We have investigated the mechanism of shikonin function on protection of dopaminergic neurons against 6-OHDA-induced neurotoxicity. Treatment of rat pheochromocytoma cell line PC12 by serial dilutions of shikonin determined 10 μM of the compound as its optimum concentration for protection saving nearly 70 % of the cells against toxicity. Reverse transcription-PCR analysis of shikonin-treated cells showed threefold increase in mRNA levels of glutathione peroxidase-1 (GPX-1) as a representative component of the intracellular anti-oxidant defense system. To elucidate shikonin-GPX1 relationships and maximize protection, we transduced PC12 cells using recombinant lentivirus vectors that harbored GPX-1 coding sequence. This change upregulated GPX-1 expression, increased peroxidase activity and made neuronal cells resistant to 6-OHDA-mediated toxicity. More importantly, addition of shikonin to GPX1-overexpressing PC12 cells augmented GPX-1 protein content by eightfold leading to fivefold increase of enzymatic activity, 91 % cell survival against neurotoxicity and concomitant increases in intracellular glutathione (GSH) levels. Depletion of intracellular GSH rendered all cell groups highly susceptible to toxicity; however, shikonin was capable of partially saving them. Subsequently, GSH-independent superoxide dismutase mRNA was found upregulated by shikonin. As signs of apoptosis inhibition, the compound upregulated Bcl-2, downregulated Bax, and prevented cell nuclei from undergoing morphological changes typical of apoptosis. Also, a co-staining method demonstrated GPX-1 overexpression significantly increases the percent of live cells that is maximized by shikonin treatment. Our data indicate that shikonin as an antioxidant compound protects dopaminergic neurons against 6-OHDA toxicity and enhances their survival via both glutathione-dependent and direct anti-apoptotic pathways.

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The multifactorial basis of preeclampsia (PE) implies that there are several genes and risk factors that are important in the development of the disease. Therefore, the exact etiology and pathogenesis of preeclampsia remains unclear. It is suggested that inappropriate regulation of the renin-angiotensin system (RAS) is a risk factor for hypertension during pregnancy. The angiotensin I-converting enzyme (ACE) serum level, a key component of the RAS, affects the blood pressure. It is hypothesized that the ACE gene polymorphisms contribute to preeclampsia development. In a case-control study containing 296 subjects (165 PE patients and 131 normotensive controls), we aimed to examine the association of the ACE gene I/D and rs4343 polymorphisms with preeclampsia in Iranian women. Genotyping for rs4343 and ACE I/D polymorphisms was performed by using TP-ARMS-PCR and conventional PCR, respectively. The rs4343 G allele frequency was higher in the case group (OR = 1.90, 95% CI, 1.37-2.65; P = 0.0001). Besides, a significant difference was detected for the genotype frequencies between the studied groups under dominant (OR = 3.94, 95% CI, 2.05-7.56; P < 0.0001) and recessive (OR = 2.21, 95% CI, 1.22-4.01; P = 0.009) inheritance models. For the I/D polymorphism, no significant differences were detected in the genotype and allele frequencies or any of the inheritance models between PE patients and controls. To verify the current results and validate the significance of the studied genetic variations, additional studies in diverse ethnic populations are required.

Multiple sclerosis (MS) is a common inflammatory disease of the central nervous system. Although the exact etiology of the disease is largely unknown, it is identified that cytokines may play an important role in the pathogenesis of MS. In this study, the effects of curcumin has been investigated on the expression levels of selected cytokine coding genes as well as the extent of demyelination in the corpus callosum of C57BL/6 experimental autoimmune encephalomyelitis (EAE) model of MS. Gene expression analyses revealed that treatment with curcumin could lead to a significant reduction in the expression levels of pro-inflammatory cytokine coding genes including IL-6 (p = 0.001), IL-17 (p = 0.001), tumor necrosis factor (TNF)-α (p = 0.008), and interferon (IFN)-γ (p = 0.033) as well as a significant increase in the expression level of transforming growth factor (TGF)-β (p = 0.006) as an anti-inflammatory cytokine.Moreover, the expression of glutathione peroxidase (GPX)-1 gene and the activity of anti-oxidant enzymes were significantly higher (p < 0.001) in curcumin-treated mice.Luxol fast blue staining also confirmed a significant reduction in the extent of demyelination in the curcumin-treated group (p < 0.001). Our results have confirmed that curcumin is an effective therapeutic agent that could ameliorate the severity of EAE.

Objective Nod-like receptor pyrin domain containing 3 ( NLRP3) gene encodes an intracellular receptor whose dysregulation in systemic lupus erythematosus (SLE) has been reported in multiple studies. Activation of NLRP3 inflammasome leads to the induction of inflammatory response via cleaving and producing of specific cytokines. In the present study, we assessed the possible association between three functional polymorphisms in this gene and SLE risk in the Iranian population. These variants include two gain of function (rs4612666 and rs10754558) and one loss of function (rs6672995) which are correlated with modulation of expression of NLRP3. Methods A case-control study involving 110 SLE patients and 116 control subjects was undertaken to estimate the frequency of rs4612666, rs10754558, and rs6672995 genotypes using real-time PCR high resolution melting method (HRM). Results Our findings revealed significant associations between GG genotype and G allele of rs10754558 with increased risk of SLE (OR for GG genotype= 2.82; 95%CI [1.45–5.46]/OR for G allele= 1.97; 95%CI [1.36–2.87]). Although, no significant associations were recognized between allele and genotype frequencies of rs4612666 and rs6672995 polymorphisms with SLE risk ( P > 0.05). Also, our analysis revealed that the C allele in rs4612666 and G allele in rs10754558 was correlated with the severity of disease activity (P < 0.001). Moreover, these common variants were associated with lower age of onset and some clinical symptoms in the patient group, such as skin manifestation, neurological symptom and, renal involvement (P < 0.05). Conclusion This study demonstrates a substantial association between NLRP3 polymorphisms with increased risk, clinical symptoms, and the severity of disease activity of SLE.