Kallistatin, a new and reliable biomarker for the diagnosis of liver cirrhosis

Role of human Kallistatin in glucose and energy homeostasis in mice

OBJECTIVE

Kallistatin (KST), also known as SERPIN A4, is a circulating, broadly acting human plasma protein with pleiotropic properties. Clinical studies in humans revealed reduced KST levels in obesity. The exact role of KST in glucose and energy homeostasis in the setting of insulin resistance and type 2 diabetes is currently unknown.

METHODS

Kallistatin mRNA expression in human subcutaneous white adipose tissue (sWAT) of 47 people with overweight to obesity of the clinical trial "Comparison of Low Fat and Low Carbohydrate Diets With Respect to Weight Loss and Metabolic Effects (B-SMART)" was measured. Moreover, we studied transgenic mice systemically overexpressing human KST (hKST-TG) and wild type littermate control mice (WT) under normal chow (NCD) and high-fat diet (HFD) conditions.

RESULTS

In sWAT of people with overweight to obesity, KST mRNA increased after diet-induced weight loss. On NCD, we did not observe differences between hKST-TG and WT mice. Under HFD conditions, body weight, body fat and liver fat content did not differ between genotypes. Yet, during intraperitoneal glucose tolerance tests (ipGTT) insulin excursions and HOMA-IR were lower in hKST-TG (4.42 ± 0.87 AU, WT vs. 2.20 ± 0.27 AU, hKST-TG, p < 0.05). Hyperinsulinemic euglycemic clamp studies with tracer-labeled glucose infusion confirmed improved insulin sensitivity by higher glucose infusion rates in hKST-TG mice (31.5 ± 1.78 mg/kg/min, hKST-TG vs. 18.1 ± 1.67 mg/kg/min, WT, p < 0.05). Improved insulin sensitivity was driven by reduced hepatic insulin resistance (clamp hepatic glucose output: 7.7 ± 1.9 mg/kg/min, hKST-TG vs 12.2 ± 0.8 mg/kg/min, WT, p < 0.05), providing evidence for direct insulin sensitizing effects of KST for the first time. Insulin sensitivity was differentially affected in skeletal muscle and adipose tissue. Mechanistically, we observed reduced Wnt signaling in the liver but not in skeletal muscle, which may explain the effect.

CONCLUSIONS

KST expression increases after weight loss in sWAT from people with obesity. Furthermore, human KST ameliorates diet-induced hepatic insulin resistance in mice, while differentially affecting skeletal muscle and adipose tissue insulin sensitivity. Thus, KST may be an interesting, yet challenging, therapeutic target for patients with obesity and insulin resistance.

Elevated Kallistatin promotes the occurrence and progression of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide, and the development of non-alcoholic steatohepatitis (NASH) might cause irreversible hepatic damage. Hyperlipidemia (HLP) is the leading risk factor for NAFLD. This study aims to illuminate the causative contributor and potential mechanism of Kallistatin (KAL) mediating HLP to NAFLD. 221 healthy control and 253 HLP subjects, 62 healthy control and 44 NAFLD subjects were enrolled. The plasma KAL was significantly elevated in HLP subjects, especially in hypertriglyceridemia (HTG) subjects, and positively correlated with liver injury. Further, KAL levels of NAFLD patients were significantly up-regulated. KAL transgenic mice induced hepatic steatosis, inflammation, and fibrosis with time and accelerated inflammation development in high-fat diet (HFD) mice. In contrast, KAL knockout ameliorated steatosis and inflammation in high-fructose diet (HFruD) and methionine and choline-deficient (MCD) diet-induced NAFLD rats. Mechanistically, KAL induced hepatic steatosis and NASH by down-regulating adipose triglyceride lipase (ATGL) and comparative gene identification 58 (CGI-58) by LRP6/Gɑs/PKA/GSK3β pathway through down-regulating peroxisome proliferator-activated receptor γ (PPARγ) and up-regulating kruppel-like factor four (KLF4), respectively. CGI-58 is bound to NF-κB p65 in the cytoplasm, and diminishing CGI-58 facilitated p65 nuclear translocation and TNFα induction. Meanwhile, hepatic CGI-58-overexpress reverses NASH in KAL transgenic mice. Further, free fatty acids up-regulated KAL against thyroid hormone in hepatocytes. Moreover, Fenofibrate, one triglyceride-lowering drug, could reverse hepatic steatosis by down-regulating KAL. These results demonstrate that elevated KAL plays a crucial role in the development of HLP to NAFLD and may be served as a potential preventive and therapeutic target.

Multi-omic identification of key transcriptional regulatory programs during endurance exercise training

Transcription factors (TFs) play a key role in regulating gene expression and responses to stimuli. We conducted an integrated analysis of chromatin accessibility, DNA methylation, and RNA expression across eight rat tissues following endurance exercise training (EET) to map epigenomic changes to transcriptional changes and determine key TFs involved. We uncovered tissue-specific changes and TF motif enrichment across all omic layers, differentially accessible regions (DARs), differentially methylated regions (DMRs), and differentially expressed genes (DEGs). We discovered distinct routes of EET-induced regulation through either epigenomic alterations providing better access for TFs to affect target genes, or via changes in TF expression or activity enabling target gene response. We identified TF motifs enriched among correlated epigenomic and transcriptomic alterations, DEGs correlated with exercise-related phenotypic changes, and EET-induced activity changes of TFs enriched for DEGs among their gene targets. This analysis elucidates the unique transcriptional regulatory mechanisms mediating diverse organ effects of EET.

Extracellular matrix-related and serine protease proteins in the amniotic fluid of women with early preterm labor: Association with spontaneous preterm birth, intra-amniotic inflammation, and microbial invasion of the amniotic cavity

PROBLEM

We aimed to determine whether altered levels of various extracellular matrix (ECM)-related and serine protease proteins in the amniotic fluid (AF) are associated with imminent spontaneous preterm birth (SPTB; ≤7 days) and intra-amniotic inflammation and/or microbial invasion of the amniotic cavity (IAI/MIAC) in women with early preterm labor (PTL).

METHOD OF STUDY

This retrospective cohort study included 252 women with singleton pregnancies undergoing transabdominal amniocentesis who demonstrated PTL (24-31 weeks). The AF was cultured for microorganism detection to characterize MIAC. IL-6 concentrations were determined in the AF samples to identify IAI (≥2.6 ng/mL). The following mediators were measured in the AF samples using ELISA: kallistatin, lumican, MMP-2, SPARC, TGFBI, and uPA.

RESULTS

Kallistatin, MMP-2, TGFBI, and uPA levels were significantly higher and SPARC and lumican levels were significantly lower in the AF of women who spontaneously delivered within 7 days than in the AF of those who delivered after 7 days; the levels of the first five mediators were independent of baseline clinical variables. In the multivariate analysis, elevated levels of kallistatin, MMP-2, TGFBI, and uPA and low levels of lumican and SPARC in the AF were significantly associated with IAI/MIAC and MIAC, even after adjusting for the gestational age at sampling. The areas under the curves of the aforementioned biomarkers ranged from 0.58 to 0.87 for the diagnoses of each of the corresponding endpoints.

CONCLUSION

ECM-related (SPARC, TGFBI, lumican, and MMP-2) and serine protease (kallistatin and uPA) proteins in the AF are involved in preterm parturition and regulation of intra-amniotic inflammatory/infectious responses in PTL.

Lipid and renal profile in assessing the severity of alcoholic liver disease

Lipid and Renal dysfunction in Alcoholic liver disease (ALD) patients occurs either due to multi-organ involvement or secondary to alcoholism. This study was conducted to evaluate the role of lipid and renal parameters in assessing the severity of progression of ALD. Sixty cases of ALD (two groups based on compensated and decompensated features) and thirty healthy controls for comparison were included. Lipid profile (Total Cholesterol, LDL, HDL and Triglycerides) and renal parameters (serum urea, creatinine and uric acid), total and direct bilirubin, total protein and albumin were measured using automated chemistry analyzer. There was a significant decrease in Total cholesterol ,LDL and HDL levels and increased triglycerides when compared to controls (mean of 128.4 ± 59 vs 155 ± 27.2, 77 ± 44.3 vs 97.4 ± 27.2, 28.3 ± 18 vs 39.5 ± 14.1 and 115.8 ± 70.4 vs 91 ± 38 mg/dL respectively). Lipid profile showed a linear decrease while progressing from compensated to decompensated ALD. Renal parameters revealed a statistically significant decrease in serum urea ,increased creatinine and uric acid levels when compared to controls (17.57±2.96 vs23.73±4.94, 1.12±0.55 vs0.88±0.16,6.60±1.32 vs 4.68±1.40 mg/dL respectively).Total cholesterol and HDL showed a linear decrease when ALD progresses. Serum uric acid showed an early increase in compensated stage of ALD. This study inferred that Total cholesterol, TGL, HDL and uric acid can be used for assessing the severity of progression of ALD.

Construction of 2DE Patterns of Plasma Proteins: Aspect of Potential Tumor Markers

The use of tumor markers aids in the early detection of cancer recurrence and prognosis. There is a hope that they might also be useful in screening tests for the early detection of cancer. Here, the question of finding ideal tumor markers, which should be sensitive, specific, and reliable, is an acute issue. Human plasma is one of the most popular samples as it is commonly collected in the clinic and provides noninvasive, rapid analysis for any type of disease including cancer. Many efforts have been applied in searching for “ideal” tumor markers, digging very deep into plasma proteomes. The situation in this area can be improved in two ways—by attempting to find an ideal single tumor marker or by generating panels of different markers. In both cases, proteomics certainly plays a major role. There is a line of evidence that the most abundant, so-called “classical plasma proteins”, may be used to generate a tumor biomarker profile. To be comprehensive these profiles should have information not only about protein levels but also proteoform distribution for each protein. Initially, the profile of these proteins in norm should be generated. In our work, we collected bibliographic information about the connection of cancers with levels of “classical plasma proteins”. Additionally, we presented the proteoform profiles (2DE patterns) of these proteins in norm generated by two-dimensional electrophoresis with mass spectrometry and immunodetection. As a next step, similar profiles representing protein perturbations in plasma produced in the case of different cancers will be generated. Additionally, based on this information, different test systems can be developed.

Biodistribution Profile of Magnetic Nanoparticles in Cirrhosis-Associated Hepatocarcinogenesis in Rats by AC Biosusceptometry

Since magnetic nanoparticles (MNPs) have been used as multifunctional probes to diagnose and treat liver diseases in recent years, this study aimed to assess how the condition of cirrhosis-associated hepatocarcinogenesis alters the biodistribution of hepatic MNPs. Using a real-time image acquisition approach, the distribution profile of MNPs after intravenous administration was monitored using an AC biosusceptometry (ACB) assay. We assessed the biodistribution profile based on the ACB images obtained through selected regions of interest (ROIs) in the heart and liver position according to the anatomical references previously selected. The signals obtained allowed for the quantification of pharmacokinetic parameters, indicating that the uptake of hepatic MNPs is compromised during liver cirrhosis, since scar tissue reduces blood flow through the liver and slows its processing function. Since liver monocytes/macrophages remained constant during the cirrhotic stage, the increased intrahepatic vascular resistance associated with impaired hepatic sinusoidal circulation was considered the potential reason for the change in the distribution of MNPs.

Application of Nanomicelles in Enhancing Bioavailability and Biological Efficacy of Bioactive Nutrients

Nutraceuticals provide many biological benefits besides their basic nutritional value. However, their biological efficacies are often limited by poor absorption and low bioavailability. Nanomaterials have received much attention as potential delivery systems of nutrients and phytonutrients for multiple applications. Nanomicelles are nanosized colloidal structures with a hydrophobic core and hydrophilic shell. Due to their unique characteristics, they have shown great perspectives in food and nutraceutical science. In this review, we discussed the unique properties of nanomicelles. We also emphasized the latest advances on the design of different nanomicelles for efficient delivery and improved bioavailability of various nutrients. The role of nanomicelles in the efficacy improvement of bioactive components from nutraceutical and health foods has been included. Importantly, the safety concerns on nano-processed food products were highlighted.

Plasma E-selectin and kallistatin as predictive markers of histologic chorioamnionitis in women with preterm premature rupture of membranes

PROBLEM

We aimed to assess the predictive potential of 12 plasma biomarkers to predict acute histologic chorioamnionitis (HCA) in women with preterm premature rupture of membranes (PPROM) and to develop multi-biomarker panels based on these biomarkers in combination with widely used conventional laboratory markers.

METHOD OF STUDY

This was a retrospective cohort study involving 81 singleton pregnant women (24-34 weeks of gestation) who delivered within 96 h of blood sampling. White blood cell (WBC) count, differential counts, and C-reactive protein (CRP) levels were measured at admission. The levels of DKK-3, Fas, haptoglobin, IGFBP-2, kallistatin, MIP-1α, MMP-2, MMP-8, pentraxin 3, progranulin, E-selectin, and P-selectin were evaluated by ELISA using stored plasma samples. The primary outcome measure was acute HCA.

RESULTS

Multivariate analyses showed that low plasma E-selectin and kallistatin levels were independently associated with HCA occurrence after adjusting for gestational age. Using a stepwise regression analysis, a multi-biomarker panel comprising plasma E-selectin, serum CRP, and WBC was developed, which provided a good prediction of acute HCA in women with PPROM (area under the curve [AUC], 0.899), with a significantly higher AUC than that of any single variable included in the panel (P<0.05). The plasma levels of DKK-3, Fas, haptoglobin, IGFBP-2, MIP-1α, MMP-2, MMP-8, pentraxin 3, and P-selectin were not significantly associated with HCA occurrence.

CONCLUSIONS

This study identified E-selectin and kallistatin as potential plasma biomarkers associated with acute HCA in women with PPROM. Their combined analysis with serum CRP and WBC counts significantly improved acute HCA diagnosis. This article is protected by copyright. All rights reserved.

Serum kallistatin level is decreased in women with preeclampsia

OBJECTIVES

To evaluate the serum levels of the serine proteinase inhibitor kallistatin in women with preeclampsia (PE).

METHODS

The clinical and laboratory parameters of 55 consecutive women with early-onset PE (EOPE) and 55 consecutive women with late-onset PE (LOPE) were compared with 110 consecutive gestational age (GA)-matched (±1 week) pregnant women with an uncomplicated pregnancy and an appropriate for gestational age fetus.

RESULTS

Mean serum kallistatin was significantly lower in women with PE compared to the GA-matched-controls (27.74±8.29 ng/mL vs. 37.86±20.64 ng/mL, p<0.001); in women with EOPE compared to that of women in the control group GA-matched for EOPE (24.85±6.65 ng/mL vs. 33.37±17.46 ng/mL, p=0.002); and in women with LOPE compared to that of women in the control group GA-matched for LOPE (30.87±8.81 ng/mL vs. 42.25±22.67 ng/mL, p=0.002). Mean serum kallistatin was significantly lower in women with EOPE compared to LOPE (24.85±6.65 ng/mL vs. 30.87±8.81 ng/mL, p<0.001). Serum kallistatin had negative correlations with systolic and diastolic blood pressure, creatinine, and positive correlation with GA at sampling and GA at birth.

CONCLUSIONS

Serum kallistatin levels are decreased in preeclamptic pregnancies compared to the GA-matched-controls. This decrease was also significant in women with EOPE compared to LOPE. Serum kallistatin had negative correlation with systolic and diastolic blood pressure, creatinine and positive correlation with GA at sampling and GA at birth.

Kallistatin correlates with inflammation in abdominal aortic aneurysm and suppresses its formation in mice

Background

Kallistatin (KS), encoded by SERPINA4, was suggested to play a protective role in many cardiovascular diseases. However, its role in the pathogenesis of abdominal aortic aneurysm (AAA) remains unclear. The aim of this study was to examine the potential association of KS with AAA pathogenesis.

Methods

We examined KS (SERPINA4) expression in human AAA by PCR, immunohistochemistry, western blotting, and enzyme-linked immunosorbent assay (ELISA) and analyzed correlations between kallistain and clinical data. We then analyzed the effect of recombinant KS on AAA formation and the Wingless (Wnt) signaling pathway in a mouse AAA model developed by angiotensin II (AngII) infusion to apolipoprotein E-deficient (ApoE^-/-) mice.

Results

In AAA tissue samples, KS was significantly increased compared with samples from the control group (P<0.001, P<0.001, respectively). Clinically, decreased SERPINA4 expression in AAA tissue samples represented an increased rate of iliac artery aneurysm [odds ratio (OR): 0.017; P=0.040]. And decreased plasma KS level represented a high risk for rupture (OR: 0.837; P=0.034). KS inhibited AAA formation and blocked the Wnt signaling pathway in AngII-infused ApoE^-/- mice.

Conclusions

The present study demonstrates that aberrant changes in KS expression occur in AAA. KS plays an important anti-inflammatory role and showed important clinical correlations in AAA. Decreased KS (SERPINA4) level is a risk factor of AAA rupture. Our pre-clinical animal experiments indicate that treatment with recombination KS suppresses AngII-induced aortic aneurysm formation and might be a new target for the drug therapy of AAA.

Targeted delivery of hyaluronic acid nanomicelles to hepatic stellate cells in hepatic fibrosis rats

Hepatic fibrosis is one kind of liver diseases with a high mortality rate and incidence. The activation and proliferation of hepatic stellate cells (HSCs) is the most fundamental reason of hepatic fibrosis. There are no specific and effective drug delivery carriers for the treatment of hepatic fibrosis at present. We found that when hepatic fibrosis occurs, the expression of CD44 receptors on the surface of HSCs is significantly increased. Based on this finding, we designed silibinin-loaded hyaluronic acid (SLB-HA) micelles to achieve the treatment of hepatic fibrosis. Meanwhile, we constructed liver fibrosis rat model using Sprague–Dawley rats. We demonstrated that HA micelles had specific uptake to HSCs in vitro while avoiding the distribution in normal liver cells and the phagocytosis of macrophages. Importantly, HA micelles showed a significant liver targeting effect in vivo, especially in fibrotic liver which highly expressed CD44 receptors. In addition, SLB-HA micelles could selectively kill activated HSCs, having an excellent anti-hepatic fibrosis effect in vivo and a significant sustained release effect, and also had a good biological safety and biocompatibility. Overall, HA micelles represented a novel nanomicelle system which showed great potentiality in anti-hepatic fibrosis drugs delivery.

Kallistatin inhibits tumour progression and platinum resistance in high-grade serous ovarian cancer

Ovarian cancer is the most lethal gynaecologic malignancy. Although there are various subtypes of ovarian cancer, high-grade serous ovarian cancer (HGSOC) accounts for 70% of ovarian cancer deaths. Chemoresistance is the primary reason for the unfavourable prognosis of HGSOC. Kallistatin (KAL), also known as SERPINA4, is part of the serpin family. Kallistatin has been discovered to exert multiple effects on angiogenesis, inflammation and tumour progression. However, the roles and clinical significance of kallistatin in HGSOC remain unclear. Here, we showed that kallistatin was significantly downregulated in HGSOC compared to normal fallopian tube (FT) tissues. Low expression of kallistatin was associated with unfavourable prognosis and platinum resistance in HGSOC. Overexpression of kallistatin significantly inhibited proliferation and metastasis, and enhanced platinum sensitivity and apoptosis in ovarian cancer cells. Collectively, these findings demonstrate that kallistatin serves as a prognostic predictor and provide a potential therapeutic target for HGSOC.

Reduced Plasma Kallistatin Is Associated With the Severity of Coronary Artery Disease, and Kallistatin Treatment Attenuates Atherosclerotic Plaque Formation in Mice

Background Kallistatin exerts beneficial effects on organ injury by inhibiting oxidative stress and inflammation. However, the role of kallistatin in atherosclerosis is largely unknown. Here, we investigated the role and mechanisms of kallistatin in patients with coronary artery disease ( CAD ), atherosclerotic plaques of apoE-/- mice, and endothelial activation. Methods and Results Plasma kallistatin levels were analyzed in 453 patients at different stages of CAD . Kallistatin levels were significantly lower in patients with CAD and negatively associated with CAD severity and oxidative stress. Human kallistatin cDNA in an adenoviral vector was injected intravenously into apoE-/- mice after partial carotid ligation, with or without nitric oxide synthase inhibitor (Nω-nitro-L-arginine methyl ester) or sirtuin 1 inhibitor (nicotinamide). Kallistatin gene delivery significantly reduced macrophage deposition, oxidative stress, and plaque volume in the carotid artery, compared with control adenoviral injection. Kallistatin administration increased endothelial nitrous oxide synthase, sirtuin 1, interleukin-10, superoxide dismutase 2, and catalase expression in carotid plaques. The beneficial effects of kallistatin in mice were mitigated by Nω-nitro-L-arginine methyl ester or nicotinamide. Furthermore, human kallistatin protein suppressed tumor necrosis factor-α-induced NADPH oxidase activity and increased endothelial nitrous oxide synthase and sirtuin 1 expression in cultured human endothelial cells. These effects were also abolished by Nω-nitro-L-arginine methyl ester or nicotinamide. Conclusions This was the first study to demonstrate that reduced plasma kallistatin levels in patients are associated with CAD severity and oxidative stress. Kallistatin treatment prevents carotid atherosclerotic plaque formation in mice by stimulating the sirtuin 1/endothelial nitrous oxide synthase pathway. These findings indicate the potential protective effects of kallistatin on atherosclerosis in human subjects and mouse models.

Novel protective role of kallistatin in obesity by limiting adipose tissue low grade inflammation and oxidative stress

OBJECTIVE

Kallistatin plays an important role in the inhibition of inflammation, oxidative stress, fibrosis and angiogenesis. We aimed to determine the impact of kallistatin on obesity and its associated metabolic alterations as well as its role in adipocyte inflammation and oxidative stress.

METHODS

Samples obtained from 95 subjects were used in a case-control study. Circulating concentrations and expression levels of kallistatin as well as key inflammation, oxidative stress and extracellular matrix remodelling-related genes were analyzed. Circulating kallistatin concentrations were measured before and after weight loss achieved by Roux-en-Y gastric bypass (RYGB). The impact of kallistatin on lipopolysaccharide (LPS)- and tumour necrosis factor (TNF)-α-mediated inflammatory as well as oxidative stress signalling pathways was evaluated.

RESULTS

We show that the reduced (P < 0.00001) circulating levels of kallistatin in obese patients increased (P < 0.00001) after RYGB. Moreover, gene expression levels of SERPINA4, the gene coding for kallistatin, were downregulated (P < 0.01) in the liver from obese subjects with non-alcoholic fatty liver disease. Additionally, we revealed that kallistatin reduced (P < 0.05) the expression of inflammation-related genes (CCL2, IL1B, IL6, IL8, TNFA, TGFB) and, conversely, upregulated (P < 0.05) mRNA levels of ADIPOQ and KLF4 in human adipocytes in culture. Kallistatin inhibited (P < 0.05) LPS- and TNF-α-induced inflammation in human adipocytes via downregulating the expression and secretion of key inflammatory markers. Furthermore, kallistatin also blocked (P < 0.05) TNF-α-mediated lipid peroxidation as well as NOX2 and HIF1A expression while stimulating (P < 0.05) the expression of SIRT1 and FOXO1.

CONCLUSIONS

These findings provide, for the first time, evidence of a novel role of kallistatin in obesity and its associated comorbidities by limiting adipose tissue inflammation and oxidative stress.

Lower serum kallistatin level is associated with 28-day mortality in patients with septic shock

PURPOSE

Investigation for whether serum levels of kallistatin, vascular cell adhesion molecule-1 (VCAM-1), and E-selectin are associated with outcomes in patients with septic shock MATERIAL AND METHODS: Biomarker levels were measured using blood samples from patients with septic shock at admission, 24 h, and 72 h and from healthy volunteers. The primary outcome was 28-day mortality.

RESULTS

Fifty-eight survivors, fourteen non-survivors, and six healthy volunteers were enrolled. Serum kallistatin level was lower and serum VCAM-1 and E-selectin levels were higher in patients at admission compared with healthy volunteers. Serum kallistatin levels were higher in survivors compared with non-survivors at all time points (4.4 μg/mL [2.9-6.1] vs. 2.5 μg/mL [2.1-5.0], P = 0.019 at admission; 4.3 μg/mL [3.3-5.2] vs. 3.2 μg/mL [2.2-3.8], P = 0.004 at 24 h; 3.1 μg/mL [2.5-4.2] vs. 2.3 μg/mL [1.7-3.1], P = 0.012 at 72 h), while VCAM-1 and E-selectin levels showed no difference. In the multivariable analysis, serum kallistatin level at 24 h was independently associated with 28-day mortality (OR, 0.29; 95% CI, 0.08-0.69, P = 0.024).

CONCLUSIONS

Lower serum kallistatin level at 24 h was independently associated with 28-day mortality in patients with septic shock.

Liver fibrosis: a compilation on the biomarkers status and their significance during disease progression

Liver fibrosis occurs in response to different etiologies of chronic liver injury. Diagnosing degree of liver fibrosis is a crucial step in evaluation of severity of the disease. An invasive liver biopsy is the gold standard method associated with pain and complications. Biomarkers to detect liver fibrosis include direct markers of extracellular matrix turnover and indirect markers as a reflection of liver dysfunction. Although a single marker may not be useful for successful management, a mathematical equation combining tests might be effective. The main purpose of this review is to understand the diagnostic accuracy of biomarkers and scoring systems for liver fibrosis. Advances in -omics approach have generated clinically significant biomarker candidates for liver fibrosis that need further evaluation.

Cirrhosis of liver: Interference of serpins in quantification of SERPINA4 - A preliminary study

BACKGROUND

Cirrhosis of liver is a pathological condition, wherein functions of liver are impaired by chronic liver exploitations. Due to decrease in synthetic capacity, expressions of plasma proteins tend to decrease in blood stream. Serpins (Serine protease inhibitors) are class of plasma proteins expressed from liver with structural similarities and diverse functions. SERPINA4 (Kallistatin) is a multifunctional serpin clade A protein expressed from liver and concentration in serum is the reflection of extent of liver dysfunction.

OBJECTIVE

To identify interference of other serpins by immunological cross reactivity with SERPINA4 in cirrhotic liver and healthy subjects.

MATERIALS AND METHODS

Blood samples were collected from 20 subjects (10 cirrhotic liver, 10 healthy) from R.L. Jalappa Hospital and Research Centre, Kolar, Karnataka, India. Separation of proteins was carried out by SDS-PAGE. Cross reactivity study was analyzed using western blot.

RESULTS

Proteins present in cirrhotic liver and healthy subject's serum were separated by SDS PAGE. There was no band detection on both (cirrhotic liver and healthy) PVDF (polyvinylidene diflouride) membranes. However, a significant band was observed with recombinant kallistatin.

CONCLUSION

Structurally similar serpins with minor amino acid sequence similarities did not show any immunological cross reactivity with SERPINA4 due to non identical epitope in cirrhotic liver and healthy subjects. Present study revealed that there is no interference of serpins for immunological reactions in quantitative estimation of kallistatin which needs further validation.

Kallistatin: double-edged role in angiogenesis, apoptosis and oxidative stress

Kallistatin, via its two structural elements – an active site and a heparin-binding domain – displays a double-edged function in angiogenesis, apoptosis and oxidative stress. First, kallistatin has both anti-angiogenic and pro-angiogenic effects. Kallistatin treatment attenuates angiogenesis and tumor growth in cancer-bearing mice. Kallistatin via its heparin-binding site inhibits angiogenesis by blocking vascular endothelial growth factor (VEGF)-induced growth, migration and adhesion of endothelial cells. Conversely, kallistatin via the active site promotes neovascularization by stimulating VEGF levels in endothelial progenitor cells. Second, kallistatin inhibits or induces apoptosis depending on cell types. Kallistatin attenuates organ injury and apoptosis in animal models, and its heparin-binding site is essential for blocking tumor necrosis factor (TNF)-α-induced apoptosis in endothelial cells. However, kallistatin via its active site induces apoptosis in breast cancer cells by up-regulating miR-34a and down-regulating miR-21 and miR-203 synthesis. Third, kallistatin can act as an antioxidant or pro-oxidant. Kallistatin treatment inhibits oxidative stress and tissue damage in animal models and cultured cells. Kallistatin via the heparin-binding domain antagonizes TNF-α-induced oxidative stress, whereas its active site is crucial for stimulating antioxidant enzyme expression. In contrast, kallistatin provokes oxidant formation, leading to blood pressure reduction and bacterial killing. Kallistatin-mediated vasodilation is partly mediated by H2O2, as the effect is abolished by the antioxidant enzyme catalase. Moreover, kallistatin exerts a bactericidal effect by stimulating superoxide production in neutrophils of mice with microbial infection as well as in cultured immune cells. Thus, kallistatin’s dual roles in angiogenesis, apoptosis and oxidative stress contribute to its beneficial effects in various diseases.

Plasma kallistatin in critically ill patients with severe sepsis and septic shock

Kallistatin, an endogenous serine proteinase inhibitor, is protective against sepsis in animal models. The aim of this study was to determine the plasma concentration of kallistatin in intensive care unit (ICU) patients with severe sepsis and septic shock and to determine their potential correlation with disease severity and outcomes. We enrolled 86 ICU patients with severe sepsis and septic shock. Their plasma concentrations of kallistatin, kallikrein, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-8 were measured by enzyme-linked immunosorbent assay. The association of kallistatin levels with disease severity and patient outcomes was evaluated. The relationship between kallistatin and other biomarkers was also analyzed. Plasma kallistatin levels on day 1 of ICU admission were lower in patients with septic shock compared with patients with severe sepsis (p = 0.004). Twenty-nine patients who died in the hospital had significantly lower day 1 kallistatin levels than patients who survived (p = 0.031). Using the optimal cutoff value (4 μg/ml) of day 1 plasma kallistatin determined by receiver operating characteristic curves for 60-day mortality, we found that high kallistatin levels were associated with a preferable 60-day survival (p = 0.012) by Kaplan-Meier analysis and lower Sequential Organ Failure Assessment (SOFA) scores over the first 5 days in the ICU (p = 0.001). High kallistatin levels were also independently associated with a decreased risk of septic shock, the development of acute respiratory distress syndrome, and positive blood cultures. In addition, there were inverse correlations between day 1 kallistatin levels and the levels of TNF-α, IL-1β, IL-6, and C-reactive protein, and SOFA scores on day 1. Our results indicate that during severe sepsis and septic shock, a decrease in plasma concentrations of kallistatin reflects increased severity and poorer outcome of disease.

Kallistatin suppresses cancer development by multi-factorial actions

Kallistatin was first identified in human plasma as a tissue kallikrein-binding protein and a serine proteinase inhibitor. Kallistatin via its two structural elements regulates differential signaling cascades, and thus a wide spectrum of biological functions. Kallistatin's active site is essential for: inhibiting tissue kallikrein's activity; stimulating endothelial nitric oxide synthase and sirtuin 1 expression and activation; and modulating the synthesis of the microRNAs, miR-34a, miR-21 and miR-203. Kallistatin's heparin-binding site is crucial for antagonizing the signaling pathways of vascular endothelial growth factor, tumor necrosis factor-α, Wnt, transforming growth factor-β and epidermal growth factor. Circulating kallistatin levels are markedly reduced in patients with prostate and colon cancer. Kallistatin administration attenuates angiogenesis, inflammation, tumor growth and invasion in animal models and cultured cells. Therefore, tumor progression may be substantially suppressed by kallistatin's pleiotropic activities. In this review, we will discuss the role and mechanisms of kallistatin in the regulation of cancer development.

Clinical diagnostics and therapy monitoring in the congenital disorders of glycosylation

Abnormal protein glycosylation is observed in many common disorders like cancer, inflammation, Alzheimer’s disease and diabetes. However, the actual use of this information in clinical diagnostics is still very limited. Information is usually derived from analysis of total serum N-glycan profiling methods, whereas the current use of glycoprotein biomarkers in the clinical setting is commonly based on protein levels. It can be envisioned that combining protein levels and their glycan isoforms would increase specificity for early diagnosis and therapy monitoring. To establish diagnostic assays, based on the mass spectrometric analysis of protein-specific glycosylation abnormalities, still many technical improvements have to be made. In addition, clinical validation is equally important as well as an understanding of the genetic and environmental factors that determine the protein-specific glycosylation abnormalities. Important lessons can be learned from the group of monogenic disorders in the glycosylation pathway, the Congenital Disorders of Glycosylation (CDG). Now that more and more genetic defects are being unraveled, we start to learn how genetic factors influence glycomics profiles of individual and total serum proteins. Although only in its initial stages, such studies suggest the importance to establish diagnostic assays for protein-specific glycosylation profiling, and the need to look beyond the single glycoprotein diagnostic test. Here, we review progress in and lessons from genetic disease, and review the increasing opportunities of mass spectrometry to analyze protein glycosylation in the clinical diagnostic setting. Furthermore, we will discuss the possibilities to expand current CDG diagnostics and how this can be used to approach glycoprotein biomarkers for more common diseases.