Spatiotemporal expression of RCAN1 and its isoform RCAN1-4 in the mouse hippocampus after pilocarpine-induced status epilepticus.

Regulator of calcineurin 1 (RCAN1) can be induced by an intracellular calcium increase and oxidative stress, which are characteristic features of temporal lobe epilepsy. Thus, we investigated the spatiotemporal expression and cellular localization of RCAN1 protein and mRNA in the mouse hippocampus after pilocarpine-induced status epilepticus (SE). Male C57BL/6 mice were given pilocarpine hydrochloride (280 mg/kg, i.p.) and allowed to develop 2 h of SE. Then the animals were given diazepam (10 mg/kg, i.p.) to stop the seizures and sacrificed at 1, 3, 7, 14, or 28 day after SE. Cresyl violet staining showed that pilocarpine-induced SE resulted in cell death in the CA1 and CA3 subfields of the hippocampus from 3 day after SE. RCAN1 immunoreactivity showed that RCAN1 was mainly expressed in neurons in the shammanipulated hippocampi. At 1 day after SE, RCAN1 expression became detected in hippocampal neuropils. However, RCAN1 signals were markedly enhanced in cells with stellate morphology at 3 and 7 day after SE, which were confirmed to be reactive astrocytes, but not microglia by double immunofluorescence. In addition, real-time reverse transcriptase-polymerase chain reaction showed a significant upregulation of RCAN1 isoform 4 (RCAN1-4) mRNA in the SE-induced hippocampi. Finally, in situ hybridization with immunohistochemistry revealed astrocytic expression of RCAN1-4 after SE. These results demonstrate astrocytic upregulation of RCAN1 and RCAN1-4 in the mouse hippocampus in the acute and subacute phases of epileptogenesis, providing foundational information for the potential role of RCAN1 in reactive astrocytes during epileptogenesis.

Seizure-induced LIN28A disrupts pattern separation via aberrant hippocampal neurogenesis.

Prolonged seizures can disrupt stem cell behavior in the adult hippocampus, an important brain structure for spatial memory. Here, using a mouse model of pilocarpine-induced status epilepticus (SE), we characterized spatiotemporal expression of Lin28a mRNA and proteins after SE. Unlike Lin28a transcripts, induction of LIN28A protein after SE was detected mainly in the subgranular zone, where immunoreactivity was found in progenitors, neuroblasts, and immature and mature granule neurons. To investigate roles of LIN28A in epilepsy, we generated Nestin-Cre:Lin28aloxP/loxP (conditional KO [cKO]) and Nestin-Cre:Lin28a+/+ (WT) mice to block LIN28A upregulation in all neuronal lineages after acute seizure. Adult-generated neuron- and hippocampus-associated cognitive impairments were absent in epileptic LIN28A-cKO mice, as evaluated by pattern separation and contextual fear conditioning tests, respectively, while sham-manipulated WT and cKO animals showed comparable memory function. Moreover, numbers of hilar PROX1-expressing ectopic granule cells (EGCs), together with PROX1+/NEUN+ mature EGCs, were significantly reduced in epileptic cKO mice. Transcriptomics analysis and IHC validation at 3 days after pilocarpine administration provided potential LIN28A downstream targets such as serotonin receptor 4. Collectively, our findings indicate that LIN28A is a potentially novel target for regulation of newborn neuron-associated memory dysfunction in epilepsy by modulating seizure-induced aberrant neurogenesis.

Osteopontin: correlation with phagocytosis by brain macrophages in a rat model of stroke.

Osteopontin (OPN) is an adhesive glycoprotein linked to a variety of pathophysiological processes. We investigated whether OPN might act as an opsonin in the diseased brain by studying the postischemic expression and localization of OPN mRNA and protein in a rat model of ischemic stroke. In addition, we characterized the subcellular localization of OPN protein in the ischemic brain core. Induction of OPN mRNA occurred in activated microglia/macrophages in the ischemic core on days 3-7 after reperfusion and this was sustained up to day 28, at least. OPN protein was synthesized and secreted by brain macrophages, which first surrounded damaged striatal white matter tracts and then infiltrated into them. Punctate OPN-immunoreactive profiles were scattered throughout the infarction core except in white matter bundles. Electron microscopy showed the localization of OPN protein along the membranes lining what appeared to be the debris of dead neurons. These were located in the extracellular space and within the cytoplasm of brain macrophages, indicating that the OPN protein accumulated selectively on the surface of dead cells, most of which were phagocytosed subsequently by brain macrophages. However, no significant induction of OPN occurred in degenerating striatal white matter tracts or in brain macrophage-engulfed axonic or myelin debris. These data suggest that OPN secreted by brain macrophages in this rat model of stroke might be involved in the phagocytosis of fragmented cell debris and possibly not in the phagocytosis of axonic or myelin debris.

Expression of vascular endothelial growth factor receptor-3 mRNA in the developing rat cerebellum.

Vascular endothelial growth factor receptor (VEGFR)-3, a receptor for VEGF-C and VEGF-D, has recently been suggested to play an important role during neuronal development. To characterize its potential role in CNS ontogenesis, we investigated the spatiotemporal and cellular expression of VEGFR-3 in developing and mature rat cerebellum using in situ hybridization. VEGFR-3 expression appeared as early as E15, and was restricted to the ventricular zone of the cerebellar primordium, the germinative neuroepithelium, but was absent by E20. Instead, the expression area of VEGFR-3 in the cerebellum grew in parallel with cerebellar development. From E20 on, two populations of VEGFR-3-expressing cells can be clearly distinguished in the developing cerebellum: a population of differentiating and postmitotic neurons and the Bergmann glia. VEGFR-3 expression in neurons occurred during the period of neuronal differentiation, and increased with maturation. In particular, the expression of VEGFR-3 mRNA revealed different temporal patterns in different neuronal populations. Neurons generated early, Purkinje cells, and deep nuclear neurons expressed VEGFR-3 mRNA during late embryonic stages, whereas VEGFR-3 transcription in local interneurons appeared by P14 with weaker expression. In addition, Bergmann glia expressed VEGFR-3 throughout cerebellar maturation into adulthood. However, receptor expression was absent in the progenitors in the external granular layer and during further migration. The results of this study suggest that VEGFR-3 has even broader functions than previously thought, regulating both developmental processes and adult neuronal function in the cerebellum.

The expression of Müllerian inhibiting substance/anti-Müllerian hormone type II receptor protein and mRNA in benign, borderline and malignant ovarian neoplasia.

This study investigated the expression patterns of Müllerian inhibiting substance/anti-Müllerian hormone type II receptor (MIS/AMHRII) and mRNA in various types of ovarian neoplasia and evaluated the clinical significance of MIS/AMH as a biological response modifier for MIS/AMHR-positive tumors. Reverse transcriptase polymerase chain reaction was used to detect MIS/AMHRII mRNA expression and in situ hybridization and immunohistochemistry were used to localize MIS/AMHRII mRNA and protein expression. The degree of expression was scored from 0 (no staining) to 3 (strong staining). There was no significant difference in expression intensity between MIS/AMHRII protein and mRNA on all ovarian samples whether benign or malignant. MIS/AMHRII protein and mRNA were weakly expressed on 45.45% of benign ovarian tumors. In borderline tumors, expression rates of MIS/AMHRII protein and mRNA were 77.78% with score 1.22 and 55.56% with score 1, respectively. In malignant ovarian tumors, expression rates of MIS/AMHRII protein and mRNA were 70% with score 1.23 and 75% with score 1.43, respectively. Among malignant ovarian tumors, sex cord stromal tumors showed the highest expression rate and the strongest intensity of MIS/AMHRII protein and mRNA followed by germ cell tumor and epithelial ovarian tumor. Non-epithelial malignant tumors showed stronger expression than that of epithelial tumors (P<0.05, P<0.001, respectively). In serous borderline malignant and malignant tumors, MIS/AMHRII protein and mRNA expression was 63.64 and 81.82% with expression intensity of 1.27 and 1.46, respectively, which were not statistically different from non-epithelial malignant tumors. MIS/AMHRII and MIS/AMHRII mRNA demonstrate significantly variable expression among different ovarian tumor types. Non-epithelial cell tumors show higher expression than those of epithelial cell tumors. The highest expression rate and intensity were observed on sex cord stromal tumors. MIS/AMHRII expression was not different according to the differentiation, but showed tissue-type specificity. These data support that MIS/AMH may be used as a biological modifier or therapeutic modulator in MIS/AMHRII-expressed ovarian tumors.

Connected in cinema: educational effects of filmmaking classes on medical students.

PURPOSE: The purpose of this study is to explore what the students experienced in short filmmaking class performed to 1st grade premedical students of a medical school, and to trace educational effects of the class. METHODS: Taking a qualitative approach, the authors used semi-structured interviews to collect the data. This study employed the quota sampling method to purposefully select students to interview. Data coding and analysis were performed based on the grounded theory. The filmmaking experiences consistently described by the interviewees were labeled and reorganized into categories through the open, axial, and selective coding. RESULTS: The students experience the group filmmaking class as a participatory class. Learners also experienced the procedure of performing complicated group tasks according to detailed and scheduled processes. Participation leads to collaboration. Collaboration here is through communication and participation, not through mechanical cooperation. Students also experience various dimensions of communication. The students learned that successful performance of the group filmmaking process is enabled through consideration towards others, and experience a sense of connectedness resulting in a type of community spirit. Having fun and interest, finally, the students experience the sense of accomplishment and sharing through joint screening. CONCLUSION: Students' shared experiences and their education effects of the filmmaking class can be explained in terms of the above mentioned seven closely intertwined categories. In this class, the students were able to express emotions they would not normally express. Through this, the students were able to find the true character and new aspects of their fellow students, forming intimacy, which led to a sense of belonging and connectedness.

Differential regulation of vascular endothelial growth factor-C and its receptor in the rat hippocampus following transient forebrain ischemia.

We investigated the changes in the expression of vascular endothelial growth factor-C (VEGF-C) and its receptor, VEGFR-3, in the rat hippocampus following transient forebrain ischemia. The expression profiles of VEGF-C and VEGFR-3 were very similar in the control hippocampi, where both genes were constitutively expressed in neurons in the pyramidal cell and granule cell layers. The spatiotemporal expression pattern of VEGF-C was similar to that of VEGFR-3 in the ischemic hippocampus, and in the CA1 and dentate hilar regions both VEGF-C and VEGFR-3 were strongly expressed in activated glial cells rather than in neurons. Most of the activated glial cells expressing both genes were reactive astrocytes, although some were a subpopulation of brain macrophages. In the dentate gyrus, however, VEGFR-3 expression was transiently increased in the innermost layer of granule cells on days 7-10 after reperfusion, coinciding with an increase in polysialylated neural cell adhesion molecule staining--a marker for immature neurons. These data suggest that VEGF-C may be involved in glial reaction via paracrine or autocrine mechanisms in the ischemic brain and may carry out specific roles in adult hippocampal neurogenesis during ischemic insults.

Differential regulation of osteopontin receptors, CD44 and the alpha(v) and beta(3) integrin subunits, in the rat hippocampus following transient forebrain ischemia.

We have examined the spatiotemporal regulation of CD44 and the alpha(v)beta(3) integrin subunits, which have been identified as receptors for osteopontin (OPN), in the rat hippocampus following transient forebrain ischemia. Immunoreactivity for CD44 and the integrin subunits, alpha(v) and beta(3), showed characteristic time- and cell-dependent patterns in the ischemic hippocampus. CD44 immunoreactivity was induced at day 1 after reperfusion, reached a peak at day 3, and returned to basal levels by day 7. CD44 was induced in a subset of activated microglial cells within sites of intense neural damage, and the concomitant induction of OPN and CD44 was observed in the same cells in the ischemic hippocampus. In contrast, increased immunoreactivity for alpha(v) and beta(3), which shared overlapping expression patterns in the ischemic hippocampus, occurred in the majority of reactive astrocytes and only a few microglia at day 3 after reperfusion, and was sustained for more than 2 weeks. Immunoreactivity for both integrin subunits colocalized with OPN immunoreactivity in reactive astrocytes, and OPN immunoreactivity was also diffusely localized over the extracellular matrix around the reactive astrocytes. These data indicated that the rapid and transient induction of CD44 and OPN occurred in activated microglia/macrophages, whereas the long-lasting induction of alpha(v) and beta(3) integrin subunits and OPN occurred in reactive astrocytes, suggesting that the multifunctional role of OPN in the ischemic brain may be attributed, in part, to a time- and cell-dependent interaction with CD44 or integrin alpha(v)beta(3).

Induction of suppressor of cytokine signaling-3 in astrocytes of the rat hippocampus following transient forebrain ischemia.

We investigated the spatiotemporal expression of suppressor of cytokine signaling-3 (SOCS-3) in the rat hippocampus following transient forebrain ischemia using in situ hybridization and reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. Messenger RNA for SOCS-3 was constitutively expressed in neurons of the pyramidal cell and granule cell layers in control animals; however, significant induction was detected in reactive astrocytes preferentially located in the CA1 and the dentate hilar regions of the ischemic hippocampus. SOCS-3 mRNA was induced within 3 days of ischemia and maintained for more than 2 weeks. The in situ hybridization data agreed with the semiquantitative RT-PCR analysis. These results demonstrate SOCS-3 induction occurs in reactive astrocytes of the post-ischemic hippocampus, suggesting that SOCS-3 is involved in regulating the astroglial reaction to an ischemic insult.

Expression of Müllerian-Inhibiting Substance/Anti-Müllerian Hormone Type II Receptor in the Human Theca Cells.

Context: Müllerian-inhibiting substance/anti-Müllerian hormone (MIS/AMH) is produced in the ovarian granulosa cells, and it is believed to inhibit ovarian folliculogenesis and steroidogenesis in women of reproductive age. Objective: To investigate the expression of MIS/AMH type II receptor (MISRII/AMHRII) that binds MIS/AMH in the ovaries of reproductive-age women; to identify the exact targets of MIS/AMH. Design: Laboratory study using human ovarian tissue. Setting: University hospital. Patients: Tissue samples from 25 patients who had undergone ovarian surgery. Interventions: The segregation of ovarian granulosa and theca cells by laser microdissection was followed by RT-PCR, analyzing MISRII/AMHRII mRNA expression. Afterward, in situ hybridization and immunohistochemistry were performed to determine the localization of MISRII/AMHRII mRNA and protein expression. Main Outcome Measures: MISRII/AMHRII mRNA expression by RT-PCR, in situ hybridization, and immunohistochemistry. Results: MISRII/AMHRII were expressed in granulosa and theca cells of preantral and antral follicles. The granulosa cells showed stronger MISRII/AMHRII expression than theca cells. MISRII/AMHRII mRNA staining of granulosa and theca cells in large antral follicles, early atretic follicles, and corpus luteum waned but were still detected weakly, showing higher expression in theca cells than in granulosa cells. However, MISRII/AMHRII protein in the granulosa layer of the atretic follicle and corpus luteum could not be assessed. Conclusions: As MISRII/AMHRII is expressed in both granulosa and theca cells, this indicates that MIS/AMH, produced in the granulosa cells, is active in the theca cells as well. MIS/AMH is most likely actively involved not only in the autocrine and endocrine processes but also in the paracrine processes involving theca cells.

Upregulation of vascular endothelial growth factor receptors Flt-1 and Flk-1 following acute spinal cord contusion in rats.

To investigate the possible role of vascular endothelial growth factor (VEGF) in the injured spinal cord, we analyzed the distribution and time course of the two tyrosine kinase receptors for VEGF, Flt-1 and Flk-1, in the rat spinal cord following contusion injury using a weight-drop impactor. The semi-quantitative RT-PCR analysis of Flt-1 and Flk-1 in the spinal cord showed slight upregulation of these receptors following spinal cord injury. Although mRNAs for Flt-1 and Flk-1 were constitutively expressed in neurons, vascular endothelial cells, and some astrocytes in laminectomy control rats, their upregulation was induced in association with microglia/macrophages and reactive astrocytes in the vicinity of the lesion within 1 day in rats with a contusion injury and persisted for at least 14 days. The spatiotemporal expression of Flt-1 in the contused spinal cord mirrored that of Flk-1 expression. In the early phase of spinal cord injury, upregulation of Flt-1 and Flk-1 mRNA occurred in microglia/macrophages that infiltrated the lesion. In addition, the expression of both receptors increased progressively in reactive astrocytes within the vicinity of the lesion, predominately in the white matter, and almost all reactive astrocytes coexpressed Flt-1 or Flk-1 and nestin. These results suggest that VEGF may be involved in the inflammatory response and the astroglial reaction to contusion injuries of the spinal cord via specific VEGF receptors.

Upregulation of vascular endothelial growth factor receptors Flt-1 and Flk-1 in rat hippocampus after transient forebrain ischemia.

This study characterizes the distribution of the two tyrosine kinase receptors for vascular endothelial growth factor (VEGF), Flt-1 and Flk-1, in the rat hippocampus following transient forebrain ischemia. The semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis of Flt-1 and Flk-1 in hippocampal CA1 showed upregulation of these receptors following ischemic injury. Expression of Flt-1 and Flk-1 mRNA was restricted to neurons in the pyramidal cell and granule cell layers in control animals; however, upregulation was detected in activated glial cells and in the vascular endothelial cells rather than in neurons, in ischemic hippocampi. Most of the activated glial cells expressing Flt-1 and Flk-1 were reactive astrocytes, although some were microglial cells. The spatiotemporal expression of Flt-1 in the ischemic hippocampus mirrored that of Flk-1 expression. Expression of mRNA for both receptors was induced after 12 h, appeared to be increased progressively until 3 days when the highest expression was reached, and was sustained for more than 2 weeks. Flt-1 and Flk-1 immunoreactivity in the ischemic hippocampus matched the mRNA induction patterns except for a somewhat delayed onset. These data suggest that VEGF may be involved in the glial response via specific VEGF receptors in the rat hippocampus following transient forebrain ischemia.

Transient microglial and prolonged astroglial upregulation of osteopontin following transient forebrain ischemia in rats.

Osteopontin (OPN) is an adhesive glycoprotein linked to a variety of pathophysiological processes, with neuroprotective properties in ischemic injury. We examined the postischemic expression and localization of OPN in the rat brain after transient forebrain ischemia. The semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) analysis showed that OPN expression in the hippocampal CA1 region was biphasic, peaking at day 3 after reperfusion and again between days 14 and 28. The two phases of OPN induction occurred in a time- and cell-dependent manner in the ischemic hippocampus. OPN mRNA expression in activated microglia was first induced 1 day after reperfusion, reached a peak at 3 days, and returned to basal levels by 7 days. In contrast, OPN expression in reactive astrocytes was first induced by 10 days after reperfusion in the hippocampal CA1. Astroglial OPN expression further increased, reaching a peak at day 14 and was maintained up to day 28, the latest time point we examined. OPN immunoreactivity in the ischemic hippocampus matched the mRNA induction patterns. OPN protein was first localized in the astroglial cytoplasm and later in the extracellular matrix of the hippocampal CA1. The temporal and cellular patterns of OPN induction in the ischemic hippocampus suggest a multifunctional capacity in the pathogenesis of ischemic injury, with the increased OPN production and secretion by reactive astrocytes being involved in subsequent tissue repair and reorganization.

Expression of vascular endothelial growth factor receptors Flt-1 and Flk-1 in embryonic rat forebrain.

To define better the putative targets of vascular endothelial growth factor (VEGF) in the developing brain we have examined the ontogeny of the two VEGF tyrosine kinase receptors, Flt-1 and Flk-1, in embryonic rat forebrain. Semiquantitative reverse transcriptase-polymerase chain reaction and immunoblot analysis showed expression of both receptors in the forebrain at all embryonic ages studied. Messenger RNAs for Flt-1 and Flk-1 appeared along most of the ventricular zone of the lateral ventricle as early as embryonic day (E) 13. Messages gradually became restricted to a limited ventricular zone at E20. Expression of VEGF receptors was also observed in the cerebral cortex, hippocampus and thalamic nuclei. In the cortex, expression of mRNA for both receptors was detected in the cortical plate around E15, and became relatively weak and restricted to the deeper layers of the cortical plate at E20. These data suggest that VEGF may contribute to early developmental processes including the proliferation, differentiation and maturation of specific neuronal populations via specific VEGF receptors in the developing rat forebrain.

Ischemic preconditioning-induced activation of ERK1/2 in the rat hippocampus.

We investigated the activation and cellular localization of the extracellular signal-regulated kinases ERK1/2 in a rat model of ischemic tolerance induction. Adult male Sprague-Dawley rats were subjected to 3 min of sublethal ischemic preconditioning. Activation of ERK1/2 showed the characteristic time- and cell-dependent patterns. Rapid and short-lasting activation of ERK after 3 min of cerebral ischemia was noted immediately in the dentate granule cells and mossy fibers of the hippocampus, and then occurred sequentially in CA3 and CA1 neurons and dentate hilar neurons at 10 min. Phosphorylation of ERK1/2 in hippocampal neurons returned to the basal level in an ordered manner. Basal level phosphorylation was attained first, at 30 min, by the CA1 neurons, and was then observed in CA3 and granule cells by 1 h and noted in some dentate hilar neurons at 12 h. By contrast, phosphorylation of ERK1/2 in mossy fibers and the CA1 dendritic field was sustained for at least 3 d. Transient activation of ERK1/2 was induced also in astrocytes of the dentate hilar region at 1 d post-stimulation. These data demonstrate that the short cerebral-ischemic preconditioning induced rapid and transient activation of ERK1/2 in tolerance-acquired CA1 neurons as well as in ischemia-resistant CA3 and dentate granule cells, and that the short preconditioning sustained activation in mossy fibers and neuropil areas, suggesting that ERK1/2 activation may be involved in the mechanism of ischemic tolerance in the rat hippocampus.

Altered immune cell proportions in the radiodermatitis induced hairless mice-1 (HR-1).

Accidental radiation exposures or radiation therapy can cause internal and external damage including radiodermatitis. Even though radiodermatitis is one of the dose limiting factors in radiotherapy, the immunological nature of it is not yet been clearly understood. In this study, we have examined the alteration in immune cell population during the radiodermatitis process. A radiodermatitis model was established in HR-1 mice by locally exposing a posterior dorsal region to 10 Gy X-ray/day for 4 consecutive days. Collagen accumulation, redness, erythema, and dry desquamation of the skin were detected after X-irradiation. The size and total cell number of the spleen decreased immediately after X-irradiation, compared to those of the sham-irradiated mice, and recovered to the normal levels two weeks later. Reduction and recovery of the bone marrow cell population preceded a similar change of the spleen cell population. The proportion of CD4+ T cell increased, while the proportion of CD8+ T cell decreased ahead of the obvious skin damage, in both lymph node and spleen of the irradiated mice. Interestingly, the proportion of splenic monocytes/macrophages was expanded gradually at a similar kinetics with the aggravation of the radiodermatitis. The infiltration of the CD11b+ monocyte/macrophage to the X-irradiated skin also coincided with the development of radiodermatitis. These altered proportions of immune cells may play important roles in radiodermatitis.

Combined effects of losartan and pravastatin on interstitial inflammation and fibrosis in chronic cyclosporine-induced nephropathy.

BACKGROUND: Statins and angiotensin II type I receptor blockers have synergistic effects on vascular smooth-muscle-cell proliferation and the progression of renal diseases. We evaluated whether combined treatment with losartan (LSRT) and pravastatin (PRVT) affords superior protection compared with their respective monotherapies in treating chronic cyclosporine (CsA)-induced nephropathy in rats. METHODS: Rats maintained on a low salt diet were given vehicle, CsA (15 mg/kg), CsA and LSRT (10 mg/kg), CsA and PRVT (5 mg/kg), or a combination of CsA, LSRT, and PRVT for 28 days. Basic parameters (renal function, systolic blood pressure, serum high-sensitivity C-reactive protein [hs-CRP], and lipid profiles), histopathology (arteriolopathy, tubulointerstitial fibrosis, and inflammatory cell infiltration), and inflammatory and fibrotic factors (intrarenal CRP, angiotensin II, osteopontin, and transforming growth factor [TGF]-beta1) were studied. RESULTS: LSRT or PRVT treatment significantly attenuated the histopathologic changes induced by CsA, and combined treatment with LSRT and PRVT further decreased these parameters compared with giving each drug alone. Increased levels of angiotensin II, intrarenal CRP, osteopontin, and TGF-beta1 in CsA-treated rat kidney were reduced by treatment with either LSRT or PRVT and were further decreased by the combination of the two drugs. There were no significant differences in systolic blood pressure or serum lipid parameters between groups. CONCLUSIONS: Combined treatment with LSRT and PRVT provided synergistic effects in attenuating inflammatory and fibrotic processes in a rat model of chronic CsA-induced nephropathy, and this effect was independent of their hypolipidemic and hypotensive actions.

Induction and temporal changes of osteopontin mRNA and protein in the brain following systemic lipopolysaccharide injection.

We analyzed expression of osteopontin (OPN), a cytokine regulating tissue repair and inflammation, in astrocytes and microglia in response to systemic lipopolysaccharide (LPS) administration (250 microg/100 g). OPN mRNA expression appeared in subpial astrocytes as early as 6 h, and then spread over the brain parenchyma. The signal for OPN mRNA reached a peak at 24 h post-injection, and returned to basal levels after 48 h. Changes in OPN immunoreactivity in the LPS-injected rat mirrored OPN mRNA induction patterns. These results provide the first evidence of OPN induction in astrocytes and microglia following peripheral immune challenge, and suggest that OPN may play a key role in the pathogenesis of neuroinflammation.

Synergistic effects of mycophenolate mofetil and losartan in a model of chronic cyclosporine nephropathy.

BACKGROUND: Combined treatments of mycophenolate mofetil (MMF) and losartan (LSRT) have synergistic effects on various renal diseases through their hemodynamic and anti-inflammatory effects. This study investigated whether MMF treatment is effective in inhibiting inflammatory processes in chronic cyclosporine A (CsA) nephrotoxicity, and whether combined treatment using MMF and LSRT affords superior protection compared with the respective monotherapies. METHODS: Rats on a low-salt diet were given vehicle (VH group, olive oil, 1 mg/kg per day), CsA (15 mg/kg per day), CsA and LSRT (CsA+LSRT group, 100 mg/L per day), CsA and MMF (CsA+MMF group; 40 mg/kg per day), or CsA, LSRT and MMF (CsA+LSRT MMF group). Control groups received each drug without CsA treatment. Renal function, histologic parameters (arteriolopathy, tubulointerstitial fibrosis, and inflammatory cell infiltration), and mediators of CsA-induced nephrotoxicity (angiotensin-II, osteopontin, and transforming growth factor [TGF]-beta1) were studied. RESULTS: The CsA-treated rats showed decreased renal function and increased histologic parameters compared with the VH-treated rats. The CsA+MMF treatment significantly improved renal function and histopathologic parameters compared with the CsA group, and combined treatment with MMF and LSRT further improved those parameters compared with the CsA+LSRT and CsA+MMF groups. At a molecular level, increased expression of angiotensin II protein, osteopontin, and TGF-beta1 mRNAs in the CsA group were significantly decreased with MMF, and further decrease was observed with the combined treatment using MMF and LSRT. CONCLUSIONS: MMF treatment decreases CsA-induced nephrotoxicity, and combined treatment with LSRT has a synergistic effect in preventing chronic CsA nephrotoxicity.

Upregulation of gp130 and differential activation of STAT and p42/44 MAPK in the rat hippocampus following kainic acid-induced seizures.

We investigated the activation and cellular distribution of two signaling pathways, the signal transducers and activators of transcription (STATs) and mitogen-activated protein kinases (MAPKs) following kainic acid (KA)-induced seizures, in relation to the expression of gp130, a common cytokine signal transducer for the interleukin (IL)-6 family of cytokines. Rapid and short-lasting upregulation of gp130 was observed in the granule cells. This became evident in astrocytes by 3 h, increased progressively to peak at 3 days, and was sustained for 10 days. STATs, including STAT1 and STAT3, and p42/44 MAPK were activated in distinct cellular and spatial distributions within the hippocampus following seizures. A rapid and sustained seizure-induced activation of STAT3 and STAT1, revealed by nuclear STAT3 and STAT1 immunoreactivities, was observed exclusively in reactive astrocytes in the hippocampus, nearly coinciding with the time course of gp130 expression; however, STAT3 activation was greater. In contrast, seizure induced the rapid and transient activation of p42/44 MAPK in a subpopulation of hippocampal neurons and in astrocytes, although with weaker staining intensity. Two signaling pathways involving gp130, STATs and MAPK, were differentially activated in reactive astrocytes after KA injection, indicating that STATs and MAPK may differentially mediate the astroglial reaction in the rat hippocampus after KA-induced seizures.