ß-Catenin overexpression causes an increase in inflammatory cytokines and NF-κB activation in cardiomyocytes.

ß-Catenin has been implicated in various developmental and physiological processes. Defective Wnt signaling can result in different cardiac and vascular abnormalities and is activated under pathological conditions such as inflammation and obesity. In this study, roles of ß-catenin in inflammation in cardiomyocytes were investigated. 10 samples from hearts of patients with acute infarction and 10 from normal ones were collected in order to access roles of ß-catenin in cardiomyocytes. H9c2 cardiomyoblasts and primary neonatal rat cardiomyocytes were transfected with porcine cytomegalovirus (pCMV)-ß-catenin plasmid in order to overexpress ß-catenin. Protein level of ß-catenin protein was increased in human acute infarction tissues compared to ones from normal patients. The transcription factor had increased nuclear localization in cardiomyocytes of the Wistar rats with cardiac hypertension. Furthermore, expression of fibrosis protein markers increased. Protein expression of ß-catenin was increased in human acute infarction inflammatory heart tissues and in hearts of inflammatory obesity rats. After pCMV-ß-catenin plasmid was transfected in a dose-dependent manner, inflammation protein markers, TNF-α and IL-8, were upregulated in hypertensive neonatal rat cardiomyocytes and H9c2 cardiomyoblasts. In addition, overexpression of ß-catenin induced activation and nuclear localization of NF-κB. Therefore, ß-catenin is a potential molecular target for treatment of inflammation and fibrosis in cardiomyocytes.

D-serine added to clozapine for the treatment of schizophrenia.

OBJECTIVE: D-Serine is a full agonist at the glycine site on the N-methyl-D-aspartate (NMDA) receptor. Previous administration of D-serine to schizophrenic patients taking nonclozapine antipsychotics improved positive, negative, and cognitive symptoms, whereas the partial agonist D-cycloserine improved negative symptoms of patients taking conventional antipsychotics but worsened symptoms in clozapine-treated patients. To study the difference between full and partial agonists at the NMDA receptor glycine site, the clinical effects of adding D-serine to clozapine were assessed. METHOD: In a 6-week double-blind trial, 20 schizophrenic patients received placebo or D-serine (30 mg/kg per day) in addition to clozapine. Clinical efficacy, side effects, and serum levels of D-serine were determined every other week. RESULTS: The patients exhibited no improvement with D-serine, nor did their symptoms worsen, as previously reported with D-cycloserine. CONCLUSIONS: The results suggest either that clozapine may have an agonistic effect on the NMDA system or that clozapine-treated patients do not respond to D-serine.

D-serine added to antipsychotics for the treatment of schizophrenia.

BACKGROUND: Hypofunction of N-methyl-D-aspartate (NMDA) subtype glutamate receptor has been implicated in the pathophysiology of schizophrenia. D-serine is a full agonist of the glycine site of NMDA receptor, an endogenous cotransmitter enriched in corticolimbic regions and distributed in parallel with NMDA receptor. Supplementation of D-serine may improve the symptoms of schizophrenia. METHODS: Thirty-one Taiwanese schizophrenic patients enrolled in a 6-week double-blind, placebo-controlled trial of D-serine (30 mg/kg/day), which was added to their stable antipsychotic regimens. Of these, 28 completed the trial. Measures of clinical efficacy, side effects, and serum levels of amino acids and D-serine were determined every other week. Wisconsin Card Sorting Test (WCST) was performed at the beginning and end of the trial. RESULTS: Patients who received D-serine treatment revealed significant improvements in their positive, negative, and cognitive symptoms as well as some performance in WCST. D-serine levels at week 4 and 6 significantly predicted the improvements. D-serine was well tolerated and no significant side effects were noted. CONCLUSIONS: The significant improvement with the D-serine further supports the hypothesis of NMDA receptor hypofunction in schizophrenia. Given the effects of D-serine on positive symptoms, a trial of D-serine alone in schizophrenia should be considered.

Intraoral juvenile xanthogranuloma. A case report and literature review.

Juvenile xanthogranuloma rarely occurs in the oral cavity and has received little attention. A case of histologically documented juvenile xanthogranuloma of the oral cavity is described. This is the first intraoral case reported in the Oriental race and in the vestibule. Pertinent literature regarding intraoral lesions of this condition is also reviewed.

Type VII collagen gene expression by cultured human cells and in fetal skin. Abundant mRNA and protein levels in epidermal keratinocytes.

Type VII collagen, a genetically distinct member of the collagen family, is present in the cutaneous basement membrane zone as an integral component of the anchoring fibrils. We have recently isolated several cDNAs that correspond to human type VII collagen sequences. One of these cDNAs (clone K-131) was utilized to examine type VII collagen gene expression in cultures of human cells by Northern analyses, in situ hybridizations and indirect immunofluorescence. Northern hybridizations revealed the presence of an approximately 9-kb mRNA transcript, and indicated a high level of expression in epidermal keratinocytes as well as in an oral epidermoid carcinoma cell line (KB), while the expression was considerably lower in skin fibroblasts and in several virally or spontaneously transformed epithelial cell lines. In situ hybridizations of cultured keratinocytes supported the notion of a high level of gene expression. Indirect immunofluorescence of skin from a 19-wk fetus revealed type VII collagen gene expression at the dermal-epidermal basement membrane zone. These results indicate that several different cell types including epidermal keratinocytes and dermal fibroblasts express the type VII collagen gene, but epidermal keratinocytes may be the primary cell source of type VII collagen in developing human skin.

Human type VII collagen: genetic linkage of the gene (COL7A1) on chromosome 3 to dominant dystrophic epidermolysis bullosa.

Epidermolysis bullosa (EB) is a heterogeneous group of heritable blistering disorders affecting the skin and the mucous membranes. Previous ultrastructural studies on the dystrophic (scarring) forms of EB have demonstrated abnormalities in the anchoring fibrils, morphologically distinct structures below the basal lamina at the dermal/epidermal basement membrane zone. Type VII collagen is the major collagenous component of the anchoring fibrils, and it is therefore a candidate gene for mutations in some families with dystrophic forms of EB. In this study, we performed genetic linkage analyses in a large kindred with dominant dystrophic EB. A 1.9-kb type VII collagen cDNA clone was used to identify a PvuII RFLP to follow the inheritance of the gene. This RFLP cosegregated with the EB phenotype in this family, strongly supporting genetic linkage (Z = 5.37; theta = .0). In addition, we assigned the type VII collagen gene (COL7A1) to chromosome 3 by hybridization to a panel of human x rodent somatic cell hybrids. These data demonstrate very close genetic linkage between the clinical phenotype in this family and the polymorphism in the type VII collagen gene mapped to chromosome 3. The absence of recombination between EB and the type VII collagen gene locus, as well as the observed abnormalities in the anchoring fibrils, strongly suggest that this collagen gene is the mutant locus in this kindred.

Human type VII collagen: cDNA cloning and chromosomal mapping of the gene.

A human keratinocyte cDNA expression library in bacteriophage lambda gt11 was screened with the purified IgG fraction of serum from a patient with epidermolysis bullosa acquisita, which had a high titer of anti-type VII collagen antibodies. Screening of approximately 3 x 10(5) plaques identified 8 positive clones, the largest one (K-131) being approximately 1.9 kilobases in size. Dideoxynucleotide sequencing of K-131 indicated that it consisted of 1875 base pairs and contained an open reading frame coding for a putative N-terminal noncollagenous domain of 439 amino acids and a collagenous C-terminal segment of 186 amino acids. The collagenous domain was characterized by repeating Gly-Xaa-Yaa sequences that were interrupted in several positions by insertions or deletions of 1-3 amino acids. The deduced amino acid sequence also revealed a peptide segment that had a high degree of identity with a published type VII collagen protein sequence. Northern hybridization of the K-131 cDNA with human epidermal keratinocyte and skin fibroblast RNA revealed an mRNA of approximately 8.5 kilobases. The fusion protein produced by the K-131 cDNA, when incubated with epidermolysis bullosa acquisita serum, bound to antibodies that reacted in Western blots with type VII collagen. The genomic location of the type VII collagen gene (COL7A1) was determined by chromosomal in situ hybridization with the K-131 cDNA. The results mapped the COL7A1 to the locus 3p21. The cDNA clones characterized in this study will be valuable for understanding the protein structure and gene expression of type VII collagen present in anchoring fibrils and its aberrations in the dystrophic forms of heritable epidermolysis bullosa.

Renal excretion of citrate in patients with chronic renal failure or nephrolithiasis.

Using a specific citrate lyase method, renal excretion of citrate was studied in 32 normal Chinese males, 30 nondialysed uremic male patients and 35 male subjects who had a history of nephrolithiasis. Patients with uremia or nephrolithiasis were found to have a lower urinary citrate excretion. Tubular reabsorption of citrate was markedly decreased in uremic patients, but in stone patients, the increased renal tubular reabsorption of citrate was only found in patients with hypocitraturia, whose renal citrate excretion was below 650 mumol/day and whose urinary magnesium was also low. Hypocitraturia was found in 45% (16/35) of the patients with renal stones whether their filtered load of citrate was normal or subnormal. Urinary citrate excretion was correlated with renal creatinine clearance in both normal subjects and in patients with renal stones or chronic renal failure. However, urinary phosphate correlating with urinary citrate was only found in normal subjects and in patients with kidney stones. In normal subjects, we found a positive correlation between urinary citrate and phosphate, but in stone patients, we found a negative correlation. Hypercalciuria and hyperoxalaturia were noted in some stone formers, who had, moreover, a lower urinary citrate and ascorbate excretion level. Mean urinary ascorbate excretion in patients with renal stones was markedly below that in normal subjects. Thus, we suggest that low urinary citrate excretion may be prevalent in patients with renal stones or chronic renal failure, and that hypocitraturia can be found in some stone formers, whose tubular reabsorption of citrate may be increased.