Chronic Administration of Δ ⁹ -Tetrahydrocannabinol Induces Intestinal Anti-Inflammatory MicroRNA Expression during Acute Simian Immunodeficiency Virus Infection of Rhesus Macaques

Abstract

Recreational and medical use of cannabis among human immunodeficiency virus (HIV)-infected individuals has increased in recent years. In simian immunodeficiency virus (SIV)-infected macaques, chronic administration of ⌬9 -tetrahydrocannabinol (⌬ 9 -THC) inhibited viral replication and intestinal inflammation and slowed disease progression. Persistent gastrointestinal disease/inflammation has been proposed to facilitate microbial translocation and systemic immune activation and promote disease progression. Cannabinoids including ⌬ 9 -THC attenuated intestinal inflammation in mouse colitis models and SIV-infected rhesus macaques. To determine if the anti-inflammatory effects of ⌬ 9 -THC involved differential microRNA (miRNA) modulation, we profiled miRNA expression at 14, 30, and 60 days postinfection (days p.i.) in the intestine of uninfected macaques receiving ⌬ 9 -THC (n ‫؍‬ 3) and SIV-infected macaques administered either vehicle (VEH/ SIV; n ‫؍‬ 4) or THC (THC/SIV; n ‫؍‬ 4). Chronic ⌬ 9 -THC administration to uninfected macaques significantly and positively modulated intestinal miRNA expression by increasing the total number of differentially expressed miRNAs from 14 to 60 days p.i. At 60 days p.i., ϳ28% of miRNAs showed decreased expression in the VEH/SIV group compared to none showing decrease in the THC/SIV group. Furthermore, compared to the VEH/SIV group, THC selectively upregulated the expression of miR-10a, miR-24, miR-99b, miR-145, miR-149, and miR-187, previously been shown to target proinflammatory molecules. NOX4, a potent reactive oxygen species generator, was confirmed as a direct miR-99b target. A significant increase in NOX4 ؉ crypt epithelial cells was detected in VEH/SIV macaques compared to the THC/SIV group. We speculate that miR-99b-mediated NOX4 downregulation may protect the intestinal epithelium from oxidative stress-induced damage. These results support a role for differential miRNA induction in THC-mediated suppression of intestinal inflammation. Whether similar miRNA modulation occurs in other tissues requires further investigation. IMPORTANCE Gastrointestinal (GI) tract disease/inflammation is a hallmark of HIV/SIV infection. Previously, we showed that chronic treatment of SIV-infected macaques with ⌬9 -tetrahydrocannabinol (⌬ 9 -THC) increased survival and decreased viral replication and infection-induced gastrointestinal inflammation. Here, we show that chronic THC administration to SIV-infected macaques induced an anti-inflammatory microRNA expression profile in the intestine at 60 days p.i. These included several miRNAs bioinformatically predicted to directly target CXCL12, a chemokine known to regulate lymphocyte and macrophage trafficking into the intestine. Specifically, miR-99b was significantly upregulated in THC-treated SIV-infected macaques and confirmed to directly target NADPH oxidase 4 (NOX4), a reactive oxygen species generator known to damage intestinal epithelial cells. Elevated miR-99b expression was associated with a significantly decreased number of NOX4...

Longitudinal Examination of the Intestinal Lamina Propria Cellular Compartment of Simian Immunodeficiency Virus-Infected Rhesus Macaques Provides Broader and Deeper Insights into the Link between Aberrant MicroRNA Expression and Persistent Immune Activation

“…We recently demonstrated that chronic ⌬ 9 -THC administration induced the expression of several anti-inflammatory miRNAs in the intestines of SIV-infected macaques compared to those receiving vehicle (45). In the same study, THC treatment prevented the downregulation of miR-150 (45), indirectly suggesting that THC inhibits immune activation by modulating miRNA expression.…”

Behavioral, Metabolic, and Immune Consequences of Chronic Alcohol or Cannabinoids on HIV/AIDs: Studies in the Non-Human Primate SIV Model

“…Our most recent findings show selective upregulation of miR-10a, miR-24, miR-99b, miR-145, miR-149 and miR-187 expression in the duodenum of THC-treated SIV-infected macaques. These miRs, particularly miR-99b, have been shown to target proinflammatory molecules including NOX4, which may serve to protect the intestinal epithelium from oxidative stress-induced damage (Chandra et al 2014). Others have shown a role for CB2-mediated attenuation of pro-inflammatory cytokine-mediated mucosal damage without direct effects on human colonic mucosal epithelial barrier function (Harvey et al 2013).…”

Δ9-Tetrahydrocannabinol (Δ9-THC) Promotes Neuroimmune-Modulatory MicroRNA Profile in Striatum of Simian Immunodeficiency Virus (SIV)-Infected Macaques

“…These findings provide evidence that these protective effects may derive, in part, from Δ9-THC-dependent changes in the expression of miRs (Chandra et al 2015; Molina et al 2014). The functional consequences of alterations in miR are not yet fully understood.…”

“…Chronic administration of Δ9-THC [or 0.05ml/kg VEH] was started four weeks before SIV infection at 0.18 mg/kg. Similar to previous studies, the dose was increased to 0.32 mg/kg over two weeks and continued for the entire duration of the study (Chandra et al 2015; Molina et al 2014). Vehicle-treated animals were further assigned to no infection (Group 1; VEH, n=2) or intravenous inoculation with 100 TCID50 of SIVmac251 (Group 2; VEH/SIV, n=4).…”