Identification of a wide spectrum of ciliary gene mutations in nonsyndromic biliary atresia patients implicates ciliary dysfunction as a novel disease mechanism

Background: Biliary atresia (BA) is the most common obstructive cholangiopathy in neonates, often progressing to end-stage cirrhosis. BA pathogenesis is believed to be multifactorial, but the genetic contribution, especially for nonsyndromic BA (common form: > 85%) remains poorly defined. Methods: We conducted whole exome sequencing on 89 nonsyndromic BA trios to identify rare variants contributing to BA etiology. Functional evaluation using patients’ liver biopsies, human cell and zebrafish models were performed. Clinical impact on respiratory system was assessed with clinical evaluation, nasal nitric oxide (nNO), high speed video analysis and transmission electron microscopy. Findings: We detected rare, deleterious de novo or biallelic variants in liver-expressed ciliary genes in 31.5% (28/89) of the BA patients. Burden test revealed 2.6-fold (odds ratio (OR) [95% confidence intervals (CI)]= 2.58 [1.15–6.07], adjusted p = 0.034) over-representation of rare, deleterious mutations in liver-expressed ciliary gene set in patients compared to controls. Functional analyses further demonstrated absence of cilia in the BA livers with KIF3B and TTC17 mutations, and knockdown of PCNT, KIF3B and TTC17 in human control fibroblasts and cholangiocytes resulted in reduced number of cilia. Additionally, CRISPR/Cas9-engineered zebrafish knockouts of KIF3B, PCNT and TTC17 displayed reduced biliary flow. Abnormally low level of nNO was detected in 80% (8/10) of BA patients carrying deleterious ciliary mutations, implicating the intrinsic ciliary defects. Interpretation: Our findings support strong genetic susceptibility for nonsyndromic BA. Ciliary gene mutations leading to cholangiocyte cilia malformation and dysfunction could be a key biological mechanism in BA pathogenesis. Funding: The study is supported by General Research Fund, HMRF Commissioned Paediatric Research at HKCH and Li Ka Shing Faculty of Medicine Enhanced New Staff Start-up Fund

Leptin-adiponectin ratio in pre-diabetic patients undergoing percutaneous coronary intervention

BACKGROUND: The obesity-related hormones leptin and adiponectin are independently and oppositely associated with insulin resistance, which is an important risk factor for coronary artery disease (CAD) and restenosis after coronary intervention. In this report, we set out to determine the role of the leptin-adiponectin ratio (LAR) in non-diabetic patients with or without impaired glucose tolerance undergoing a percutaneous coronary intervention. METHODS: 300 PCI patients were enrolled in this prospective single-centre study. Patients with known diagnosis of diabetes (n = 50) and newly diagnosed diabetes (2h OGTT > 200 mg/dL, n = 25) were excluded. In both stable and acute subjects, assessment was done on the day of discharge and included a fasting glucose level, leptin, adiponectin and an oral glucose tolerance test (OGTT). RESULTS: LAR was significantly higher in diabetic (7.2 ± 0.7) than in non-diabetic patients (3.9 ± 0.3, P = 0.001), and even higher in newly diagnosed diabetics (9.8 ± 1.5, P < 0.001). Likewise, among non-diabetic patients, LAR was significantly higher in patients with impaired glucose tolerance. LAR was significantly higher in pre-diabetic (4.57 ± 0.48) versus normoglycaemic patients (3.45 ± 0.33, P = 0.05). LAR was found to be numerically higher in pre-diabetic versus normoglycaemic patients with two- and three-vessel disease (VD), but not in patients with single VD. In pre-diabetic patients, LAR was found to be significantly increased with more advanced CAD (P = 0.021), independent of stable versus unstable presentation. CONCLUSIONS: LAR is related to the extent of CAD in pre-diabetic patients but not in normoglycaemic patients. This finding might in part explain the poorer outcome in revascularized patients with impaired glucose tolerance compared to normoglycaemic patients.status: publishe

Phytochemical investigation of the leaves of tetracera scandens Linn and in vitro antidiabetic activity of hypoletin

Tetracera scandens Linn. (Dilleniaceae), locally known as Mempelas Kasar, is traditionally used in folk remedies by various indigenous people in different countries including Malaysia for the treatment of rheumatism, inflammatory diseases, hepatitis, internal pains, urinary disorders, dysentery, sore throat, gout and diabetes infirmities; for lowering hypertension; and for child birth. In this study, phytochemical analysis of T. scandens leaf methanol (MeOH) extract was carried out for the first time and afforded three terpenoids (stigmasterol, betulinic acid and an isomeric mixture of sitosterol (∆5) glycoside and stigmasterol (∆5,22) glycoside) and six flavonoids (namely, kaempferol, quercetin, isoscutellarein, hypoletin, astragalin and kaempferol-3-O-(6″-O-p-trans-coumaroyl) glucoside, a rare compound which has been isolated for the first time from family Dilleniaceae). Structures of all compounds were elucidated through extensive UV–Vis, mass, IR and NMR spectral analysis. The occurrence of all these compounds is being reported for the first time from this plant. Due to the rare occurrence of hypoletin (3′,4′,5,7,8-pentahydroxyflavone) in plants, its in vitro antidiabetic effect was explored. Hence, the treatment of hypoletin in a dose-dependent manner was examined on the induction of lipid accumulation by using Oil Red O staining and glucose regulation in 3T3-L1 adipocytes in vitro with regard to its preventive role in the management of diabetes. After 8 days, morphological changes and high lipid accumulation activity were observed in cells treated with 10 μg/mL of hypoletin concentration (P < 0.01). In addition, the intracellular fat accumulation increased by up to 79.7 % relative to MDI-treated control cells at a dose of 10 μg/mL. Furthermore, insulin-induced 2-deoxy-d-[3H] glucose uptake was significantly increased (P < 0.001) in hypoletin-treated cells as compared to control (DMSO cells). Our results suggest that hypoletin could be useful for the management of type 2 diabetes due to its adipocyte stimulation and glucose uptake activity