Dilated Endoplasmic Reticulum Research Articles

Reversible neurotoxicity of kanamycin on dorsal cochlear nucleus

The time course of aminoglycoside neurotoxic effect on cochlear nucleus is still obscure. We examined dynamic pathological changes of dorsal cochlear nucleus (DCN) and investigated whether apoptosis or autophagy was upregulated in the neurotoxic course of kanamycin on DCN after kanamycin treatment. Rats were treated with kanamycin sulfate/kg/day at a dose of 500mg by subcutaneous injection for 10 days. Dynamic pathological changes, neuron density and neuron apoptosis of the DCN were examined at 1, 7, 14, 28, 56, 70 and 140 days after kanamycin treatment. The expressions of JNK1, DAPK2, Bcl-2, p-Bcl-2, Caspase-3, LC3B and Beclin-1 were also detected. Under transmission electron microscopy, the mitochondrial swelling and focal vacuoles as well as endoplasmic reticulum dilation were progressively aggravated from 1 day to 14 days, and gradually recovered from 28 days to 140 days. Meanwhile, both autophagosomes and autolysosomes were increased from 1 day to 56 days. Only few neurons were positive to the TUNEL staining. Moreover, neither the expressions of caspase-3 and DAPK2 nor neurons density of DCN changed significantly. LC3-II was drastically increased at 7 days. Beclin-1 was upgraded at 1 and 7 days. P-Bcl-2 increased at 1, 7, 14 and 28 days. JNK1 increased at 7 days, and Bcl-2 was downgraded at 140 days. LC3-B positive neurons were increased at 1, 7 and 14 days. These data demonstrated that the neurons damage of the DCN caused by kanamycin was reversible and autophagy was upregulated in the neurotoxic course of kanamycin on DCN through JNK1-mediated phosphorylation of Bcl-2 pathway.

The Histopathological Effect of Sildenafil Citrate on Superior Colliculus of Adult Male Rat

Objective: Preclinical and very limited clinical studies suggest that sildenafil may have therapeutic potential in selected neurological disorders. However, many neurological side effects of sildenafil have been reported. This work aimed to clarify the histopathological effect of sildenafil citrate on the superior colliculus (SC) of adult male albino rat. Material and methods: 24 adult male albino rats were used and divided into 4 groups. The first 3 groups were received respectively sildenafil citrate orally at doses 0.25, 0.70 and 1.43mg/kg body weight daily for 30 days while the 4 th group was used as control. At end of the treatment, the superior colliculi were undergone light and electron microscopic investigation. Results: In the control group, superficial part of the SC has neural cells and myelinated nerve fibers. With least dose of sildenafil, the superficial part of SC revealed disturbance in neural tissue with dilated capillaries and vacuoles. Some neurons showed deeply stained nuclei shrunken cytoplasm. Some cells showed enlarged mitochondria and dilated endoplasmic reticulum. With medium dose of sildenafil, SC showed more disturbances; stripped myelin sheaths or widely separated myelin lamellae, dilated blood vessels with large vacuoles around them and many neurons with apoptotic criteria. However, maximum dose of sildenafil induced massive destruction of edematous neural tissue; invasion of the surface with massive blood vessels, marked decrease in thickness of myelin sheaths and the neural cells revealed degenerative and apoptotic changes. The mean number and size of cells revealed significantly progressive decrease in all treated rats with increasing doses of the drug. Conclusion: Long-term, daily use of sildenafil can lead to pathological effect in the superior colliculus which may be implicated in visual disturbance and this effect is dose dependent, so neurological effect of sildenafil necessitates further investigations. © 2013 GESDAV

Liver-specificAquaporin 11knockout mice show rapid vacuolization of the rough endoplasmic reticulum in periportal hepatocytes after amino acid feeding

Aquaporin 11 (AQP11) is a protein channel expressed intracellularly in multiple organs, yet its physiological function is unclear. Aqp11 knockout (KO) mice die early due to malfunction of the kidney, a result of hydropic degeneration of proximal tubule cells. Here we report the generation of liver-specific Aqp11 KO mice, allowing us to study the role of AQP11 protein in liver of mice with normal kidney function. The unchallenged liver-specific Aqp11 KO mice have normal longevity, their livers appeared normal, and the plasma biochemistries revealed only a minor defect in lipid handling. Fasting of the mice (24 h) induced modest dilatation of the rough endoplasmic reticulum (RER) in the periportal hepatocytes. Refeeding with standard mouse chow induced rapid generation of large RER-derived vacuoles in Aqp11 KO mice hepatocytes. Similar effects were observed following oral administration of pure protein or larger doses of various amino acids. The fasting/refeeding challenge is associated with increased expression of markers of ER stress Grp78 and GADD153 and decreased glutathione levels, suggesting that ER stress may play role in the development of vacuoles in the AQP11-deficient hepatocytes. NMR-based metabolome analysis of livers from mice subject to amino acid challenge showed decreased amount of extractable metabolites in the AQP11-deficient livers and particularly a decrease in glucose levels. In conclusion, in the liver, deletion of AQP11 results in disrupted RER homeostasis and increased sensitivity to RER injury upon metabolic challenge with amino acids.

5-Benzylglycinyl-Amiloride Kills Proliferating and Nonproliferating Malignant Glioma Cells through Caspase-Independent Necroptosis Mediated by Apoptosis-Inducing Factor

5'-Βenzylglycinyl-amiloride (UCD38B) and glycinyl-amiloride (UCD74A) are cell-permeant and cell-impermeant derivatives of amiloride, respectively, and used here to identify the cellular mechanisms of action underlying their antiglioma effects. UCD38B comparably kills proliferating and nonproliferating gliomas cells when cell cycle progression is arrested either by cyclin D1 siRNA or by acidification. Cell impermeant UCD74A inhibits plasmalemmal urokinase plasminogen activator (uPA) and the type 1 sodium-proton exchanger with potencies analogous to UCD38B, but is cytostatic. In contrast, UCD38B targets intracellular uPA causing mistrafficking of uPA into perinuclear mitochondria, reducing the mitochondrial membrane potential, and followed by the release of apoptotic inducible factor (AIF). AIF nuclear translocation is followed by a caspase-independent necroptotic cell death. Reduction in AIF expression by siRNA reduces the antiglioma cytotoxic effects of UCD38B, while not activating the caspase pathway. Ultrastructural changes shortly following treatment with UCD38B demonstrate dilation of endoplasmic reticulum (ER) and mitochondrial swelling followed by nuclear condensation within hours consistent with a necroptotic cell death differing from apoptosis and from autophagy. These drug mechanism of action studies demonstrate that UCD38B induces a cell cycle-independent, caspase-independent necroptotic glioma cell death that is mediated by AIF and independent of poly (ADP-ribose) polymerase and H2AX activation.

Morphologic Changes of Corneal Epithelial Flap: Ethanol-mediated versus Mechanical Removal

Purpose: To evaluate morphologic changes in human corneal epithelial flap removed mechanically or after ethanol application.Method: Epithelial corneal flap was removed after ethanol application (20 eyes) or mechanically (19 eyes). Any changes were studied by transmission electron microscopy.Results: Thirty-nine eyes were enrolled in the study. The following changes were found in the alcohol-applied group: apoptotic cells, membrane-bound blebs with marked dilatation of endoplasmic reticulum, and short intercellular cleavage with approximately one-third of cell length depth. In mechanical debridement, cleavages extended more than half of the cell length by tearing hemidesmosomes.Conclusion: Alcohol application leads to cell damage in basal epithelial cells but cleavage plane remains smooth. Generally, none of the methods caused trauma to the basement membrane.

Vitiligo-Inducing Phenols Activate the Unfolded Protein Response in Melanocytes Resulting in Upregulation of IL6 and IL8

Vitiligo is characterized by depigmented skin patches due to loss of epidermal melanocytes. Oxidative stress may play a role in vitiligo onset, while autoimmunity contributes to disease progression. In this study we sought to identify mechanisms that link disease triggers and spreading of lesions. A hallmark of melanocytes at the periphery of vitiligo lesions is dilation of the endoplasmic reticulum (ER). We hypothesized that oxidative stress results in redox disruptions that extend to the ER, causing accumulation of misfolded peptides, which activates the unfolded protein response (UPR). We used 4-tertiary butyl phenol (4-TBP) and monobenzyl ether of hydroquinone (MBEH), known triggers of vitiligo. We show that expression of key UPR components, including the transcription factor X-box binding protein 1 (XBP1), are increased following exposure of melanocytes to phenols. XBP1 activation increases production of immune mediators interleukin-6 (IL6) and IL8. Co-treatment with XBP1 inhibitors reduced IL6 and IL8 production induced by phenols, while over-expression of XBP1 alone increased their expression. Thus, melanocytes themselves produce cytokines associated with activation of an immune response following exposure to chemical triggers of vitiligo. These results expand our understanding of the mechanisms underlying melanocyte loss in vitiligo and pathways linking environmental stressors and autoimmunity.

Impairment of endoplasmic reticulum in liver as an early consequence of the systemic inflammatory response in rats

It is well known that systemic inflammatory response (SIR) often causes liver dysfunction. The aim of this study was to identify the intracellular compartment in the liver most susceptible to SIR. We analyzed morphology, ultrastructure, proteome, and expression of relevant genes in livers of rats subjected to endotoxic shock. Histological examination revealed that focal necrosis in liver was insignificant to explain liver dysfunction. Electron microscopy revealed no morphological changes in the mitochondrial structure and in the cytosol, but dilated endoplasmic reticulum (ER) cisterns were frequently observed. Apoptosis was found in white blood cells within liver tissue but not in hepatocytes. Mitochondrial, ER, and cytosolic fractions were subjected to proteome analysis by difference gel electrophoresis, and the protein spots with the highest degree of differential regulation were identified with mass spectrometry. The most pronounced proteome changes appeared in the ER, manifested as a remarkable downregulation of several proteins essential for ER functions, such as protein synthesis and transport, whereas the changes in mitochondrial and cytosolic fractions suggested a compensatory response. ER stress, as an underlying mechanism for ER impairment, was confirmed by analysis of upstream (splicing X-box-binding protein 1 mRNA) and downstream (e.g., 78-kDa glucose-regulated protein mRNA) markers, suggesting ongoing unresolved ER stress as a cause for ER dilation. Because ER is the intracellular compartment responsible for the major liver functions, our data suggest that inflammatory mediators induce unresolved ER stress, resulting in the biochemical, functional, and morphological impairment of ER that in turn causes liver dysfunction. The pathway activating ER stress in response to SIR is not known yet.

Effect of Trichlorfon on Hepatic Lipid Accumulation in Crucian Carp Carassius auratus gibelio

This study evaluated the toxic effects of the organophosphate pesticide trichlorfon on hepatic lipid accumulation in crucian carp Carassius auratus gibelio. Seventy-five fish were divided into five groups (each group in triplicate), and then exposed to 0, 0.5, 1.0, 2.0, and 4.0 mg/L of trichlorfon and fed with commercial feed for 30 d. At the end of the experiment, plasma and hepatic lipid metabolic biochemical status were analyzed. Triglyceride contents were significantly (P < 0.05) increased in liver but decreased in plasma after 1.0, 2.0, and 4.0 mg/L trichlorfon treatments. Plasma insulin contents were markedly (P < 0.05) increased when trichlorfon concentrations were 0.5, 1.0, and 4.0 mg/L. There were no significant differences in hepatic hormone-sensitive lipase contents between the trichlorfon-treated fish and the controls. Hepatic cyclic adenosine 3′, 5′-monophosphate, very-low-density lipoprotein, and apolipoprotein B100 contents were decreased in the fish when trichlorfon concentration was 2.0 mg/L. Furthermore, electron microscope observations showed rough endoplasmic reticulum dilatation and mitochondrial vacuolization in hepatocytes with trichlorfon exposure. On the basis of morphological and physiological evidence, trichlorfon influenced crucian carp hepatic pathways of lipid metabolism and hepatocellular ultrastructure, which resulted in lipid accumulation in the liver.

Effects of Helicobacter pylori on biological characteristics of gastric epithelial cells.

Infection with Helicobacter pylori (H. pylori) strains is linked to an increased risk of inflammation and gastric cancer. To investigate the effects of H. pylori on biological characteristics of gastric epithelial cells SGC-7901, derived from human adenocarcinoma, morphological appearances of both the pathogen and these cells, as well as features of attachment and internalization were observed by using transmission electron microscopy (TEM). We also investigated cell junctions and invasion by TEM and Transwell Invasion Assay. Cell proliferation and apoptosis were assessed by using chromogenic methylthiazol tetrazolium bromide (MTT) dye and flow cytometry. Three types of H. pylori were observed around, attaching to, or invading tumor cells. Cellular damage was characterized by vacuolar degeneration, dilated endoplasmic reticulum (ER), and reduction of organelles. Cell junctions and cell microvilli reduced or disappeared. H. pylori inhibited cell proliferation, whereas it had no effect on apoptosis. It also promoted gastric carcinoma cell invasion. H. pylori damages cell construction, destroys cell junctions, inhibits cell proliferation, promotes cell invasive ability, and, therefore, might accelerate the malignant progress and metastasis of gastric cancer.

Opaque1 Encodes a Myosin XI Motor Protein That Is Required for Endoplasmic Reticulum Motility and Protein Body Formation in Maize Endosperm

Myosins are encoded by multigene families and are involved in many basic biological processes. However, their functions in plants remain poorly understood. Here, we report the functional characterization of maize (Zea mays) opaque1 (o1), which encodes a myosin XI protein. o1 is a classic maize seed mutant with an opaque endosperm phenotype but a normal zein protein content. Compared with the wild type, o1 endosperm cells display dilated endoplasmic reticulum (ER) structures and an increased number of smaller, misshapen protein bodies. The O1 gene was isolated by map-based cloning and was shown to encode a member of the plant myosin XI family (myosin XI-I). In endosperm cells, the O1 protein is associated with rough ER and protein bodies. Overexpression of the O1 tail domain (the C-terminal 644 amino acids) significantly inhibited ER streaming in tobacco (Nicotiana benthamiana) cells. Yeast two-hybrid analysis suggested an association between O1 and the ER through a heat shock protein 70-interacting protein. In summary, this study indicated that O1 influences protein body biogenesis by affecting ER morphology and motility, ultimately affecting endosperm texture.

Qualitative study of young, adult, and aged wistar rats temporomandibular synovial membrane employing light, scanning, and transmission electron microscopy

The aim of this study was to analyze the rat temporomandibular joint (TMJ) synovial membrane at different ages using light, scanning, and transmission electron microscopy. Under light microscopic analysis, the TMJ structures were observed such as condyle, capsule, disk, the synovial membrane collagen type, and cells distribution. In the scanning electron microscopy, the synovial membrane surface exhibited a smooth aspect in young animals and there was an increase with ageing in the number of folds. The transmission electron microscopic analysis showed more synoviocytes in the synovial layer in the young group and still a great number of vesicles and cisterns dilation of rough endoplasmic reticulum in the aged group. In the three groups, a dense layer of collagen fibers in the synovial layer and cytoplasmic extensions were clearly seen. It was possible to conclude that synovial membrane structures in aged group showed alterations contributing to the decrease in joint lubrication and in the sliding between disk and joint surfaces. These characteristic will reflect in biomechanics of chewing, and may cause the TMJ disorders, currently observed in clinical processes.

Effects of neem oil (Azadirachta indica A. Juss) on midgut cells of predatory larvae Ceraeochrysa claveri (Navás, 1911) (Neuroptera: Chrysopidae)

The effects of ingested neem oil, a botanical insecticide obtained from the seeds of the neem tree, Azadirachta indica, on the midgut cells of predatory larvae Ceraeochrysa claveri were analyzed. C. claveri were fed on eggs of Diatraea saccharalis treated with neem oil at a concentration of 0.5%, 1% and 2% during throughout the larval period. Light and electron microscopy showed severe damages in columnar cells, which had many cytoplasmic protrusions, clustering and ruptured of the microvilli, swollen cells, ruptured cells, dilatation and vesiculation of rough endoplasmic reticulum, development of smooth endoplasmic reticulum, enlargement of extracellular spaces of the basal labyrinth, intercellular spaces and necrosis. The indirect ingestion of neem oil with prey can result in severe alterations showing direct cytotoxic effects of neem oil on midgut cells of C. claveri larvae. Therefore, the safety of neem oil to non-target species as larvae of C. claveri was refuted, thus the notion that plants derived are safer to non-target species must be questioned in future ecotoxicological studies.

Ultrastructural Studies of Involuting Bursa and Thymus of Giriraja Birds (Gallus domesticus)

The ultra structural changes of involuting cells of bursa of fabricius and thymus could be classified as nuclear and cytoplasmic changes. Major cytoplasmic changes include arrangement of cytoskeleta l filaments in parallel arrays, cytoplasmic membrane blebbing and dilatation of endoplasmic reticulum. Nuclear changes included clumping of chromatin, elongation and appearance of convolutions of the nuclear membrane with karyorrhexis, karyolysis and nucleolar disintegration. There is consequent cell volume reduction, detachment of cell from surroundings, formation of several membrane bound apoptotic bodies and its ingestion by neighboring cells.

Combinatorial inhibitory effects on VSV‐GtsO45GFP trafficking in human endothelial cells due to functional haploinsufficiency of BMPRII, eNOS, STAT5a and STAT5b

Lung lesions in idiopathic pulmonary arterial hypertension (PAH) contain enlarged “vacuolated” endothelial and smooth muscle cells with enlarged and fragmented Golgi apparatus and dilated endoplasmic reticulum (ER) cisternae. Familial PAH often involves mutations in or haploinsuffciency of BMPRII but with low penetrance (10–15%) setting up a search for “second‐hit” genes. Recently we observed that acute knockdown of STAT5a or STAT5b or both in HPAECs using siRNAs led to marked Golgi enlargement and fragmentation and cisternal dilatation of the ER. In the present study we used the VSV‐GtsO45GFP ER to Golgi to plasma membrane trafficking assay in EA.hy926 human endothelial cells to quantitatively assess the combinatorial effects of functional haploinsufficiency of BMPRII, eNOS, STAT5a and STAT5b using respective siRNAs. Knockdown of STAT5a, STAT5b, BMPRII, or eNOS one at a time did not significantly affect intracellular trafficking. However, down‐regulation of STAT5a plus STAT5b inhibited VSV‐G trafficking from the ER/Golgi apparatus to the cell surface by 60–70%. STAT5a or STAT5b combined with eNOS siRNA treatments had a similar inhibitory effect. STAT5a or STAT5b combined with BMPRII siRNA also inhibited VSV‐G trafficking. These observations suggest that combinatorial functional haploinsufficiency of BMPRII, eNOS, STAT5a and STAT5b may contribute to intracellular trafficking defects.

Bee (Apis mellifera) Venom Produced Toxic Effects of Higher Amplitude in Rat Thoracic Aorta than in Skeletal Muscle—An Ultrastructural Study

In this study, changes produced in aorta and triceps surae muscle of Wistar rats as response to bee venom (BV) envenomation were analyzed by transmission electron microscopy and morphometry. A subchronic treatment of 30 days with daily doses of 700 μg BV/kg and an acute-lethal treatment with a single dose of 62 mg BV/kg were performed. The subchronic treatment resulted in endothelial cell retraction, a thicker subendothelial layer, and thinner elastic laminae and musculoelastic layers in aorta, and thicker endothelium and basal laminae in skeletal muscle. In both tissues polymorphous, swollen mitochondria with disrupted cristae were observed. The acute treatment produced extensive endothelial lesions, breakdown of the collagen layer and migration of muscle cells toward the intima in the aorta, and dilatation of endoplasmic reticulum in the skeletal muscle cells. Mitochondria were almost devoid of cristae or with few circular cristae in the smooth muscle cells while most of the mitochondria presented abnormal circular cristae in the skeletal muscle cells. Degenerative alterations in the aorta were of higher intensity in our experiments-both the intima and media strongly responded to BV, in contrast to those found at the level of the skeletal muscle cells where a moderate degenerative myopathy was recorded.

Effects of low level testosterone on the corpus cavernosum cells in rats with diabetes mellitus-induced erectile dysfunction

Objective To investigate the changes of testosterone levels and the effect of low level testosterone on the corpus cavernosum tissue and its ultrastructure in rats with diabetes mellitus-induced erectile dysfunction.Methods Three-month-old male Wistar rats ( n =20) were divided into 2 groups:the contorl group (n =10) and the diabetes mellitus-induced erectile dysfunction group (n =10).Serum levels of testosterone were measured by radioimmunoassay and the percentage of corporal smooth muscle cells was detected by Masson staining.The ultrastructures of corporal smooth muscle cells were examined under the transmission electron microscopy.Results The serum levels of testosterone in the diabetes mellitus-induced erectile dysfunction group ( 17.445 ± 2.540) nmol/L were obviously lower than in the contorl group (338.457 ± 63.802) nmol/L,P ＜ 0.01.The percentage of corporal smooth muscle cells ( 19.890 ±1.957) ％ was higher in the control group than in the diabetes mellitus-induced erectile dysfunction group (5.640 ± 0.597)％,P ＜0.01.Ultrastructurally,in the smooth muscle cells of cavernous tissue,there were more Goigi bodies and secretory vacuoles,and the karyoplasmic ratio was higher in the diabetes mellitus-induced erectile dysfunction group than in the control group.Aslo the degeneration of mitochondria,the dilatation of endoplasmic reticulum and the decreases of glycogen particles and microfilaments could be observed.Conclusion The decline of testosterone levels may lead to the pathological changes of corpus caveruosum cells in rats with diabetes mellitus-induced erectile dysfunction. Key words: Testosterone; Erectile dysfunction; Diabetes mellitus; Ultrastructu

Paraptosis accompanied by autophagy and apoptosis was induced by celastrol, a natural compound with influence on proteasome, ER stress and Hsp90

In the present study, we found that celastrol, a natural compound with well-known apoptosis-inducing effect, could also induce paraptosis-like cytoplasmic vacuolization in cancer cell lines including HeLa cells, A549 cells and PC-3 cells derived from cervix, lung and prostate, respectively. Further study using HeLa cells indicated that the vacuoles induced by celastrol might be derived from dilation of endoplasmic reticulum. And, in celastrol-treated cells, markers of autophagy such as transformation of microtubule-associated protein 1 light chain 3 (LC3)I to LC3II and LC3 punctates formation were identified. Interestingly, autophagy inhibitors could not interrupt but enhance the induction of cytoplasmic vacuolization. Furthermore, MAPK pathways were activated by celastrol and inhibitors of MEK and p38 pathways could prevent the formation of cytoplasmic vacuolization. Celastrol treatment also induced G2/M cell cycle arrest and apoptosis in HeLa cells. In conclusion, celastrol induced a kind of paraptosis accompanied by autophagy and apoptosis in cancer cells. The coincidence of apoptosis and autophagy together with paraptosis might contribute to the unique characteristics of paraptosis in celastrol-treated cells such as the dependence of paraptosis on MAPK pathways and dynamic change of LC3 proteins. Both paraptosis and apoptosis could contribute to the cell death induced by celastrol while autophagy might serve as a kind of survival mechanism. The potency of celastrol to induce paraptosis, apoptosis and autophagy at the same dose might be related to its capability to affect a variety of pathways including proteasome, ER stress and Hsp90.

Melatonin prevents testicular damage in hyperlipidaemic mice

The damaging effect of hyperlipidaemia on testicular structure was determined, and the influence of melatonin was evaluated in testicular damage related to hyperlipidaemia. Hyperlipidaemia was induced in ApoE-knockout C57BL/6J male mice fed with high-fat diet alone (group A), or with high-fat diet and melatonin (group B). Six ApoE wild-type C57BL/6J male mice were fed with normal diet, served as controls. At the end of the experimental period, ultrastructural observations showed dramatically histopathological alterations in testicular tissues of group A. The basement membranes of seminiferous tubules were partially thickened and wavy-like in testes of mice with hyperlipidaemia, and vacuolar degeneration of mitochondria and dilation of endoplasmic reticulum were identified as well as the number of mitochondria and lipid droplets decreased significantly in Leydig cells and Sertoli cells. Electrondense deposits were observed in cytoplasms of germ cells. The testicular histostructure in group B treated with melatonin was similar to that of control. Apoptosis was determined by terminal-deoxynucleotidyl-transferase-mediated dUTP nick end labelling. Apoptotic germ cells were significantly more numerous in group A than in group B and controls. The results suggest that melatonin may be potential to attenuate testicular damage by improving histopathological changes and reducing germ cell apoptosis in hyperlipidaemic mice.

Evidence of endoplasmic reticulum stress and protein synthesis inhibition in the placenta of non-native women at high altitude.

Pregnancy at high altitude is associated with a reduction in birth weight of ∼100 g/1000 m of ascent. The underlying mechanisms are unclear but may involve alteration in energy-demanding activities, such as protein synthesis. To test this hypothesis, both in vivo and in vitro approaches were used. Placental tissues from pregnant women residing at 3100 m were studied, and placental cells were incubated under hypoxia. In the 3100-m placentas, we observed dilation of endoplasmic reticulum (ER) cisternae, increased phosphorylation of eukaryotic initiation factor 2 subunit α (P-eIF2α), reduced AKT phosphorylation, and reduced P-4E-BP1 but increased 4E-BP1 protein compared to sea level controls. These findings suggest the presence of ER stress and protein synthesis inhibition. Hypoxia (1% O2) reduced proliferation of trophoblast-like JEG-3 cells, BeWo cells, and placental fibroblasts by ∼40, ∼60, and ∼18%, respectively. Sublethal dosage of salubrinal, an eIF2α phosphatase inhibitor, increased P-eIF2α and reduced BeWo cell and placental fibroblast proliferation by ∼50%. Administration of the PI-3K inhibitor LY294002 also reduced JEG-3 proliferation. Our results demonstrate that exposure to chronic hypobaric hypoxia causes mild placental ER stress, which, in turn, modulates protein synthesis and slows proliferation. These effects may account for the reduced placental villous volume, and contribute to the low birth weight that typifies high-altitude populations.—Yung, H. W., Cox, M., Tissot van Patot, M., Burton, G. J. Evidence of endoplasmic reticulum stress and protein synthesis inhibition in the placenta of non-native women at high altitude.

Immature rat seminal vesicles show histomorphological and ultrastructural alterations following treatment with kisspeptin-10.

BackgroundDegenerative effects of critical regulators of reproduction, the kisspeptin peptides, on cellular aspects of sexually immature male gonads are known but similar information on accessory sex glands remain elusive.MethodsPrepubertal laboratory rats were injected kisspeptin-10 at three different dosage concentrations (10 pg, 1 ng and 1 microgram) for a period of continuous 12 days at the rate of two doses per day. Control rats were maintained in parallel. The day following the end of the experimental period, seminal vesicles were removed and processed for light and electron microscopic examination using the standard methods. DNA damage was estimated by DNA ladder assay and DNA fragmentation assay.ResultsThe results demonstrated cellular degeneration. Epithelial cell height of seminal vesicles decreased significantly at all doses (P < 0.05). Marked decrease in epithelial folds was readily noticeable, while the lumen was dilated. Ultrastructural changes were characterized by dilatation of endoplasmic reticulum and Golgi complex, heterochromatization of nuclei, invagination of nuclear membranes and a decreased number of secretory granules. Percent DNA damage to the seminal vesicle was 19.54 +/- 1.98, 38.06 +/- 2.09 and 58.18 +/- 2.59 at 10 pg, 1 ng and 1 microgram doses respectively.ConclusionThe study reveals that continuous administration of kisspeptin does not lead to an early maturation but instead severe degeneration of sexually immature seminal vesicles.