Characterization of renal biomarkers for use in clinical trials: effect of preanalytical processing and qualification using samples from subjects with diabetes

Trefoil factor 3 can stimulate Th17 cell response in the development of type 2 diabetes mellitus

This study aims to evaluate the role of trefoil factor 3 (TFF3) peptides in type 2 diabetes mellitus (T2DM) from an inflammatory perspective. The focus was on exploring how TFF3 affects the function of T cells. TFF3 overexpression model was constructed using lentivirus in Jurkat cell lines. We evaluated the impact of TFF3 on the proliferation, apoptosis, and IL-17A levels of Jurkat cells cultured in high glucose. The T2DM model was induced in TFF3 knockout (KO) mice through streptozotocin combined with high-fat diet. The measurements included glucose tolerance, insulin tolerance, inflammation markers, Th17 cell proportion, and pancreatic pathological changes. The T2DM modeling led to splenomegaly in mice, and increased expression of TFF3 in their spleens. Overexpression of TFF3 increased the proportion of IL-17+ T cells and the levels of Th17-related cytokines in Jurkat cells. There was no difference in body weight and blood glucose levels between wild-type and TFF3 KO mice. However, T2DM mice lacking the TFF3 gene showed improved glucose utilization, ameliorated pancreatic pathology, decreased inflammation levels, and reduced Th17 cell ratio. TFF3 may be involved in the chronic inflammatory immune response in T2DM. Its mechanism may be related to the regulation of the RORγt/IL-17 signaling pathway and its impact on T cell proliferation and apoptosis.

Trefoil factor 3: New highlights in chronic kidney disease research

Trefoil factor 3 (TFF3, also known as intestinal trefoil factor) is a small-molecule peptide containing a typical trefoil structure. TFF3 has several biological effects, such as wound healing, immune regulation, neuroprotection, and cell migration and proliferation promotion. Although TFF3 binding sites were identified in rat kidneys more than a decade ago, the specific effects of this small-molecule peptide on kidneys remain unclear. Until recently, much of the research on TFF3 in the kidney field has focused exclusively on its role as a biomarker. Notably, a large prospective randomized study of patients with 29 common clinical diseases revealed that chronic kidney disease (CKD) was associated with the highest serum TFF3 levels, which were 3-fold higher than in acute gastroenteritis, which had the second-highest levels. Examination of each stage of CKD revealed that urine and serum TFF3 levels significantly increased with the progression of CKD. These results suggest that the role of TFF3 in CKD needs further research. The present review summarizes the renal physiological expression, biological functions, and downstream signaling of TFF3, as well as the upstream events that lead to high expression of TFF3 in CKD.

Pathological and therapeutic roles of bioactive peptide trefoil factor 3 in diverse diseases: recent progress and perspective

Trefoil factor 3 (TFF3) is the last small-molecule peptide found in the trefoil factor family, which is mainly secreted by intestinal goblet cells and exerts mucosal repair effect in the gastrointestinal tract. Emerging evidence indicated that the TFF3 expression profile and biological effects changed significantly in pathological states such as cancer, colitis, gastric ulcer, diabetes mellitus, non-alcoholic fatty liver disease, and nervous system disease. More importantly, mucosal protection would no longer be the only effect of TFF3, it gradually exhibits carcinogenic activity and potential regulatory effect of nervous and endocrine systems, but the inner mechanisms remain unclear. Understanding the molecular function of TFF3 in specific diseases might provide a new insight for the clinical development of novel therapeutic strategies. This review provides an up-to-date overview of the pathological effects of TFF3 in different disease and discusses the binding proteins, signaling pathways, and clinical application.

Toxicologic Pathology Forum Opinion Paper*: Recommendations for a Tiered Approach to Nonclinical Mechanistic Nephrotoxicity Evaluation

Nephrotoxicity is one of the more common causes of attrition in nonclinical drug development. Like most tissues, the kidney has a limited number of ways of responding to toxicological insults from diverse mechanistic pathways, which can limit the ability to determine mechanisms of renal injury using the assays routinely performed in preclinical toxicologic studies. In situations where the renal injury is unusual in morphology or if a therapeutic margin is low, additional investigative techniques may be needed to identify a potential mechanism of toxicity in order to inform clinical risk assessment or establish human relevance and translatability of the toxicity. While routine microscopic evaluation can suggest a specific pathogenesis, understanding the mechanism of renal injury often requires additional hypothesis-driven investigations and specialized techniques to obtain the data necessary to identify a nephrotoxic mechanism. Nonclinical mechanistic investigations can be resource-intensive and often yield limited new information. Although there are multiple avenues to investigate renal toxicity, no single mechanistic study or prescriptive battery of tests will identify the pathophysiologic basis for every potential mechanism of renal injury. To aid the nonclinical investigator, we outline a tiered approach for prioritizing investigations to provide a rational and linear road map for the exploration of mechanisms of drug-induced kidney injury.

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Comparative validation of a microcapsule-based immunoassay for the detection of proteins and nucleic acids

To detect and study diseases, research and clinical laboratories must quantify specific biomarkers in the plasma and urine of patients with precision, sensitivity, and cost-effectiveness. Newly developed techniques, such as particle-based immunoassays, must be validated in these terms against standard methods such as enzyme-linked immunosorbent assays (ELISAs). Here, we compare the performance of assays that use hollow polyelectrolyte microcapsules with assays based on solid plastic beads, and with standard microplate immunoassays. The polyelectrolyte microcapsules detect the disease biomarker beta-2 microglobulin with a fifty-fold increase in sensitivity than polystyrene (PS) beads. For sequence-specific nucleic acid detection, the oligonucleotide-coated microcapsules exhibit a two-fold lower increase in sensitivity over PS beads. The microcapsules also detect the presence of a monoclonal antibody in hybridoma supernatant at a fifty-six-fold increase in sensitivity compared to a microplate assay. Overall, polyelectrolyte microcapsule-based assays are more sensitive for the detection of protein and nucleic acid analytes than PS beads and microplate assays, and they are viable alternatives as a platform for the rapid quantitative detection of analytes at very low concentrations.

The Promise of Systems Biology for Diabetic Kidney Disease

Diabetic kidney disease (DKD) has a complex and prolonged pathogenesis involving many cell types in the kidney as well as extrarenal factors. It is clinically silent for many years after the onset of diabetes and usually progresses over decades. Given this complexity, a comprehensive and unbiased molecular approach is best suited to help identify the most critical mechanisms responsible for progression of DKD and those most suited for targeted intervention. Systems biological investigations provide such an approach since they examine the entire network of molecular changes that occur in a disease process in a comprehensive way instead of focusing on a single abnormal molecule or pathway. Systems biological studies can also start with analysis of the disease in humans, not in animal or cell culture models that often poorly reproduce the changes in human DKD. Indeed, in the last decade, systems biological approaches have led to the identification of critical molecular abnormalities in DKD and have directly led to development of new biomarkers and potential treatments for DKD.

The ZDSD rat: a novel model of diabetic nephropathy

The ZDSD rat is a new obese-diabetic rat model that expresses type 2 diabetes in the presence of an intact leptin pathway. During a long pre-diabetic state, the animals exhibit most of the features of metabolic syndrome including obesity, hyperlipidemia, hypertension, insulin resistance and decreased glucose disposal. The animals used in these studies were either allowed to become spontaneously diabetic at 16-30 weeks of age, or diabetes was induced with a diabetogenic diet. In the presence of either spontaneous or diet-induced diabetes, they develop progressive albuminuria as well as increases in other urinary markers of impaired renal function (kidney injury molecule-1 (KIM-1), β2-microglobulin, clusterin and cystatin C). Typical morphological changes of nephropathy, such as glomerular capillary basement membrane thickening and podocyte effacement, accompany these marker increases. Lisinopril (ACEi) treatment (30 mg/kg/day via the diet) dramatically reduced diabetes-induced albuminuria by 85%, independent of the duration of diabetes or the initial albumin excretion. These results position the ZDSD rat as a relevant model of diabetic nephropathy that can be treated with clinically effective compounds.

Osteopontin as a discriminating marker for pancreatic cancer and chronic pancreatitis

INTRODUCTION

We analyzed concentrations of osteopontin (OPN) in patients with pancreatic ductal adenocarcinoma (PDAC) in order to determine firstly whether it is useful to distinguish between PDAC patients and those with chronic non-hereditary pancreatitis (CP) and type 2 diabetes mellitus (T2DM), and secondly whether OPN concentrations depend on the PDAC stage.

METHODS

Groups consisting of 64 patients with PDAC, 71 with CP, 67 with T2DM and 48 healthy controls (CON) were enrolled in the study. Controls were compared with regard to levels of OPN, oxidative stress markers, conventional tumor markers and other biochemical parameters.

RESULTS

Levels of OPN were higher in patients with PDAC compared with CP patients (P< 0.001), T2DM (P< 0.001) and CON (P< 0.001). There were increased OPN levels in CP patients in comparison with T2DM (P< 0.001) and CON (P< 0.001). Patients with PDAC in stage IV had higher OPN levels than PDAC patients in stage III (P< 0.01). There was no difference in OPN levels of PDAC patients in stage III compared to patients in stage II.

CONCLUSION

Our pilot study demonstrates the usefulness of estimating OPN levels to differentiate between pancreatic cancer and chronic pancreatitis. Higher OPN levels over 102 ng/ml could be a potential diagnostic biomarker for pancreatic cancer.

Interpreting and Integrating Clinical and Anatomic Pathology Results

The continuing education course on integrating clinical and anatomical pathology data was designed to communicate the importance of using a weight of evidence approach to interpret safety findings in toxicology studies. This approach is necessary, as neither clinical nor anatomic pathology data can be relied upon in isolation to fully understand the relationship between study findings and the test article. Basic principles for correlating anatomic pathology and clinical pathology findings and for integrating these with other study end points were reviewed. To highlight these relationships, a series of case examples, presented jointly by a clinical pathologist and an anatomic pathologist, were used to illustrate the collaborative effort required between clinical and anatomical pathologists. In addition, the diagnostic utility of traditional liver biomarkers was discussed using results from a meta-analysis of rat hepatobiliary marker and histopathology data. This discussion also included examples of traditional and novel liver and renal biomarker data implementation in nonclinical toxicology studies to illustrate the relationship between discrete changes in biochemistry and tissue morphology.

Urinary Markers of Tubular Injury in Early Diabetic Nephropathy

Diabetic nephropathy (DN) is a common and serious complication of diabetes associated with adverse outcomes of renal failure, cardiovascular disease, and premature mortality. Early and accurate identification of DN is therefore of critical importance to improve patient outcomes. Albuminuria, a marker of glomerular involvement in early renal damage, cannot always detect early DN. Thus, more sensitive and specific markers in addition to albuminuria are needed to predict the early onset and progression of DN. Tubular injury, as shown by the detection of tubular injury markers in the urine, is a critical component of the early course of DN. These urinary tubular markers may increase in diabetic patients, even before diagnosis of microalbuminuria representing early markers of normoalbuminuric DN. In this review we summarized some new and important urinary markers of tubular injury, such as neutrophil gelatinase associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), liver-type fatty acid binding protein (L-FABP), N-acetyl-beta-glucosaminidase (NAG), alpha-1 microglobulin (A1M), beta 2-microglobulin (B2-M), and retinol binding protein (RBP) associated with early DN.