Bradykinin-forming components in Kuwaiti patients with type 2 diabetes

Type 2 Diabetes Coagulopathy Proteins May Conflict With Biomarkers Reflective of COVID-19 Severity

OBJECTIVE

Detailed proteomic analysis in a cohort of patients with differing severity of COVID-19 disease identified biomarkers within the complement and coagulation cascades as biomarkers for disease severity has been reported; however, it is unclear if these proteins differ sufficiently from other conditions to be considered as biomarkers.

METHODS

A prospective, parallel study in T2D (n = 23) and controls (n = 23). A hyperinsulinemic clamp was performed and normoglycemia induced in T2D [4.5 ± 0.07 mmol/L (81 ± 1.2 mg/dl)] for 1-h, following which blood glucose was decreased to ≤2.0 mmol/L (36 mg/dl). Proteomic analysis for the complement and coagulation cascades were measured using Slow Off-rate Modified Aptamer (SOMA)-scan.

RESULTS

Thirty-four proteins were measured. At baseline, 4 of 18 were found to differ in T2D versus controls for platelet degranulation [Neutrophil-activating peptide-2 (p = 0.014), Thrombospondin-1 (p = 0.012), Platelet factor-4 (p = 0.007), and Kininogen-1 (p = 0.05)], whilst 3 of 16 proteins differed for complement and coagulation cascades [Coagulation factor IX (p < 0.05), Kininogen-1 (p = 0.05), and Heparin cofactor-2 (p = 0.007)]; STRING analysis demonstrated the close relationship of these proteins to one another. Induced euglycemia in T2D showed no protein changes versus baseline. At hypoglycemia, however, four proteins changed in controls from baseline [Thrombospondin-1 (p < 0.014), platelet factor-4 (p < 0.01), Platelet basic protein (p < 0.008), and Vitamin K-dependent protein-C (p < 0.00003)], and one protein changed in T2D [Vitamin K-dependent protein-C, (p < 0.0002)].

CONCLUSION

Seven of 34 proteins suggested to be biomarkers of COVID-19 severity within the platelet degranulation and complement and coagulation cascades differed in T2D versus controls, with further changes occurring at hypoglycemia, suggesting that validation of these biomarkers is critical. It is unclear if these protein changes in T2D may predict worse COVID-19 disease for these patients.

CLINICAL TRIAL REGISTRATION

https://clinicaltrials.gov/, identifier NCT03102801.

Moving Past Anti-VEGF: Novel Therapies for Treating Diabetic Retinopathy

Diabetic retinopathy is the leading cause of blindness in working age adults, and is projected to be a significant future health concern due to the rising incidence of diabetes. The recent advent of anti-vascular endothelial growth factor (VEGF) antibodies has revolutionized the treatment of diabetic retinopathy but a significant subset of patients fail to respond to treatment. Accumulating evidence indicates that inflammatory cytokines and chemokines other than VEGF may contribute to the disease process. The current review examines the presence of non-VEGF cytokines in the eyes of patients with diabetic retinopathy and highlights mechanistic pathways in relevant animal models. Finally, novel drug targets including components of the kinin-kallikrein system and emerging treatments such as anti-HPTP (human protein tyrosine phosphatase) β antibodies are discussed. Recognition of non-VEGF contributions to disease pathogenesis may lead to novel therapeutics to enhance existing treatments for patients who do not respond to anti-VEGF therapies.

Altered activities of kininase II, an angiotensin converting enzyme, prekallikrein, and nitric oxide in Kuwaiti patients with type 2 diabetes

The current investigation was conducted to examine kininase II or angiotensin converting enzyme (ACE), plasma prekallikrein (PK), and nitric oxide (NO) concentrations in healthy Kuwaiti subjects and newly diagnosed Kuwaiti type 2 diabetic patients before and after treatment for 6 weeks with metformin hydrochloride 500 mg twice daily after meal. With the consent of volunteers, blood and urine samples were collected after an overnight fasting. Samples were collected from the diabetic patients before and after treatment for 6 weeks. Enzyme linked immunosorbent assay (ELISA) was carried out on the aliquoted samples to measure the concentration of kininase II. NO was detected via colorimetry. Plasma Kininase II or ACE levels were significantly ( P <0.01) increased by 18% in untreated diabetics when compared with healthy volunteers. However, after treatment there was a significant decrease of 20% in their ACE levels. Plasma prekallikrein levels were raised significantly ( P <0.01) by 28% in diabetic patients in contrast with the control subjects and the levels were significantly reduced ( P <0.0001) by 44% after treatment with metformin hydrochloride. NO levels were found to be significantly decreased in plasma by 56% and in urine by 62% in untreated diabetic patients as compared with the healthy subjects. However, when the treated diabetic patients were compared with untreated diabetics, there was an increase of 50% in plasma and 37% in urine samples. The high levels of kininase II, prekallikrein, and reduced NO may be partly responsible for the induction of renal, cardiac, and hypertensive complications associated with type 2 diabetes. Reduced NO level is an indication of endothelial dysfunction resulting in increased blood pressure. Oral anti-diabetic treatment is associated with protective effects through the reduction of kininase II (ACE), prekallikrein, and elevation of NO levels.