Plasma and urine levels of urinary trypsin inhibitor in patients with chronic liver diseases and hepatocellular carcinoma

Urinary biomarkers for hepatocellular carcinoma: current knowledge for clinicians

Hepatocellular carcinoma (HCC) is the most predominant primary liver cancer, causing many illnesses and deaths worldwide. The insidious clinical presentation, difficulty in early diagnosis, and the highly malignant nature make the prognosis of HCC extremely poor. The complex and heterogeneous pathogenesis of HCC poses significant challenges to developing therapies. Urine-based biomarkers for HCC, including diagnostic, prognostic, and monitoring markers, may be valuable supplements to current tools such as serum α-fetoprotein (AFP) and seem promising for progress in precision medicine. Herein, we reviewed the major urinary biomarkers for HCC and assessed their potential for clinical application. Molecular types, testing platforms, and methods for building multimolecule models in the included studies have shown great diversity, thus providing abundant novel tools for future clinical transformation and applications.

Molecular and pathobiological insights of bikunin/UTI in cancer

Bikunin is a small chondroitin sulfate proteoglycan (PG) with Ser-protease inhibitory activity that plays pleiotropic roles in health and disease. It is involved in several physiological processes including stabilization of the extracellular matrix (ECM) of connective tissues and key reproductive events. Bikunin is also implicated in both acute and chronic inflammatory conditions and represents a non-invasive circulating and/or urinary (as Urinary Trypsin Inhibitor or UTI) biomarker. It exerts inhibitory effects on urokinase-type plasminogen activator (uPA) and its receptor (uPAR) mediating tumor invasiveness by a down-regulation of uPA mRNA expression, thus representing an anti-metastatic agent. However, only limited data on its potential as a diagnostic and/or prognostic marker of cancer have been reported so far. Recent technological advances in mass spectrometry-based proteomics have provided researchers with a huge amount of information allowing for large-scale surveys of the cancer proteome. To address such issues, we analyzed bikunin expression data across several types of tumors, by using UALCAN proteogenomic analysis portal. In this article we critically review the roles of bikunin in human pathobiology, with a special focus on its inhibitory effects and mechanisms in cancer aggressiveness as well as its significance as cancer circulating biomarker.

A Method for Urinary Trypsin Inhibitor (UTI) Purification Combining Anion-Exchange Chromatography Enrichment and Preparative SDS-PAGE

This chapter describes a method for the purification of urinary trypsin inhibitor (UTI), a small chondroitin sulfate proteoglycan with Ser-proteinase inhibitory activity, excreted at high levels into urine following an inflammatory condition. The method consists of two fractionation steps: an anion-exchange chromatography and a sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) followed by Coomassie Brilliant Blue G-250 gel staining. Several UTI bands are excised from gel, minced, destained, and dehydrated for extraction with SDS-containing buffer, at 60 °C for 24 h. This allows for obtaining a highly purified UTI sample useful for both structural and functional studies.

Chemical Synthesis and Anti-Inflammatory Activity of Bikunin Associated Chondroitin Sulfate 24-mer

Bikunin, a chondroitin sulfate (CS) proteoglycan clinically used to treat acute inflammation and sepsis, contains a CS chain with more than 20 monosaccharide units. To understand the function of the CS chain of bikunin, synthesis of long CS chains is needed. After exploring multiple glycosylation approaches and protective group chemistry, we report herein the successful generation of the longest CS chain to date (24-mer) in an excellent overall yield on a multi-mg scale. The anti-inflammatory activities of both bikunin and the synthetic 24-mer were determined, and the results demonstrate that both the glycan and the core protein are important for anti-inflammatory activities of bikunin by reducing macrophage production of proinflammatory cytokines.

Role of the small proteoglycan bikunin in human reproduction

PURPOSE

Female reproductive events, including ovulation, menstruation, implantation, and delivery, are physiologically characterized by deep tissue remodeling and display hallmark signs of inflammation. This review discusses the pleiotropic roles played by bikunin in human reproduction.

METHODS

A comprehensive literature search of the Medline/PubMed database was performed on the following topics: bikunin structure, roles in pathophysiological conditions and involvement in human reproduction, and usefulness as a marker of gestational complications or as a drug to improve pregnancy outcomes.

RESULTS

Bikunin is a small chondroitin sulfate proteoglycan found in blood, urine, and amniotic and cerebrospinal fluids, known for its anti-inflammatory and anti-proteolytic activities. Its levels are usually low, but they can increase several-fold in both acute and chronic inflammatory diseases. Bikunin plays key roles in reproductive events, such as cumulus-oocyte complex formation, pregnancy, and delivery. Its levels have been associated with the most common pregnancy complications such as preterm delivery, pre-eclampsia, and gestational diabetes mellitus. Finally, its intravaginal administration has been reported to reduce the risk of preterm delivery and to improve neonatal outcomes.

CONCLUSIONS

Because of its pleiotropic roles in several reproductive events and its association with some life-threatening pathological conditions of pregnancy, bikunin may represent a non-invasive marker for improving follow-up and early diagnosis. Studies showing its usefulness as a drug for reducing the risk of preterm delivery and improving neonatal outcomes have yielded interesting results that deserve to be investigated through further research.

Levels of Urinary Trypsin Inhibitor and Structure of Its Chondroitin Sulphate Moiety in Type 1 and Type 2 Diabetes

BACKGROUND

Diabetes mellitus is a global health problem representing the fifth leading cause of mortality and a major risk factor for cardiovascular diseases. In the last years, we reported an association among urinary trypsin inhibitor (UTI), a small proteoglycan that plays pleiotropic roles in many inflammatory processes, and both type 1 and 2 diabetes and developed a method for its direct quantitation and structural characterization.

METHODS

Urine from 39 patients affected by type 1 diabetes, 32 patients with type 2 diabetes, and 52 controls were analysed. UTI was separated from the main glycosaminoglycans physiologically present in urine by anion exchange chromatography, treated for chondroitin sulphate (CS) chain complete depolymerisation, and analysed for both UTI content and CS structure. UTI identification was performed by nano-LC-MS/MS analysis.

RESULTS

We evidenced increased UTI levels, as well as reduced sulphation of its CS moiety in association with diabetes, regardless of both age and medium-term glycaemic control. Furthermore, no association between UTI and albumin excretion rate was found.

CONCLUSIONS

Evidences suggest that UTI levels are not directly correlated with renal function or, otherwise, that they may increase before the onset of renal impairment in diabetes, representing a potential marker for the underlying inflammatory condition.

Significance of urinary glycosaminoglycans/proteoglycans in the evaluation of type 1 and type 2 diabetes complications

Because of the high incidence of kidney disease in diabetic patients, the early diagnosis of renal impairment is a key point for intervention and management. Although urinary albumin excretion currently represents the accepted standard to assess both diabetic nephropathy and cardiovascular risk, it has some limitations as structural changes in the glomerular basement membrane may occur before the onset of microalbuminuria. It is therefore important to identify urinary markers that may provide greater sensitivity, earlier detection, and greater predictive power for diabetes complications. In this respect, urinary glycosaminoglycans/proteoglycans (GAGs/PGs) have been long associated with several kidney diseases as well as diabetic nephropathies as their levels increase more readily than albuminuria. In particular, heparan sulfate, a key component of the glomerular basement membrane responsible for its charge-dependent permeability, is excreted into urine at higher concentrations during the early kidney remodeling events caused by the altered glucose metabolism in diabetes. Over the past few years, also urinary trypsin inhibitor has been linked to a chronic inflammatory condition in both type 1 and 2 diabetes. The underlying mechanisms of such increase are not completely known since either a systemic inflammatory condition or a more localized early renal impairment could play a role. Nevertheless, the association with other inflammatory markers and a detailed urinary trypsin inhibitor structural characterization in diabetes remain to be elucidated. This review will discuss a great deal of information on the association between urinary GAGs/PGs and type 1 and 2 diabetes, with particular emphasis on renal involvement, and their potential as markers useful in screening, diagnosis and follow up to be associated with the current standard tests.

Urine bikunin as a marker of renal impairment in Fabry's disease

Fabry's disease is a rare lysosomal storage disorder caused by the deficiency of α-galactosidase A that leads to the accumulation of neutral glycosphingolipids in many organs including kidney, heart, and brain. Since end-stage renal disease represents a major complication of this pathology, the aim of the present work was to evaluate if urinary proteoglycan/glycosaminoglycan excretion could represent a useful marker for monitoring kidney function in these patients at high risk. Quali-quantitative and structural analyses were conducted on plasma and urine from 24 Fabry's patients and 43 control subjects. Patients were sorted for presence and degree of renal impairment (proteinuria/renal damage). Results showed that levels of urine bikunin, also known as urinary trypsin inhibitor (UTI), are significantly higher in patients with renal impairment than in controls. In this respect, no differences were evidenced in plasma chondroitin sulfate isomers level/structure indicating a likely direct kidney involvement. Noteworthy, urine bikunin levels are higher in patients since early symptoms of renal impairment occur (proteinuria). Overall, our findings suggest that urine bikunin level, as well as proteinuria, could represent a useful parameter for monitoring renal function in those patients that do not present any symptoms of renal insufficiency.

Urinary trypsin inhibitor as a therapeutic option for endotoxin-related inflammatory disorders

IMPORTANCE OF THE FIELD

Urinary trypsin inhibitor (UTI), a serine protease inhibitor, has been widely used as a drug for patients with inflammatory disorders such as pancreatitis, shock and disseminated intravascular coagulation (DIC). Previous in vitro studies have demonstrated that serine protease inhibitors may have anti-inflammatory properties at sites of inflammation. However, the therapeutic effects of UTI in vivo remain unclarified, as commercial UTI has been developed to act against humans, with the activity and selectivity toward the relevant animal UTI being less characterized.

AREAS COVERED IN THIS REVIEW

In this review, we introduce the roles of UTI in experimental endotoxin (lipopolysaccharide; LPS)-related inflammatory disorders using UTI-deficient (-/-) and corresponding wild-type mice.

WHAT THE READER WILL GAIN

Our experiments using genetic approach suggest that endogenous UTI can protect against the systemic inflammatory response and subsequent organ injury induced by LPS, at least partly, through the inhibition of pro-inflammatory cytokine and chemokine expression, which provide important in vivo evidence and understanding about a protective role of UTI in inflammatory conditions.

TAKE HOME MESSAGE

Using genetically targeted mice selectively lacking UTI, UTI has been evidenced to provide an attractive 'rescue' therapeutic option for endotoxin-related inflammatory disorders such as DIC, acute lung injury and acute liver injury.

Plasma bikunin as a favorable prognostic factor in ovarian cancer

PURPOSE

Bikunin is a multifunctional glycoprotein, which mediates suppression of tumor cell invasion and metastasis. The measurement of bikunin levels in the tissue of patients with malignant diseases has been introduced as a new and simple diagnostic tool for the evaluation of prognosis. The high bikunin expression in ovarian cancer tissue would enable the use of soluble bikunin protein present in the circulation of ovarian cancer patients as a biomarker of disease.

PATIENTS AND METHODS

We developed a double-antibody immunoassay for bikunin and detected its presence in normal human circulation. We quantified, by enzyme-linked immunosorbent assay and/or immunoblot assay bikunin in sera from 200 healthy women (controls), 200 patients with benign gynecologic diseases, and 327 patients with ovarian cancer before surgical removal of the tumor.

RESULTS

When the values of bikunin corresponding to the median were used as the cutoff value (11.5 microg/mL), low plasma bikunin was strongly associated with late-stage, suboptimal debulking with large residual tumor (> 2 cm) and low response to chemotherapy. The median survival time of the patients with a high bikunin level was more than 60 months as compared with 26 months among those with low bikunin level (P = .002). This difference corresponded to a 2.2-fold increased risk of dying for the lower plasma bikunin patients (hazard ratio, 0.45; P = .023) and remained significant in multivariate analysis (hazard ratio, 0.63; P = .041).

CONCLUSION

Preoperative plasma bikunin concentration is a strong and independent favorable prognostic marker for ovarian cancer.