Calcitriol modulate post-ischemic TLR signaling pathway in ischemic stroke patients.

BACKGROUND: Neuroinflammation is a significant contributor to post-ischemic neuronal death after stroke, and Toll-Like Receptors (TLRs) are one of the essential mediators in many inflammatory pathways. TLRs activate the nuclear factor kappa ß (NF-kß), which promotes the expression of various pro-inflammatory genes such as interleukin (IL-1ß) and IL-6. 1,25(OH)2D3, also known as calcitriol, is an active form of vitamin D3 that acts as a neurosteroid compound with anti-inflammatory properties. This study aimed to determine the modulatory effects of calcitriol hormone on post-ischemic immunity response. METHODS: Neurological tests and conventional blood factors were evaluated in patients with stroke symptoms upon arrival (n = 38) to confirm the stroke. A blood sample was taken from each stroke patient immediately upon admission and again after 24 h. The experimental group was given 10 µg calcitriol orally. The gene expression levels of TLR4, TLR2, NF-kß, IL-1ß, and IL-6 pro-inflammatory factors were measured using real-time PCR. The protein expression of TLR4 and NF-kß markers was assessed using the flow cytometry technique. RESULTS: TLR4, NF-kß, and pro-inflammatory factors IL-1ß and IL-6 expression increased significantly after an ischemic stroke, and calcitriol could modulate the TLR4/NF-kß signaling pathway 24 h after ischemia. CONCLUSIONS: Calcitriol may be considered a protective reagent after ischemia by reducing the TLR4/NF-kB activation cascade and probably plays a beneficial role in reducing and improving ischemic stroke patients' symptoms. TRIAL REGISTRATION: Iranian Registry of Clinical Trials identifier: IRCT2017012532174N1.

The effect of female sex hormones on Hsp27 phosphorylation and histological changes in prefrontal cortex after tMCAO.

BACKGROUND: Female sex hormones are protective factors against many neurological disorders such as brain ischemia. Heat shock protein like HSP27 is activated after tissue injury. The main purpose of the present study is to determine the effect of a combined estrogen / progesterone cocktail on the morphology of astrocytes, neurons and Hsp27 phosphorylation after cerebral ischemia. METHODS: One hour after the MCAO induction, a single dose of estrogen and progesterone was injected. The infarct volume was calculated by TTC staining 24 h after ischemia. Immunohistochemistry was used to show the effects of estrogen and progesterone on astrocyte and neuron morphology, as well as the Western blot technique used for the quantitation of phosphorylated Hsp27. RESULTS: The combined dose of estrogen and progesterone significantly decreased astrocytosis after ischemia and increased neuron survival. There was a large increase in Hsp27 phosphorylation in the penumbra ischemic region after stroke, which was significantly reduced by hormone therapy. CONCLUSION: Our results indicate that the neuroprotective effect of neurosteroids in the brain may be due to the modulation of heat shock proteins.

Neuroprotective Effects of Oxytocin Hormone after an Experimental Stroke Model and the Possible Role of Calpain-1.

BACKGROUND: Different mechanisms will be activated during ischemic stroke. Calpain proteases play a pivotal role in neuronal death after ischemia damage through apoptosis. Anti-apoptotic activities of the oxytocin (OT) in different ischemic tissues were reported in previous studies. Recently, a limited number of studies have noted the protective effects of OT in the brain. In the present study, the neuroprotective potential of OT in an animal model of transient middle cerebral artery occlusion (tMCAO) and the possible role of calpain-1 in the penumbra region were assessed. METHODS: Adult male Wistar rats underwent 1 hour of tMCAO and were treated with nasal administration of OT. After 24 hours of reperfusion, infarct size was evaluated by triphenyltetrazolium chloride. Immunohistochemical staining and Western blotting were used to examine the expression of calpain-1. Nissl staining was performed for brain tissue morphology evaluation. RESULTS: OT reduced the infarct volume of the cerebral cortex and striatum compared with the ischemia control group significantly (P < .05). Calpain-1 overexpression, which was caused by ischemia, decreased after OT administration (P < .05). The number of pyknotic nuclei in neurons increased dramatically in the ischemic area and OT attenuated the apoptosis of neurons in the penumbra region (P < .01). CONCLUSION: We provided evidence for the neuroprotective role of OT after tMCAO through calpain-1 attenuation.

Learning styles and strategies preferences of Iranian medical students in gross anatomy courses and their correlations with gender.

The learning approaches can help anatomy teachers design a suitable curriculum in harmony with their students' learning styles. The research objective is to evaluate gross anatomy learning styles and strategies preferences of Iranian medical students at Kashan University of Medical Sciences (KAUMS). This cross-sectional questionnaire-based study was carried out on 237 Iranian medical students. The students answered questions on approaches to learning anatomy and expressed opinions about learning anatomy in medical curriculum. The data were analyzed to disclose statistically significant differences between male and female students. Iranian male and female students were interested in learning anatomy using notes, plastic models, pictures and diagrams, clinical context, dissection and prosection of cadavers; however, they rarely used cross-sectional images and web-based resources. Both groups of medical students used region and system in learning anatomy. However, there existed some striking differences, particularly in having difficulty in studying anatomy using cadaveric specimens, using books alone, and learning it in small groups. Male students were less interested in learning with cadavers than female counterparts. However, female students were more interested in learning anatomy in small groups. This study suggests that instructors should design gross anatomy curriculum based on limitations of using dissection of cadaver in Iranian universities, emphasis on the applied anatomy, and learning of gross anatomy in small groups.

Cultural acceptability and personal willingness of Iranian students toward cadaveric donation.

Cadaver dissection stands as a crucial component in medical curricula around the world, although computer-based multimedia programs have been introduced in order to replace the need for cadaver donations. Due to a decrease in the number of unclaimed bodies and rather few donations, there is an insufficient number of cadavers for anatomical studies in Iran. This study was carried out to evaluate medical students' awareness and willingness regarding body donation in Kashan University of Medical Sciences, Iran. In this study, a questionnaire was designed to focus on the cultural acceptability and personal willingness to donate one's body after death. Students from the university's anatomy classes (n = 331) participated in this study. Seventy-seven percent of the students expressed their agreement toward the idea of utilizing body donation services, though only 25.4% of participants were willing to donate their own bodies. None of the demographic factors were associated with cultural acceptability or personal willingness towards body donation. These findings indicated that besides "payment", other factors were associated with students' willingness to become donors. All factors of awareness except "previous awareness of organization" were associated with cultural acceptability. In this study, students suggested that encouraging people to register for body donation using mass media (25.6%) and teaching students to respect cadavers in the dissection environment (24.8%) were the best solutions for addressing the lack of cadavers. These findings indicated that a lack of awareness about body donation might be the main factor responsible for unwillingness towards body donation; therefore, improving the public's awareness and addressing the willingness of students regarding body donation may help overcome the current lack of donated cadavers. Anat Sci Educ 10: 120-126. © 2016 American Association of Anatomists.

Gonadal steroids block the calpain-1-dependent intrinsic pathway of apoptosis in an experimental rat stroke model.

OBJECTIVES: Apoptosis plays an important role in the progression of the ischemic penumbra after reperfusion. Estrogen and progesterone have neuroprotective effects against ischemic brain damage, however the exact mechanisms of neuroprotection and signaling pathways is not completely understood. In this study, we investigated the possible regulatory effects of a combined steroid treatment on extrinsic and intrinsic apoptotic signaling pathways after cerebral ischemia. METHODS: Adult male Wistar rats were subjected to transient middle cerebral artery occlusion (tMCAO) using an intraluminal filament technique for 1 h followed by 23 h reperfusion. Estrogen and progesterone were immediately injected after tMCAO subcutaneously. Sensorimotor functional tests and the infarct volume were evaluated 24 h after ischemia. Protein expression of calpain-1 and Fas receptor (FasR), key members of intrinsic and extrinsic apoptosis, were determined in the penumbra region of the ischemic brain using western blot analysis, immunohistochemistry, and TUNEL staining. RESULTS: Neurological deficits and infarct volume were significantly reduced following hormone therapy. Calpain-1 up-regulation and caspase-3 activation were apparent 24 h after ischemia in the peri-infarct area of the cerebral cortex. Steroid hormone treatment reduced infarct pathology and attenuated the induction of both proteases. FasR protein levels were not affected by ischemia and hormone application. CONCLUSION: We conclude that a combined steroid treatment inhibits ischemia-induced neuronal apoptosis through the regulation of intrinsic pathways.

Expression of galectin-3 as a testis inflammatory marker in vasectomised mice.

OBJECTIVE: Vasectomy, though in some cases are being confronted with irreversibility, has been accepted as an effective contraceptive method. It is estimated that near 2-6% of vasectomised men ultimately show a tendency to restore their fertility. In some cases, vasectomy has been considered as an irreversible procedure due to many post-vasectomy complications causing this debate. The aim of present study was to investigate the pattern of expression of galectin-3, an inflammatory factor secreted by macrophages and immune cells, following the vasectomy in mice testis tissue. MATERIALS AND METHODS: IN THIS EXPERIMENTAL STUDY, TWENTY MATURE MALE BALB/C MICE, AGED TWO MONTHS, WERE DIVIDED INTO TWO EQUAL GROUPS: sham and vasectomised groups (n=10). They were sacrificed four months after vasectomy, while the pattern of galectin-3 expression was investigated using a standard immunohistochemistry technique on testicular tissues. Stereological analyses of testes parameters in vasectomised and shamoperated groups were compared by mixed model analysis. RESULTS: Based on observations, although galectin-3 was not expressed in sham-operated group, it was expressed in 40% of testicular tissues of vasectomised mice, like: seminiferous tubules, interstitial tissues and tunica albugina. Also, our result showed a significant alteration in number of germ and sertoli cells of testicular tissue in vasectomised group in comparison to sham-operated group. In addition, the result of mixed model method confirmed a significant reduction in germ and sertoli cells of vasectomised group. CONCLUSION: The expression of galectin-3 at different parts of testicular tissue in vasectomised group is higher than sham group. This express illustrates the increase of degenerative changes and inflammation reactions in testicular tissue, leading to chronic complications and infertility, after the vasovasostomy.

Regional regulation of glutamate signaling during cuprizone-induced demyelination in the brain.

Glutamate excitotoxicity is associated with a wide range of neurodegenerative disorders and also seems to be involved in the pathology of demyelinating disorders such as multiple sclerosis (MS). Cuprizone-induced toxic demyelination shows clear characteristics of MS such as demyelination and axonal damage without the involvement of the innate immune system. In this study, we have evaluated glutamate signaling during cuprizone-induced demyelination in the white and gray matter of mouse brain by studying the expression of ionotropic and metabotropic glutamate-receptors and -transporters by Affymetrix gene array analysis, followed by real-time PCR and western blot analysis. Cellular localization of glutamate transporters was investigated by fluorescence double-labeling experiments. Comparing white and gray matter areas, the expression of glutamate receptors was region-specific. Among NMDA receptor subunits, NR2A was up-regulated in the demyelinated corpus callosum (CC), whereas the metabotropic glutamate receptor mGluR2 was down-regulated in demyelinated gray matter. Glutamate-aspartate transporter (GLAST) co-localizing with GFAP(+) astrocytes was increased in both demyelinated CC and telencephalic cortex, whereas Slc1a4 transporter was up-regulated only in CC. Our data indicate that cuprizone treatment affects glutamate-receptors and -transporters differently in gray and white matter brain areas revealing particularly regulation of GLAST and Slc1a4 compared with other genes. This might have an important influence on brain-region selective sensitivity to neurotoxic compounds and the progression of demyelination as has been reported for MS and other demyelinating neurological diseases.

Morphology of Rat Hippocampal CA1 Neurons Following Modified Two and Four-Vessels Global Ischemia Models.

BACKGROUND: An appropriate animal model of ischemia stroke is essential for evaluation of different therapeutic methods. Two and four-vessel global ischemia models are one of the most common types of transient cerebral ischemia. OBJECTIVES: In this study, the morphology of rat hippocampal CA1 neurons in modified models of two and four-vessel ischemia and reperfusion were evaluated. MATERIALS AND METHODS: In this study, 20 Wistar rats were randomly divided into five groups. In group 2 and 3, both common carotid arteries were occluded for 10 minutes in either 3 or 24 hours of reperfusions, respectively. In group 4 and 5, both common carotid and vertebral arteries were occluded for 10 minutes in either 3 or 24 hours of reperfusions, respectively. Group 1 as control, underwent the whole surgery without any arteries occlusion. Hippocampi of the rats in all groups were processed and tissue sections were stained using the Nissl method. The morphology of CA1 neurons were studied under a light microscope and compared different groups. RESULTS: In all groups ischemic changes were apparently observed in hippocampus CA1 neurons. In two-vessel occlusion model, after 3 and 24 hours of reperfusions, ischemic cells accounted for 14.9% and 23.2%, respectively. In four-vessel occlusion model, after 3 and 24 hours of reperfusions, ischemic cells accounted for 7.6% and 44.9% (P < 0.0001), respectively. CONCLUSIONS: Modified four-vessel occlusion model resulted in significant ischemic changes after 24 hours of reperfusion in CA1 neurons of rat hippocampus.

Expression Cloning of Recombinant Escherichia coli lacZ Genes Encoding Cytoplasmic and Nuclear ß-galactosidase Variants.

OBJECTIVES: Nonviral vector can be an attractive alternative to gene delivery in experimental study. In spite of some advantages in comparison with the viral vectors, there are still some limitations for efficiency of gene delivery in nonviral vectors. To determine the effective expression, the recombinant Escherichia coli lacZ genes were cloned into the different variants of pcDNA3.1 and then the mammalian cells were transfected. METHODS AND MATERIALS: The coding sequences of cytoplasmic and nuclear variants of lacZ gene were inserted downstream of the human cytomegalovirus immediate-early gene promoter of plasmid pcDNA3.1/myc-His C. The new cytoplasmic and nuclear constricts of E. coli ß-galactosidase-coding sequences were introduced into HeLa cells with the aid of linear polyethylenimine and at 2 days post-transfection the cells were stained using 5-bromo-4-chloro-3-indolyl-ß-D-galactopyranoside (X-gal). RESULTS: Restriction enzyme analyses revealed the proper insertion of E. coli ß-galactosidase-coding sequences into the multiple cloning site of pcDNA3.1/myc-His C. The functionality of the resulting constructs designated pcDNA3.1-cyt.lacZ and pcDNA3.1-nls.lacZ(+) was confirmed by X-gal staining of HeLa cells transfected with these recombinant plasmids. While pcDNA3.1-cyt.lacZ directed the synthesis of cytoplasmically located ß-galactosidase molecules, the ß-galactosidase protein encoded by pcDNA3.1-nls.lacZ(+) was predominantly detected in the cell nucleus. CONCLUSION: The expression of cytoplasmic and nuclear variant of LacZ gene confirmed the ability of pcDNA3.1 as versatility nonviral vector for the experimental gene delivery study in mammalian cells.