Tag Archives: meclofenoxate

br Introduction Hepatitis C Virus HCV affects more than million

Introduction
Hepatitis C Virus (HCV) affects more than 170 million people worldwide, or 3% of the world population (Perz et al., 2006), with 4 million new cases and more than 300,000 deaths per year (Bukh, 2012). Clinical conditions of the disease range from an asymptomatic carrier state to persistent infections. Of those individuals infected, 70% will develop chronic HCV infections, and 20% of chronic infections will progress to cirrhosis and terminal hepatocellular carcinoma (Bradley, 2000; Lauer and Walker, 2001; Seeff, 2002; Hoofnagle, 1997). There are currently no vaccines available to the public to prevent HCV due to the high genetic variability of the virus and its ability to escape host immune defenses (Di Lorenzo et al., 2011).
The current standard of care (SOC) treatments may include a combination of pegylated interferon-α and ribavirin (Christie and Chapman, 1999) and direct acting antivirals such as Sofosbuvir and Simeprevir (Belousova et al., 2015). The drug combination has unfavorable side effects and may ultimately lead to drug resistance and relapse. One of the main reasons may be attributed to the generation of quasispecies genome meclofenoxate common for HCV infections, a phenomenon that results in infection by a swarm of microvariants derived from a predominant “master sequence” within an individual host (Bukh et al., 1995). Quasispecies are more prominent in the setting of persistent infections and may be responsible for drug treatment failures (Farci et al., 2000; Domingo and Gomez, 2007). Quasispecies result from the high error rate of the non-proofreading HCV RNA-dependent RNA polymerase (RdRp) leading to continuous production of mutated virus sequences which is one mechanism the virus employs to escape immune system defense (Carmichael, 2002). This warrants a continued intensive search for alternative antiviral approaches to combating HCV.
HCV is a plus-strand RNA virus of the Hepacivirus genus, having a 9600 nt long genome encoding a single ORF flanked by highly conserved 5′ and 3′ untranslated regions (UTRs) (Takamizawa et al., 1991). The ORF encodes a single polyprotein that is modified post-translationally by both cellular and viral proteases to produce 3 structural (C, E1, E2) and 7 non-structural (p7, NS2, NS3, NS4A, NS4B, NS5A, and NS5B) proteins (Fauvelle et al., 2013). The 5′ UTR of the viral RNA contains an internal ribosome entry site (IRES) that is highly conserved among most known HCV quasispecies (Brown et al., 1992). The 5′ UTR of HCV facilitates viral replication and mediates cap-independent viral protein translation by acting as a scaffold and recruiting multiple protein factors during the initiation of translation upon early infection (Rosenberg, 2001; Kieft et al., 1999; Friebe and Bartenschlager, 2002). Because the IRES serves a crucial function for viral infection and propagation and is therefore highly conserved, it represents an ideal target for anti-HCV approaches employing nucleic acid homologies such as trans-splicing group I introns (Ryu et al., 2003).
Trans-splicing group I introns derived from the cis-splicing group I intron of Tetrahymena thermophila mediate RNA splicing through two successive transesterification steps (Cech, 1991). First, the intron recognizes a specific uracil on the target RNA during complementary base pairing with the surrounding sequence. The target RNA is then cleaved at that uracil, and the intron-attached 3′ exon is cleaved from the group I intron and appended onto the cleaved target RNA to create a product RNA. If that product is capable of translation it will express a new protein encoded by the sequence of the 3′ exon (Long et al., 2003). Group I introns have been used successfully in a number of anti-viral applications including targeting of Dengue Fever virus (Carter et al., 2010), HCV (Ryu et al., 2003), and HIV (Kohler et al., 1999) genomes, and in posttranscriptional gene manipulations including the restoration of wild-type p53 activity in three cancerous cell lines (Shin et al., 2004) and the repair of sickle β-globin mRNAs in erythrocyte precursors (Lan et al., 1998).

Secretion of adipokines was related to

Secretion of adipokines was related to BCS, indicating that body condition impacts secretion of adipokines in healthy dogs. The effect of BCS on adipokine secretion was similar in visceral and subcutaneous fat, as indicated by the lack of interaction between fat depot and BCS. Various processes that occur within the adipose tissue as it expands may affect the production and secretion of adipokines. Reduction in adipose tissue PPARγ meclofenoxate has been demonstrated in obese dogs (Gayet et al., 2007). In addition, the number of macrophages increases in adipose tissue in obesity (Weisberg et al., 2003). These changes might result in decreased production of adiponectin by the adipocytes and increased production of TNFα by the adipose tissue macrophages in obesity. Our findings are consistent with previous findings in dogs (Ishioka et al., 2006; Gayet et al., 2007) and humans (Fain et al., 2004a). In contrast, a lack of association between body condition and adipose tissue expression of adiponectin and TNFα was reported by Ryan et al. (2010). Inclusion of dogs within a wider range of body condition in the present study was more likely to reveal present associations. Additional potential explanations for these different findings include those mentioned above.
The inverse relationship between BCS and secretion of IL6 from the SVC in the present study cannot be simply explained in view of the opposite findings for TNFα. Feeding might have an effect on IL6 that could explain these unexpected findings. Acute hyperinsulinemia raised plasma IL6 concentrations in humans and this effect was inversely associated with body mass index (Ruge et al., 2009). A similar effect in the present study could potentially lead to a larger stimulatory postprandial effect on IL6 in dogs with lower BCS, and consequently higher IL6 concentrations. Although the dogs were fasted for 8 h prior to the procedure, a longer fast may be required to avoid a postprandial effect on IL6 secretion. A direct relationship between body condition and IL6 concentrations was reported in human subjects (Vozarova et al., 2001; Browning et al., 2008; Belza et al., 2009). These conflicting findings might be explained by potential species or age differences, as the dogs in the present study were younger relative to the population of human subjects in those previous studies. A lack of association of percent body fat to adipose tissue expression of IL6 was reported in the study by Ryan et al. (2010). A gender effect on the relationship between circulating IL6 concentrations and body fat was reported in human subjects (Popko et al., 2010) and might provide an additional explanation for the different results.
This study showed a differential effect of troglitazone on secretion of adiponectin with a stimulatory effect only in visceral adipose tissue but not in subcutaneous adipose tissue. Troglitazone might have exerted a more potent effect on the visceral adipocytes due to their lower basal expression of PPARγ and the ability of troglitazone to up-regulate this nuclear receptor (Davies et al., 2002). Nevertheless, a potential stimulatory effect in the subcutaneous tissue in dogs cannot be completely ruled out, due to the smaller sample size. Our findings agree with a previous study that reported increased expression of adiponectin in response to rosiglitazone in canine adipocytes differentiated in culture (Ryan et al., 2010). Studies on primary adipocytes culture from humans and rodents and adipocytes cell lines demonstrated similar effects of PPARγ agonists on adiponectin (Motoshima et al., 2002; Bodles et al., 2006; Lorente-Cebrian et al., 2006; Phillips et al., 2008; Tishinsky et al., 2011).
The inhibitory effect of troglitazone on IL6 and TNFα secretion that was demonstrated in the present study might result from activation of PPARγ in the macrophages. Studies on primary adipocytes culture from humans and rodents and adipocytes cell lines demonstrated similar effects of PPARγ agonists on IL6 and TNFα (Jiang et al., 1998; Skurk et al., 2006). These results are also consistent with the reported decreased expression of IL6 and TNFα in canine adipocytes differentiated in culture in response to rosiglitazone###http://www.PRECISIONFDA.ORG/image/1-s2.0-S1871403X15001805-gr1.jpg#### (Ryan et al., 2010). However, in contrast to the findings in the present study, no change in IL6 and TNFα protein secretion was documented in that previous study. This disagreement might be due to a lower dose of the PPARγ agonist used in the previous study compared with the present study. In addition, it might be inherent to the different culture design used in these studies. The previous study used newly-differentiated adipocytes with a much lower baseline secretion of inflammatory cytokines compared to the undifferentiated SVC used in the present study. The higher baseline secretion of inflammatory cytokines by the undifferentiated SVC might be attributed to the presence of resident macrophages that are responsible for most of the secretion of inflammatory cytokines from adipose tissue and are removed from the culture in the process of differentiation (Fain et al., 2004a; Fain, 2006). It might also result from the state of mild inflammation in the undifferentiated SVC due to the recent digestion process (Fain, 2010).