Systemic rosiglitazone administration leads to cementocytes apoptosis in wild type mice

It has been shown that a class of drugs for diabetes control, the thiazolidinediones, leads to increased apoptosis in osteocytes. Considering the correlations between osteocytes and cementocytes, the aim of this study was to demonstrate the apoptosis on cementocytes of wild type mice that had received rosiglitazone. Twenty-four male C57BL/6 mice were divided into 3 groups: 1 control, which received only the vehicle administration via oral for 1 week (PBS+DMSO 10%) and other two groups, which received 10 mg/kg of RGZ+PBS+DMSO 10% for 1 or 2 weeks, respectively. Upon completion of the time courses, mice were killed by CO2 and the mandibles were dissected and subjected to routine histotechnical processing. The sections were analyzed through transferase-mediated dUTP nick-end labeling (TUNEL) and 4’,6- diamidino-2-phenylindole (DAPI) staining of nuclear morphology (α=0.05). Control group showed significantly lower apoptotic cells/total cells ratio when compared to the experimental groups with TUNEL and DAPI methods (p=0.010 and 0.004, respectively). TUNEL method showed approximately 20% TUNEL-positive cementocytes in control and 26% in both experimental groups, while the DAPI technique showed approximately 32% of DAPI-positive cementocytes in control and 38% to 40% in experimental groups. The rosiglitazone systemic administration can lead to cementocytes apoptosis in mice. Despite the differences between the experimental and control groups, the death of cementocytes occurred as a physiological phenomenon, important in understanding the role of these cells in periodontal tissue.

The effects of feed naturally contaminated with Fusarium mycotoxins on the thymus in suckling piglets

In this study, feed naturally containing Fusarium mycotoxins was fed to gilts during the perinatal period, and the effects on the thymus were investigated in one-week-old piglets. Twenty gilts were divided into equal control (0.26 mg deoxynivalenol, DON) and experimental (5.08 mg DON, 0.09 mg zearalenone and 21.61 mg fusaric acid per kg of feed) groups. One suckling piglet from each litter (n = 20) was sacrificed at one week of age to obtain thymus samples for further analysis. The cortex to medulla ratio of the thymus was morphometrically analysed using NIS Elements BR (Nikon) software. Paraffin-embedded thymus sections were stained to quantify apoptosis (with terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling – TUNEL method), cellular proliferation (Ki-67) and macrophages (MAC 387). The results showed that the thymus cortex (P = 0.023) to medulla (P = 0.023) ratio was significantly lower in the experimental group. The number of apoptotic cells (cortex, P = 0.010, medulla, P = 0.001) and the number of proliferating cells in the thymus cortex (P = 0.001) and medulla (P < 0.001) were significantly higher in the experimental group. Our results indicate that feeding Fusarium mycotoxins to a parent animal during the perinatal period induces significant alterations in the thymus of one-week-old piglets, which indicates an immunosuppressive effect in piglets.

Ethanol-Induced Autophagy in Sertoli Cells Is Specifically Marked at Androgen-Dependent Stages of the Spermatogenic Cycle: Potential Mechanisms and Implications

In a recent study, we reported that acute ethanol exposure enhanced autophagy in Sertoli cells (SCs) of adult rats. However, further research is needed to clarify the specific spermatogenic stage exhibiting the highest autophagic response, the mechanisms behind such specificity, and the related relevance to sperm. This brief report provides results indicating that stages VII–VIII (androgen-dependent or spermiation stages) of the spermatogenic cycle exhibited more marked autophagic response in acute-ethanol treated rats (ETRs) than other stages based on suppression of androgen receptor (AR), analysis of microtubule-associated protein 1 light chain 3 (LC3) (an autophagosomal marker) immunostaining in SCs, double labeling of LC3 and lysosomal proteins and electron microscopy. Ultrastructural observations and TUNEL method revealed a notable presence of phagocytosed apoptotic germ cells and retained sperm in SCs of ETRs at these specific stages—a finding rarely observed in control testes. In addition, PTEN-induced putative kinase 1 ( PINK1) (a sensor of mitochondrial damage and mitophagy) and giant lipid droplets were found to have accumulated in SCs of ETRs at same stages. Our data show novel findings indicating that stages VII–VIII of the spermatogenic cycle exhibit high levels of autophagy, specifically under stress conditions, as expressed by the term autophagic stages. This stage-specific upregulation of autophagy in SCs may be related to AR suppression, mitochondrial damage, lipid accumulation, and phagocytosis of apoptotic cells. The phenomenon may be an essential part of ensuring the viability of SCs and supporting germ cells in toxic environments.

Effect of t (11; 19) (q23; p13.1) Gene on Proliferation and Apoptosis of SGC 7901 Gastric Cancer Cell Line

Objective: To investigate the effect of t (11; 19) (q23; p13.1) gene on proliferation and apoptosis 0f SGC 7901 gastric cancer cell line Methods: Gastric cancer cell line SGC 7901 cells were selected to transfect t (11; 19) (q23; p13.1) gene. MRNA levels of t (11; 19) (q23; p13.1) in each group were regulated after 24, 48 and 72h byRT- PCR. Cell proliferation was determined MTT assay. The apoptosis status of the SGC 7901 cells was detected TUNEL method. Immunohistochemical staining evaluated the expression of apoptotic genes Bcl-2 and Bax. Results: The MTT assay showed that t (11; 19) (q23; p13.1) decreased the proliferation of SGC 7901 cells. TUNEL method detected t (11; 19) (q23; p13.1) could improve apoptosis of SGC 7901 cells. In addition, t (11; 19) (q23; p13.1) could improve the expression of apoptotic gene Bcl-2 and reduce the expression of apoptotic gene Bax. Conclusion: T (11; 19) (q23; p13.1) gene can inhibit gastric cancer cell proliferation and improve apoptosis of gastric cancer cell.

Topical Administration of Bosentan Prevents Retinal Neurodegeneration in Experimental Diabetes

Experimental evidence suggests that endothelin 1 (ET-1) is involved in the development of retinal microvascular abnormalities induced by diabetes. The effects of ET-1 are mediated by endothelin A- and B-receptors (ETA and ETB). Endothelin B-receptors activation mediates retinal neurodegeneration but there are no data regarding the effectiveness of ETB receptor blockage in arresting retinal neurodegeneration induced by diabetes. The main aim of the present study was to assess the usefulness of topical administration of bosentan (a dual endothelin receptor antagonist) in preventing retinal neurodegeneration in diabetic (db/db) mice. For this purpose, db/db mice aged 10 weeks were treated with one drop of bosentan (5 mg/mL, n = 6) or vehicle (n = 6) administered twice daily for 14 days. Six non-diabetic (db/+) mice matched by age were included as the control group. Glial activation was evaluated by immunofluorescence using specific antibodies against glial fibrillary acidic protein (GFAP). Apoptosis was assessed by TUNEL method. A pharmacokinetic study was performed in rabbits. We found that topical administration of bosentan resulted in a significant decrease of reactive gliosis and apoptosis. The results of the pharmacokinetic study suggested that bosentan reached the retina through the trans-scleral route. We conclude that topical administration of bosentan was effective in preventing neurodegeneration in the diabetic retina and, therefore, could be a good candidate to be tested in clinical trials.

Silver Nanoparticles: Cytotoxic and Apoptotic Activity on HT-29 and A549 Cell Lines

Silver nanoparticles (Ag-NPs) are versatile materials with a broad range of applications in various fields such as cancer therapy, drug delivery. In this work, cytotoxic and apoptotic activities of silver nanoparticles was evaluation against lung (A549) and colon (HT-29) cell lines. The cytotoxic activity of nanoparticles was performed by MTT assay, while their apoptotic activity was tested through TUNEL method. The results of MTT of A549 have illustrate that fifty percent of cells destruction in concentrations more than 250 µg/ml of Ag-NPs. Apoptotic results of nanoparticles have shown more than fifty percent of apoptosis on A549 cell line. HT-29 display full apoptosis at concentrations more than 500 µg/ml. It seems that synthesized Ag-NPs by using P. farcta extract can be candidate as anti-cancer agent in treatment many cancers through creating or discovering new drug forms

Apoptosis in chicken ovarian follicles following in vitro exposure to TCDD, PCB 126 and PCB 153

The study was conducted in order to compare the in vitro effect of 2,3,7,8-tetrachlorodibenzo-pdioxin (TCDD), 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126) and 2,2′,4,4′,5,5′-hexachlorobiphenyl (PCB 153) on the number of apoptotic cells and the activity of caspase-3 in chicken ovarian follicles. The ovarian stroma, white (WF) and yellowish (YF) prehierarchical follicles and fragments of the theca and granulosa layers of the 3 largest preovulatory follicles (F3-F1) were in vitro exposed to TCDD (10 nM), PCB 126 (10 nM) and PCB 153 (10 μM) for 24 h. After incubation the number of apoptotic cells and caspase-3 activity were determined by TUNEL method and fluorometric assay, respectively. PCB 126 and PCB 153 increased the number of apoptotic cells in the ovarian stroma while TCDD and PCB 126 elevated it in the WF follicles. Under the control conditions, caspase-3 activity steadily increased along with maturation of the follicles, reaching the highest level in the theca layer of the F1 follicle. The activity of this enzyme in the granulosa layer of F3-F1 follicles was on average 60% lower in comparison to the stroma. Exposure to TCDD elevated caspase-3 activity in prehierarchical follicles and in the granulosa layer of F2 and F1 preovulatory follicles. On the contrary, PCB 126 exerted a suppressive effect on caspase-3 activity in the WF follicles and the granulosa layer of the F2 follicle, and PCB 153 in the theca layer of F2 and F1 and the granulosa layer of the F3 follicle. In conclusion, the results indicate that TCDD and PCBs affect apoptosis in chicken ovarian follicles and in consequence may disrupt follicle development.