Development of Liver Fibrosis Represented by the Fibrosis-4 Index Is a Specific Risk Factor for Tubular Injury in Individuals with Type 2 Diabetes.

Although hyperglycemia and hypertension are well-known risk factors for glomerular injury in individuals with type 2 diabetes (T2D), specific risk factors for tubular injury remain unclear. We aimed to clarify the differences between risk factors for glomerular injury and risk factors for tubular injury in individuals with T2D. We categorized 1243 subjects into four groups based on urinary biomarkers, including the albumin-to-creatinine ratio (uACR) and L-type fatty acid-binding protein-to-creatinine ratio (uL-ABPCR) as a normal (N) group (uACR < 30 mg/gCr and uL-FABPCR < 5 µg/gCr; n = 637), a glomerular specific injury (G) group (uACR ≥ 30 mg/gCr and uL-FABPCR < 5 µg/gCr; n = 248), a tubular specific injury (T) group (uACR < 30 mg/gCr and uL-FABPCR ≥ 5 µg/gCr; n = 90), and a dual injury (D) group (uACR ≥ 30 mg/gCr and uL-FABPCR ≥ 5 µg/gCr; n = 268). Logistic regression analysis referencing the N group revealed that BMI, current smoking, and hypertension were risk factors for the G group, creatinine (Cr) and Fibrosis-4 (FIB-4) index were risk factors for the T group, and BMI, hypertension, HbA1c, Cr, and duration of diabetes were risk factors for the D group. While hypertension was a distinct specific risk factor for glomerular injury, the FIB-4 index was a specific contributor to the prevalence of tubular injury. On the other hand, the logistic regression analysis revealed that the hepatic steatosis index (HSI) did not show any significant association with the G group, T group, or D group. Taken together, the development of liver fibrosis rather than liver steatosis is an inherent threat relating to tubular injury in individuals with T2D.

Plasma Heparin Cofactor II Activity Is Inversely Associated with Hepatic Fibrosis of Non-Alcoholic Fatty Liver Disease in Patients with Type 2 Diabetes Mellitus.

AIMS: Thrombin exerts various pathophysiological functions by activating protease-activated receptors (PARs), and thrombin-induced activation of PARs promotes the development of non-alcoholic fatty liver disease (NAFLD). Since heparin cofactor II (HCII) specifically inactivates thrombin action, we hypothesized that plasma HCII activity correlates with the severity of NAFLD. METHODS: A cross-sectional study was conducted. Plasma HCII activity and noninvasive clinical markers of hepatic fibrosis including fibrosis-4 (FIB-4) index, NAFLD fibrosis score (NFS) and aspartate aminotransferase-to-platelet ratio index (APRI) were determined in 305 Japanese patients with type 2 diabetes mellitus (T2DM). The relationships between plasma HCII activity and the clinical markers were statistically evaluated. RESULTS: Multiple regression analysis including confounding factors showed that plasma HCII activity independently contributed to decreases in FIB-4 index (p＜0.001), NFS (p＜0.001) and APRI (p=0.004). In addition, logistic regression analysis for the prevalence of advanced hepatic fibrosis defined by the cutoff points of the clinical scores showed that plasma HCII activity was the sole and common negative factor for prevalence of advanced hepatic fibrosis (FIB-4 index: p=0.002, NFS: p=0.026 and APRI: p=0.012). CONCLUSIONS: Plasma HCII activity was inversely associated with clinical hepatic fibrosis indices including FIB-4 index, NFS and APRI and with the prevalence of advanced hepatic fibrosis in patients with T2DM. The results suggest that HCII can serve as a novel biomarker for assessment of hepatic fibrosis of NAFLD in patients with T2DM.

Plasma heparin cofactor II activity is inversely associated with albuminuria and its annual deterioration in patients with diabetes.

AIMS/INTRODUCTION: Thrombin exerts various pathophysiological functions by activating protease-activated receptors (PARs). Recent data have shown that PARs influence the development of glomerular diseases including diabetic kidney disease (DKD) by regulating inflammation. Heparin cofactor II (HCII) specifically inactivates thrombin; thus, we hypothesized that low plasma HCII activity correlates with DKD development, as represented by albuminuria. MATERIALS AND METHODS: Plasma HCII activity and spot urine biomarkers, including albumin and liver-type fatty acid-binding protein (L-FABP), were determined as the urine albumin-to-creatinine ratio (uACR) and the urine L-FABP-to-creatinine ratio (uL-FABPCR) in 310 Japanese patients with diabetes mellitus (176 males and 134 females). The relationships between plasma HCII activities and those DKD urine biomarkers were statistically evaluated. In addition, the relationship between plasma HCII activities and annual uACR changes was statistically evaluated for 201/310 patients (115 males and 86 females). RESULTS: The mean plasma HCII activity of all participants was 93.8 ± 17.7%. Multivariate-regression analysis including confounding factors showed that plasma HCII activity independently contributed to the suppression of the uACR and log-transformed uACR values (P = 0.036 and P = 0.006, respectively) but not uL-FABPCR (P = 0.541). In addition, plasma HCII activity significantly and inversely correlated with annual uACR and log-transformed uACR increments after adjusting for confounding factors (P = 0.001 and P = 0.014, respectively). CONCLUSIONS: The plasma HCII activity was inversely and specifically associated with glomerular injury in patients with diabetes. The results suggest that HCII can serve as a novel predictive factor for early-stage DKD development, as represented by albuminuria.

Human pituitary adenomas infrequently contain inactivation of retinoblastoma 1 gene and activation of cyclin dependent kinase 4 gene.

Components of cyclinD1/cyclin-dependent kinase 4 (CDK4)/p16INK4a/pRb pathway are the frequent target of many tumor types. We examined the role of retinoblastoma susceptibility gene (RB1) and the CDK4 gene in human pituitary tumorigenesis. For the RB1 gene, pRb expression and loss of heterozygosity (LOH) on 13q in pituitary adenomas were analysed. Immunostaining of pRb revealed lack of expression in 1 of 29 pituitary adenomas. In 4 of 31 pituitary adenomas, allelic imbalances including LOH of RB1 on 13q14 were detected. Three of 4 pituitary adenomas, in which one adenoma lacked pRb expression, had a common LOH region at least from D13S219 on 13q12.3-q13 to D13S265 on 13q31-32. Interphase fluorescence in situ hybridization with a probe of RB1 showed 2 copies of RB1 gene suggesting that mitotic recombination events, not deletion or chromosome loss, led to LOH in the 3 pituitary adenomas analyzed. All 27 exons, intron-exon boundaries, and essential promoter region of RB1 gene were then sequenced in genomic DNA from 4 pituitary adenomas with allelic imbalance on 13q14 including one adenoma without pRb expression and 3 adenomas with pRb expression. Any somatic mutations, insertions, or microdeletions in the RB1 gene were not detected in 4 pituitary adenomas. Methylation sensitive (MS)-polymerase chain reaction (PCR) and bisulfite sequencing analysis revealed hypomethylated status of CpG islands in the promoter region of the RB1 genes of 4 pituitary adenomas. In addition, activating mutations of CDK4 gene, which is a component of cyclinD1/CDK4/p16INK4a/pRb pathway, were not detected in 31 pituitary adenomas. Based on these results, it is concluded that somatic mutations of the RB1 gene or CDK4 gene do not appear to play a major role in pituitary tumorigenesis. This supports the presence of potential tumor suppressor gene(s) on 13q12.3-q13 to 13q31-32 in pituitary adenomas.