Genetic organization and diversity of the hepatitis C virus

The nucleotide sequence of the RNA genome of the human hepatitis C virus (HCV) has been determined from overlapping cDNA clones. The sequence (9379 nucleotides) has a single large open reading frame that could encode a viral polyprotein precursor of 3011 amino acids. While there as little overall amino acid and nucleotide sequence homology with other viruses, the 5' HCV nucleotide sequence upstream of this large open reading frame has substantial similarity to the 5' termini of pestiviral genomes. The polyprotein also has significant sequence similarity to helicases encoded by animal pestiviruses, plant potyviruses, and human flaviviruses, and it contains sequence motifs widely conserved among viral replicases and trypsin-like proteases. A basic, presumed nucleocapsid domain is located at the N terminus upstream of a region containing numerous potential N-linked glycosylation sites. These HCV domains are located in the same relative position as observed in the pestiviruses and flaviviruses and the hydrophobic profiles of all three viral polyproteins are similar. These combined data indicate that HCV is an unusual virus that is most related to the pestiviruses. Significant genome diversity is apparent within the putative 5' structural gene region of different HCV isolates, suggesting the presence of closely related but distinct viral genotypes.

Haplotype variation and linkage disequilibrium in 313 human genes

Variation within genes has important implications for all biological traits. We identified 3899 single nucleotide polymorphisms (SNPs) that were present within 313 genes from 82 unrelated individuals of diverse ancestry, and we organized the SNPs into 4304 different haplotypes. Each gene had several variable SNPs and haplotypes that were present in all populations, as well as a number that were population-specific. Pairs of SNPs exhibited variability in the degree of linkage disequilibrium that was a function of their location within a gene, distance from each other, population distribution, and population frequency. Haplotypes generally had more information content (heterozygosity) than did individual SNPs. Our analysis of the pattern of variation strongly supports the recent expansion of the human population.

Isolation of full-length putative rat lysophospholipase cDNA using improved methods for mRNA isolation and cDNA cloning

We have cloned a full-length putative rat pancreatic lysophospholipase cDNA by an improved mRNA isolation method and cDNA cloning strategy. These new methods allow the construction of a cDNA library from the adult rat pancreas in which the majority of recombinant clones contained complete sequences for the corresponding mRNAs. A previously recognized but unidentified long and relatively rare cDNA clone containing the entire sequence from the cap site at the 5' end to the poly(A) tail at the 3' end of the mRNA was isolated by single-step screening of the library. The size, amino acid composition, and the activity of the protein expressed in heterologous cells strongly suggest this mRNA codes for lysophospholipase [Van den Bosch, H., Aarsman, A. J., DeJong, G. N., & Van Deenen, L. M. (1973) Biochim. Biophys. Acta 296, 94-104].

Characterization of the terminal regions of hepatitis C viral RNA: identification of conserved sequences in the 5' untranslated region and poly(A) tails at the 3' end

We have determined the nucleotide sequence at the extreme 5' and 3' termini of the hepatitis C virus (HCV) genome. Our analyses of these sequences show (i) the nucleotide sequence in the 5' untranslated region is highly conserved among HCV isolates of widely varying geographical origin, (ii) within this region, there are blocks of nucleotide sequence homology with pestiviruses but not with other viruses, (iii) the relative position of short open reading frames present in the same region of the HCV genome is similar to that of the pestiviral genome, (iv) RNAs truncated at the 5' and 3' ends are found, but the origin and functions of these RNAs are unknown, and (v) poly(A) tails appear to be present on 3' subgenomic RNAs. These data differentiate HCV from the flaviviruses and indicate a closer evolutionary relationship of HCV with the pestiviruses. However, HCV also appears to be substantially different from other known pestiviruses. These data are consistent with the assignment of HCV to a separate viral genus.

Macrophage inflammatory protein-1alpha is an osteoclastogenic factor in myeloma that is independent of receptor activator of nuclear factor kappaB ligand

A complementary DNA expression library derived from marrow samples from myeloma patients was recently screened and human macrophage inflammatory protein-1alpha (hMIP-1alpha) was identified as an osteoclastogenic factor expressed in these samples. hMIP-1alpha enhanced osteoclast (OCL) formation in human marrow cultures and by highly purified OCL precursors in a dose-dependent manner (5-200 pg/mL). Furthermore, hMIP-1alpha enhanced OCL formation induced by human interleukin-6 (IL-6), which is produced by marrow stromal cells when they interact with myeloma cells. hMIP-1alpha also enhanced OCL formation induced by parathyroid hormone-related protein (PTHrP) and receptor activator of nuclear factor kappaB ligand (RANKL), factors also implicated in myeloma bone disease. Time-course studies revealed that the hMIP-1alpha acted during the last 2 weeks of the 3-week culture period. Reverse transcription-polymerase chain reaction analysis showed that the chemokine receptors for hMIP-1alpha (CCR1 and CCR5) were expressed by human bone marrow and highly purified early OCL precursors. Furthermore, hMIP-1alpha did not increase expression of RANKL. These data demonstrate that hMIP-1alpha is an osteoclastogenic factor that appears to act directly on human OCL progenitors and acts at the later stages of OCL differentiation. These data further suggest that in patients with myeloma, MIP-1alpha produced by myeloma cells, in combination with RANKL and IL-6 that are produced by marrow stromal cells in response to myeloma cells, enhances OCL formation through their combined effects on OCL precursors. (Blood. 2001;97:3349-3353)

C-terminal domain of the hepatitis C virus NS3 protein contains an RNA helicase activity

The Hepatitis C Virus (HCV) NS3 protein contains amino acid motifs of a serine proteinase, a nucleotide triphosphatase (NTPase), and an RNA helicase based on amino acid sequence analysis. Proteinase and NTPase activities of the HCV NS3 protein were reported by several investigators. Here, we show that the recombinant HCV NS3 protein purified from a T7 promoter and His-tag expression system possesses an RNA helicase activity. The recombinant HCV NS3 protein consists of 466 amino acids from the carboxy terminal of a HCV NS3 open reading frame and 25 additional residues from the vector. The recombinant HCV NS3 protein was purified by metal-binding chromatography. The helicase activity requires ATP and divalent cations such as Mg2+ and Mn2+. The helicase activity was abolished by monoclonal antibody specific to the HCV NS3 protein.

An inducible gene product for 6-phosphofructo-2-kinase with an AU-rich instability element: role in tumor cell glycolysis and the Warburg effect

Cancer cells maintain a high glycolytic rate even in the presence of oxygen, a phenomenon first described over 70 years ago and known historically as the Warburg effect. Fructose 2,6-bisphosphate is a powerful allosteric regulator of glycolysis that acts to stimulate the activity of 6-phosphofructo-1-kinase (PFK-1), the most important control point in mammalian glycolysis. The steady state concentration of fructose 2,6-bisphosphate in turn depends on the activity of the enzyme 6-phosphofructo-2-kinase (PFK-2)/fructose-2, 6-bisphosphatase, which is expressed in several tissue-specific isoforms. We report herein the identification of a gene product for this enzyme that is induced by proinflammatory stimuli and which is distinguished by the presence of multiple copies of the AUUUA mRNA instability motif in its 3'-untranslated end. This inducible gene for PFK-2 is expressed constitutively in several human cancer cell lines and was found to be required for tumor cell growth in vitro and in vivo. Inhibition of inducible PFK-2 protein expression decreased the intracellular level of 5-phosphoribosyl-1-pyrophosphate, a product of the pentose phosphate pathway and an important precursor for nucleic acid biosynthesis. These studies identify a regulatory isoenzyme that may be essential for tumor growth and provide an explanation for long-standing observations concerning the apparent coupling of enhanced glycolysis and cell proliferation.

Vertical transmission of hepatitis C virus

There is evidence that hepatitis C virus (HCV) may be vertically transmitted from infected mothers to their children. To test this hypothesis, we prospectively studied 10 pregnant women at high risk from parenterally or sexually transmitted diseases with the polymerase chain reaction. HCV RNA was found in 8 newborn babies delivered by women who were anti-HCV seropositive, and persisted for 2-19 months of follow-up. Anti-HCV detected in 7 infants cleared by 9 months and remained undetectable thereafter. Serum alanine aminotransferase was raised in 3 infants. The findings provide evidence of vertical transmission of HCV and suggest that perinatal infection may initiate a silent disease process or chronic carrier state.

Photoresponse of CsPbBr3 and Cs4PbBr6 Perovskite Single Crystals

High-quality and millimeter-sized perovskite single crystals of CsPbBr₃ and Cs₄PbBr₆ were prepared in organic solvents and studied for correlation between photocurrent generation and photoluminescence (PL) emission. The CsPbBr₃ crystals, which have a 3D perovskite structure, showed a highly sensitive photoresponse and poor PL signal. In contrast, Cs₄PbBr₆ crystals, which have a 0D perovskite structure, exhibited more than 1 order of magnitude higher PL intensity than CsPbBr₃, which generated an ultralow photoresponse under illumination. Their contrasting optoelectrical characteristics were attributed to different exciton binding energies, induced by coordination geometry of the [PbBr₆]^4- octahedron sublattices. This work correlated the local structures of lead in the primitive perovskite and its derivatives to PL spectra as well as photoconductivity.

Preferential killing of human lung cancer cell lines with mitochondrial dysfunction by nonthermal dielectric barrier discharge plasma

The distinctive cellular and mitochondrial dysfunctions of two human lung cancer cell lines (H460 and HCC1588) from two human lung normal cell lines (MRC5 and L132) have been studied by dielectric barrier discharge (DBD) plasma treatment. This cytotoxicity is exposure time-dependent, which is strongly mediated by the large amount of H₂O₂ and NO_x in culture media generated by DBD nonthermal plasma. It is found that the cell number of lung cancer cells has been reduced more than that of the lung normal cells. The mitochondrial vulnerability to reactive species in H460 may induce distinctively selective responses. Differential mitochondrial membrane potential decrease, mitochondrial enzymatic dysfunction, and mitochondrial morphological alteration are exhibited in two cell lines. These results suggest the nonthermal plasma treatment as an efficacious modality in lung cancer therapy.

Psychiatric epidemiology in Korea. Part I: Gender and age differences in Seoul

The most dramatic finding was the very high prevalence of alcohol abuse, using DSM-III criteria, among men in Seoul, Korea. The prevalence of other psychiatric disorders was lower than in St. Louis, Missouri. With the current biological emphasis in psychiatry, questions may be raised regarding the different prevalence rates of schizophrenia, affective disorders, and even alcoholism. The deficit of the aldehyde dehydrogenase isoenzyme 1 has been hypothesized to reduce the prevalence of alcohol abuse among Asians. Twenty-five percent of Koreans have been found to be deficient in the enzyme, but despite this their prevalence of alcohol abuse is higher than among Americans. Cultural issues are paramount in the much lower prevalence of alcohol abuse among women in Korea.

Prevalence of diabetes and impaired fasting glucose in Korea: Korean National Health and Nutrition Survey 2001

OBJECTIVE

The purpose of this study was to estimate the prevalence of diabetes and impaired fasting glucose (IFG) and their association with risk factors in the Korean population.

RESEARCH DESIGN AND METHODS

The Korean National Health and Nutrition Survey 2001 was a nationally representative survey with a stratified multistage sampling design. Data from a comprehensive questionnaire, a physical examination, and blood tests were obtained from 5,844 Korean adults (2,513 men and 3,331 women) aged >20 years.

RESULTS

The age-adjusted prevalence of diabetes in this Korean population was 7.6%, and the age-adjusted prevalences of previously diagnosed diabetes and newly diagnosed diabetes were 4.4 and 3.3%, respectively (fasting plasma glucose > or = 7.0 mmol/l). Overall, these results indicate that 8.1% or 1.4 million Korean men and 7.5% or 1.3 million Korean women have diabetes. The age-adjusted prevalence of IFG was 23.9%, using the new American Diabetes Association criteria (fasting plasma glucose 5.6-6.9 mmol/l). Diabetes prevalence increased with age and peaked in the oldest age-group; however, IFG prevalence did not show the same trend. Diabetes was found to be associated with age, BMI, blood pressure, triglyceride, HDL cholesterol, education levels, alcohol consumption, exercise, and a family history of diabetes.

CONCLUSIONS

This study shows that diabetes and IFG are common in Korea, and about one-half of diabetes cases remain undiagnosed. These results emphasize the need to develop an urgent public program to improve the detection, prevention, and treatment of diabetes.

Evolution of the genome and the genetic code: selection at the dinucleotide level by methylation and polyribonucleotide cleavage

Noting the scarcity of CpG dinucleotide in total genomic DNA derived from higher organisms and the scarcity of TpA dinucleotide in total genomic DNA derived from most life forms, we examined the distribution of these dinucleotides in sequences derived from functionally distinct types of human DNA, including mitochondrial DNA, intergenic DNA, intron DNA, and DNA destined to be represented in the cytoplasm as mRNA, tRNA, or rRNA. While CpG frequency has fallen to its lowest levels in DNA that is transcriptionally silent, TpA is most stringently excluded in DNA destined to be expressed as mRNA in the cytosol. This observation suggests that the selective pressures leading to the removal of CpG and TpA operate at different levels. With respect to TpA, dinucleotide scarcity may reflect a requirement for mRNA stability and may indicate the action of UpA-selective ribonucleases. We propose that, by reason of its instability, UpA must have been very rare in primordial RNA. Therefore, tRNA with the anticodon for this dinucleotide may have failed to evolve, making UpA the primordial doublet "stop" codon. The modern triplet code has faithfully conserved this arrangement in the two universal stop codons, UAA and UAG.

Characterization of RNA binding activity and RNA helicase activity of the hepatitis C virus NS3 protein

The Hepatitis C Virus (HCV) NS3 protein has RNA binding activity, RNA-stimulated NTPase activity, and RNA helicase activity. The RNA binding activity of the C-terminal domain of the HCV NS3 protein is less sensitive to pH, KCl, and MgCl2 than NTPase and the RNA helicase activity. The overall order of the binding of homoribopolymer for the NS3 protein was poly(U) > > poly(A) > poly(G), poly(C). The minimal RNA binding size of the HCV NS3 protein was determined using a gel retardation assay and is estimated between 7 nt and 20 nt. The HCV RNA helicase unwinds RNA/DNA heteroduplexes as well as RNA/RNA duplexes and it catalytically translocates in the 3' to 5' direction.

Mutational analysis of the hepatitis C virus RNA helicase

The carboxyl-terminal three-fourths of the hepatitis C virus (HCV) NS3 protein has been shown to possess an RNA helicase activity, typical of members of the DEAD box family of RNA helicases. In addition, the NS3 protein contains four amino acid motifs conserved in DEAD box proteins. In order to inspect the roles of individual amino acid residues in the four conserved motifs (AXXXXGKS, DECH, TAT, and QRRGRTGR) of the NS3 protein, mutational analysis was used in this study. Thirteen mutant proteins were constructed, and their biochemical activities were examined. Lys1235 in the AXXXXGKS motif was important for basal nucleoside triphosphatase (NTPase) activity in the absence of polynucleotide cofactor. A serine in the X position of the DEXH motif disrupted the NTPase and RNA helicase activities. Alanine substitution at His1318 of the DEXH motif made the protein possess high NTPase activity. In addition, we now report inhibition of NTPase activity of NS3 by polynucleotide cofactor. Gln1486 was indispensable for the enzyme activity, and this residue represents a distinguishing feature between DEAD box and DEXH proteins. There are four Arg residues in the QRRGRTGR motif of the HCV NS3 protein, and the second, Arg1488, was important for RNA binding and enzyme activity, even though it is less well conserved than other Arg residues. Arg1490 and Arg1493 were essential for the enzymatic activity. As the various enzymatic activities were altered by mutation, the enzyme characteristics were also changed.

Multiple transcription start sites, DNase I-hypersensitive sites, and an opposite-strand exon in the 5' region of the CHO dhfr gene

Transcription of the 26-kilobase (kb) dihydrofolate reductase (dhfr) gene in CHO cells is initiated at two sites: a major site (approximately 85% of the dhfr mRNA) at -63 relative to the translation start and a minor site (approximately 15%) at -107. Transcription also occurs from the opposite DNA strand in the dhfr 5' region, with a probable initiation site at approximately -195 relative to the dhfr translation start. A 4-kb polyadenylated RNA that is derived from the opposite-strand transcription increases threefold in abundance after serum starvation of CHO cells for 24 h. dhfr mRNA levels do not change during this time. The first dhfr exon lies within a 1-kb genomic region marked by exceptionally high G + C content and lack of DNA methylation. This region also includes a 214-base-pair (bp) exon for the opposite-strand transcript and five of the six DNase I-hypersensitive sites identified at the dhfr locus. Analysis of the DNA sequences of hamster, human (M. Chen, T. Shimada, A. D. Moulton, A. Cline, R. K. Humphries, J. Maizel, and A. W. Nienhuis, J. Biol. Chem. 259:3933-3943, 1984), and mouse (M. McGrogan, C. C. Simonsen, D. T. Smouse, P. J. Farnham, and R. T. Schimke, J. Biol. Chem. 260:2307-2314, 1985) dhfr genes reveals the presence of a 29-bp unit that is conserved 45 to 49 bp upstream of major and minor dhfr transcription start sites. This unit follows the consensus: GRGGCGGTGGCCTNNNNTGTCRCAARTRGGTR. The 5' part of the 29-bp unit contains a GC box that agrees with the GGGCGG consensus-binding site for the RNA polymerase II transcription factor Sp1 (D. Gidoni, W. A. Dynan, and R. Tjian, Nature (London) 312:409-413, 1984). Each of the three mammalian dhfr genes has several G-rich GC boxes proximal to the major dhfr transcription start site and several GC boxes of the opposite orientation (C rich) in a distal region about 500 bp upstream.

Use of a signature nucleotide sequence of hepatitis C virus for detection of viral RNA in human serum and plasma

The nucleic acid sequence of the putative 5'-untranslated (5PUT) region of hepatitis C virus (HCV), determined for samples obtained from a variety of geographic origins, was found to be over 98% conserved among all isolates. On the basis of this signature sequence for HCV, a viral RNA assay was developed by using cDNA synthesis with reverse transcriptase, followed by polymerase chain reaction (PCR). The new assay was compared with the Ortho-Chiron C100-3 HCV enzyme-linked immunosorbent assay to research radioimmunoassays for antibodies to the C33c and C22 HCV antigens and to the first reported set of HCV PCR primers designed from the NS3 domain. Plasma samples from 16 Japanese patients with non-A, non-B hepatitis (NANBH) and 16 immunoassay-positive blood donors from the United States were investigated. The 5PUT PCR primers were found to be superior to the NS3 primers in sensitivity and specificity (15 of 25 versus 3 of 25 of the C100 enzyme-linked immunosorbent assay-positive samples, respectively). Samples from two C100-negative patients with acute NANBH were found to react with the 5PUT primers but not with the NS3 primers. Also, two of three patients with chronic NANBH converted from reverse transcriptase PCR positive to negative after interferon treatment. Although the clinical significance of the presence or absence of HCV RNA in samples from patients is not fully understood, the use of probes and primers from the 5PUT region (as opposed to primers from other segments) should not lead to false-negative results due to nucleic acid sequence variations in viral isolates.

Psychiatric epidemiology in Korea. Part II: Urban and rural differences

This paper compares the findings in rural Korea and in the urban capital city of Seoul, Korea. In rural Korea 1966 subjects and in Seoul 3134 subjects were interviewed with the National Institute of Mental Health Diagnostic Interview Schedule. We found that the prevalence of psychiatric disorders, including alcohol dependence, was higher in rural Korea than in the urban setting. Comparing men and women, the prevalence of psychiatric disorders was higher in women. The exception was alcohol abuse/dependence, which was much higher among men, as was antisocial personality disorder. Comparison of prevalence by age groups showed that, in contrast to American studies, there was a tendency for prevalence to increase with increasing age. Alcohol abuse/dependence was much higher in rural Korea compared with St. Louis. Drug abuse/dependence was much higher in St. Louis. Other interesting similarities and differences are discussed.

Differentiation of a Vero cell adapted porcine epidemic diarrhea virus from Korean field strains by restriction fragment length polymorphism analysis of ORF 3

A porcine epidemic diarrhea virus (PEDV) designated DR13 was isolated in Vero cells and serially passaged by level 100. The virus was titrated at regular intervals of the passage level. Open reading frame (ORF) 3 sequences of the virus at passage levels 20, 40, 60, 80, and 100 were aligned and compared using a computer software program. Suitability of the restriction fragment length polymorphism (RFLP) analysis for differentiating the virus from other Korean field strains was investigated. The DR13 field isolate was successively adapted in Vero cells as observed through polymerase chain reaction (PCR) and titration of the virus. RFLP analysis identified change in cleavage sites of HindIII and Xho II from passage levels 75 and 90, respectively; these RFLP patterns of ORF 3 differentiated the Vero cell-adapted virus from its parent strain, DR13, and 12 other strains of PEDV studied. The cell adapted DR13 was tested for its pathogenicity and immunogenicity in piglets and pregnant sows. The results indicated that cell adapted DR13 revealed reduced pathogenicity and induced protective immune response in pigs. Differentiation between highly Vero cell-adapted virus and wild-type virus could be the marker of adaptation to cell culture and a valuable tool for epidemiologic studies of PEDV infections. The results of this study supported that the cell attenuated virus could be applied as a marker vaccine candidate against PEDV infection.

Inactivation of Escherichia coli O157:H7 in packaged ground beef by allyl isothiocyanate

Commercial allyl isothiocyanate (AIT) was examined for its ability to reduce numbers of Escherichia coli O157:H7 inoculated in fresh ground beef packaged under nitrogen and stored refrigerated or frozen. A five-strain cocktail of E. coli O157:H7 containing 3 or 6 log10 cfu/g was inoculated into 100 g ground beef and formed into 10x1-cm patties. A 10-cm diameter filter paper disk treated with AIT suspended in sterile corn oil was placed on top of a single patty. One patty and paper disk were placed in a bag of Nylon/EVOH/PE with O2 permeability of 2.3 cm3 m(-2) 24 h atm at 23 degrees C. The bags were back-flushed with 100% nitrogen, heat-sealed and stored at 10, 4 and -18 degrees C for 8, 21 or 35 days, respectively. During storage, the AIT levels in the package headspaces were determined by gas liquid chromatography, and mesophilic bacteria and E. coli O157:H7 were counted. The mesophilic aerobic bacteria in ground beef patties were largely unaffected by the addition of AIT. At an initial population of 3 log10 cfu/g, E. coli O157:H7 was reduced by AIT to undetectable levels after 18 days at 4 degrees C or 10 days at -18 degrees C. In samples inoculated with 6 log10 cfu/g, a >3 log10 reduction of E. coli O157:H7 was observed after 21 days at 4 degrees C, while a 1 log10 reduction was observed after 8 and 35 days at 10 and -18 degrees C, respectively. The final AIT concentrations in the headspaces after storage at 10, 4, and -18 degrees C were 444, 456, and 112 microg/ml at 8, 21, and 35 days, respectively. Results showed that AIT can substantially reduce numbers of E. coli O157:H7 in fresh ground beef during refrigerated or frozen storage.

ADAM8: a novel osteoclast stimulating factor

We used polymerase chain reaction (PCR)-selective complementary DNA (cDNA) subtraction hybridization with an immortalized murine osteoclast (OCL) precursor cell line to identify genes that are highly expressed in OCLs compared with OCL precursors and which may be involved in the OCL differentiation process. ADAM8 was one of the 50 genes identified. ADAM (a disintegrin and metalloproteinase) peptides are membrane-bound proteins that can act as cell-to-cell and cell-to-matrix adhesion molecules, degrade the extracellular matrix, and play a role in tissue morphogenesis. Addition of antisense (AS) S-oligonucleotides for ADAM8 (1-10 nM) to mouse bone marrow cultures treated with 10(-9) M 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] significantly inhibited OCL formation compared with treatment with the control S-oligonucleotide. Furthermore, conditioned media from 293 cells transiently transfected with a secretable form of the ADAM8 cDNA increased OCL formation in a dose-dependent manner. In addition, treatment of OCLs with soluble ADAM8 conditioned media significantly increased pit formation per dentin slice compared with control OCLs. Time course studies indicated that ADAM8 increased OCL formation only when it was present during days 4-7 of the 7-day culture period. Structural analysis, using truncated constructs of ADAM8, showed that the cysteine-rich/disintegrin domain was responsible for its OCL stimulatory activity. Western blot analysis confirmed that the soluble form of ADAM8 is present in normal marrow cultures. These data suggest that ADAM8 plays an important role in OCL formation and acts primarily at the later stages of OCL differentiation.

Transfection of a differentiated human hepatoma cell line (Huh7) with in vitro-transcribed hepatitis C virus (HCV) RNA and establishment of a long-term culture persistently infected with HCV

T7 RNA polymerase transcripts of a putative full-length cDNA clone of hepatitis C virus type 1 (HCV-1) were used to transfect a differentiated human hepatoma cell line, Huh7. The transfected genome replicated in cells, as evidenced by the appearance of progeny HCV RNA, detection of negative-strand viral RNA, and incorporation of [3H]uridine into the viral genome. Incubation of naive Huh7 cells with conditioned medium from transfected cells resulted in a new HCV infection, suggesting the production of biologically active virus in the inoculum. Maintenance of the transfected cells under serum-free culture conditions resulted in the selection of persistently infected cells which displayed a distinctive cellular morphology. This is the first demonstration that HCV RNA produced from cloned HCV cDNA is infectious and replication competent. This approach should provide a valuable system for studying HCV replication, persistence, and pathogenicity.

Human hair growth enhancement in vitro by green tea epigallocatechin-3-gallate (EGCG)

Green tea is a popular worldwide beverage, and its potential beneficial effects such as anti-cancer and anti-oxidant properties are believed to be mediated by epigallocatechin-3-gallate (EGCG), a major constituent of polyphenols. Recently, it was reported that EGCG might be useful in the prevention or treatment of androgenetic alopecia by selectively inhibiting 5alpha-reductase activity. However, no report has been issued to date on the effect of EGCG on human hair growth. This study was undertaken to measure the effect of EGCG on hair growth in vitro and to investigate its effect on human dermal papilla cells (DPCs) in vivo and in vitro. EGCG promoted hair growth in hair follicles ex vivo culture and the proliferation of cultured DPCs. The growth stimulation of DPCs by EGCG in vitro may be mediated through the upregulations of phosphorylated Erk and Akt and by an increase in the ratio of Bcl-2/Bax ratio. Similar results were also obtained in in vivo dermal papillae of human scalps. Thus, we suggest that EGCG stimulates human hair growth through these dual proliferative and anti-apoptotic effects on DPCs.

Recombinant expression, biochemical characterization, and biological activities of the human MGSA/gro protein

Melanoma growth stimulatory activity (MGSA) is a mitogenic protein secreted by Hs294T melanoma cells that corresponds to the polypeptide encoded by the human gro gene. The MGSA/gro cDNA has been expressed in mammalian cells and the secreted recombinant factor has been purified. Biochemical and biological characterization shows that the recombinant protein is identical with the natural protein and is devoid of posttranslational glycosylation, sulfation, and phosphorylation. The two C-terminal amino acids are proteolytically removed from the mature recombinant MGSA, indicating a length of 71 instead of the predicted 73 amino acids. The recombinant MGSA is mitogenically active on the Hs294T melanoma cells. The purified MGSA competes with interleukin 8 for binding to neutrophil receptors and exhibits neutrophil chemotactic activity equivalent to that of interleukin 8.

Overexpression of and RNA interference with the CCAAT enhancer-binding protein on long-term facilitation of Aplysia sensory to motor synapses

In the marine mollusk Aplysia, the CCAAT/enhancer-binding protein, ApC/EBP, serves as an immediate early gene in the consolidation of long-term facilitation in the synaptic connection between the sensory and motor neurons of the gill-withdrawal reflex. To further examine the role of ApC/EBP as a molecular switch of a stable form of long-term memory, we cloned the full-length coding regions of two alternatively spliced forms, the short and long form of ApC/EBP. Overexpression of each isoform by DNA microinjection resulted in a l6-fold increase in the expression of the coinjected luciferase reporter gene driven by an ERE promoter. In addition, when we overexpressed ApC/EBP in Aplysia sensory neurons, we found that the application of a single pulse of 5-HT that normally induced only short-term facilitation now induced long-term facilitation. Conversely, when we attempted to block the synthesis of native ApC/EBP by microinjecting double-strand RNA or antisense RNA, we blocked long-term facilitation in a sequence-specific manner. These data support the idea that ApC/EBP is both necessary and sufficient to consolidate short-term memory into long-term memory. Furthermore, our results suggest that this double-strand RNA interference provides a powerful tool in the study of the genes functioning in learning and memory in Aplysia by specifically inhibiting both the constitutive and induced expression of the genes.