Death of adrenocortical cells during murine acute T. cruzi infection is not associated with TNF-R1 signaling but mostly with the type II pathway of Fas-mediated apoptosis

Very early environmental enrichment protects against apoptosis and improves functional recovery from hypoxic-ischemic brain injury

Appropriate rehabilitation of stroke patients at a very early phase results in favorable outcomes. However, the optimal strategy for very early rehabilitation is at present unclear due to the limited knowledge on the effects of very early initiation of rehabilitation based on voluntary exercise (VE). Environmental enrichment (EE) is a therapeutic paradigm for laboratory animals that involves complex combinations of physical, cognitive, and social stimuli, as well as VE. Few studies delineated the effect of EE on apoptosis in very early stroke in an experimental model. Although a minimal benefit of early rehabilitation in stroke models has been claimed in previous studies, these were based on a forced exercise paradigm. The aim of this study is to determine whether very early exposure to EE can effectively regulate Fas/FasL-mediated apoptosis following hypoxic-ischemic (HI) brain injury and improve neurobehavioral function. C57Bl/6 mice were housed for 2 weeks in either cages with EE or standard cages (SC) 3 h or 72 h after HI brain injury. Very early exposure to EE was associated with greater improvement in motor function and cognitive ability, reduced volume of the infarcted area, decreased mitochondria-mediated apoptosis, and decreased oxidative stress. Very early exposure to EE significantly downregulated Fas/FasL-mediated apoptosis, decreased expression of Fas, Fas-associated death domain, cleaved caspase-8/caspase-8, cleaved caspase-3/caspase-3, as well as Bax and Bcl-2, in the cerebral cortex and the hippocampus. Delayed exposure to EE, on the other hand, failed to inhibit the extrinsic pathway of apoptosis. This study demonstrates that very early exposure to EE is a potentially useful therapeutic translation for stroke rehabilitation through effective inhibition of the extrinsic and intrinsic apoptotic pathways.

Trigeminal neuralgia causes neurodegeneration in rats associated with upregulation of the CD95/CD95L pathway

Objectives

To explore the effects of trigeminal neuralgia on neurodegeneration in rats and the underlining mechanism.

Methods

Sixty adult male Sprague Dawley rats were divided randomly into Chronic Constriction Injury of the Rat’s Infraorbital Nerve (ION-CCI) group and sham group (n = 30). Right suborbital nerve was ligated in ION-CCI group to establish a trigeminal neuralgia model. In sham group, suborbital nerve was exposed without ligation. Pain thresholds were measured before surgery and 1, 7, 15, and 30 days after surgery (n = 10). Morris water maze tests (n = 10) were conducted at 1, 15, and 30 days after surgery to evaluate the changes in learning and memory ability of rats. At 5, 19, and 34 days after surgery, serum S100β protein concentration and hippocampal Aβ1-42 protein expression were detected by enzyme-linked immunosorbent assay; total tau protein expression was detected by Western blotting; changes of neurons in hippocampus were observed by Nissl staining; and the expression of ^ser404p-tau, cluster of differentiation (CD)95, CD95L, and cleaved caspase-3 proteins was detected by immunofluorescence and Western blotting.

Results

Hyperalgesia occurred in ION-CCI group, and mechanical pain threshold decreased significantly (P < 0.05). On the 15th and 30th days after surgery, ION-CCI group showed lower learning and memory ability than sham group (P < 0.05). Serum S100β protein concentration, hippocampal A β1-42, and ^ser404p-tau protein expression increased in the ION-CCI group 19 and 34 days after surgery (P < 0.05), hippocampal CD95 expression increased in the ION-CCI group after surgery (P < 0.05), hippocampal CD95L expression increased at 19 and 34 days after surgery (P < 0.05), and cleaved caspase-3 expression increased at 5 and 19 days after surgery (P < 0.05). Nissl bodies in ION-CCI group decreased significantly at 15 days after surgery. The expression of cleaved caspase-3 protein in ION-CCI group was positively correlated with the expression of CD95 and CD95L (P < 0.05).

Conclusions

Trigeminal neuralgia may lead to neuronal inflammation and neuronal apoptosis associated with upregulation of CD95/CD95L expression, thus causing neurodegeneration.

Immune-neuroendocrine and metabolic disorders in human and experimental T. cruzi infection: New clues for understanding Chagas disease pathology

Studies in mice undergoing acute Trypanosoma cruzi infection and patients with Chagas disease, led to identify several immune-neuroendocrine disturbances and metabolic disorders. Here, we review relevant findings concerning such abnormalities and discuss their possible influence on disease physiopathology.

Ginsenoside Rg5 induces apoptosis and autophagy via the inhibition of the PI3K/Akt pathway against breast cancer in a mouse model

Breast cancer is the most frequently diagnosed cancer and has become the main cause of cancer-related death among women worldwide. Traditional chemotherapy for breast cancer has serious side effects for patients, such as the first-line drug docetaxel. Ginsenoside Rg5, a rare ginsenoside and the main ingredient extracted from fine black ginseng, has been proved to have anti-breast cancer efficacy in vitro. Here, the in vivo anti-breast cancer efficacy, side effects and potential molecular mechanisms of Rg5 were investigated on a BALB/c nude mouse model of human breast cancer. The tumor growth inhibition rate of high dose Rg5 (20 mg kg-1) was 71.4 ± 9.4%, similar to that of the positive control docetaxel (72.0 ± 9.1%). Compared to docetaxel, Rg5 showed fewer side effects in the treatment of breast cancer. Treatment with Rg5 induced apoptosis and autophagy in breast cancer tissues. Rg5 was proved to induce caspase-dependent apoptosis via the activation of the extrinsic death receptor and intrinsic mitochondrial signaling pathways. The autophagy induction was related to the formation of an autophagosome and accumulation of LC3BII, P62 and critical Atg proteins. Further studies showed that Rg5 in a dose-dependent manner induced apoptosis and autophagy through the inhibition of the PI3K/Akt signaling pathway as indicated by the reduced phosphorylation level of PI3K and Akt. Taken together, Rg5 could be a novel and promising clinical antitumor drug targeting breast cancer.

Evidence in Favor of an Alternative Glucocorticoid Synthesis Pathway During Acute Experimental Chagas Disease

It is well-established that infectious stress activates the hypothalamus-pituitary-adrenal axis leading to the production of pituitary adrenocorticotropin (ACTH) and adrenal glucocorticoids (GCs). Usually, GC synthesis is mediated by protein kinase A (PKA) signaling pathway triggered by ACTH. We previously demonstrated that acute murine Chagas disease courses with a marked increase of GC, with some data suggesting that GC synthesis may be ACTH-dissociated in the late phase of this parasitic infection. Alternative pathways of GC synthesis have been reported in sepsis or mental diseases, in which interleukin (IL)-1β, prostaglandin E2 (PGE2), and/or cAMP-activated guanine nucleotide exchange factor 2 (EPAC2) are likely to play a role in this regard. Accordingly, we have searched for the existence of an ACTH-independent pathway in an experimental model of a major parasitic disease like Chagas disease, in addition to characterizing potential alternative pathways of GC synthesis. To this end, C57BL/6 male mice were infected with T. cruzi (Tc), and evaluated throughout the acute phase for several parameters, including the kinetic of GC and ACTH release, the adrenal level of MC2R (ACTH receptor) expression, the p-PKA/PKA ratio as ACTH-dependent mechanism of signal transduction, as well as adrenal expression of IL-1β and its receptor, EPAC2 and PGE2 synthase. Our results reveal the existence of two phases involved in GC synthesis during Tc infection in mice, an initial one dealing with the well-known ACTH-dependent pathway, followed by a further ACTH-hyporesponsive phase. Furthermore, inflamed adrenal microenvironment may tune the production of intracellular mediators that also operate upon GC synthesis, like PGE2 synthase and EPAC2, as emerging driving forces for GC production in the advanced course of Tc infection. In essence, GC production seems to be associated with a biphasic action of PGE2, suggesting that the effect of PGE2/cAMP in the ACTH-independent second phase may be mediated by EPAC2.

Therapeutic effects of vaccine derived from amastigote surface protein-2 (ASP-2) against Chagas disease in mouse liver

This study investigated the efficacy of the vaccine in liver of mice infected with the Trypanosoma cruzi (T. cruzi) and immunized with AdASP-2. For this purpose, histopathological analysis and gene expression of COX-2, TNF-alpha, TNFR, iNOS, cytochrome C, caspase-3, TLR4, IL-6 and IL10 were evaluated. The following groups were used in this study: Group 1 - Control Group (CTRL) animals received AdβGal vehicle; Group 2 - Infected Group (TC) animals were infected with T. cruzi; Group 3 - Immunized Group (AdASP-2): animals were immunized by AdASP-2 vaccine; Group 4 - Immunized and Infected Group (AdASP-2+TC) animals were infected with T. cruzi and immunized by AdSP-2 vaccine. A significant decrease of amastigote nests was noticed in the group of animals that were immunized with AdASP-2 and infected on the same day. COX-2 and TNF-alpha gene expressions increased in TC group, whereas TNF-alpha decreased in the TC+AdASP-2 group. TNFR expression was high in AdASP-2+TC group. iNOS expression was high for all experimental groups whereas cytochrome C decreased for all experimental groups. Caspase 3 increased in TC and TC+AdASP-2 groups. The gene expression of TLR4 and IL-10 showed an increase in AdASP-2+TC group. Finally, hepatic fibrosis was noticed to TC and AdASP-2 + TC groups. Taken together, our results demonstrated that vaccination with AdASP-2 was effective against the acute phase of experimental Chagas disease as a result of a more powerful and rapid immune response closely related to expression of some inflammatory genes, such as iNOS, TNF-alpha, TLR 4, and IL-10.

MiR-152 Regulates Apoptosis and Triglyceride Production in MECs via Targeting ACAA2 and HSD17B12 Genes

Mammary epithelial cells (MECs) affect milk production capacity during lactation and are critical for the maintenance of tissue homeostasis. Our previous studies have revealed that the expression of miR-152 was increased significantly in MECs of cows with high milk production. In the present study, bioinformatics analysis identified ACAA2 and HSD17B12 as the potential targets of miR-152, which were further validated by dual-luciferase repoter assay. In addition, the expressions of miR-152 was shown to be negatively correlated with levels of mRNA and protein of ACAA2, HSD17B12 genes by qPCR and western bot analysis. Furthermore, transfection with miR-152 significantly up-regulated triglyceride production, promoted proliferation and inhibited apoptosis in MECs. Furthermore, overexpression of ACAA2 and HSD17B12 could inhibit triglyceride production, cells proliferation and induce apoptosis; but sh234-ACAA2-181/sh234-HSD17B12-474 could reverse the trend. These findings suggested that miR-152 could significantly influence triglyceride production and suppress apoptosis, possibly via the expression of target genes ACAA2 and HSD17B12.