Immunohistochemical distribution of calcium binding proteins in the cochlear nuclear complex of circling mice / Distribución inmunohistoquímica de proteínas de unión a calcio en el complejo nuclear coclear de ratones circulantes

SUMMARY: The term "circling mouse" refers to an animal model of deafness, in which the mouse exhibits circling, head tossing, and hyperactivity, with pathological features including degenerated spiral ganglion cells in the cochlea, and the loss of the organ of Corti. The cochlear nuclear (CN) complex, a part of the auditory brain circuit, is essential to process both ascending and descending auditory information. Considering calcium's (Ca2+) importance in homeostasis of numerous biological processes, hearing loss by cochlear damage, either by ablation or genetic defect, could cause changes in the Ca2+ concentration that might trigger functional and structural alterations in the auditory circuit. However, little is known about the correlation of the central nervous system (CNS) pathology in circling mice, especially of the auditory pathway circuit and Ca2+ changes. This present study investigates the distribution of Ca2+- binding proteins (CaBPs), calbindin D-28k (CB), parvalbumin (PV), and calretinin (CR) by using a free floating immunohistochemical method inthe CN of the wild-type mouse (+/+), the heterozygous mouse (+/cir), and the homozygous (cir/cir) mouse. CaBPs are well known to be an important factor that regulates Ca2+ concentrations. Compared with the dorsal and ventral cochlear nuclei of +/+ and +/ cirmice, prominent decreases of CaBPs' immunoreactivity (IR) in cir/cirmice were observed in the somas, as well as in the neuropil. The present study reportson the overall distribution and changes in the immunoreactivity of CaBPs in the CN of cir/cirmice because ofa hearing defect. This data might be helpful to morphologically elucidate CNS disorders and their relation to CaBPs immunoreactivity related to hearing defects.

RESUMEN: El término "ratón circulante" se refiere a un modelo animal con sordera, en el que el ratón exhibe hiperactividad, movimientos circulares y movimientos de la cabeza, con características patológicas que incluyen células ganglionares espirales degeneradas en la cóclea, un canal de Rosenthal vacío y la pérdida del órgano de Corti. El complejo nuclear coclear (CN), una parte del circuito cerebral auditivo, es esencial para procesar la información auditiva tanto ascendente como descendente. Considerando la importancia del calcio (Ca2+) en la homeostasis de numerosos procesos biológicos, la hipoacusia por daño coclear, por ablación o por defecto genético, podría provocar cambios en la concentración de Ca2+que pueden desencadenar alteraciones funcionales y estructurales en el circuitoauditivo. Sin embargo, existe poca información de la correlación de la patología del sistema nervioso central (SNC) en ratones circulantes, especialmente del circuito de la víaauditiva y los cambios de Ca2+. Este estudio nvestiga la distribución de proteínas de unión a Ca2+ (CaBP), calbindina D-28k (CB), parvalbúmina (PV) y calretinina (CR) mediante el uso de un método inmunohistoquímico de flotaciónlibre en el CN del ratón de tiposalvaje (+/+), el ratón heterocigoto (+/cir) y el ratón homocigoto (cir/cir). Se sabe que los CaBP son un factor importante que regula las concentraciones de Ca2+. En comparación con los núcleos cocleares dorsal y ventral de los ratones +/+ y +/ cir, se observaron disminuciones prominentes de la inmunorreactividad (IR) de CaBPs en los ratonescir/cir en los somas, asícomo en el neuropilo. El presente estudio informa sobre la distribución general y los cambios en la inmunorreactividad de CaBP en el CN de ratones cir/cir debido a un defecto auditivo. Estos datos podrían ser útiles para dilucidar morfológicamente los trastornos del SNC y su relación con la inmunorreactividad de CaBP relacionada con los defectosauditivos.

Effect of periapical inflammation on calcium binding proteins and ERK in the trigeminal nucleus / Efecto de la inflamación periapical sobre las proteínas fijadoras de calcio y ERK en el núcleo trigeminal

Peripheral inflammation induces plastic changes in neurons and glia which are regulated by free calcium and calcium binding proteins (CaBP). One of the mechanisms associated with the regulation of intracellular calcium is linked to ERK (Extracellular Signal-Regulated Kinase) and its phosphorylated condition (pERK). ERK phosphorylation is important for intracellular signal transduction and participates in regulating neuroplasticity and inflammatory responses. The aim of this study is to analyse the expression of two CaBPs and pERK in astrocytes and neurons in rat trigeminal subnucleus caudalis (Vc) after experimental periapical inflammation on the left mandibular first molar. At seven days post-treatment, the periapical inflammatory stimulus induces an increase in pERK expression both in S100b positive astrocytes and Calbindin D28k positive neurons, in the ipsilateral Vc with respect to the contralateral side and control group. pERK was observed coexpressing with S100b in astrocytes and in fusiform Calbindin D28k neurons in lamina I. These results could indicate that neural plasticity and pain sensitization could be maintained by ERK activation in projection neurons at 7 days after the periapical inflammation.

La inflamación periférica induce cambios plásticos en las neuronas y en la glía, los cuales están regulados por el calcio libre y las proteínas fijadoras calcio (CaBP). Uno de los mecanismos asociados con la regulación del calcio intrace-lular está vinculado con la fosforilación de la pro teína quinasa ERK. Asimismo, ERK fosforilado es importante para la trans-ducción de señales intracelulares y participa en la regulación de la neuroplasticidad y las respuestas inflamatorias. El objetivo de este estudio es analizar la expresión de dos CaBPs y pERK en astrocitos y neuronas del subnúcleo caudal del trigémino (Vc) después de una inflamación periapical experimental en el primer molar inferior izquierdo en ratas. A los siete días posteriores al tratamiento, el estímulo inflamatorio periapical induce un aumento en la expresión de pERK, en el número de astrocitos positivos para la proteína marcadora astroglial S100b y en neuronas positivas para Calbindina D28k, en el Vc ipsilateral respecto del lado contralateral y el grupo de control. Además, se observó coexpresión de pERK tanto en astrocitos S100b positivos, como en neuronas fusiformes Calbindin D28k positivas, de la lámina I. Estas observaciones podrían indicar que la neuroplasticidad y la sensibilización al dolor podrían mantenerse mediante la activación de ERK en las neuronas de proyección a los 7 días de la inflamación periapical.

Entry of rabies virus in the olfactory bulb of mice and effect of infection on cell markers of neurons and astrocytes / Ingreso del virus de la rabia en el bulbo olfatorio de ratones y efecto de la infección en marcadores celulares de neuronas y astrocitos

There are few studies of infection by rabies virus in the olfactory bulb (OB). This work was carried out with the purpose of establishing the time required to detect rabies antigens in the OB of mouse, after the intramuscular inoculation of the virus and to evaluate the effect of the infection on the expression of three proteins: calbindin (CB), parvalbumin (PV) and the glial fibrillary acidic protein (GFAP). Mice were inoculated with rabies virus intramuscularly in the hind limbs. Every 8 hours, after 72 hours postinoculation (p.i.), animals were sacrificed by perfusion with paraformaldehyde and coronal sections of OB were obtained for immunohistochemical study. These cuts were used to reveal the entry and spread of viral antigens. Tissue sections obtained in the terminal phase of the disease (144 hours p.i.), and controls of the same age were also processed for immunohistochemistry of CB, PV and GFAP. Rabies virus antigens were initially detected at 80 hours p.i. in a few mitral cells. At 88 hours p.i. the antigens had spread through most of these neurons but until the terminal phase of the disease there was little dispersion of the virus towards other cellular layers of the OB. The CB protein was expressed in cells of the glomerular stratum, the PV in cells of the outer plexiform layer and the GFAP was expressed in all the layers of the OB. Viral infection generated loss of CB expression and increase of PV expression. Immunoreactivity to GFAP was increased in the outer plexiform layer of the OB as a response to infection.

Son escasos los estudios de la infección por virus de la rabia en el bulbo olfatorio (OB). Este trabajo se realizó con el objetivo de establecer el tiempo requerido para detectar antígenos de rabia en el OB del ratón, luego de la inoculación intramuscular del virus y evaluar el efecto de la infección en la expresión de tres proteínas: calbindina (CB), parvoalbúmina (PV) y la proteína ácida fibrilar glial (GFAP). Los ratones fueron inoculados con virus de la rabia por vía intramuscular en las extremidades posteriores. Cada 8 horas, después de 72 horas de inoculación (p.i.), los animales se sacrificaron por perfusión con paraformaldehído y se obtuvieron secciones coronales de OB para el estudio inmunohistoquímico. Estos cortes se usaron para revelar la entrada y propagación de antígenos virales. Las secciones de tejido obtenidas en la fase terminal de la enfermedad (144 horas p.i.), y los controles de la misma edad también se procesaron para inmunohistoquímica de CB, PV y GFAP. Los antígenos del virus de la rabia se detectaron inicialmente a las 80 horas p.i. en unas pocas células mitrales. A las 88 horas p.i. los antígenos se habían diseminado a través de la mayoría de estas neuronas, pero hasta la fase terminal de la enfermedad había poca dispersión del virus hacia otras capas celulares del OB. La proteína CB se expresó en las células del estrato glomerular, la PV en células de la capa plexiforme externa y la GFAP se expresó en todas las capas del OB. La infección viral generó pérdida de expresión de CB y aumento en la expresión de PV. La inmunorreactividad a GFAP aumentó en la capa plexiforme externa del OB como respuesta a la infección.

The distribution of calbindin-D28k, parvalbumin, and calretinin immunoreactivity in the inferior colliculus of circling mouse / 대한해부학회지

The circling mice with tmie gene mutation are known as an animal deafness model, which showed hyperactive circling movement. Recently, the reinvestigation of circling mouse was performed to check the inner ear pathology as a main lesion of early hearing loss. In this trial, the inner ear organs were not so damaged to cause the hearing deficit of circling (cir/cir) mouse at 18 postnatal day (P18) though auditory brainstem response data indicated hearing loss of cir/cir mice at P18. Thus, another mechanism may be correlated with the early hearing loss of cir/cir mice at P18. Hearing loss in the early life can disrupt the ascending and descending information to inferior colliculus (IC) as integration site. There were many reports that hearing loss could result in the changes in Ca²⁺ concentration by either cochlear ablation or genetic defect. However, little was known to be reported about the correlation between the pathology of IC and Ca²⁺ changes in circling mice. Therefore, the present study investigated the distribution of calcium-binding proteins (CaBPs), calbindin-D28k, parvalbumin, and calretinin immunoreactivity (IR) in the IC to compare among wild-type (+/+), heterozygous (+/cir), and homozygous (cir/cir) mice by immunohistochemistry. The decreases of CaBPs IR in cir/cir were statistically significant in the neurons as well as neuropil of IC. Thus, this study proposed overall distributional alteration of CaBPs IR in the IC caused by early hearing defect and might be helpful to elucidate the pathology of central auditory disorder related with Ca²⁺ metabolism.

La inmunorreactividad a calbindina en células de purkinje del cerebelo de ratones no es afectada por la infección con virus de la rabia / Immunoreactivity to calbindin in purkinje cells in the cerebellum of mice is not affected by rabies virus infection

Introducción: La calbindina (CB) es una proteína reguladora del calcio intracelular y la célula de Purkinje del cerebelo es la neurona con más alta concentración de CB. Se ha demostrado pérdida de inmunorreactividad a CB en diferentes áreas del sistema nervioso en ratones inoculados con virus de la rabia, pero faltaba estudiar este fenómeno en el cerebelo. Objetivo: Determinar el efecto de la inoculación con virus de la rabia sobre la expresión de CB en células de Purkinje del cerebelo de ratones. Metodología: Se inocularon ratones con el virus por vía intramuscular. Se sacrificaron los animales cuando alcanzaron la fase avanzada de la enfermedad y se fijaron mediante perfusión intracardiaca con paraformaldehído al 4%. Se les extrajo el cerebelo y se hicieron cortes sagitales de 50 micrómetros de espesor en un vibrátomo. Estos se procesaron mediante inmunohistoquímica para revelar la presencia de CB o de antígenos del virus de la rabia. El mismo procedimiento se realizó con animales no infectados (controles). Resultados: Las células de Purkinje fueron masivamente infectadas con el virus de la rabia. En las imágenes panorámicas observadas en el microscopio se comprobó que sólo estas células fueron inmunorreactivas a CB. No se hallaron diferencias significativas en la inmunorreactividad a CB, evaluada por densitometría óptica, entre los animales infectados y los controles. Conclusión: La expresión de CB en las células de Purkinje del cerebelo parece no afectarse por la infección con rabia, a diferencia de lo que se ha demostrado en otras áreas del sistema nervioso del ratón.

Introduction: Calbindin (CB) is a regulatory protein of intracellular calcium, and the cerebellar Purkinje cell is the neuron with the highest concentration of CB. Loss of CB immunoreactivity has been demonstrated in different areas of the nervous system in rabies virus-infected mice, but the study of this phenomena in the cerebellum lacked. Objective: To determine the effect of inoculation with rabies virus on the expression of CB in Purkinje cells of the cerebellum of mice. Methodology: Mice were intramuscularly inoculated with rabies virus. Animals were sacrificed when they reached an advanced stage of the disease and then they were fixed by intracardiac perfusion with 4% paraformaldehyde. Cerebellums were extracted and sagittal sections 50 microns thick were obtained in a vibratome. These were processed by immunohistochemistry to reveal the presence of CB protein or rabies virus antigens. The same procedure was performed with uninfected animals (controls). Results: Purkinje cells were massively infected with rabies virus. In the microscopic panoramic images observed was found that only these cells are immunoreactive to CB. No significant difference in CB immunoreactivity evaluated by optical densitometry was found between infected animals and controls. Conclusion: The expression of CB in Purkinje cells of the cerebellum appears not to be affected by infection with rabies unlike what has been shown in other areas of the mouse nervous system.

The Usefulness of Calretinin Immunohistochemistry for Rectal Suction Biopsy to Diagnose Hirschsprung’s Disease / 소아외과

PURPOSE: Hirschsprung’s disease (HD) is a congenital intestinal disorder with absence of ganglion cells in the intestinal muscle and submucosa. Diagnosis is based on histopathological study such as H&E, and acetylcholinesterase (AchE) immunohistochemistry. Calretinin immunohistochemistry was introduced as a new diagnostic method against limitations of other staining. The aim of this study is to investigate the usefulness of calretinin immunohistochemistry for the diagnosis of HD compared to H&E and AchE. METHODS: Ten patients with HD and 22 non-HD patients were included in the study. H&E staining, AchE and calretinin immunohistochemistry were performed in all 32 patients. All slides were evaluated by same single pathologist and the diagnostic value was calculated for each H&E stain, AchE immunohistochemical staining, and calretinin immunohistochemical staining. RESULTS: Calretinin method had sensitivity of 100% and specificity of 100% for diagnosis of HD. Its diagnostic accuracy was 100%. AchE staining showed 100% of specificity and 80% of sensitivity. Diagnostic accuracy of H&E staining was 56.3%. CONCLUSION: We concluded that calretinin immunohistochemistry is a very useful and valuable method to diagnosis HD patient.

Differential effects of estrogen and estrogen receptor antagonist, ⅡCI 182780 on the expression of Calbindin-D9k in rat pituitary prolactinoma GH3 cells / 中华内分泌外科杂志

Objective To detect the effects of 17 β-estradiol(E2)on the expression of Calbindin-D9k (CaBP-9k) in pituitary GH3 cells,and to investigate the antagonistic effect of a selective estrogen receptor antagonist,ⅡCI 182780 on CaBP-9k expression.Methods A rat pituitary prolactinoma cell line,GH3 cell was used as the in vitro model.The localization of CaBP-9k in GH3 cells was observed by immunofluorescence.GH3 cells were cultured with exogenous E2-added medium for 24 hours,and the concentrations of E2 were 10-8,10-9,10-10M,respectively.mRNA and protein expression levels of CaBP-9k in different groups were analyzed by RT-PCR and Western blot analysis.The estrogen receptor antagonist,and ⅡCI 182780 was added to GH3 cells before E2 administration (10-8M)with the concentration of 10-6M,in order to investigate the regulation of ER-mediated pathway on the expression of CaBP-9k.Immunoprecipitation was used to detect the interaction between CaBP-9k and ERα.Results E2 had significant stimulatory effect on the CaBP-9k expression of GH3 cells in a dose dependent manner,and the expression level of CaBP-9k was higher when treated with a higher concentration of E2.ⅡCI 182780 could suppress the stimulatory effect of E2 on the CaBP-9k expression of GH3 cells.The expression level of CaBP-9k was significantly reduced by coadministration of E2 with ⅡCI 182780 in GH3 cells,which meant the CaBP-9k expression was mediated through ERα pathway.The immunoprecipitation results further illustrated the fact that CaBP-9k could directly interact with ERα,and E2 could increase the interaction between CaBP-9k and ERα.Conclusion Estrogen might induce CaBP-9k expression via ERα mediated pathway and CaBP-9k could directly combine with ERα,suggesting that CaBP-9k might be involved in the biological effects mediated by ER pathway in GH3 cells.

Unilateral olfactory functional deprivation model in the left peripheral nostrils by electric cautery injury:olfactory bulb neurogenesis and transformation / 中国组织工程研究

BACKGROUND:Olfactory bulb neurogenesis, transformation and maturation have been considered the hot topic. Olfactory bulb experience and nervous activity can influence olfactory bulb neurogenesis. However, no study reports that olfactory bulb functions can affect olfactory bulb neurogenesis in guinea pigs. OBJECTIVE:To investigate the effect of unilateral olfactory functional deprivation on doublecortin, calbindin and parvalbumin expression in olfactory bulb of juvenile guinea pigs. METHODS:Total y 24 guinea pigs were randomly divided into two groups, which were kil ed after establishing olfactory functional deprivation model through electric cautery injury at the left peripheral nostrils. At 3 and 6 weeks after modeling, the specimens were harvested. The expression change of doublecortin, calbindin and parvalbumin in two sides’ olfactory bulb of juvenile guinea pigs was detected by immunohistochemistry. RESULTS AND CONCLUSION:The number of doublecortin, calbindin and parvalbumin positive cells in olfactory bulb at the un-deprived side was significantly higher than that at the deprived side at 3 and 6 weeks (P<0.05). This finding indicates that olfactory neural activities can affect neurogenesis and transformation in guinea pigs.

Calbindin-D28K Prevents Staurosporin-induced Bax Cleavage and Membrane Permeabilization

Calbindin-D28K has been implicated in the regulation of neuronal cell death. Previously, we demonstrated that calbindin-D28K prevents staurosporine (STS)-induced caspase activation and subsequent apoptosis in a neuronal cell line. However, the role of calbindin-D28K in STS-induced activation of calpain and necrotic cell death was not identified. Staurosporine induced the elevation of intracellular calcium after 1 hr of treatment. Overexpression of calbindin-D28K and presence of a calcium chelator, BAPTA, prevented the increase of calcium in STS-treated cells. Cleavage of Bax by calpain was prevented by the overexpressed calbindin-D28K. Permeabilization of the plasma membrane, a factor in necrosis, as well as apoptotic change of the nucleolus induced by STS, was prevented by calbindin-D28K. Thus, our study suggests that calbindin-D28K may exert its protective functions by preventing calpain activation in necrotic cell death, in addition to its effect on the caspase-apoptosis pathway.

Focal cerebral ischemic injury decreases calbindin expression in brain tissue and HT22 cells / 한국실험동물학회지

Calbindin is a calcium binding protein that controls intracellular calcium levels and has a neuroprotective function against apoptotic stimuli. We investigated the expression of calbindin in ischemic brain injury. Focal cerebral ischemia was induced in male rats by middle cerebral artery occlusion (MCAO) and cerebral cortices were collected 24 h after MCAO. Cerebral ischemia significantly increased infarct volume. RT-PCR and Western blot analyses showed that MCAO injury induced a decrease of calbindin expression. Moreover, immunohistochemical staining showed that the number of calbindin-positive cells decreased in ischemic regions of MCAO-operated animals. In cultured hippocampal-derived cell lines, glutamate exposure increased intracellular Ca2+ concentrations and decreased calbindin expression. Taken together, both in vivo and in vitro results demonstrated decreases of calbindin after neuronal cell injury. These results suggest that decreases of calbindin in ischemic brain injury contribute to neuronal cell death.

Time-dependent changes of calbindin D-28K and parvalbumin immunoreactivity in the hippocampus of rats with streptozotocin-induced type 1 diabetes

The hippocampus is affected by various stimuli that include hyperglycemia, depression, and ischemia. Calcium-binding proteins (CaBPs) have protective roles in the response to such stimuli. However, little is known about the expression of CaBPs under diabetic conditions. This study was conducted to examine alterations in the physiological parameters with type 1 diabetes induced with streptozotocin (STZ) as well as time-dependent changes in the expression of two CaBPs changes of were being evaluated. Rats treated with STZ (70 mg/kg) had high blood glucose levels (>21.4 mmol/L) along with increased food intake and water consumption volumes compared to the sham controls. In contrast, body weight of the animals treated with STZ was significantly reduced compared to the sham group. CB-specific immunoreactivity was generally increased in the hippocampal CA1 region and granule cell layer of the dentate gyrus (DG) 2 weeks after STZ treatment, but decreased thereafter in these regions. In contrast, the number of PV-immunoreactive neurons and fibers was unchanged in the hippocampus and DG 2 weeks after STZ treatment. However, this number subsequently decreased over time. These results suggest that CB and PV expression is lowest 3 weeks after STZ administration, and these deficits lead to disturbances in calcium homeostasis.

Distribution Patterns of Calbindin-D28K and NADPH-Diaphorase Positive Neurons in the Midbrain Periaqueductal Gray of the Rabbit / 신경정신의학

OBJECTIVES: We attempted to compartmentalize the periaqueductal gray (PAG) of the rabbit in terms of the different distribution patterns between NADPH-diaphorase (NADPHd)- and calbindin D28K (CB)-positive neurons. METHODS: Immunohistochemistry and immunofluorescent labelling for CB and histochemistry for NADPHd were carried out on coronally-sectioned midbrain slices of the rabbit. RESULTS: NADPHd-positive neurons were selectively localized in the dorsolateral (DL), the middle one-third of the lateral (L), the dorsal half of the ventrolateral (VLd) PAG, and the supraoculomotor cap nucleus (Su3C). Clusters of CB-immunoreactive perikarya marked the dorsal half of DL (DLd), Su3C, the ventral one-third of L, and the ventral half of the ventrolateral (VLv) PAG. Double labelling for NADPHd and CB revealed that two markers labelled different neuronal groups in DLd and Su3C subdivisions. CONCLUSION: The present data suggest that NADPHd and CB can be regarded as reliable neurochemical markers to reveal the longitudinally-columnar organization within the PAG and to subdivide each columnar area.

Effect of Electroacupuncture on the Expression of Hippocampal Calbindin-D28K in Hyperlipemia Rats with Concurrent Cerebral Ischemia / 针刺研究

Objective To observe the effect of electroacupuncture(EA) on Calbindin D28K(CB) expression and apoptosis in hippocampus in hyperlipemia rats with concomitant cerebral ischemia(CI).Methods Forty male SD rats were rando-mized into control,hyperlipemia+CI(model),acupuncture Ⅰ,and acupuncture Ⅱ groups,with 10 cases in each.Hyperlipemia model was established by feeding the animals with high fat forage for 6 weeks and CI model established by occlusion of the unila-teral middle cerebral artery.For rats of acupuncture Ⅰ group,EA(1-3 mA,15 Hz) was applied to bilateral "Sanyinjiao"(SP 6) and "Fenglong"(ST 40) for 20 min every time,once daily for 10 days before CI.For rats of both acupuncture Ⅰ and Ⅱ groups,after CI,EA was applied to SP 6,ST 40,"Baihui"(GV 20) and "Shuigou"(GV 26) were punctured with filiform needles and stimulated by twirled the needle with hand continuously for 1 min,once daily for 7 days.The apoptotic cells of hippocampal CA 3 area were displayed by TUNEL(terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling) method.CB antibody staining with immunohistochemistry was used to show CB-positive cells which were observed by optic microscope.Results In comparison with control group,the percentage of apoptotic cells of the hippocampal CA 3 area in model group increased considerably(P

Immunohistochemical study on the expression of calcium binding proteins (calbindin-D28k, calretinin, and parvalbumin) in the cerebellum of the nNOS knock-out(-/-) mice / 대한해부학회지

Nitric Oxide (NO) actively participates in the regulation of neuronal intracellular Ca2+ levels by modulating the activity of various channels and receptors. To test the possibility that modulation of Ca2+ buffer protein expression level by NO participates in this regulatory effect, we examined expression of calbindin-D28k, calretinin, and parvalbumin in the cerebellum of neuronal NO synthase knock-out (nNOS(-/-)) mice using immunohistochemistry. We observed that in the cerebellar cortex of the nNOS(-/-) mice, expression of calbindin-D28k and parvalbumin were significantly increased while expression of calretinin was significantly decreased. These results suggest another mechanism by which NO can participate in the regulation of Ca2+ homeostasis.

Changes in transcript and protein levels of calbindin D28k, calretinin and parvalbumin, and numbers of neuronal populations expressing these proteins in an ischemia model of rat retina / 대한해부학회지

Excessive calcium is thought to be a critical step in various neurodegenerative processes including ischemia. Calbindin D28k (CB), calretinin (CR), and parvalbumin (PV), members of the EF-hand calcium-binding protein family, are thought to play a neuroprotective role in various pathologic conditions by serving as a buffer against excessive calcium. The expression of CB, PV and CR in the ischemic rat retina induced by increasing intraocular pressure was investigated at the transcript and protein levels, by means of the quantitative real-time reverse transcription-polymerase chain reaction, western blot and immunohistochemistry. The transcript and protein levels of CB, which is strongly expressed in the horizontal cells in both normal and affected retinas, were not changed significantly and the number of CB-expressing horizontal cells remained unchanged throughout the experimental period 8 weeks after ischemia/reperfusion injury. At both the transcript and protein levels, however, CR, which is strongly expressed in several types of amacrine, ganglion, and displaced amacrine cells in both normal and affected retinas, was decreased. CR-expressing ganglion cell number was particularly decreased in ischemic retinas. Similar to the CR, PV transcript and protein levels, and PV-expressing AII amacrine cell number were decreased. Interestingly, in ischemic retinas PV was transiently expressed in putative cone bipolar cell types possibly those that connect with AII amacrine cells via gap junctions. These results suggest that these three calcium binding proteins may play different neuroprotective roles in ischemic insult by their ability to buffer calcium in the rat retina.

Transcriptional and translational expression of calbindin-D9k in the duodenum, kidney and uterus of a female canine model

Calbindin-D9k (CaBP-9k) is a cytosolic calcium-binding protein expressed in tissues in the intestine, uterus, placenta, kidney, pituitary gland and bone. Its exact function is unknown, but it is considered to regulate intracytoplasmic concentration and transport of free ions (Ca2+). CaBP-9k protein is involved in intestinal calcium absorption in the intestine and in the regulation of myometrial activity by intracellular calcium in the uterus. Renal CaBP-9k protein is expressed at the site of calcium re-absorption in the kidney and expressed in distal convoluted tubules, where it is thought to facilitate calcium re-absorption. Expression of the CaBP-9k gene has been explored in most mammalians except in a canine model. Presently, we elucidated the expression of CaBP-9k mRNA and protein in the duodenum, kidney and uterus in a canine model involving two adult (2.5-year-old) female beagles. To collect tissues, the dogs were euthanized and then the abdominal cavity was exposed by midline incision. The proximal duodenum, cortex of kidney and uterine horn were collected. Expression of CaBP-9k mRNA was confirmed by reverse transcription-polymerase chain reaction (RT-PCR) and real-time PCR. CaBP-9k protein expression and localization were ascertained by Western blot analysis and immunohistochemistry, respectively. CaBP-9k mRNA was detected in the duodenum, but not in the kidney and uterus. Its protein was expressed only in the enterocytes of the duodenum. Taken together, the results indicate that CaBP-9k mRNA and protein are highly expressed in the enterocytes of the duodenum of a canine model, consistent with findings in other mammalian species.

Optimized Immunohistochemical Analysis of Cerebellar Purkinje Cells Using a Specific Biomarker, Calbindin D28k

Cerebellar Purkinje cells (PCs) play a crucial role in motor functions and their progressive degeneration is closely associated with spinocerebellar ataxias. Although immunohistochemical (IHC) analysis can provide a valuable tool for understanding the pathophysiology of PC disorders, the method validation of IHC analysis with cerebellar tissue specimens is unclear. Here we present an optimized and validated IHC method using antibodies to calbindin D28k, a specific PC marker in the cerebellum. To achieve the desired sensitivity, specificity, and reproducibility, we modified IHC analysis procedures for cerebellar tissues. We found that the sensitivity of staining varies depending on the commercial source of primary antibody. In addition, we showed that a biotin-free signal amplification method using a horseradish peroxidase polymer-conjugated secondary antibody increases both the sensitivity and specificity of ICH analysis. Furthermore, we demonstrated that dye filtration using a 0.22 micrometer filter eliminates or minimizes nonspecific staining while preserving the analytical sensitivity. These results suggest that our protocol can be adapted for future investigations aiming to understand the pathophysiology of cerebellar PC disorders and to evaluate the efficacy of therapeutic strategies for treating these diseases.

Changes in Calcium-binding Proteins in the Rat Hippocampus after Involuntary Treadmill Exercise / 대한해부학회지

In this study, we investigated the effects of treadmill exercise on hippocampal levels of calcium-binding proteins - calbindin D-28k (CB), calretinin (CR) and parvalbumin (PV) - using immunohistochemistry and Western blot analysis. At 6 weeks of age, male Wistar rats were put on a treadmill with or without running for 1 h/day/5 consecutive days at a pace of 22 m/min for a period of 5 weeks. In sedentary and exercise groups, CB immunoreaction was detected in granule cells of the dentate gyrus, mossy fibers, and CA1 pyramidal cells. In addition, CB immunoreaction was observed in interneurons of the CA1-3 region. Exercise significantly increased CB immunoreactivity in dentate granule cells, CA1 pyramidal cells and CA1-3 interneurons. CR immunoreaction was mainly observed in interneurons of the dentate gyrus and CA1-3 regions. Similar number of CR-immunoreactive neurons was observed in the exercise and sedentary groups. PV immunoreaction was detected in interneurons of the dentate gyrus and CA1-3 regions. PVimmunoreactive fibers were significantly increased in all regions of the hippocampus in the exercise group, as compared to the sedentary group. Similar to the immunohistochemical findings, protein levels of CB and PV were also increased in the exercise group compared to the sedentary group. These increases in CB and PV in the hippocampus may induce neuronal plasticity after treadmill exercise and may be related to the enhancement of synaptic plasticity in the hippocampus by exercise.

The Effect of 835 MHz Radiofrequency Radiation Exposure on the Immunohistochemical Distribution of Calbindin D28k and Calretinin in the Mouse Cerebellar Cortex / 체질인류학회지

Widespread use of mobile phones and subsequent electromagnetic field (EMF) exposure have raised crucial question of their possible biological effects on the nervous system. The study on the effect of radiofrequency(RF) radiation on the nervous system, however, did not precede enough to determine the biological hazard to brain. Until now, several studies have reported decreases in neuron number and neuronal damage in the cortex, hippocampus, and basal ganglia in the brains of animals exposed to RF radiation. However, there were few reports about the cerebellum, the main voluntary motor control center. In this regard, by using immunohistochemisty, current study intended to investigate the changes in the calbindin D28k (CB) and calretinin (CR)-immunoreactivity (IR) in the mouse cerebellar cortex after EMF exposure at 835 MHz for different exposure times and absorption rates, 1 h/day for 5 days at 1.6 W/kg, 1 h/day for 5 days at 4.0 W/kg, 5 h/day for 1 day at 1.6 W/kg, 5 h/day for 1 day at 4.0 W/kg, daily exposure for one month at 1.6 W/kg. Among groups, most prominent CB IR was observed in the Purkinje cell layer followed by molecular and granular layer. The highest CB IR was noted in 5 h/day for 1 day at 1.6 W/kg in the entire three layers while the lowest was noted in one month at 1.6 W/kg. Similarly CR IR was maximum in one month at 1.6 W/kg whilst the lowest was observed in 1 h/day for 5 days at 4.0 W/kg. EMF exposure for 5 days at 1.6 W/kg reduced CB-IR. The CR-IR was mainly localized in small cells in the granular layer, with maximum IR observed after one month exposure. Therefore, the present study suggest the possibility of alterations of calcium ion concentration, which play a role in maintaining metabolic homeostasis, in the cerebellum after long-term exposure to 835 MHz of RF radiation, which might lead to thedisruption of normal trait.

Evaluación inmunohistoquímica de la expresión de calbindina en el cerebro de ratones en diferentes tiempos después de la inoculación con el virus de la rabia / Immunohistochemical evaluation of calbindin expression in mouse brain at different times after rabies virus inoculation

Introducción: La calbindina (CB) es una proteína reguladora del metabolismo del calcio intracelular. Previamente se demostró que la infección con virus fijo de la rabia induce pérdida de la expresión de CB, en el cerebro de ratones en estado terminal de la enfermedad, a los 7-8 días de post-inoculación (p.i.) intramuscular. Objetivo: Determinar si la pérdida de expresión de CB se presenta también en etapas tempranas de la infección y si es una consecuencia inmediata a la aparición de antígenos virales en el cerebro. Materiales y métodos: Se inocularon ratones con virus fijo de la rabia, por vía intramuscular, en su extremidad posterior izquierda. Diariamente se tomaron entre 4 y 6 animales infectados y sus respectivos controles, se fijaron por perfusión intracardíaca con paraformaldehído, se extrajeron sus cerebros y se obtuvieron cortes coronales en un vibratomo. Estos se sometieron a reacciones inmunohistoquímicas para evaluar la presencia de antígenos virales y la expresión de CB. Esta última fue cuantificada mediante densitometría óptica en un microscopio con anßlisis de imßgenes. Resultados: La inmunorreactividad a la rabia fue positiva en el cerebro a partir del día 3 p.i.; se observó primero en neuronas piramidales de la corteza frontal. La inmunotinción para CB no sufrió ninguna alteración cualitativa ni cuantitativa en la corteza cerebral y el estriado hasta el día 6 p.i. Conclusiones: Estos resultados coinciden con los de otros estudios sobre la rabia en los que se han encontrado alteraciones moleculares, metabólicas o fisiopatológicas en el sistema nervioso sólo en la fase terminal de la enfermedad.

Introduction: The calcium-binding protein calbindin (CB) plays a critical role in intracellular calcium metabolism. In a previous study we demonstrated that the infection with fixed rabies virus caused loss of CB expression in mouse brain during terminal state of the disease, 7-8 days after intramuscular inoculation. Objectives: To determine loss of CB expression also appears in early stages of the infection and if it is a consequence immediate to the appearance of viral antigens in the brain. Materials and methods: Mice were inoculated with fixed rabies virus, by intramuscular route, in the left hind limbs. Daily, to sixth day, 4-6 animals and their respective controls were killed and fixed by intracardiac perfusion with paraformaldehyde and their brains were extracted to obtain coronal sections using a vibratome. Free-floating sections were treated by immunohistochemical procedures to evaluate the presence of rabies viral antigens and the expression of CB. The last one was quantified by optical densitometry in a microscope with a system of image analysis. Results: Rabies immunoreactivity was observed in the brain three days after virus inoculation, beginning in pyramidal neurons of the frontal cortex whereas the immunostaining for CB did not undergo any qualitative nor quantitative changes neither in the cerebral cortex or striatum during the six days post-inoculation. Conclusions: These results agree with other studies in which it has been settled down that the rabies molecular or metabolic effects on the nervous system are well-known only in the final stage of the disease.