic miR-1290 oligonucleotides significantly rescued differentiation deficits in ASD cell lines. Based on our earlier published study and the observations from the data presented here, we conclude that miR-1290 regulation could play a critical role during neuronal differentiation in early brain development.

Recent spread of the promoter variant (4-κB) Human immunodeficiency virus-1 clade C (HIV-1C) strain is attributed to duplication of the Nuclear Factor Kappa B (NF-κB) binding sites and potential increased heroin consumption in India. To study the underlying biology of 4-κB HIV-1C in rhesus macaques, we engineered a promoter-chimera variant (4NF-κB) Simian Human Immunodeficiency Virus (SHIV) by substituting the HIV-1C Long Terminal Repeat (LTR) region consisting of 4 NF-κB and 3 Sp-1 sites with the corresponding segment in the LTR of SHIV AD8EO. The wild-type (3NF-κB) promoter-chimera SHIV was generated by inactivating the 5 ′ proximal NF-κB binding site in SHIV 4NF-κB. CD8-depleted rhesus macaque PBMCs (RM-PBMCs) were infected with the promoter-chimera and AD8EO SHIVs to determine the effects of opioid-exposure on inflammation, NF-κB activation, neurotoxicity in neuronal cells and viral replication. Morphine-exposure of RM-PBMCs infected with SHIVs 4NF-κB, 3NF-κB, and AD8EO altered cellular transcript levels of monocyte chemoattractant protein 1, interleukin 6, interleukin 1β, and Tumor Necrosis Factor α. Of note, divergent alteration of the cytokine transcript levels was observed with these promoter-chimera wild-type and variant SHIVs. NF-κB activation was observed during infection of all three SHIVs with morphine-exposure. Finally, we observed that SHIV AD8EO infection and exposure to both morphine and naloxone had the greatest impact on the neurotoxicity. The promoter-chimera SHIV 4NF-κB and SHIV 3NF-κB did not have a similar effect on neurotoxicity as compared to SHIV AD8EO. All SHIVs replicated efficiently at comparable levels in RM-PBMCs and morphine-exposure did not alter viral replication kinetics. Future in vivo studies in rhesus macaques will provide greater understanding of 4-κB HIV-1C viral immunopathogenesis and onset of disease in the central nervous system during morphine-exposure.

Due to the large geographical overlap of populations exposed to Zika virus (ZIKV) and human immunodeficiency virus (HIV), understanding the disease pathogenesis of co-infection is urgently needed. This warrants the development of an animal model for HIV-ZIKV co-infection. In this study, we used adult non-pregnant macaques that were chronically infected with simian immunodeficiency virus/chimeric simian human immunodeficiency virus (SIV/SHIV) and then inoculated with ZIKV. Plasma viral loads of both SIV/SHIV and ZIKV co-infected animals revealed no significant changes as compared to animals that were infected with ZIKV alone or as compared to SIV/SHIV infected animals prior to ZIKV inoculation. ZIKV tissue clearance of co-infected animals was similar to animals that were infected with ZIKV alone. Furthermore, in co-infected macaques, there was no statistically significant difference in plasma cytokines/chemokines levels as compared to prior to ZIKV inoculation. Collectively, these findings suggest that co-infection may not alter disease pathogenesis, thus warranting larger HIV-ZIKV epidemiological studies in order to validate these findings.

PP2A holoenzymes are the majority of Ser/Thr phosphatases in human cells and each PP2A complex contains one scaffold subunit, one catalytic subunit, and one regulatory subunit. PP2A regulatory subunits, existing in four sub-families encoded by 15 genes, determine the substrate specificities and intracellular localizations of PP2A. We previously reported an essential role for PR55α, a PP2A regulatory subunit, in the support of malignant potential of pancreatic cancer cells, which includes promoting YAP-activation that supports anchorage-independent growth and metastasis. Furthermore, our data showed that PR55α level is elevated in pancreatic cancer relative to normal tissues and high PR55α levels correlate with poor patient survival. The studies in this report reveal a novel mechanism by which the p53 tumor suppressor negatively regulates PR55α protein stability. The results show that p53 inactivation by siRNA-knockdown, gene-deletion, HPV-E6 promoted degradation, or p53R175H mutant expression all results in the increase of PR55α expression. Subsequent studies demonstrate that this p53 function is mediated through its target gene FBXL20, a substrate recognition component of the SCF (Skp_Cullin_F-box) ubiquitin ligase complex that facilitates proteasomal degradation. As a result, the expression of mutant p53R175H in human pancreatic ductal cells mimics the PR55α effect, increasing c-Myc protein stability, and promoting anchorage-independent proliferation. Additionally, FBXL20 mRNA levels are significantly reduced in pancreatic cancers relative to normal control, and low FBXL20 levels correlate with poor patient survival, both of which inversely resemble the pathological effects of PR55α in pancreatic cancer. Collectively, these results define a novel p53 function in the suppression of PR55α expression. Citation Format: Ying Yan, Lepakshe Madduri, Nichole Brandquist, Chitra Palanivel, Sumin Zhou, Charles Enke, Michel Ouellette. p53/FBXL20 axis negatively regulates the protein stability of PR55α, a PP2A regulatory subunit [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1986.

Due to the large geographical overlap of populations exposed to Zika virus (ZIKV) and human immunodeficiency virus (HIV), understanding disease pathogenesis in such coinfections is urgently needed. We used chronically infected simian immunodeficiency virus and chimeric simian human immunodeficiency virus (SIV/SHIV) macaques and inoculated with ZIKV. Plasma viral loads of both SIV/SHIV and ZIKV showed no significant changes as compared to ZIKV alone-infected animals. Tissue clearance of ZIKV was observed similarly. Furthermore, minimal changes in cytokines/chemokines were observed. Collectively, these data suggest that coinfection may not alter disease pathogenesis and warrants large HIV-ZIKV epidemiological studies to validate these findings.Author SummaryThe co-infection incidence of human immunodeficiency virus (HIV) infection and neglected tropical infectious diseases is increasing due to the large geographical overlap of populations exposed to both of these viruses. Thus, researching on such coinfection is of particular importance. In this study, we investigated HIV-ZIKV coinfection dynamics in adult non-pregnant Rhesus Macaques model chronically infected with simian immunodeficiency virus (SIV) - or chimeric simian human immunodeficiency virus (SHIV). We found that post ZIKV inoculation, plasma viral loads were similar to ZIKV alone infected animals in addition to minimal changes of cytokines. Dynamics of SIV and SHIV also did not change. Tissue clearance of ZIKV was found 67 months later. Our findings provide insights into HIV-ZKIV coinfection to determine the alteration of their pathogenesis.

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