Circulating Tissue Factor-Positive Procoagulant Microparticles in Patients with Type 1 Diabetes

Phospholipids and their metabolites as diagnostic biomarkers of human diseases

Phospholipids that occur predominantly in the plasma membrane of mammalian cells are phosphatidylcholine (PC), phosphatidylserine (PS), phosphatidylethanolamine (PE), sphingomyelin (SM), and phosphatidylinositol (or phosphoinositide; PI). These membrane phospholipids are a promising source of disease-related biomarkers. Phospholipids and their metabolites are altered by the type of disease or disease progression. Metabolomics has shown that increased or decreased levels of altered phospholipids and their metabolites can be useful indicators for the diagnosis of various human diseases. In this review, we discuss the utility of the five major membrane phospholipids (PC, PS, PE, and SM, and PI) and their metabolites as diagnostic biomarkers of human diseases.

Deposition of platelet-derived microparticles in podocytes contributes to diabetic nephropathy

BACKGROUND

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease in the developed world. Podocyte injury is a critical cellular event involved in the progression of DN. Our previous studies demonstrated that platelet-derived microparticles (PMPs) mediated endothelial injury in diabetic rats. This study aimed to investigate whether PMPs are deposited in podocytes and to assess their potential effects on podocyte injury in DN.

METHODS

The deposition of PMPs in podocytes was assessed by immunofluorescent staining and electron microscopy. The changes in renal pathology and ultra-microstructure were assessed by periodic acid-Schiff staining and electron microscopy, respectively. The expression of inflammatory cytokines and extracellular matrix proteins was measured by immuno-histochemical staining and western blot.

RESULTS

PMPs were widely deposited in podocytes of glomeruli in diabetic patients and animal models and closely associated with DN progression. Interestingly, aspirin treatment significantly inhibited the accumulation of PMPs in the glomeruli of diabetic rats, alleviated mesangial matrix expansion and fusion of foot processes, and decreased the protein expression of inflammatory cytokines and extracellular matrix secretion. An in vitro study further confirmed the deposition of PMPs in podocytes. Moreover, PMP stimulation induced the phenotypic transition of podocytes through decreased podocin protein expression and increased protein expression of α-SMA and fibronectin, which was correlated with increased production of inflammatory cytokines.

CONCLUSION

Our findings demonstrated for the first time that the deposition of PMPs in podocytes contributed to the development of DN.

Role of tissue factor in delayed bone repair induced by diabetic state in mice

Background

Tissue factor (TF) is the primary activator of the extrinsic coagulation protease cascade. Although TF plays roles in various pathological states, such as thrombosis, inflammatory diseases, cancer, and atherosclerosis, its involvement in bone metabolism remains unknown.

Materials and methods

The present study examined the roles of TF in delayed bone repair induced by a diabetic state in mice using wild-type (WT) and low TF-expressing (LTF) male mice. A diabetic state was induced by intraperitoneal injections of streptozotocin (STZ).

Results

A prolonged diabetic state significantly reduced total and trabecular bone mineral densities (BMD) as well as cortical bone thickness in WT and LTF mice; these BMD parameters were similar between WT and LTF mice treated with or without STZ. The diabetic state induced in WT mice delayed the repair of the femur following injury. The diabetic state induced in LTF mice was associated with further delays in bone repair. In in vitro experiments, TF significantly decreased receptor activator of nuclear factor-κB ligand-induced osteoclast formation and osteoclastogenic gene expression in RAW264.7 cells. However, it did not affect the gene expression levels of runt-related transcription factor 2 and osterix as well as alkaline phosphatase activity in mouse primary osteoblasts.

Conclusion

Low TF state was associated with enhanced bone repair delay induced by diabetic state in mice. The TF-induced suppression of bone remodeling may be a contributing factor to the protective effects of TF against delayed bone repair in a diabetic state.

Antiviral anticoagulation

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel envelope virus that causes coronavirus disease 2019 (COVID-19). Hallmarks of COVID-19 are a puzzling form of thrombophilia that has elevated D-dimer but only modest effects on other parameters of coagulopathy. This is combined with severe inflammation, often leading to acute respiratory distress and possible lethality. Coagulopathy and inflammation are interconnected by the transmembrane receptor, tissue factor (TF), which initiates blood clotting as a cofactor for factor VIIa (FVIIa)-mediated factor Xa (FXa) generation. TF also functions from within the nascent TF/FVIIa/FXa complex to trigger profound changes via protease-activated receptors (PARs) in many cell types, including SARS-CoV-2-trophic cells. Therefore, aberrant expression of TF may be the underlying basis of COVID-19 symptoms. Evidence suggests a correlation between infection with many virus types and development of clotting-related symptoms, ranging from heart disease to bleeding, depending on the virus. Since numerous cell types express TF and can act as sites for virus replication, a model envelope virus, herpes simplex virus type 1 (HSV1), has been used to investigate the uptake of TF into the envelope. Indeed, HSV1 and other viruses harbor surface TF antigen, which retains clotting and PAR signaling function. Strikingly, envelope TF is essential for HSV1 infection in mice, and the FXa-directed oral anticoagulant apixaban had remarkable antiviral efficacy. SARS-CoV-2 replicates in TF-bearing epithelial and endothelial cells and may stimulate and integrate host cell TF, like HSV1 and other known coagulopathic viruses. Combined with this possibility, the features of COVID-19 suggest that it is a TFopathy, and the TF/FVIIa/FXa complex is a feasible therapeutic target.

The 100 Top-Cited Systematic Reviews/Meta-Analyses on Diabetic Research

OBJECTIVE

The objective of this study was to analyze the 100 top-cited systematic reviews/meta-analyses on diabetic research.

METHODS

The Science Citation Index Expanded database was searched to identify top-cited studies on diabetic research up to March 4^th, 2020. Studies were analyzed using the following characteristics: citation number, publication year, country and institution of origin, authorship, topics, and journals.

RESULTS

The 100 top-cited diabetic systematic reviews/meta-analyses were published in 43 different journals, with Diabetes Care having the highest numbers (n = 17), followed by The Journal of the American Medical Association (n = 14) and Lancet (n = 9). The majority of studies are published in the 2000s. The number of citations ranged from 2197 to 301. The highest number of contributions was from the USA, followed by England and Australia. The leading institution was Harvard University. The hot topic was a risk factor (n = 33), followed by comorbidity (n = 27).

CONCLUSIONS

The 100 top-cited systematic reviews/meta-analyses on diabetic research identify impactful authors, journals, institutes, and countries. It will also provide the most important references to evidence-based medicine in diabetes and serve as a guide to the features of a citable paper in this field.