[PMC free article] [PubMed] [CrossRef] [Google Scholar] 2. to activate HIV-1 similar to that of suberoylanilide hydroxamic acid or phorbol 12-myristate 13-acetate using latently infected cell models. These findings improve our understanding of lncRNA regulation of HIV-1 replication and latency, providing new insights into potential targeted therapeutic interventions. IMPORTANCE The latent viral reservoir is the primary obstacle to curing HIV-1 Salinomycin sodium salt disease. To date, only a few lncRNAs, which play major roles in various biological processes, including viral infection, have been identified as regulators in HIV-1 latency. In this study, we demonstrated that lncRNA uc002yug.2 is important for both HIV-1 replication and activation of latent viruses. Moreover, uc002yug.2 was shown to activate latent HIV-1 through regulating alternative splicing of RUNX1 and increasing the expression of Tat protein. These findings highlight the potential merit of targeting lncRNA uc002yug.2 as an activating agent for latent HIV-1. = 12) and HIV-1 patients who had not received HAART (= 12) were detected by qRT-PCR. The geometric means of the -actin, GAPDH, and HMBS genes were used for normalization. (B) The HIV-1 Salinomycin sodium salt loads and uc002yug.2 RNA levels of HIV-1-infected patients who had not received HAART were plotted, and linear regression analysis was performed. The geometric means of the -actin, GAPDH, and HMBS genes were used for normalization. (C) uc002yug.2 increases viral replication. Primary CD4+ T lymphocytes from healthy donors were nucleofected with uc002yug.2 or control vector and then were infected with HIV-1 NL4-3. HIV-1 production in the supernatant was quantified with p24 ELISA at indicated time points postinfection. (D) uc002yug.2 increases HIV-1 reactivation in primary resting Rabbit Polyclonal to MMP-8 CD4+ T cells from patients. Resting CD4+ T cells were isolated from HAART-treated patients and nucleofected with Salinomycin sodium salt uc002yug.2 or control vector. P1 to P3 represent three patients. HIV-1 reactivation in CD4+ T cells upon PHA-M (5 ng/ml) stimulation was detected by measuring p24 levels in the supernatants by ELISA. DISCUSSION In the current study, we found that lncRNA uc002yug.2 plays an important role in the regulation of HIV-1 transcription and replication as well as reactivation of latent HIV-1. Due to different mRNA levels of uc002yug.2 in various cell lines (data not shown), we overexpressed uc002yug.2 in HeLa cells and stably infected HEK293T cells with a lentivirus encoding shRNA against lncRNA uc002yug.2 to detect its effect on HIV-1 replication. Ectopic expression of uc002yug.2 in HeLa cells potentially enhanced the replication of HIV-1 in a dose-dependent manner (Fig. 1A to ?toD).D). The depletion of uc002yug.2 in HEK293T cells reduced the replication and infectivity of HIV-1 by 35% (Fig. 1F and ?andG),G), while the mRNA level of RUNX1b and -1c was upregulated (Fig. 1E) as reported by Wu et al. (26). Further investigation confirmed that RUNX1b and -1c but not RUNX1a indeed strongly inhibited HIV-1 replication, in particular when combined Salinomycin sodium salt with CBF- (Fig. 2A and ?andB).B). Upon knockdown of RUNX1b and -1c with siRNA in uc002yug.2-sh cells, the reduced expression and infectivity of HIV-1 were restored compared to those in control uc002yug.2-sh cells (Fig. 2D and ?andE),E), indicating that upregulation of RUNX1b and -1c induced by uc002yug.2 partially contributed to the suppression of HIV-1 replication. Thus, we deduced that the upregulation of RUNX1b and -1c by knockdown of uc002yug.2 was the main determinant mediating the reduction in HIV-1 infectivity in HEK293T-uc002yug.2sh cells. Our data are consistent with the conclusion that RUNX1 and CBF- overexpression could reduce expression of viral proteins and viral replication, as reported by Klase et al. (30), and further demonstrate that RUNX1b and -1c but not RUNX1a could inhibit HIV-1 infectivity. We also observed that lncRNA uc002yug. 2 did not always downregulate RUNX1b and -1c. The depletion of uc002yug.2 indeed led to decreased RUNX1a and increased RUNX1b and -1c in HEK293T cells (Fig. 1E), whereas overexpression of uc002yug.2 or upregulated uc002yug.2 by replicating HIV-1 induced the increase in mRNA levels of all RUNX1 isoforms, including RUNX1a, -1b, and -1c, in Jurkat cells (Fig. 2I). These results indicated that uc002yug.2 had different regulatory effects on the expression of RUNX1 isoforms in different cell lines. Upregulation of RUNX1b and -1c in Jurkat cells might compromise the ability of uc002yug.2 to enhance the replication of HIV-1. However, another line of evidence was shown with latently infected cell lines J-Lat 6.3 and ACH-2, in which reactivation of HIV-1 replication using PMA stimulation increased along with increased uc002yug.2,.