Recently identified a novel neuropeptide manserin colocalize with the TUNEL-positive cells in the top villi of the rat duodenum.

We recently isolated a novel 40 amino acid neuropeptide designated manserin from the rat brain. Manserin is derived from secretogranin II, a member of granin acidic secretory protein family by proteolytic processing, as previously reported secretoneurin and EM66. Manserin peptide are localized in the endocrine cells of the pituitary. In this study, we further investigated the manserin localization in the digestive system by immunohistochemical analysis using antimanserin antibody. In the duodenum, manserin immunostaining was exclusively observed in the nuclei of top villi instead of cytosol as observed in neurons in our previous study. Interestingly, manserin-positive cells in the duodenum are colocalized with terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) positive cells, the cells whose DNA was damaged. Since the top villi of duodenum epithelial cells are known to undergo spontaneous apoptosis during epithelial cell turn over, and since other peptides such as secretoneurin and EM66 derived from SgII have been reported to be cancer-related, these results indicated that manserin peptide may have a role in apoptosis and/or cancer pathogenesis in the digestive organ.     

Apoptosis in mouse taste buds after denervation

Apoptotic cells in the taste buds of mouse circumvallate papillae after the sectioning of bilateral glossopharyngeal nerves were examined by the method of DNA nick-end labeling (TUNEL), together with standard electron microscopy. The taste buds decreased in number and size 3–11 days after denervation and disappeared at 11 days. The TUNEL method revealed only a few positively stained nuclei in normal taste buds but, in those of mice 1–5 days after denervation, the number of positive nuclei had increased to 3–5 times that of taste buds from normal mice. Electron-microscopic observation after denervation demonstrated taste bud cells containing condensed and fragmentary nuclei in a cytoplasm with increased density. The results show that taste bud cells under normal conditions die by apoptosis at the end of their life span, and that gustatory nerve sectioning causes apoptosis of taste bud cells with taste buds decreasing in number and ultimately disappearing. Received: 20 November 1995 / Accepted: 15 May 1996     

The effect of beta glucan on MTX induced testicular damage in rats

We investigated the histopathological effects of methotrexate (MTX), a chemotherapeutic agent, and beta glucan (BG), an antioxidant, on rat testis. We used four groups of Sprague-Dawley male rats: MTX, MTX + BG, BG, and control. The MTX group was exposed to a single dose of MTX on the first day of experiment. The MTX + BG group was exposed to a single dose of MTX and BG on the first day of experiment followed by BG for 4 additional days. The BG group was exposed to BG for 5 days. The control group was given saline for 5 days. On day five, all animals were sacrificed and testicular tissue was evaluated for histopathology and the terminal deoxynucleotidyl transferase (TdT) deoxyuridine triphosphate nick-end labeling assay (TUNEL) was used to detect apoptosis. The apoptotic index (AI) and testicular damage increased in the MTX group compared to the other three groups. Histopathology was reduced in the MTX + BG group compared to the MTX group. Seminiferous tubule diameter was reduced in the MTX group compared to the BG group; we found no difference between control and BG groups. The thickness of th e germinal epithelium was reduced in the MTX group compared to the other groups. We found no difference in testicular weight among the groups. We compared body weight before and after the experiment; weights in the MTX and MTX + BG groups were significantly reduced compared to controls. In the control groups, we found a statistically significant increase in body weight, whereas there was no change in the BG group. We found that MTX causes deleterious effects on testicular tissue and that beta glucan may be protective.     

Detection of Apoptotic Cells in Vitro: A Practical Standardized Experimental Protocol Using Human Fibroblasts for Initial Laboratory Studies

This technical report presents a practical experimental protocol using human fibroblasts that is useful for initiating in situ methods for detection of apoptotic cells in vitro. The protocol details the growth of cells in multichamber wells, and includes a negative control, two positive controls, and untreated fibroblasts to be evaluated for apoptosis localization. Technical tips on handling of solutions, cell culture designs, and separation of slides by treatment are valuable steps for the laboratory beginning such studies. The methods proposed are both time and cost effective.     

Detection of apoptotic bodies in nickel-treated root apical cells of <Emphasis Type="Italic">Allium cepa</Emphasis>

Nickel, a phytotoxic metal, is easily taken up by plant roots. Excessive Ni in soil can induce programmed cell death in root tips. DNA fragmentation was assessed by deoxyuracyl nick end labeling with fluorescein mediated by terminal deoxynucleotide transferase (TUNEL). In control roots, programmed cell death was observed by using TUNEL assay in the root cap and xylem vessels. At moderate Ni²⁺ concentrations (10–25 µM), cortical cells also showed TUNEL-positive reaction, indicating the Ni-induced cell death. The Ni-induced cell death differs from natural cell death in the appearance of spherical bodies of condensed chromatin and formation of apoptotic bodies. These apoptotic bodies resemble those appearing during animal apoptosis.From Fiziologiya Rastenii, Vol. 52, No. 1, 2005, pp. 151–153.Original English Text Copyright © 2005 by Samadi, Behboodi.This article was presented by the authors in English.     

The antifungal plant defensin RsAFP2 from radish induces apoptosis in a metacaspase independent way in Candida albicans

We show that the antifungal plant defensin Raphanus sativus antifungal protein 2 (RsAFP2) from radish induces apoptosis and concomitantly triggers activation of caspases or caspase-like proteases in the human pathogen Candida albicans. Furthermore, we demonstrate that deletion of C. albicans metacaspase 1, encoding the only reported (putative) caspase in C. albicans, significantly affects caspase activation by the apoptotic stimulus acetic acid, but not by RsAFP2. To our knowledge, this is the first report on the induction of apoptosis with concomitant caspase activation by a defensin in this pathogen. Moreover, our data point to the existence of at least two different types of caspases or caspase-like proteases in C. albicans.     

Ovarian development and modes of apoptosis during oogenesis in various castes of the termite Reticulitermes aculabialis

Reproductive division in termites is the most significant biological process that leads to the formation of caste‐specific differences in tasks and status. However, little is known about the mechanism of reproductive division that underlies caste differentiation. In the present study, ovarian development and stage‐specific apoptotic patterns are investigated during oogenesis in reproductive, worker and soldier termites Reticulitermes aculabialis Tsai & Hwang. The results show that the mean lengths of the ovaries of reproductives are two‐fold longer compared with those of workers and six‐fold longer compared with soldiers. By contrast to the reproductives, the process of oogenesis in the workers includes only the oogonium differentiation stage (stage I) and oocyte growth stage (stage II), and oogenesis in the soldiers stops at stage I. Vitelogenic oocytes (stage III) are absent from workers and soldiers. During stage II in the reproductives and workers, the layer of follicle cells has a thickness of 7.56 ± 0.52 and 2.81 ± 0.34 µm, respectively. In addition, there are significant differences in the number and size of the germ cells at the same stage in the various castes. The existence of two apoptotic patterns during oogenesis is demonstrated by the terminal deoxynucleotidyl transferase‐mediated dUTP nick end labelling (TUNEL) assay. First, the majority of the cells showing apoptosis occur at stage I of oogenesis in reproductives, workers and soldiers. Second, DNA fragmentation is demonstrated by TUNEL staining of the follicle cell layers and oocytes at stage II in reproductives. Finally, the proliferation activity of follicle cells in the reproductives is observed by 5‐bromo‐2′‐deoxy‐uridine labelling. The level of oogenesis may explain the significant discrepancies in the reproductive capacity among the reproductives, soldiers and workers. These large discrepancies are controlled by apoptosis during early oogenesis.