These characteristic mechanisms of FC accumulation in HSCs are potential targets to treat liver fibrosis in liver diseases including NASH.

We previously Isolated from a rat regeneratbig islet cDNA library a gene named Reg, which Is expressed in regenerating Islets but is not expressed in normal islets. Here we examined the effect of rat Reg protein on pancreatic beta-cell replication using both 90% depancreatized rats and isolated Islets. The depancreatized rats that received i. Hydrated 5-pm sections of paraffin-embedded pancreatic tissues were stained for insulin by the labeled streptavidinbiotin method, using an LSAB kit (Dakopatts, Glostrup, Denmark). After being stained, the relative volumes of beta cells were measured by the point-counting method (1, 13).In Vitro Experiment. Pancreatic islets were isolated from male Wistar rats (body weight 200-250 g) by using density separation on a dextran gradient and cultured free-floating in RPMI 1640 medium/10%o fetal calf serum/penicillin G at 100 pg/ml/streptomycin at 100 g/ml for 48 hr to allow recovery from the isolation procedure (14). After this initial period, islets were transferred to 24-well culture dishes in groups of 50 islets. The islets were cultured in RPMI 1640 medium/2.7 mM D-glucose/2% fetal calf serum/penicillin G at 100 ;g/ ml/streptomycin at 100 ;g/ml in the presence of increased concentrations of Reg protein for 72 hr. During the last 24 hr, the islets were cultured in the above medium to which [methyl-3H]thymidine at 10 puCi/ml (Amersham; 1 Ci = 37 GBq) had been added. To estimate the amount of [3H]thymidine incorporated into newly synthesized DNA, the islets were washed as described (14) after the culture period and sonicated in 10 mM Tris.HCl/5 mM EDTA. DNA was precipitated by the addition of 7% ice-cold trichloroacetic acid and trapped by filtration on a glass-fiber disc (Whatman GF/C). The discs were dried, and radioactivity was counted after the addition of scintillation fluid (Packard Ultima Gold F). The DNA content of the islets was measured by a flurometric DNA assay using Hoechst 33258. To estimate labeling indices for insulin-positive cells, the [3H]thymidinelabeled islets were fixed in 4% paraformaldehyde for 20 min and embedded in OCT compound. Ten-micrometer sections were cut with a cryostat and immunostained with antiporcine insulin guinea pig antiserum (DAKO, 1:500) and Vectastain ABC-GO kit (Vector Laboratories). Autoradiography of the immunostained sections was performed by using lTo whom reprint requests should be addressed at:

No abstract

No abstract

Hepatitis C virus (HCV) is a causative agent of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. HCV in circulating blood associates with lipoproteins such as very low density lipoprotein (VLDL) and low-density lipoprotein (LDL). Although these associations suggest that lipoproteins are important for HCV infectivity, the roles of lipoproteins in HCV production and infectivity are not fully understood. To clarify the roles of lipoprotein in the HCV life cycle, we analyzed the effect of apolipoprotein E (ApoE), a component of lipoprotein, on virus production and infectivity. The production of infectious HCV was significantly reduced by the knockdown of ApoE. When an ApoE mutant that fails to be secreted into the culture medium was used, the amount of infectious HCV in the culture medium was dramatically reduced; the infectious HCV accumulated inside these cells, suggesting that infectious HCV must associate with ApoE prior to virus release. We performed rescue experiments in which ApoE isoforms were ectopically expressed in cells depleted of endogenous ApoE. The ectopic expression of the ApoE2 isoform, which has low affinity for the LDL receptor (LDLR), resulted in poor recovery of infectious HCV, whereas the expression of other isoforms, ApoE3 and ApoE4, rescued the production of infectious virus, raising it to an almost normal level. Furthermore, we found that the infectivity of HCV required both the LDLR and scavenger receptor class B, member I (SR-BI), ligands for ApoE. These findings indicate that ApoE is an essential apolipoprotein for HCV infectivity.