Effect of genipin on cholestasis induced by estradiol‐17β‐glucuronide and lithocholate‐3‐O‐glucuornide in rats

Aim: Genipin is reported to stimulate the insertion of multidrug resistance protein 2 (Mrp2) in the bile canalicular membrane, thereby causing choleresis by the increased the biliary excretion of glutathione, which has been considered to be a substrate of Mrp2. In the present study, we examined the effect of genipin on cholestasis induced by estradiol‐17β‐glucuronide and lithocholate‐3‐O‐glucuronide, Mrp2 substrates, in rats. Further, the effect of genipin on the biliary excretion of substrates of P‐glycoprotein (P‐gp), vinblastine and erythromycin, was also studied. Methods: The effect of genipin infusion at the rate of 0.5 µmol/min/100 g on cholestasis induced by estradiol‐17β‐glucuronide (0.075 µmol/min/100 g for 20 min) and lithocholate‐3‐O‐glucuronide (0.15 µmol/min/100 g for 40 min) was studied. The effect of genipin infusion on the biliary excretion of a tracer dose of vinblastine and erythromycin infused at the rate of 0.1 µmol/min/100 g was also studied. Results: Genipin relieved estradiol‐17β‐glucuronide‐induced cholestasis, and cumulative biliary estradiol‐17β‐glucuronide excretion for 120 min was increased from 50 ± 20%–81 ± 20% dose. In contrast, genipin had no effect on lithocholate‐3‐O‐glucuronide‐induced cholestasis. Biliary excretion of a tracer dose of vinblastine and the maximum biliary excretion of erythromycin were significantly decreased by genipin. Conclusions: Genipin protected estradiol‐17β‐glucuronide‐induced cholestasis. The mechanism of the protection of cholestasis by genipin is unknown, but it is speculated to be due to a conformational change of P‐gp by genipin, in addition to the stimulation of Mrp2 insertion into the bile canaliculi.     

Structure‐oriented review of 14‐3‐3 protein isoforms in geriatric neuroscience

This review focuses on the possible relevance of 14‐3‐3 proteins in geriatric neuroscience. 14‐3‐3 proteins are mainly localized in the synapses and neuronal cytoplasm. These proteins regulate intracellular signal cascades for differentiation, development, growth, apoptosis and survival. Seven isoforms have so far been identified in mammals. The binding motifs and potential functions of 14‐3‐3 proteins are now recognized to have a wide range of functional relevance. First, we provide a brief summary of the molecular structure and multiple functions of 14‐3‐3 proteins. Second, we review the involvement of 14‐3‐3 proteins in common diseases of geriatric neurology, such as Alzheimer's disease and tauopathies, Parkinson's disease and α‐synucleinopathies, Huntington's disease and polyglutamine diseases, Creutzfeldt–Jakob disease and prion diseases, cerebral infarction, and atherosclerosis. Finally, we discuss the immunohistochemical localization of 14‐3‐3 proteins and its isoforms during the postnatal development of rat brains as a basis for understanding adult neurogenesis. The elucidation of the isoform‐dependent functions of 14‐3‐3 proteins with regard to brain development might be promising for the future development of novel therapeutic interventions for common diseases of geriatric neurology. Geriatr Gerontol Int 2012; ??: ??–??.     

Effect of peroxisome proliferator‐activated receptors‐γ and co‐activator‐1α genetic polymorphisms on plasma adiponectin levels and susceptibility of non‐alcoholic fatty liver disease in Chinese people

Background/Aims: Peroxisome proliferator‐activated receptors‐γ (PPAR‐γ) and its co‐activator‐1α (PGC‐1α) are involved in the regulation of lipid and glucose metabolisms. This study aimed to investigate the genetic polymorphisms of PPAR‐γ and PGC‐1α in Chinese people and their influence on plasma adiponectin levels and non‐alcoholic fatty liver disease (NAFLD) susceptibility. Methods: Ninety‐six patients with NAFLD and 96 healthy controls were included. The single nucleotide polymorphisms (SNPs) of C161T PPAR‐γand Gly482Ser PGC‐1α genes were analysed by polymerase chain reaction and restriction fragment length polymorphism. Result: The CC, CT and TT genotypic distributions of the NAFLD group were significantly different from those of controls (55.2, 39.6, 5.2 vs. 74.0, 25.0, 1.0%; P=0.015). The allelic frequencies of C and T were also different between the two groups (P=0.004). As for the PGC‐1α gene, there was no difference of the genotypic and allelic frequencies between the two groups (P>0.05). In NAFLD patients, the plasma adiponectin concentrations were lower in the PPAR‐γ CT/TT genotypes compared with those in the CC genotype group (3.0±0.6 vs. 4.3±0.9, P=0.02). Multivariate logistic regression analysis showed that CT/TT genotypes of PPAR‐γ, TG, waist hip ratio, hypoadiponectinaemia and homoeostasis model assessment (HOMA)‐IR were the risk factors for NAFLD. Conclusion: SNPs in the PPAR‐γ, but not PGC‐1α, gene are associated with NAFLD susceptibility possibly through the adiponectin pathway.     

Clinical significance of half‐lives of tumor markers α‐fetoprotein and des‐γ‐carboxy prothrombin after hepatectomy for hepatocellular carcinoma

Aim

The prognostic significance of the half‐lives (HLs) of α‐fetoprotein (AFP) and des‐γ‐carboxy prothrombin (DCP) in patients undergoing hepatectomy for hepatocellular carcinoma (HCC) is unclear. We evaluated the HLs of AFP and DCP in a cohort of such patients.

Methods

This study included data on 202 patients with HCC who underwent curative hepatectomy and had preoperative AFP concentrations ≥100 ng/mL or DCP ≥200 mAU/mL. We calculated the HLs of AFP and DCP from their values just before and 1 month after hepatectomy. We identified three groups: a normalization group, tumor marker concentrations within normal range 1 month post‐hepatectomy; a long group, HL of AFP ≥7 days or DCP ≥4 days; and a short group, remaining patients. We evaluated associations between HL and prognosis.

Results

Three‐year recurrence‐free survival (RFS) in the normalization (n = 70), short (n = 71), and long groups (n = 61) was 41.3%, 46.0%, and 16.8%, respectively (P = 0.002). Five‐year overall survival (OS) of normalization, short, and long groups was 72.6, 70.6 and 43.8%, respectively (P = 0.002). Multivariate analysis revealed that long HL is an independent risk factor for poor RFS (hazard ratio [HR] 2.21, P = 0.0006) and poor OS (HR 2.70, P = 0.004). The extrahepatic recurrence rate was 21.3% (13/61) in the long group, which is higher than in the normalization group (8.6%, 6/70) (P = 0.04) and short group (9.9%, 7/71) (P = 0.07).

Conclusion

Post‐hepatectomy HLs of AFP and DCP are predictors of long‐term outcome in patients with HCC.     

Induction of interferon‐λ contributes to Toll‐like receptor‐3‐activated hepatic stellate cell–mediated hepatitis C virus inhibition in hepatocytes

There is limited information about the role of hepatic stellate cells (HSC) in liver innate immunity against hepatitis C virus (HCV). We thus examined whether HSC can produce antiviral factors that inhibit HCV replication in human hepatocytes. HSC expressed functional Toll‐like receptor 3 (TLR‐3), which could be activated by its ligand, polyinosine‐polycytidylic acid (poly I:C), leading to the induction of interferon‐λ (IFN‐λ) at both mRNA and protein levels. TLR‐3 signalling of HSC also induced the expression of IFN regulatory factor 7 (IRF‐7), a key regulator of IFN signalling pathway. When HCV JFH‐1‐infected Huh7 cells were co‐cultured with HSC activated with poly I:C or incubated in media conditioned with supernatant (SN) from poly I:C‐activated HSC, HCV replication was significantly suppressed. This HSC SN action on HCV inhibition was mediated through IFN‐λ, which was evidenced by the observation that antibody to IFN‐λ receptors could neutralize the HSC‐mediated anti‐HCV effect. The role of IFN‐λ in HSC‐mediated anti‐HCV activity is further supported by the observation that HSC SN treatment induced the expression of IRF‐7 and IFN‐stimulated genes (ISGs), OAS‐1 and MxA in HCV‐infected Huh7 cells. These observations indicate that HSC may be a key regulatory bystander, participating in liver innate immunity against HCV infection using an IFN‐λ‐dependent mechanism.     

Prevalence of allo‐immunization anti‐HLA and anti‐integrin αIIbβ3 in Glanzmann Thromboasthenia patients

Summary. Platelet transfusions, main therapy of Glanzmann Thromboasthenia (GT), can induce an allo‐immunization against human leucocyte antigen and integrin αIIbβ3. We have investigated in our GT patients the rate of allo‐immunization and of refractoriness to platelet transfusions. From 1975 until December 2005, we have followed 17 GT patients: 14 type 1, 3 variant type; nine females, eight males; median age at diagnosis 9.8 years (range 1–44.5); median age at the time of the study 35.5 years (range 23.6–68.5). In our patients, 121 bleeding episodes occurred (24 severe, 37 moderate, and 60 mild). Ten major and 22 minor surgical procedures have been performed. Two spontaneous deliveries and three caesarian sections with five live births were performed; moreover, one late foetal loss occurred, and one voluntary abortion was performed. Sixteen of 17 patients have been transfused at least once in life with platelets and/or red blood cells (RBC). All transfused patients have been investigated for the presence of anti‐HLA and anti‐integrin αIIbβ3 allo‐antibodies. The positiveness of allo‐antibodies has been demonstrated in 4/16 transfused patients (25%): isolated for anti‐HLA in two; isolated for anti‐integrin αIIbβ3 in one; and combined in one. In spite of the presence of allo‐antibodies, platelet transfusions have always been effective and the haemostasis was not compromised.