Usefulness of Mac-2 binding protein glycosylation isomer in noninvasive probing liver disease in the Vietnamese population

BACKGROUND Early diagnosis is critical for successful intervention before liver disease progresses to cirrhosis and hepatocellular carcinoma.AIM To examine a novel biomarker for probing early liver disease quickly using an automated immunology system.METHODS This was a cross-sectional study.140 patients at various stages of liver disease were randomly selected.The cohort consisted of patients who were treatment naïve and currently undergoing therapy.We included patients with diverse liver disease etiologies.Mac-2 binding protein glycosylation isomer(M2BPGi)levels in addition to different clinical parameters,co-morbidities and transient elastography results were collected and compared.RESULTS M2BPGi levels were significantly correlated with transient elastography for liver fibrosis staging across all disease etiologies.Statistically significant differences were observed in patients with F0-1;F2 and>F3 liver fibrosis.Further examination showed that M2BPGi levels were two-fold higher in F4 than F3 hepatitis C(HCV)patients.M2BPGi was observed to be etiology-specific and HCV patients had higher mean M2BPGi levels.We also observed significant correlations with aspartate aminotransferase to platelet ratio index and fibrosis-4 index as well as HBV DNA levels.Mean M2BPGi levels for HBV patients with a viral load lower than 2000 IU/mL was 1.75-fold lower than those with a viral load greater than 2000 IU/mL.CONCLUSION M2BPGi was observed to be a good indicator of early liver disease in patients with different etiologies.Our results provide reference cut-offs for different causes of liver disease and demonstrated the utility of this marker for early disease monitoring.This is useful for remote regions in developing countries.

Pre-sarcopenia and Mac-2 binding protein glycosylation isomer as predictors of recurrence and prognosis of early-stage hepatocellular carcinoma

BACKGROUND The Mac-2 binding protein glycosylation isomer(M2BPGi),a fibrosis marker in various liver diseases,is reportedly a prognostic marker in patients with hepatocellular carcinoma(HCC)who underwent hepatectomy.AIM To evaluate whether the M2BPGi value,M2BP,and pre-sarcopenia before radiofrequency ablation(RFA)could be useful recurrence and prognostic markers in patients with early-stage HCC.METHODS In total,160 patients with early-stage primary HCC treated with RFA were separately analyzed as hepatitis C virus(HCV)-positive and HCV-negative.Factors contributing to recurrence and liver-related death,including M2BP,M2BPGi,and skeletal muscle mass index,were statistically analyzed.Eighty-three patients were HCV-positive and 77 were HCV-negative.RESULTS In HCV-positive patients,only des-γ-carboxy-prothrombin≥23 mAU/mL was a significant poor prognostic factor affecting survival after RFA.In HCV-negative patients,M2BPGi≥1.86 cutoff index was significantly associated with tumor recurrence,while M2BP was not.M2BPGi≥1.86 cutoff index(hazard ratio,4.89;95%confidence interval:1.97-12.18;P<0.001)and pre-sarcopenia(hazard ratio,3.34,95%confidence interval:1.19-9.37;P=0.022)were independent significant poor prognostic factors in HCV-negative patients.CONCLUSION In HCV-negative patients with primary HCC treated with RFA,lower M2BPGi contributed to a lower tumor recurrence rate and longer survival period.Pre-sarcopenia contributed to the poor prognosis independently in HCV-negative patients.These factors might be useful recurrence and prognostic markers for early-stage primary HCC.

Glycosylation of dentin matrix protein 1 is a novel key element for astrocyte maturation and BBB integrity

The blood-brain barrier （BBB） is a tight boundary formed between endothelial cells and astrocytes, which separates and protects brain from most pathogens as well as neural toxins in circulation. However, detailed molecular players involved in formation of BBB are not completely known. Dentin matrix protein I （DMP1）-proteoglycan （PG）, which is known to be involved in mineralization of bones and dentin, is also expressed in soft tissues including brain with unknown functions. In the present study, we reported that DMPI-PG was expressed in brain astrocytes and enriched in BBB units. The only glycosylation site of DMP1 is serine89 （S89） in the N-terminal domain of the protein in mouse. Mutant mice with DMP1 point mutations changing S89 to glycine （S89G）, which completely eradicated glycosylation of the protein, demonstrated severe BBB disruption. Another breed of DMP1 mutant mice, which lacked the C-terminal domain of DMP1, manifested normal BBB function. The polarity of S89G-DMP1 astrocytes was disrupted and cell-cell adhesion was loosened. Through a battery of analyses, we found that DMP1 glycosylation was critically required for astrocyte maturation both in vitro and in vivo. S89G-DMP1 mutant astrocytes failed to express aquaporin 4 and had reduced laminin and ZO1 expression, which resulted in disruption of BBB. Interestingly, overexpression of wild-type DMP1-PG in mouse brain driven by the nestin promoter elevated laminin and ZO1 expression beyond wild type levels and could effectively resisted intravenous mannitol-induced BBB reversible opening. Taken together, our study not only revealed a novel element, i.e., DMP1-PG, that reg- ulated BBB formation, but also assigned a new function to DMP1-PG.

Advanced glycosylation end products, protein kinase C and renal alterations in diabetic rats

To study the relationship between advanced glycosylation end products (AGE) and protein kinase C (PKC), and their effects on renal alteration in diabetic rats Methods Insulin or aminoguanidine was administered to diabetic rats Blood glucose, hemoglobin A 1C (HbA 1C ), glomerular tissue extracts AGE (GTE AGE), PKC, glomerular basement membrane thickness (GBMT) and urine protein/creatinine (Pr/Cr) ratio in diabetic rats were measured and analysed Results Levels of blood glucose, HbA 1C and AGE, PKC activity, the Pr/Cr ratio and GBMT were all significantly increased ( P values all less than 0 01) in diabetic rats Insulin could decrease the formation of HbA 1C and AGE, and improve PKC activity Aminoguanidine had no influence on PKC activity ( P >0 05) although it decreased the formation of AGE Both drugs could delay the increase of urine Pr/Cr ratio and GBMT ( P <0 05 or P <0 01) Conclusions Chronic hyperglycemia may lead to an increase of PKC activity HbA 1C and AGE may not directly contribute to alterations of PKC activity, but the increase of PKC activity could promote the action of AGE on GBM thickening It is important to inhibit the formation of AGE and reduce the PKC activity so as to prevent or delay the development of diabetic nephropathy