Circulating endothelial precursor cells are associated with a healed diabetic foot ulcer evaluated in a prospective cohort study

Advances in the study of microparticles in diabetic retinopathy

Diabetic retinopathy (DR) is one of the common diabetic microangiopathies, which severely impairs vision in diabetic population. The underlying mechanisms regarding the development of DR are not fully understood, and there is a lack of biomarkers to guide clinical, assessment of disease progression. Recently researchers have found that microparticles (MP) and its bioactive molecules are involved in the development of DR. MP is widely distributed in the circulation and can exert autocrine and paracrine benefits in intercellular signalling, provide a catalytic platform for the thrombospondin complex to promote coagulation, and promote the accumulation of reactive oxygen species to cause endothelial damage. MP interacts with advanced glycosylation end products (AGE) and AGE receptor (RAGE) to activate inflammatory pathways. MP carries a variety of miRNAs that regulate the vascular endothelial growth factor generation pathway. MP has also been applied to the exploration of mesenchymal stromal cell replacement therapy to treat DR. In a word, MP provides new ideas for the study of DR. MP has emerged as a marker to assess the progression of DR. As a potential therapeutic target, MP also has considerable research value.

Autologous Platelet-Rich Gel Accelerates Diabetic Wound Healing Through Inhibition of Ferritinophagy

Aims: The objective was to examine the efficacy of autologous platelet-rich gel (APG) in treating diabetic wound and investigate the association between APG and ferritinophagy. Methods: A total of 32 patients with diabetic foot (DF) and Wagner grade 1 to 2 were included. Within the APG group, individuals with DF received weekly APG treatment. In the non-APG group, DF patients received daily dressing changes. Flow cytometry quantified the proportion of endothelial progenitor cells (EPCs) in peripheral blood on days 0 and 10. The diabetic rat model was induced using Streptozotocin. Two circular skin wounds were created on the backs of rats. The normal glucose group received daily dressing changes on the wound. In the diabetic group, the left wound underwent daily dressing changes, whereas the right wound was treated with APG once a week. CD34 levels were tested 7 days after the skin damage. The levels of glutathione peroxidase 4 (GPX4), Nuclear Receptor Coactivator 4 (NCOA4), Light chain 3 (LC3), and Masson staining were quantified on 14 days. The wound area and wound healing rate were separately measured at 0 and 14 days after the injury, regardless of DF patients or diabetic rats. Results: The wound healing rate was higher in the APG group than in the non-APG group, regardless of DF patients or diabetic rats. The APG group had a greater ΔEPCs% in DF patients than the non-APG group. Regarding rat experiment, the APG group exhibited lower levels of NCOA4, and LC3 expressions and a shorter wound healing time. However, the APG group showed higher levels of CD34 expression, GPX4 protein, and collagen fibers than the non-APG group. Conclusions: Autologous platelet-rich gel accelerated the wound healing rate in diabetic populations and rats. Autologous platelet-rich gel promoted EPCs counts, collagen fiber volume, and vessel numbers. Autologous platelet-rich gel decreased LC3 and NCOA4 expression, but increased GPX4 protein expression. The possible mechanism was the inhibition of ferritinophagy.

Blood-Borne Microparticles Are an Inflammatory Stimulus in Type 2 Diabetes Mellitus

The proinflammatory state associated with diabetes mellitus (DM) remains poorly understood. We found patients with DM have 3- to 14-fold elevations of blood-borne microparticles (MPs) that bind phalloidin (Ph; Ph positive [+] MPs), indicating the presence of F-actin on their surface. We hypothesized that F-actin-coated MPs were an unrecognized cause for DM-associated proinflammatory status. Ph+MPs, but not Ph-negative MPs, activate human and murine (Mus musculus) neutrophils through biophysical attributes of F-actin and membrane expression of phosphatidylserine (PS). Neutrophils respond to Ph+MPs via a linked membrane array, including the receptor for advanced glycation end products and CD36, PS-binding membrane receptors. These proteins in conjunction with TLR4 are coupled to NO synthase 1 adaptor protein (NOS1AP). Neutrophil activation occurs because of Ph+MPs causing elevations of NF-κB and Src kinase (SrcK) via a concurrent increased association of NO synthase 2 and SrcK with NOS1AP, resulting in SrcK S-nitrosylation. We conclude that NOS1AP links PS-binding receptors with intracellular regulatory proteins. Ph+MPs are alarmins present in normal human plasma and are increased in those with DM and especially those with DM and a lower-extremity ulcer.