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S Numaguchi

Publications and source records attributed to S Numaguchi.

8 recordsLinked to original sources
PubMed1994

Modulation of collagen synthesis and degradation by retinoids and cytokines in 3T3 L1 preadipocytes.

We previously observed that a retinoid analog can protect against liver parenchymal damage and liver fibrosis, whereas it accelerates liver fibrosis which is not accompanied by any parenchymal damage. To elucidate these conflicting effects, we examined the effects of retinoid in 3T3 L1 preadipocytes as a model of liver stellate cells. Retinoids, including all-trans retinol, all-trans and 9-cis retinoic acids, enhanced the cell growth and the expression of the type I procollagen gene as well as its peptide synthesis, while reducing collagenase activities. Although no retinoid enhanced the transforming growth factor (TGF)-beta 1 mRNA, retinoids may stimulate collagen production through activating TGF-beta, as was recently reported. These results help explain the observation in the liver fibrosis model with no parenchymal damage. In contrast, we also found that interferon (IFN) alpha beta and gamma inhibited cell growth and down-regulated markedly type I procollagen as well as TGF-beta 1 mRNA, suggesting that they suppress by acting directly on extracellular matrix-producing cells.

3T3 Cells↗
PubMed1993

[Cellular retinoid-binding proteins].

This paper will review the function of cellular retinoid-binding proteins and receptors (RAR), especially to address recent works on cellular uptake, intracellular transport, biosynthesis and metabolism of retinoids. Cellular retinol-binding protein (CRBP) binds retinol and retinal, cellular retinoic acid-binding protein (CRABP) binds retinoic acid, both of which have a molecular weight of 16 kDa, and cellular retinal-binding protein (CRALBP) binds retinal with a molecular weight of 36 kDa. CRBP (I) functions in cellular uptake of retinol from the plasma, solubilizes and renders retinol nontoxic in the aqueous system, and presents retinol to the appropriate enzymes to biosynthesize retinoic acid (an active form of retinoids) or retinyl esters (a storage form). CRBP (II) mainly distributes in the absorptive cell in the small intestine and functions in absorption of retinoids and carotenoids to biosynthesize retinyl esters present in the chylomicron. CRBP (III) is recognized as one of oncofetal proteins and binds both retinol and retinoic acid, the function of which still remains unclear. CRABP (I), previously recognized as a transport protein of retinoic acid to the nucleus, is now assumed to sequester retinoic acid from retinoic acid receptor(s) in the tissue where retinoic acid levels are required to be low. CRABP (I) also functions in the catabolism of retinoic acid to modulate its concentration in the cell. CRABP (II), expressed in the developmental stage of the fetus, is suggested to modulate the action of retinoic acid as a 'morphogen'.

Animals↗
PubMed1993

The clearance rate of chylomicron retinyl ester from plasma can be used to distinguish rats with cirrhosis from those with portacaval shunt.

Effects of carbon tetrachloride treatment and portacaval shunt surgery on exogenous chylomicron retinyl ester clearance from rat plasma were analyzed assuming three-compartment model kinetics. In rats with cirrhosis and in those with Eck fistulas, the relative pool size of compartment 2 decreased (0.20 and 0.36, respectively) compared with controls (0.82). The relative mass of compartment 3 significantly increased in rats with cirrhosis (1.55) or Eck fistula (0.19) compared with control rats (0.11). The cirrhotic and Eck fistula groups were indistinguishable on the basis of these parameters and on the basis of indocyanine green test values. However, the cirrhosis and Eck fistula groups differed clearly from each other with respect to fractional efflux rate constants (l2, l3), where the constant l2 is from compartment 2 and the l3 is from compartment 3. Both values decreased in cirrhotic rats, suggesting that the hepatic uptake of chylomicron retinyl esters was impaired by carbon tetrachloride. On the other hand, Eck fistula rats did experience dramatic increases in l3, implying that the hepatic uptake of chylomicron retinyl esters from compartment 3 was enhanced by portacaval shunting. Elevation of the plasma estrogen level observed in Eck fistula rats may be responsible for the induction of low-density lipoprotein receptors on hepatocytes and for the subsequent enhancement of l3. These results suggest that a three-compartment model of plasma retinyl ester disappearance kinetics gives important quantitative information about hepatic function. Clinical application of the chylomicron retinyl ester clearance test is discussed for estimating hepatic function reserves and for differential diagnosis of portal hypertension.

Animals↗
PubMed1980

Multiple sulfatase deficiency (mucosulfatidosis): impaired degradation of labeled sulfated compounds in cultured skin fibroblasts in vivo.

Skin fibroblasts from a Japanese patient with multiple sulfatase deficiency (MSD) (Mucosulfatidosis) were studied with regard to metabolism of various sulfated compounds in vivo. Several sulfatase activities (arylsulfatases A, B and C, cholesterol sulfatase, heparin N-sulfatase) were deficient in skin fibroblasts grown in F-10 CO2 medium. The accumulation and degradation of 35S-sulfatide, 35S-mucopolysaccharides, 14C-cholesterol sulfate by MSD cells were also studied, comparing them to control, Hunter and metachromatic leukodystrophy cells. MSD fibroblasts accumulated and failed to degrade these compounds in vivo. Cholesterol sulfate was also incorporated into the control and pathological cells, and MSD cells were unable to hydrolyze cholesterol sulfate, though cholesterol sulfate is known to be hydrolyzed in the non-lysosomal subfraction. From these data it is clear that multiple enzyme deficiencies in MSD fibroblasts can be demonstrated in vivo.

Cells, Cultured↗
PubMed1979

Urinary acid mucopolysaccharides in multiple sulfatase deficiency (mucosulfatidosis).

Urinary acid mucopolysaccharides (AMPS) excretion was investigated in a Japanese case with Multiple Sulfatase Deficiency (MSD) (Mucosulfatidosis). The patient excreted AMPS 4 to 5 times more (as carbazoluronic acid) than controls. The cellulose acetate gel electrophoresis clearly indicated two major AMPS which co-migrated with heparan sulfate and chondroitin sulfate A/C. Enzymic digestion with chondroitinase AC and ABC, and by testicular hyaluronidase plus amino sugar analysis also confirmed that our case excreted heparan sulfate and chondroitin sulfate A/C. These findings suggest that there are heterogeneities of urinary AMPS excretion among cases with MSD.

Child↗
PubMedDate not supplied

Post-infectious leukoencephalopathy as a complication of Mycoplasma pneumoniae infection.

We report a 9-year-old girl with leukoencephalopathy who demonstrated serologic evidence of a Mycoplasma pneumoniae infection. She had a mild upper respiratory tract illness 10 days prior to admission and developed walking difficulty and somnolence. The neurologic symptoms progressed to semicoma and spastic paraplegia over a few days but began to improve on the fourth day. Cranial computed tomography on the eleventh day revealed an area of diffuse low density in the white matter. Cerebrospinal fluid examination was normal. The patient recovered with minimal motor deficits. Cranial computed tomography was normal. She was diagnosed as having leukoencephalopathy complicated by a Mycoplasma pneumoniae infection. The pathogenesis of this infection is believed to be an allergic reaction to Mycoplasma pneumonia of the central nervous system as well as an acute disseminated encephalomyelitis.

Child↗