Glyoxylic Acid, an α-Keto Acid Metabolite Derived from Glycine, Promotes Myogenesis in C2C12 Cells.

α-Keto acids may help prevent malnutrition in patients with chronic kidney disease (CKD), who consume protein-restricted diets, because they serve as amino acid sources without producing nitrogenous waste compounds. However, the physiological roles of α-keto acids, especially those derived from non-essential amino acids, remain unclear. In this study, we examined the effect of glyoxylic acid (GA), an α-keto acid metabolite derived from glycine, on myogenesis in C2C12 cells.

Ursolic acid improves the indoxyl sulfate-induced impairment of mitochondrial biogenesis in C2C12 cells.

Background/objectives: Patients with chronic kidney disease (CKD) have a high concentration of uremic toxins in their blood and often experience muscle atrophy. Indoxyl sulfate (IS) is a uremic toxin produced by tryptophan metabolism. Although an elevated IS level may induce muscle dysfunction, the effect of IS on physiological concentration has not been elucidated.

The Validity of Estimated Dietary Amino Acid and Protein Values via the Amino Acid Composition Table 2015.

The amino acid composition table (AACT) plays a pivotal role in examining the association between dietary amino acid intake and physical conditions. The updated version, AACT 2015, has been markedly expanded; however, most additions are not based on analytical values. The Food and Agriculture Organization (FAO) of the United Nations and the World Health Organization (WHO) recommend that protein contents be calculated as the sum of amino acid residues (PROTCAA).

A palindromic motif in the -2084 to -2078 upstream region is essential for ABCA12 promoter function in cultured human keratinocytes.

ATP-binding cassette transporter family A member 12 (ABCA12) is a keratinocyte transmembrane lipid transporter that plays a critical role in preserving the skin permeability barrier. Biallelic loss of function of the ABCA12 gene is causative of some forms of recessive congenital ichthyosis, an intractable disease marked by dry, thickened and scaly skin on the whole body. Genetic diagnosis is essential, although the results may occasionally be inconclusive, because some patients with low ABCA12 expression have one mutant allele and one apparently intact allele.

Potential of exogenous cartilage proteoglycan as a new material for cartilage regeneration.

Background: Although proteoglycan (PG) is one of the major components of cartilage matrices, its biological function is not fully elucidated.

Methods: The objectives of this study were to investigate the proliferation and differentiation of chondrocytes embedded in atelocollagen gel with exogenous cartilage PG (PG-atelocollagen gel) in vitro, and also to evaluate the repair of cartilage defects by PG-atelocollagen gel in vivo. In the in vitro study, rabbit chondrocytes were cultured in the PG-atelocollagen gel.

Expression of wild-type, but not mutant, loricrin causes programmed cell death in HaCaT keratinocytes.

The epidermal cornified cell envelope is a complex protein-lipid composite that replaces the plasma membrane of corneocytes and is crucial for epidermal barrier function. Loricrin is a major constituent of the epidermal cornified cell envelope, contributing approximately 70% by mass. In order to explore novel function of wild-type (WT) loricrin other than the major component of the epidermal cornified cell envelope, we transiently expressed construct encoding human WT and mutant loricrin (730insG) in HaCaT keratinocytes.

Novel proteoglycan glycotechnology: chemoenzymatic synthesis of chondroitin sulfate-containing molecules and its application.

Proteoglycans consist of a protein core, with one or more glycosaminoglycan chains (i.e., chondroitin sulfate, dermatan sulfate and heparin sulfate) bound covalently to it.

Up-regulation of hyaluronan synthase genes in cultured human epidermal keratinocytes by UVB irradiation.

Hyaluronan controls keratinocyte proliferation and regeneration. We examined effect of UV on the expression of hyaluronan synthases (HASs) and hyaluronidases in cultured normal human newborn foreskin epidermal keratinocytes, NHEK(F). HAS3 mRNA was expressed predominantly and HAS2 mRNA expressed in lesser amounts and both were up-regulated after a single irradiation with moderate UVB but hyaluronidases was unchanged.

Inhibitory effect of 4-methylesculetin on hyaluronan synthesis slows the development of human pancreatic cancer in vitro and in nude mice.

We report the inhibitory effect of 4-methylesculetin (ME), a 4-methylumbelliferone derivative, on hyaluronan (HA) synthesis by pancreatic cancer cells, and its resulting anticancer action. First, HA in cell culture was analyzed using competitive inhibition with hyaluronic acid-binding protein (HABP) to study HA synthesis by the human pancreatic cancer cell line KP1-NK, and cell-surface HA was visualized using a particle-exclusion assay to study the synthesis of extracellular matrix HA. We also analyzed the inhibitory effect of ME on cell adhesion and invasion, which play a role in the invasion, growth and metastasis of human pancreatic cancer.

Study of hyaluronan synthase inhibitor, 4-methylumbelliferone derivatives on human pancreatic cancer cell (KP1-NL).

The structure of 4-methylumbelliferone (MU) consists of coumarin with 4-methyl group and 7-hydroxy group. MU inhibits HA synthesis and pericellular HA matrix formation. In this study, we used 10 MU derivatives which have hydroxy groups and methyl groups at various positions of coumarin to investigate a more effective HA inhibitor than MU.

Interferon-gamma down-regulates expression of the 230-kDa bullous pemphigoid antigen gene (BPAG1) in epidermal keratinocytes via novel chimeric sequences of ISRE and GAS.

The 230-kDa bullous pemphigoid antigen (BPAG1) is an integral component of hemidesmosomes. We have previously reported that interferon-gamma (IFNgamma) inhibits the transcription of the BPAG1 gene (1). Here we investigated the target sequences of IFNgamma-signal transduction pathway in the BPAG1 promoter in epidermal keratinocytes.

A hyaluronan synthase suppressor, 4-methylumbelliferone, inhibits liver metastasis of melanoma cells.

4-Methylumbelliferone (MU) inhibits the cell surface hyaluronan (HA) formation, and that such inhibition results in suppression of adhesion and locomotion of cultured melanoma cells. Here, we examine the effect of MU on melanoma cell metastasis in vivo. MU-treated melanoma cells showed both decreased cell surface HA formation and suppression of liver metastasis after injection into the mice.

Keratinocyte-specific modulation of type VII collagen gene expression by pro-inflammatory cytokines (tumor necrosis factor-alpha and interleukin-1beta).

Previous studies have shown that pro-inflammatory cytokines such as tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta up-regulate type VII collagen gene (COL7A1) expression in cultured dermal fibroblasts. The present study was designed to investigate the effects of TNF-alpha and IL-1beta on COL7A1 expression in epidermal keratinocytes. We demonstrated that both TNF-alpha and IL-1beta reduced COL7A1 expression in epidermal keratinocytes in an additive manner, whereas they increased COL7A1 expression in dermal fibroblasts.

A novel mutation of keratin 9 gene (R162P) in a Japanese family with epidermolytic palmoplantar keratoderma.

Epidermolytic palmoplantar keratoderma (EPPK) is an autosomal dominant inherited skin disorder characterized by hyperkeratosis of the skin over the palms and soles. Mutations in keratin 9 gene (KRT9) have been demonstrated in EPPK. In this study, we screened a Japanese family with EPPK for KRT9 mutation by polymerase chain reaction amplification of genomic sequences, followed by heteroduplex analysis and direct nucleotide sequencing.

Effect of a hyaluronan synthase suppressor, 4-methylumbelliferone, on B16F-10 melanoma cell adhesion and locomotion.

Hyaluronan (HA) is a ubiquitous, major component of the extracellular matrix. It is involved in cell adhesion and locomotion, and hence in tumor metastasis. We have previously reported that 4-methylumbelliferone (MU) inhibits HA synthesis and may be a useful tool for examining the functions of HA.

Identification of COL7A1 alternative splicing inserting 9 amino acid residues into the fibronectin type III linker domain.

Type VII collagen is the major component of anchoring fibrils within the cutaneous basement membrane zone. The large amino-terminal noncollagenous domain of type VII collagen interacts with various extracellular matrix proteins and contributes to the dermal-epidermal attachment. The purpose of this study was to detect alternative splicing of COL7A1 transcript encoding the noncollagenous 1 domain.

Keratinocyte responsive element 3: analysis of a keratinocyte-specific regulatory sequence in the 230-kDa bullous pemphigoid antigen gene promoter.

The 230-kDa bullous pemphigoid antigen gene is expressed primarily, if not exclusively, in basal keratinocytes of the epidermis. Keratinocyte responsive element 3, a cis-element at position -216 to -197 of the human 230-kDa bullous pemphigoid antigen gene promoter, confers tissue-specific expression to this gene (Tamai et al: J Biol Chem 270:7609-7614, 1995). In this study, we investigated the functional characteristics of keratinocyte responsive element 3 on the 230-kDa bullous pemphigoid antigen gene core promoter by transient transfections of cultured normal human keratinocytes and normal human fibroblasts, as well as of lung carcinoma (A549), osteosarcoma (OST), and gastric adenocarcinoma (GT3TKB) cell lines.