Licochalcone A attenuates NMDA-induced neurotoxicity.

This study investigates the effect of Licochalcone A (Lico-A), a flavonoid from licorice roots known for its anti-inflammatory, anti-cancer, and antioxidant properties, on NMDA-induced neurotoxicity in primary cultured rat hippocampal neurons. The study measured cell survival following NMDA and Lico-A exposure, revealing that Lico-A at a 2.5 µg/ml significantly improved cell viability, countering the detrimental effects of NMDA. The study also analyzed synaptic changes by examining both postsynaptic density 95 (PSD95) and synaptophysin-targeted imaging, showing that Lico-A treatment resulted in a significant increase in synaptic puncta, contrasting with the reduction observed under NMDA exposure. Furthermore, levels of phosphorylated mixed lineage kinase domain-like pseudokinase (P-MLKL) and phosphorylated receptor-interacting serine/threonine-protein kinase 3 (P-RIP3), key necroptosis regulators, were measured using Western blotting. The results showed an increase in P-MLKL and P-RIP3 in neurons exposed to NMDA, which was reduced following Lico-A treatment. The response of astrocyte and microglia was also evaluated by immunostaining for glial fibrillary acidic protein (GFAP), ionized calcium-binding adaptor molecule 1 (IBA-1) and tumor necrosis factor alpha (TNF-α). These markers exhibited heightened expression in the NMDA group, which was substantially reduced by Lico-A treatment. These findings suggest that Lico-A has neuroprotective effects against NMDA-induced neurotoxicity, potentially contributing to synaptic preservation, inhibition of neuronal necroptosis, and modulation of glial activation. Therefore, Lico-A shows promise as a neuroprotective agent for conditions associated with NMDA-related neurotoxicity.

Immunofluorescent distribution of SIRT1, SIRT2, SIRT6 protein in the skin of SKH1 mouse after ultraviolet B irradiation for 10 Weeks / Distribución inmunofluorescente de la proteína SIRT1, SIRT2, SIRT6 en la piel del ratón SKH1 después de la irradiación ultravioleta B durante 10 semanas

SUMMARY: The skin, located on the outermost part of the body, is always exposed to external stimuli such as sunlight. The exposure of skin to ultraviolet B (UVB) radiation from sunlight is known to be a major environmental factor in inducing photoaging. After exposure to UVB, an increase in reactive oxygen species can affect the expression and activity of many critical proteins depending on the duration and dose of the UVB radiation. Mammalian sirtuins (SIRTs), which are nicotinamide dinucleotide-dependent protein deacetylases, are well known for playing a role in cellular longevity. However, little is known about SIRT protein alterations in keratinocytes upon UVB irradiation according to SIRT subtypes. Therefore, in this study, the distribution of non-mitochondrial SIRT1, SIRT2, and SIRT6 proteins was investigated by immunofluorescence (IF) staining of the skin of SKH-1 mice (n=12) after UVB irradiation for 10 weeks. After UVB irradiation for 10 weeks, the IF of both SIRT1 and SIRT6 was significantly increased in the UVB-irradiated mice group (UG), but the difference in SIRT2 IF was not statistically significant between the control group (CG) and the UG. The translocation of both SIRT1 and SIRT6 IF from the nucleus to the cytoplasm of keratinocytes was observed in the upper epidermis of the UG, whereas SIRT2 IF was localized in the cytoplasm of keratinocytes in the epidermis in both the CG and the UG. The translocation of SIRT1 and SIRT6 IF from the nucleus to the cytoplasm of keratinocytes may account for the physiologically protective action of keratinocytes against UVB irradiation. However, the exact role of SIRT1 and SIRT6 translocation in keratinocytes, where SIRT1 and SIRT6 shuttle from the nucleus to the cytoplasm, is not well known. Therefore, further studies are needed to understand the molecular mechanisms of SIRT1 and SIRT6 translocation in keratinocytes upon UVB irradiation.

La piel, situada en la parte más externa del cuerpo, está siempre expuesta a estímulos externos como la luz solar. Se sabe que la exposición de la piel a la radiación ultravioleta B (UVB) de la luz solar es un factor ambiental importante en la inducción del fotoenvejecimiento. Después de la exposición a los rayos UVB, un aumento en las especies reactivas de oxígeno puede afectar la expresión y la actividad de muchas proteínas críticas según la duración y la dosis de la radiación UVB. Las sirtuinas de mamíferos (SIRT), que son proteínas desacetilasas dependientes de dinucleótidos de nicotinamida, son bien conocidas por desempeñar un papel en la longevidad celular. Sin embargo, se sabe poco sobre las alteraciones de la proteína SIRT en los queratinocitos tras la irradiación UVB según los subtipos de SIRT. Por lo tanto, en este estudio, se investigó la distribución de las proteínas SIRT1, SIRT2 y SIRT6 no mitocondriales mediante tinción de inmunofluorescencia (IF) de la piel de ratones SKH-1 (n = 12), después de la irradiación con UVB durante 10 semanas. Posterior a la irradiación, el IF de SIRT1 y SIRT6 aumentaron significativamente en el grupo de ratones irradiados con UVB (UG), pero la diferencia en SIRT2 IF no fue estadísticamente significativa entre el grupo control (CG) y el UG. La translocación de SIRT1 y SIRT6 IF desde el núcleo al citoplasma de los queratinocitos se observó en la epidermis superior de la UG, mientras que SIRT2 IF se localizó en el citoplasma de los queratinocitos en la epidermis, tanto en el GC, como en la UG. La translocación de SIRT1 y SIRT6 IF del núcleo al citoplasma de los queratinocitos puede explicar la acción protectora fisiológica de estos contra la radiación UVB. Sin embargo, el papel exacto de la translocación de SIRT1 y SIRT6 en los queratinocitos, donde SIRT1 y SIRT6 se trasladan desde el núcleo al citoplasma, no se conoce bien. Por lo tanto, se necesitan más estudios para comprender los mecanismos moleculares de la translocación SIRT1 y SIRT6 en los queratinocitos tras la irradiación UVB.

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.

A Prospective Validation and Observer Performance Study of a Deep Learning Algorithm for Pathologic Diagnosis of Gastric Tumors in Endoscopic Biopsies.

PURPOSE: Gastric cancer remains the leading cause of cancer-related deaths in Northeast Asia. Population-based endoscopic screenings in the region have yielded successful results in early detection of gastric tumors. Endoscopic screening rates are continuously increasing, and there is a need for an automatic computerized diagnostic system to reduce the diagnostic burden. In this study, we developed an algorithm to classify gastric epithelial tumors automatically and assessed its performance in a large series of gastric biopsies and its benefits as an assistance tool. EXPERIMENTAL DESIGN: Using 2,434 whole-slide images, we developed an algorithm based on convolutional neural networks to classify a gastric biopsy image into one of three categories: negative for dysplasia (NFD), tubular adenoma, or carcinoma. The performance of the algorithm was evaluated by using 7,440 biopsy specimens collected prospectively. The impact of algorithm-assisted diagnosis was assessed by six pathologists using 150 gastric biopsy cases. RESULTS: Diagnostic performance evaluated by the AUROC curve in the prospective study was 0.9790 for two-tier classification: negative (NFD) versus positive (all cases except NFD). When limited to epithelial tumors, the sensitivity and specificity were 1.000 and 0.9749. Algorithm-assisted digital image viewer (DV) resulted in 47% reduction in review time per image compared with DV only and 58% decrease to microscopy. CONCLUSIONS: Our algorithm has demonstrated high accuracy in classifying epithelial tumors and its benefits as an assistance tool, which can serve as a potential screening aid system in diagnosing gastric biopsy specimens.

The prevalence of persistent metopic sutures comparing the Nepalese bone collection with Korean bone collection / Prevalencia de suturas metópicas persistentes que comparan una colección de huesos nepaleses con una colección de huesos coreanos

SUMMARY: Metopic suture can be visualized from the nasion to the bregma along the arch of the frontal bone in mid-sagittal plane. Persistent metopic suture normally closing between 1st and 2nd year of life has also been related with ethnicity. The present study reports the presence of complete and incomplete metopic sutures in Nepalese and Korean population skulls which helps to shed light on its incidence rate. Out of 121 adult skulls in Nepalese population, metopic suture was found to be present in 33 skulls. Incomplete metopic sutures showed variations of morphology, like linear (6.61 %), V-shaped (8.26 %) and double incomplete (10.74 %) and two cases with complete metopic suture, which showed variation in interdigitation between its anterior and posterior ends. Korean population showed metopic suture to be present in 8 skulls out of 104 with metopism in 3 skulls. Incomplete metopic sutures like double incomplete (1.92 %) and linear (2.88 %) were also noted. Alterations to local strains could be the contributing factor for such variation and complexity of interdigitation, which occur during the growth of the braincase. The knowledge of the metopic suture and its variations according to ethnicity is important and should be considered to prevent wrong diagnosis. The presence of different types of metopic sutures as reported by the present study provides informative value on the presence and variation of such sutures in population depending on ethnicity and ought to be helpful in diagnostic sequences in emergency setting.

RESUMEN: La sutura metópica se puede visualizar desde nasión hasta el bregma a lo largo del arco del hueso frontal en el plano mediano sagital. La sutura metópica persistente que normalmente se cierra entre el primer y segundo año de vida, también se ha relacionado con el origen étnico. El presente estudio informa la presencia de suturas metópicas completas e incompletas en los cráneos de la población nepalesa y coreana, lo que además de entregar información sobre su tasa de incidencia. De 121 cráneos adultos en la población nepalesa, en 33 de ellos se encontró la sutura metópica. Las suturas metópicas incompletas mostraron variaciones de la morfología, como lineal (6,61 %), en forma de V (8,26 %) y doble incompleta (10,74 %), además de dos casos con sutura metópica completa, que mostraron variación en la interdigitación entre sus extremos anterior y posterior. De los 104 cráneos de la población coreana en 8 se presentó la sutura metópica y en 3 metopismo. También se observaron suturas metópicas incompletas como doble incompleta (1,92 %) y lineal (2,88 %). Las alteraciones en las etnias locales podrían ser el factor contribuyente para tal variación y complejidad de la interdigitación, que ocurre durante el crecimiento de la cráneo. El conocimiento de la sutura metópica y sus variaciones según el origen étnico es importante y debe considerarse para prevenir un diagnóstico incorrecto. La presencia de diferentes tipos de suturas metópicas según lo informado en el estudio, proporciona un valor informativo sobre la presencia y la variación de tales suturas en la población, dependiendo de la etnia, y debería ser útil en las secuencias de diagnóstico en situaciones de emergencia.

A 4-Nitroquinoleneoxide-Induced Pleurotus eryngii Mutant Variety Increases Pin1 Expression in Rat Brain.

To develop Pleurotus eryngii varieties with improved medicinal qualities, protoplasts of P. eryngii were mutagenized using 4-nitroquinoleneoxide. The effects of the resulting variant mushrooms on a human cell were evaluated by applying their aqueous extracts to the human hepatoma cell line, HepG2, in vitro and examining any alteration in the proteomes of the treated HepG2. The P. eryngii mutant, NQ2A-12, was selected for its effects on increasing the expression level of Pin1 in HepG2. Pin1 is one of the peptidyl-prolyl cis-trans isomerases known to play an important role in repressing Alzheimer's disease pathogenesis. Validity of NQ2A-12 related to Alzheimer's disease was shown with an enhanced expression of Pin1 in a mouse brain tissue by injecting the NQ2A-12 extract. The mutant mushroom, NQ2A-12, could be developed as a new variety of P. eryngii with potential to protect against Alzheimer's disease.

Bone tumors in pre-modern skulls from human skeletal series of Joseon Dynasty.

To date, there are still very few reports on benign-tumor cases based on East Asian skeletal series, even though other regions and continents have been well represented. In our study on the Joseon Human Skeletal Series, we identified benign bone tumors in two skeletons (cases Nos. 75 and 96). Our radiological analyses showed both cases to be homogeneous sclerotic bone masses aligned with the cranial vault suture. In a subsequent series of differential diagnoses, we determined both cases to be osteoma, the most common bone-tumor type reported for archaeological samples. Our study is the osteoarchaeological basis for this, the first-ever report on benign bone neoplasm in a pre-modern East Asian population.

A possible case of cherubism in a 17th-century Korean mummy.

Cherubism is a benign fibro-osseous disease of childhood limited specifically to the maxilla and mandible. The progressive replacement of the jaw bones with expansile multilocular cystic lesions causes eventual prominence of the lower face, and hence the classic "cherubic" phenotype reflecting variable extents of jaw hypertrophy. Histologically, this condition has been characterized as replacement of the normal bone matrix with multicystic pockets of fibrous stroma and osteoclastic giant cells. Because of radiographic features common to both, primarily the presence of multiloculated lucencies with heterogeneous "ground-glass" sclerosis on CT imaging, cherubism was long mistaken for a craniofacial subtype of fibrous dysplasia. In 1999, however, the distinct genetic basis for cherubism was mapped to chromosome 4p16.3 and the SH-3 binding protein SH3BP2. But while there are already three suspected cases of fibrous dysplasia amongst archaeological populations, no definitive cases of cherubism have yet been reported in historical populations. In the current study we describe micro- and macro-structural changes in the face of a 17th century Joseon Dynasty Korean mummy which may coincide with the clinic-pathologic and radiologic features of cherubism.

Alteration of glycine receptor immunoreactivity in the auditory brainstem of mice following three months of exposure to radiofrequency radiation at SAR 4.0 W/kg.

The increasing use of mobile communication has triggered an interest in its possible effects on the regulation of neurotransmitter signals. Due to the close proximity of mobile phones to hearing-related brain regions during usage, its use may lead to a decrease in the ability to segregate sounds, leading to serious auditory dysfunction caused by the prolonged exposure to radiofrequency (RF) radiation. The interplay among auditory processing, excitation and inhibitory molecule interactions plays a major role in auditory function. In particular, inhibitory molecules, such a glycine, are predominantly localized in the auditory brainstem. However, the effects of exposure to RF radiation on auditory function have not been reported to date. Thus, the aim of the present study was to investigate the effects of exposure to RF radiation on glycine receptor (GlyR) immunoreactivity (IR) in the auditory brainstem region at 835 MHz with a specific absorption rate of 4.0 W/kg for three months using free-floating immunohistochemistry. Compared with the sham control (SC) group, a significant loss of staining intensity of neuropils and cells in the different subdivisions of the auditory brainstem regions was observed in the mice exposed to RF radiation (E4 group). A decrease in the number of GlyR immunoreactive cells was also noted in the cochlear nuclear complex [anteroventral cochlear nucleus (AVCN), 31.09%; dorsal cochlear nucleus (DCN), 14.08%; posteroventral cochlear nucleus (PVCN), 32.79%] and the superior olivary complex (SOC) [lateral superior olivary nucleus (LSO), 36.85%; superior paraolivary nucleus (SPN), 24.33%, medial superior olivary nucleus (MSO), 23.23%; medial nucleus of the trapezoid body (MNTB), 10.15%] of the mice in the E4 group. Auditory brainstem response (ABR) analysis also revealed a significant threshold elevation of in the exposed (E4) group, which may be associated with auditory dysfunction. The present study suggests that the auditory brainstem region is susceptible to chronic exposure to RF radiation, which may affect the function of the central auditory system.

Inflammation of temporomandibular joint increases neural activity in rat vestibular nucleus.

To determine whether the vestibular nuclei are affected by inflammation of temporomandibular joint (TMJ) region, we studied vestibular nucleus neural activity using two experimental groups: (1) normal saline 0.1cm(3) injection at right TMJ region, (2) 10% formalin 0.1cm(3) injection at right TMJ region. Neural activity after 24 hours was assessed by immunohistochemical staining with free-floating section at the level of interaural -1.30 mm to -2.00 mm for c-Fos. In inflammation group, formalin injection produced a bilateral increase in c-Fos at vestibular nucleus with ipsilesional side higher activity. In control group, expression of c-Fos protein was also observed in the vestibular nucleus (VN), especially MVN. But stain intensity of Fos-positive neurons was much weaker and mean number of c-Fos positive cells was fewer than inflammation group. This result suggests that there is a close neural connection between TMJ and vestibular nucleus, especially in case of inflammation.

Effect of 835 MHz radiofrequency radiation exposure on calcium binding proteins in the hippocampus of the mouse brain.

Worldwide expansion of mobile phones and electromagnetic field (EMF) exposure has raised question of their possible biological effects on the brain and nervous system. Radiofrequency (RF) radiation might alter intracellular signaling pathways through changes in calcium (Ca(2+)) permeability across cell membranes. Changes in the expression of calcium binding proteins (CaBP) like calbindin D28-k (CB) and calretinin (CR) could indicate impaired Ca(2+)homeostasis due to EMF exposure. CB and CR expression were measured with immunohistochemistry in the hippocampus of mice after EMF exposure at 835 MHz for different exposure times and absorption rates, 1 h/day for 5 days at a specific absorption rate (SAR)=1.6 W/kg, 1 h/day for 5 days at SAR=4.0 W/kg, 5 h/day for 1 day at SAR=1.6 W/kg, 5 h/day for 1 day at SAR=4.0 W/kg, daily exposure for 1 month at SAR=1.6 W/kg. Body weights did not change significantly. CB immunoreactivity (IR) displayed moderate staining of cells in the cornu ammonis (CA) areas and prominently stained granule cells. CR IR revealed prominently stained pyramidal cells with dendrites running perpendicularly in the CA area. Exposure for 1 month produced almost complete loss of pyramidal cells in the CA1 area. CaBP differences could cause changes in cellular Ca(2+)levels, which could have deleterious effect on normal hippocampal functions concerned with neuronal connectivity and integration.

Expression of CD95 and CD95L on astrocytes in the CA1 area of the immature rat hippocampus after hypoxia-ischemia injury.

The immature brain is affected profoundly by hypoxia-ischemia (HI) injury, which can lead to permanent neurologic sequelae in survivors. Neuronal degeneration after HI injury usually is achieved through apoptosis. Both CD95 and its natural ligand, CD95L, which are key molecules in the regulation of apoptosis, are constitutively expressed by neurons and astrocytes during embryonic and early postnatal stages. Further, CD95 or CD95L may have a functional relationship in glial cells and lead to apoptosis of these cells. The hippocampus, especially the CA1 area, is particularly susceptible to HI injury. We therefore investigated the temporal and spatial alterations in CD95 and CD95L expression in the CA1 area of 7-d-old rats after unilateral ligation of the carotid artery. Using immunohistochemistry and Western blotting, we showed that expression of CD95 and CD95L in the hippocampus peaked at 12 h and then decreased. In addition, we used terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP nick end-labeling to demonstrate apoptosis among CD95- and CD95L-reactive cells. Our findings show that increases in the expression of CD95 and CD95L after HI injury may involve astrocytic apoptosis in the 7-d-old rat hippocampus, and these molecules may act as targets or inducers of cell death.

Endoscopic investigation of the internal organs of a 15th-century child mummy from Yangju, Korea.

Our previous reports on medieval mummies in Korea have provided information on their preservation status. Because invasive techniques cannot easily be applied when investigating such mummies, the need for non-invasive techniques incurring minimal damage has increased among researchers. Therefore, we wished to confirm whether endoscopy, which has been used in non-invasive and minimally invasive studies of mummies around the world, is an effective tool for study of Korean mummies as well. In conducting an endoscopic investigation on a 15th-century child mummy, we found that well-preserved internal organs remained within the thoracic, abdominal and cranial cavities. The internal organs - including the brain, spinal cord, lung, muscles, liver, heart, intestine, diaphragm and mesentery - were easily investigated by endoscopy. Even the stool of the mummy, which accidentally leaked into the abdominal cavity during an endoscopic biopsy, was clearly observed. In addition, unusual nodules were found on the surface of the intestines and liver. Our current study therefore showed that endoscopic observation could provide an invaluable tool for the palaeo-pathological study of Korean mummies. This technique will continue to be used in the study of medieval mummy cases in the future.

Chronic blockade of the angiotensin II receptor has a differential effect on adipose and vascular PAI-1 in OLETF rats.

Angiotensinogen (AGT) and plasminogen activator inhibitor-1 (PAI-1) are expressed in both vascular and adipose tissues. Angiotensin II (AG II) has an adipogenic effect and increases PAI-1 expression. To evaluate the chronic effects of AG II type 1 receptor (AT(1)R) antagonism on adipose mass and PAI-1 expression in vascular and adipose tissues, losartan (30mg/kg/day) was administered to Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a model of type 2 diabetes, for 20 weeks. Adipose mass and regional fat distribution in the abdomen did not change after chronic AT(1)R antagonism in OLETF rats. AGT and PAI-1 mRNA expressions in adipose tissue of OLETF rats were significantly increased compared with Long-Evans Tokushima Otsuka (LETO) rats, the normal control. Chronic losartan therapy further increased the level of adipose AGT in OLETF rats, but did not affect the level of adipose PAI-1 mRNA. In contrast, aortic PAI-1 expression in OLETF rats was attenuated by chronic losartan therapy. Our results have two implications. First, adipose tissue may be an important source of AG II in metabolic syndrome even after chronic losartan therapy. Second, chronic AT(1)R antagonism with losartan causes differential effects on vascular and adipose PAI-1 expression.

Substance P immunoreactive cell reductions in cerebral cortex of Niemann-Pick disease type C mouse.

Niemann-Pick disease type C (NPC) is characterized by progressive neurodegeneration and arises from mutations in the NPC1 gene. Cholesterol has received most attention in the pathogenesis of NPC, but normalizing lipid levels in humans or mouse does not prevent neurodegeneration. In NPC mouse, neuronal degeneration in the cerebellum is the most commonly detected change, and thus previous studies have tended to focus on the cerebellum, especially Purkinje cells. Although numerous peptides have been found in the mammalian central nervous system, little data on neurotransmitters in NPC are available, and information on neurotransmitter system abnormalities could explain the complex and characteristic deficits of NPC. Thus, we performed an immunohistochemical study on NPC mouse cortices to compare cell numbers exhibiting vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY), and substance P (SP) immunoreactivity. In terms of VIP and NPY-immunoreactive (ir) cell numbers in the cerebral cortex, SP-ir cells were significantly reduced by about 90% in NPC (-/-) versus NPC (+/+) mouse, and were also mildly decreased in frontal and parietal NPC (+/-) versus NPC (+/+) mouse cortex. This study demonstrates for the first time, reduced number of SP-ir cells in the NPC mouse cortex.

Immunohistochemical study of p47Phox and gp91Phox distributions in rat brain.

NADPH oxidase is multi-component enzyme, which comprises the cytosolic proteins p40Phox, p47Phox, and p67Phox and the two membrane proteins, gp91Phox and p22Phox, and which is well characterized in phagocytic cells. NADPH oxidase is a primary source of reactive oxygen species (ROS), and recent studies indicate that free radicals and ROS might be causative factors of several brain degenerative diseases and dysfunctions. However, though previous studies have shown the presence of NADPH oxidase subunits in cell culture and mouse brain, they have not provided detailed high power resolution data. Therefore, we investigated the distributions of the p47Phox and gp91Phox subunits in rat brain using immunohistochemical approach. Cortex, hippocampus, and Purkinje cells of cerebellum were prominently stained by p47Phox and gp91Phox antibodies. As compared with the distributions of p47Phox, gp91Phox in mouse, some differences in the rat brain were observed in the hippocampus, thalamus, amygdala, reticular nucleus, and basal ganglia. Additionally, at the cellular level, most p47Phox immunoreactivity was largely confined to cell bodies and proximal portions of the dendritic tree. Taken together, the widespread observed distributions of p47Phox and gp91Phox subunits indicate that they are probably needed to maintain normal brain function.

Vasoactive intestinal peptide (VIP) and VIP mRNA decrease in the cerebral cortex of nNOS knock-out(-/-) mice.

Although there is much evidence showing that NO regulates the release of VIP in several areas, there is no report about the influence of NO on VIP in the cerebral cortex. We therefore examined changes in VIP expression in the cerebral cortex of nNOS knock-out(-/-) mice using immunohistochemistry and in situ hybridization. The nNOS((-/-)) mice had significantly fewer VIP-immunoreactive neurons than the control mice and the VIP mRNA as well as the VIP-immunoreactivity of the individual neuron was decreased in the nNOS((-/-)) mice. The first demonstration of decrease in VIP expression in the cerebral cortex of nNOS((-/-)) mice may provide useful data for investigating the relation between NO and VIP in the cerebral cortex and the mechanisms of many functions of these two neurotransmitters.

Enhanced expression of p53 in reactive astrocytes following transient focal ischemia.

The present study used immunohistochemistry to investigate p53 expression in rat brain following transient occlusion of the middle cerebral artery. In the control group, no p53-immunoreactive cells were found in any region of the central nervous system. P53 expression in reactive astrocytes was not obvious in the forebrain one day or three days following ischemic insults. Seven days following ischemic injury, increased expression of p53 was clearly detectable in reactive astrocytes in affected cortical regions, such as forelimb area, hindlimb area, and parietal cortex. At seven days of recirculation, there was also a significant increase in the number of p53-immunoreactive neurons in the cerebral cortex, striatum, and hippocampal CA1-3 regions. Although the present study has not addressed multiple mechanisms contributing to cell death following ischemic injury, the first demonstration of a significant increase in p53 expression in glial cells may prove useful for future investigations of the pathophysiology of ischemia.