Combination Antiretroviral Therapy (cART) in Diabetes Exacerbates Diabetogenic Effects on Hippocampal Microstructure, Neurogenesis and Cytokine Perturbation in Male Sprague Dawley Rats

Abstract

The increasing incidence of diabetes and HIV/AIDS–diabetes comorbidity in society has led to the prevalence of combination antiretroviral therapy (cART) in diabetes, with some reported neural effects. Therefore, the effects of cART and type two diabetes (T2D) on the hippocampal levels of cytokines, lipid peroxidation; histomorphology and neurogenesis were investigated. Adult male Sprague–Dawley rats were divided into four groups: DB (diabetic rats); DAV (diabetic rats treated with cART (efavirenz, emtricitabine and tenofovir); AV (normal rats treated with cART) and the NC group (with no treatment). Following ninety days of treatment, the rats were terminated, and the brains excised. Immunoassay (IL-1α, IL-6, TNFα and MDA); immunohistochemical (Ki67 and DCX) and cresyl violet histomorphology analyses were carried out on brain homogenates and sections, respectively. In comparison to the control, the results showed that cART significantly elevated the IL-6, TNFα and MDA levels, while DB and DAV significantly reduced the body weight, glucose tolerance, IL-1α, IL-6, TNFα and MDA levels. The hippocampal neuronal number was reduced in AV (dentate gyrus; DG region), in the DB group (Cornu Ammonis subregion 1; CA1 and DG regions only) and in DAV (all three hippocampal regions). Additionally, the expression of neurogenic markers Ki67 and doublecortin (DCX) were reduced in the diabetic group, with a greater reduction in the cART+T2D group compared to the control. Furthermore, the neuronal number at all hippocampal regions was negatively corelated with the diabetic parameters (FBG; fasting blood glucose, NFBG; non-fasting blood glucose, AUC; area under the glucose tolerance curve) but positively correlated with body weight. Additionally, the increase in the DG neuronal nuclei area of DB and DAV was significantly positively correlated with FBG, NFBG and AUC and inversely correlated with the estimated number of neurons and neurogenesis. These findings indicate that cART in diabetes (DAV) has similar effects as diabetes relative to the induction of oxidative stress and impairment of the cytokine immune response, but exacerbated neurotoxicity is observed in DAV, as shown by a significantly decreased DCX expression compared to DB and reduction in the number of Cornu Ammonis subregion 3 (CA3) hippocampal neurons, unlike in cART or the diabetes-alone groups.

Interactions of alcohol and combination antiretroviral (cART) drug in diabetic male Sprague Dawley rats: Hippocampal perturbations and toxicosis

“…The animals body weight was used to calculate the equivalent dose of cART which was added to gelatine pellets and daily fed to the animals orally. The other four groups consist of animals in which diabetes was induced using previously reported adapted protocol involving streptozotocin and fructose feeding [74] , [5] . These diabetic groups include, diabetic control, diabetic with no treatment (DB), diabetes and alcohol administration (DAL), diabetes and cART treatment (DAV), and diabetes, alcohol, and ART (DAA), all treatments commenced with the rats at 13 weeks of age-old and were carried out for 90 days after which animals were terminated, brains excised, and One hemisphere was fixed in 0.4 paraformaldehyde for histology and the other hemisphere was stored at − 80°C for immunoassay and molecular analysis.…”

“…Therefore, the presence of alcohol, cART and diabetes may induce perturbations in the normal physiological regulation of insulin receptors, BBB proteins, and cytokines which may induce a cascade of events associated with oxidative stress, apoptosis, and compromised neurogenesis which are all independently reported in alcohol, cART, and diabetes [54] , [67] , [72] , [26] . Similarly, diabetes, alcohol, and cART are independently associated with hippocampal and cognitive impairment [44] , [8] , [46] , [58] , and consequently their comorbidity (cART+ diabetes) showed an exacerbated effect [5] . However, the interaction of alcohol use with diabetes (alcohol +diabetes), the concomitant presence of cART and alcohol in the normal rat hippocampus (cART +alcohol), and in the diabetic hippocampus (alcohol + cART + diabetes) remains unclear.…”