Direct contact of fibroblasts with neuronal processes promotes differentiation to myofibroblasts and induces contraction of collagen matrix in vitro

Wound healing is often delayed in the patients whose sensory and autonomic innervation is impaired. We hypothesized that existence of neurites in the skin may promote wound healing by inducing differentiation of fibroblasts into myofibroblasts with consequent wound contraction. In the current study, we examined the effect of neurons on differentiation of fibroblasts and contraction of collagen matrix in vitro using a new co-culture model. Neuronal cell line, PC12 cells, of which the neurite outgrowth can be controlled by adding nerve growth factor, was used. Rat dermal fibroblasts were co-cultured with PC12 cells extending neurites or with PC12 cells lacking neurites. Then, differentiation of fibroblasts into myofibroblasts and contraction of the collagen matrix was evaluated. Finally, we examined whether direct or indirect contact with neurites of PC12 cells promoted the differentiation of fibroblasts. Our results showed that fibroblasts co-cultured with PC12 extending neurites differentiated into myofibroblasts more effectively and contracted the collagen matrix stronger than those with PC12 lacking neurites. Direct contact of fibroblasts with neurites promoted more differentiation than indirect contact. In conclusion, direct contact of fibroblasts with neuronal processes is important for differentiation into myofibroblasts and induction of collagen gel contraction, leading to promotion of wound healing.

TRAP1 controls mitochondrial fusion/fission balance through Drp1 and Mff expression

Mitochondria are dynamic organelles that change in response to extracellular stimuli. These changes are essential for normal mitochondrial/cellular function and are controlled by a tight balance between two antagonistic pathways that promote fusion and fission. Although some molecules have been identified to mediate the mitochondrial fusion and fission process, the underlying mechanisms remain unclear. Tumor necrosis factor receptor-associated protein 1 (TRAP1) is a mitochondrial molecule that regulates a variety of mitochondrial functions. Here, we examined the role of TRAP1 in the regulation of morphology. Stable TRAP1 knockdown cells showed abnormal mitochondrial morphology, and we observed significant decreases in dynamin-related protein 1 (Drp1) and mitochondrial fission factor (Mff), mitochondrial fission proteins. Similar results were obtained by transient knockdown of TRAP1 in two different cell lines, SH-SY5Y neuroblastoma cells and KNS-42 glioma cells. However, TRAP1 knockdown did not affect expression levels of fusion proteins. The reduction in Drp1 and Mff protein levels was rescued following treatment with the proteasome inhibitor MG132. These results suggest that TRAP1 regulates the expression of fission proteins and controls mitochondrial fusion/fission, which affects mitochondrial/cellular function.

Influence of tissue particles on Fas expression in idiopathic interstitial pneumonia

Idiopathic interstitial pneumonia (IIP) is a progressive fibrosing interstitial pneumonia of unknown etiology with a poor prognosis. The aim of this study is to prove the occurrence of particle deposition and particle-induced tissue damage in IIP by examining proapoptotic Fas expression with in-air microparticle induced X-ray emission (in-air micro-PIXE) analysis. A total of 21 patients were enrolled. Lung tissues from 12 IIP patients and nontumorous lung tissues from 9 lung cancer patients (as a control) were subjected to in-air micro-PIXE analysis. The distribution of particles in lung tissue was compared with the localization of Fas expression by immunohistochemistry. Silicon (Si) was identified in 58.3% of IIP samples and 44.4% of control samples. Iron (Fe) was identified 25% in IIP samples and 11.1% in control samples. The mean lung tissue content of Si and Fe relative to S did not differ between IIP and control patients. Only two IIP patients showed the co-localization of Si and Fe deposition with Fas expression. Adaptation of this method would contribute to assess the influence of particles on IIP.

Yokukansan inhibits neuronal death during ER stress by regulating the unfolded protein response

BACKGROUND

Recently, several studies have reported Yokukansan (Tsumura TJ-54), a traditional Japanese medicine, as a potential new drug for the treatment of Alzheimer's disease (AD). Endoplasmic reticulum (ER) stress is known to play an important role in the pathogenesis of AD, particularly in neuronal death. Therefore, we examined the effect of Yokukansan on ER stress-induced neurotoxicity and on familial AD-linked presenilin-1 mutation-associated cell death.

METHODS

We employed the WST-1 assay and monitored morphological changes to evaluate cell viability following Yokukansan treatment or treatment with its components. Western blotting and PCR were used to observe the expression levels of GRP78/BiP, caspase-4 and C/EBP homologous protein.

RESULTS

Yokukansan inhibited neuronal death during ER stress, with Cnidii Rhizoma (Senkyu), a component of Yokukansan, being particularly effective. We also showed that Yokukansan and Senkyu affect the unfolded protein response following ER stress and that these drugs inhibit the activation of caspase-4, resulting in the inhibition of ER stress-induced neuronal death. Furthermore, we found that the protective effect of Yokukansan and Senkyu against ER stress could be attributed to the ferulic acid content of these two drugs.

CONCLUSIONS

Our results indicate that Yokukansan, Senkyu and ferulic acid are protective against ER stress-induced neuronal cell death and may provide a possible new treatment for AD.

bFGF regulates PI3-kinase-Rac1-JNK pathway and promotes fibroblast migration in wound healing

Fibroblast proliferation and migration play important roles in wound healing. bFGF is known to promote both fibroblast proliferation and migration during the process of wound healing. However, the signal transduction of bFGF-induced fibroblast migration is still unclear, because bFGF can affect both proliferation and migration. Herein, we investigated the effect of bFGF on fibroblast migration regardless of its effect on fibroblast proliferation. We noticed involvement of the small GTPases of the Rho family, PI3-kinase, and JNK. bFGF activated RhoA, Rac1, PI3-kinase, and JNK in cultured fibroblasts. Inhibition of RhoA did not block bFGF-induced fibroblast migration, whereas inhibition of Rac1, PI3-kinase, or JNK blocked the fibroblast migration significantly. PI3-kinase-inhibited cells down-regulated the activities of Rac1 and JNK, and Rac1-inhibited cells down-regulated JNK activity, suggesting that PI3-kinase is upstream of Rac1 and that JNK is downstream of Rac1. Thus, we concluded that PI3-kinase, Rac1, and JNK were essential for bFGF-induced fibroblast migration, which is a novel pathway of bFGF-induced cell migration.

DISC1 regulates cell-cell adhesion, cell-matrix adhesion and neurite outgrowth

Disrupted-in-schizophrenia 1 (DISC1) is a promising susceptibility gene for major mental illness. Recent studies have implicated DISC1 in key neurodevelopmental processes, including neurite outgrowth, neuronal migration and proliferation. Here, we report that DISC1 regulates cell-cell and cell-matrix adhesion and neurite outgrowth. DISC1 overexpression increased expression of the adherence junction protein N-cadherin and enhanced cell-cell adhesion. The increased N-cadherin accumulated in the areas of cell-cell contact. DISC1 overexpression also enhanced cell-matrix adhesion by inducing expression of beta1-integrin protein. In the presence of nerve growth factor (NGF), DISC1 overexpression increased beta1-integrin expression at the cell membrane and growth cone. NGF-induced neurite extension was enhanced by DISC1, and anti-beta1-integrin antibody reduced the neurite outgrowth of DISC1-overexpressing cells to the control level. Furthermore, DISC1 also regulated N-cadherin and beta1-integrin expression at the cell membrane in primary neurons. We conclude that DISC1 regulates cell-cell adhesion and cell-matrix adhesion by regulating the expression of adhesion molecules.

Analysis on the co-localization of asbestos bodies and Fas or CD163 expression in asbestos lung tissue by in-air micro-pixe

To prevent and control disease caused by exposure to various agents, it is necessary to determine the harmful level of intervention and to establish a method for measuring that level. In-air microparticle-induced X-ray emission (in-air micro-PIXE) analysis is based on irradiation of specimens with a proton ion microbeam, and has been modified for biological application. Two-dimensional analysis and quantitative analysis using the system confirmed that asbestos induced apoptosis by upregulating Fas expression and also revealed the accumulation of CD163-expressing macrophages in the lungs of patients with asbestosis. By quantitative comparison of the area of Fas or CD163 expression and the Fas- or CD163-negative area in asbestos lung tissue, the harmful levels which caused the expression of Fas or CD163 could be estimated on Silica, Ferrous iron, and Magnesium (the components of asbestos) deposition. These results indicate that the system could be useful for investigating the pathogenesis of inhaled particle-induced immune reactions and for determining harmful levels of exogenous agents.

Role of the PACAP-PAC1-DISC1 and PACAP-PAC1-stathmin1 systems in schizophrenia and bipolar disorder: novel treatment mechanisms?

Two pituitary adenylate cyclase-activating polypeptide (PACAP)-signaling pathways linked to schizophrenia were reviewed. One pathway regulates the association between disrupted-in-schizophrenia 1 (DISC1) and DISC1-binding zinc-finger protein via PACAP, and the other inhibits stathmin1 expression via PACAP. PACAP reduces the association of the binding between DISC1 (a potential susceptibility gene for major psychiatric disease) and DISC1-binding zinc-finger protein (which binds to DISC1 near the translocation site) to induce neurite outgrowth. In addition, an association between SNPs of the PACAP or PAC1 genes and schizophrenia has been reported. On the other hand, expression of stathmin1, which induces abnormal axonal arborization, is upregulated in PACAP-knock out mice and the brains of patients with schizophrenia. Thus it is likely that, in the schizophrenic brain, the neural development depending on these two systems has been disturbed. The possibility that the regulation of these two systems could lead to new treatments for schizophrenia is also discussed.

Association studies and gene expression analyses of the DISC1-interacting molecules, pericentrin 2 (PCNT2) and DISC1-binding zinc finger protein (DBZ), with schizophrenia and with bipolar disorder

Disrupted-in-Schizophrenia 1 (DISC1) and its molecular cascade have been implicated in the pathophysiology of major psychoses. Previously, we identified pericentrin 2 (PCNT2) and DISC1-binding zinc finger protein (DBZ) as binding partners of DISC1; further, we observed elevated expression of PCNT2 in the postmortem brains and in the lymphocytes of bipolar disorder patients, compared to controls. Here, we examined the association of PCNT2 with schizophrenia in a case-control study of Japanese cohorts. We also examined the association of DBZ with schizophrenia and with bipolar disorder, and compared the mRNA levels of DBZ in the postmortem brains of schizophrenia, bipolar and control samples. DNA from 180 schizophrenia patients 201 controls were used for the association study of PCNT2 and DBZ with schizophrenia. Association of DBZ with bipolar disorder was examined in DNA from 238 bipolar patients and 240 age- and gender-matched controls. We observed significant allelic and genotypic associations of the PCNT2 SNPs, rs2249057, rs2268524, and rs2073380 (Ser/Arg) with schizophrenia; the association of rs2249057 (P = 0.002) withstand multiple testing correction. Several two SNP- and three SNP-haplotypes showed significant associations; the associations of haplotypes involving rs2249057 withstand multiple testing correction. No associations were observed for DBZ with schizophrenia or with bipolar disorder; further, there was no significant difference between the DBZ mRNA levels of control, schizophrenia and bipolar postmortem brains. We suggest a possible role of PCNT2 in the pathogenesis of schizophrenia. Abnormalities of PCNT2, the centrosomal protein essential for microtubule organization, may be suggested to lead to neurodevelopmental abnormalities.

Clinical significance of LAMB3 and COL7A1 mRNA in esophageal squamous cell carcinoma

AIMS

LAMB3 and COL7A1 genes code for the laminin-5beta3 chain and type VII collagen, respectively. They constitute the major components of the basement membrane zone. The aim of the current study was to clarify the clinical significance of LAMB3 and COL7A1 mRNA expression in esophageal squamous cell carcinoma (ESC).

METHODS

We quantitated the expression of LAMB3 mRNA and COL7A1 mRNA in malignant esophageal tissues (T) and corresponding normal tissues (N) by real-time quantitative reverse transcription-polymerase chain reaction assays. The clinicopathologic significance of LAMB3 and COL7A1 expression was also determined. Paired T and N tissues were obtained from 66 patients who underwent curative esophagectomy.

RESULTS

The expression levels of LAMB3 and COL7A1 mRNAs were higher in malignant tissues than in the corresponding normal tissues. The level of LAMB3 expression was significantly correlated with the depth of invasion and venous invasion (p=0.007 and 0.001, respectively). COL7A1 expression was significantly correlated with depth of tumor invasion and lymphatic invasion (p=0.046, 0.013, respectively). The five-year survival rate was better in the 22 patients with relatively low expression of both LAMB3 and COL7A1 in comparison with the other 44 cases (p<0.05).

CONCLUSION

The evaluation of LAMB3 and COL7A1 mRNA expression is useful for predicting the malignant properties of ESC and may prove valuable in predicting the future course of the disease.

Putative occurrence of lysine decarboxylase isoforms in soybean (Glycine max) seedlings

The activity of lysine decarboxylase was studied in 3-day-old soybean (Glycine max (L.) Meer cv. Sakai) seedlings also in relation to light conditions. Lysine decarboxylase activity was mainly localized in the roots and to a lesser extent in the hypocotyls and was detectable in both the soluble and particulate fractions. The enzyme activity levels were similar during germination under light and dark conditions. With respect to lysine concentration, the initial decarboxylation rate of the soluble fraction showed a saturating curve. Conversely, the initial decarboxylation rate of the particulate fraction showed a sigmoidal curve. These results could suggest that at least two isoforms of lysine decarboxylase are present in different organs of soybean seedlings. In the root soluble fraction, the suicide inhibitor alpha-difluoromethyl-lysine suppressed the activity of lysine decarboxylase and of ornithine decarboxylase to the same extent, but had no effect on arginine decarboxylase activity.

Regulation of pituitary adenylyl cyclase-activating polypeptide (PACAP, ADCYAP1: adenylyl cyclase-activating polypeptide 1) in the treatment of schizophrenia

BACKGROUND

Deficiency of pituitary adenylyl cyclase-activating polypeptide (PACAP) and its specific receptor, PAC1, causes a schizophrenia-like phenotype in mice. In addition, the relation of the PACAP and PAC1 genes to schizophrenia has been shown by single-nucleotide polymorphism association studies. Furthermore, PACAP is reported to be involved in the function of disrupted-in-schizophrenia 1.

OBJECTIVE

To summarize briefly the recent evidence relating the PACAP system and schizophrenia and discuss the application of PACAP to the treatment of schizophrenia.

RESULTS/CONCLUSION

The regulation of PACAPergic signals is an interesting potential treatment for schizophrenia. Further studies of PACAP signals and the association of PACAP signals with schizophrenia should shed the light on the utility of this approach in the treatment of schizophrenia.

Induction of amyloid beta accumulation by ER calcium disruption and resultant upregulation of angiogenic factors in ARPE19 cells

PURPOSE

To investigate the intracellular mechanisms that induce amyloid beta (Abeta) accumulation and angiogenesis in the human retinal pigment epithelial cell line ARPE19.

METHODS

The authors used two endoplasmic reticulum (ER) stress-inducing reagents, thapsigargin (TG), which inhibits the sarcoplasmic/endoplasmic calcium (Ca)2+-ATPase, and tunicamycin (TM), which inhibits N-linked glycosylation. The expression pattern of Abeta-precursor protein (APP) splice variants was investigated by reverse transcription (RT)-PCR. Cellular expressions of both a series of Abeta metabolism-related factors and angiogenic factors were evaluated by real-time RT-PCR and Western blot (VEGF). Expression of caspase-4 was examined by real-time RT-PCR and Western blot to evaluate the effect of the ER stressor. Intracellular Ca elevation by TG was evaluated by Ca2+ imaging experiments. Dimethyl sulfoxide and staurosporine were used as a nonreagent control and as an apoptosis-inducing reagent through mitochondria not ER, respectively.

RESULTS

TG-treated ARPE19 cells increased the mRNA expression of Abeta production-inducing APP splice variants and reduced that of neprilysin, a catabolic enzyme for Abeta. TG-treated ARPE19 cells produced increases in VEGF, TNF-alpha, TACE mRNA, and VEGF protein expressions and a decrease in PEDF mRNA expression. TG-treated ARPE19 cells induced the expression of active more than TM-treated casepase-4. The intracellular Ca concentration was elevated in only TG-treated ARPE19 cells.

CONCLUSIONS

TG-treated ARPE19 cells showed both Abeta accumulation-inducible and angiogenic factor mRNA expression patterns. This study suggests the possibility that ER stress through ER calcium disruption may induce the expression not only of Abeta deposit-promoting factors but also angiogenic factors in the retinal pigment epithelium.

In-Air Micro-Particle Induced X-ray Emission Analysis of Asbestos and Metals in Lung Tissue

Inhalation of asbestos increases the risk of lung cancer and pulmonary fibrosis. It is difficult to directly assess the distribution and content of inhaled particles in lung tissue sections. The purpose of this study is to employ an in-air micro particle induced X-ray emission (in-air micro-PIXE) system for assessment of the spatial distribution and content of asbestos and other metals in lung tissue. A proton ion-microbeam from this system was applied to irradiate lung tissue of patients with or without asbestosis, tumor tissue from both groups, and asbestos fibers ( in vitro). The content of each element composing asbestos and those of other metals were calculated and their distribution was assessed from the characteristic X-ray pattern for each element obtained after irradiation. This in-air micro-PIXE system could identify the location of asbestos bodies composed of Si, Mg, and Fe in lung tissue sections. Macrophage and lymphocytes accumulated in that area. This new system also revealed deposits of titanium, nickel, and cobalt in the lung tissues, in addition to asbestos bodies. The Si and Fe content were higher in lungs with asbestosis than in lungs without asbestosis or in tumor tissue. Analysis of asbestos fibers composed of chrysotile, crocidolite, and amosite showed that the ratios of Si, Fe, and Mg corresponded with those for the chemical structures. In-air micro-PIXE analysis is useful for assessing the distribution and quantities of asbestos bodies and also other metals in lung tissue comparing to immune-related cell localizations, and is also useful for analysis of standard asbestos fibers.

Behavioral abnormalities and dopamine reductions in sdy mutant mice with a deletion in Dtnbp1, a susceptibility gene for schizophrenia

Genetic susceptibility plays an important role in the pathogenesis of schizophrenia. Genetic evidence for an association between the dysbindin-1 gene (DTNBP1: dystrobrevin binding protein 1) and schizophrenia has been repeatedly reported in various populations worldwide. Thus, we performed behavioral analyses on homozygous sandy (sdy) mice, which lack dysbindin-1 owing to a deletion in the Dtnbp1 gene. Our results showed that sdy mice were less active and spent less time in the center of an open field apparatus. Consistent with the latter observation, sdy mice also displayed evidence of heightened anxiety-like response and deficits in social interaction. Compared to wild-type mice, sdy mice displayed lower levels of dopamine, but not glutamate, in the cerebral cortex, hippocampus, and hypothalamus. These findings indicate that sdy mice display a number of behavioral abnormalities associated with schizophrenia and suggest that these abnormalities may be mediated by reductions in forebrain dopamine transmission.

Gene and expression analyses reveal enhanced expression of pericentrin 2 (PCNT2) in bipolar disorder

BACKGROUND

DISC1 has been suggested as a causative gene for psychoses in a large Scottish kindred. PCNT2 has recently been identified as an interacting partner of DISC1. In this study, we investigated the role of PCNT2 in bipolar disorder, by gene expression analysis and genetic association study.

METHODS

By TaqMan real-time quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), we examined the messenger RNA (mRNA) levels of PCNT2 in the postmortem prefrontal cortex of bipolar disorder (n = 34), schizophrenia (n = 31), and control subjects (n = 32), obtained from Stanley Array Collection. We also compared the mRNA levels of PCNT2 in the peripheral blood lymphocytes of bipolar disorder (n = 21), schizophrenia (n = 21), depression (n = 33), and control subjects (n = 57). For the association study, 23 single nucleotide polymorphisms (SNPs) were analyzed in 285 bipolar disorder patients and 287 age-and gender-matched control subjects, all of Japanese origin. The genotypes were determined by TaqMan assay.

RESULTS

Significantly higher expression of PCNT2 was observed in the brain samples of bipolar group, compared with the control (p = .001) and schizophrenia (p = .018) groups. In the peripheral blood lymphocytes also, a significantly higher expression of PCNT2 was observed in the bipolar group, compared with the control subjects (p = .043). However, none of the SNPs analyzed in our study showed a significant association with bipolar disorder; a weak tendency toward association was observed for two intronic SNPs.

CONCLUSIONS

Our findings suggest that elevated levels of PCNT2 might be implicated in the pathophysiology of bipolar disorder.

T-even-related bacteriophages as candidates for treatment of Escherichia coli urinary tract infections

Multidrug-resistant uropathogenic Escherichia coli (UPEC) is increasing gradually on a worldwide scale. We therefore examined the possibility of bacteriophage (phage) therapy for urinary tract infections (UTIs) caused by the UPEC strains as an alternative to chemotherapy. In addition to the well-known T4 phage, KEP10, which was newly isolated, was used as a therapeutic phage candidate. KEP10 showed a broader bacteriolytic spectrum (67%) for UPEC strains than T4 (14%). Morphological and genetic analyses showed that KEP10 resembles phage T4. Phages T4 and KEP10 injected into the peritoneal cavity of mice were distributed immediately to all organs examined and maintained a high titer for at least 24 h. They were stable in the urine of both mice and humans for 24 h at 37 degrees C. Administration of these phages into the peritoneal cavity caused a marked decrease in the mortality of mice inoculated transurethrally with a UPEC strain, whereas most of the control mice died within a few days of bacterial infection. Inoculation with phage alone produced no adverse effects attributable to the phage per se. The present study experimentally demonstrated the therapeutic potential of phage for E. coli-induced UTIs, and T-even-related phages may be suitable candidates with which to treat them.

HMGA1a: sequence-specific RNA-binding factor causing sporadic Alzheimer's disease-linked exon skipping of presenilin-2 pre-mRNA

Aberrant exon 5 skipping of presenilin-2 (PS2) pre-mRNA produces a deleterious protein isoform PS2V, which is almost exclusively observed in the brains of sporadic Alzheimer's disease patients. PS2V over-expression in vivo enhances susceptibility to various endoplasmic reticulum (ER) stresses and increases production of amyloid-beta peptides. We previously purified and identified high mobility group A protein 1a (HMGA1a) as a trans-acting factor responsible for aberrant exon 5 skipping. Using heterologous pre-mRNAs, here we demonstrate that a specific HMGA1a-binding sequence in exon 5 adjacent to the 5' splice site is necessary for HMGA1a to inactivate the 5' splice site. An aberrant HMGA1a-U1 snRNP complex was detected on the HMGA1a-binding site adjacent to the 5' splice site during the early splicing reaction. A competitor 2'-O-methyl RNA (2'-O-Me RNA) consisting of the HMGA1a-binding sequence markedly repressed exon 5 skipping of PS2 pre-mRNA in vitro and in vivo. Finally, HMGA1a-induced cell death under ER stress was prevented by transfection of the competitor 2'-O-Me RNA. These results provide insights into the molecular basis for PS2V-associated neurodegenerative diseases that are initiated by specific RNA binding of HMGA1a.

Molecular mechanism of schizophrenia with reference to disrupted-in-schizophrenia 1 (DISC1)

Disrupted-in-schizophrenia 1 (DISC1) is a gene disrupted by a (1:1) (q42.1;q14.3) translocation that segregates with major psychiatric disorders in a Scottish family. To elucidate how DISC1 confers susceptibility to psychiatric disorders, identification of the molecules, which bind to the domain close to the translocation breakpoint in the DISC1 gene, was performed and fasciculation and elongation protein zeta-1 (Fez1), a novel DISC1-interacting protein, termed DISC1-binding zinc-finger protein (DBZ) and Kendrin were identified. The DISC1-Fez1 interaction is up-regulated by nerve growth factor (NGF) and involved in neurite extension. Transient dissociation of the DISC1-DBZ interaction by pituitary adenylate cyclase-activating polypeptide (PACAP) causes neurite extension. Furthermore, single-nucleotide polymorphisms association studies in a Japanese population have shown the relation of the Fez1, PACAP and PACAP receptor (PAC1) genes to schizophrenia. In schizophrenia with DISC1 translocation carrier, the DISC1-Fez1 and DISC1-DBZ interaction is disrupted, and it is likely that neural circuit formation remains immature, suggesting that schizophrenia is a neurodevelopmental disease. On the other hand, the DISC1-Kendrin interaction is suggested to be involved in microtubule network formation and an association between single-nucleotide polymorphisms of the Kendrin gene and bipolar disease has also been suggested in a Japanese population. This demonstrates that a part of bipolar disease is also a neurodevelopmental disorder.