Sitagliptin Attenuates the Cognitive Deficits in L-Methionine-Induced Vascular Dementia in Rats

Vascular dementia (VaD) is the second most prevalent type of dementia characterized by progressive cognitive deficits and is a major risk factor for the development of Alzheimer's disease and other neurodegenerative disorders. This study is aimed at determining the potential neuroprotective effect of sitagliptin (STG) on cognitive deficits in L-methionine-induced VaD in rats and the possible underlying mechanisms. 30 adult male Wistar albino rats were divided equally (n = 10) into three groups: control, VaD, and VaD + STG groups. The cognitive performance of the animals was conducted by open field, elevated plus maze, Y-maze, novel object recognition, and Morris water maze tests. Serum homocysteine, TNF-α, IL-6, IL-10, total cholesterol, and triglycerides levels were assessed together with hippocampal MDA, SOD, and BDNF. Histopathological and immunohistochemical assessments of the thoracic aorta and hippocampus (CA1 region) were also performed. Chronic L-methionine administration impaired memory and learning and induced anxiety. On the other hand, STG protected against cognitive deficits through improving oxidative stress biomarkers, inflammatory mediators, lipid profiles, and hippocampus level of BDNF as well as decreasing caspase-3 and GFAP and increasing Ki-67 immunoreactions in the hippocampus. Also, STG improved the endothelial dysfunction via upregulation of aortic eNOS immunoreaction. STG improved the cognitive deficits of L-methionine-induced VaD by its antioxidant, anti-inflammatory, antiapoptotic, and neurotrophic effects. These findings suggest that STG may be a promising future agent for protection against VaD.

Prognostic Impact of Genetic Variants of MECP2 and TIRAP on Clinical Outcomes of Systemic Lupus Erythematosus with and without Nephritis

Systemic lupus erythematosus (SLE) is a chronic autoimmune illness with a growing prevalence in many populations. Few studies have examined genetic predisposition to SLE, so we aimed to examine the clinical impact of the genetic polymorphisms MECP2 rs2734647and TIRAP rs8177374 on the outcomes and therapeutic precision of SLE with and without nephritis. This study included 110 SLE patients-divided into 63 with lupus nephritis (LN), and 47 without nephritis-and 100 controls. Laboratory measurements including CRP, ESR, ACR, CBC, anti-ds-DNA, vitamin A, C3, and C4 were carried out, along with genotyping of MECP2 rs2734647and TIRAP rs8177374 by real-time PCR and sequencing. Treg %, vitamin A, C3, and C4 were lower, whereas Th17 % was higher, in patients vs. controls (p < 0.001). The T allele of MECP2 rs2734647 was higher in LN than in non-nephritis and control subjects. Moreover, the T allele of TIRAP rs8177374 was higher in LN than in non-nephritis and control subjects. The MECP2 and TIRAP genes could play a role in predisposition to SLE, and can also predict disease progress to nephritis, helping to personalize medicine.