DIABETIC MICROVASCULAR COMPLICATIONS

People with diabetes have an increased risk of developing microvascular complications, diabetic retinopathy, diabetic nephropathy and diabetic neuropathy, which, if undetected or left untreated, can have a devastating impact on quality of life and place a significant burden on health care costs. In addition, diabetic microvascular complications can reduce life expectancy. The strongest risk factors are glycaemic control and diabetes duration; however, other modifiable risk factors such as hypertension, hyperlipidaemia and smoking, and unmodifiable risk factors including age at onset of diabetes and genetic factors may all play a part. Along with the presence of external risk factors, some associations have also been noted between diabetic microvascular complications themselves. There is evidence that diabetic retinopathy in association with increased blood pressure is an important risk factor for diabetic nephropathy progression. Significant correlations have also been shown between the presence of diabetic peripheral neuropathy and the presence of background or proliferative diabetic retinopathy. Clinical trials are currently in progress looking at a number of approaches to designing treatments to prevent the adverse effects of hyperglycaemia. It is essential however, that risk factors associated with the progression and development of diabetic microvascular complications are detected and treated at an early stage in order to further reduce morbidity and mortality. Considering all three complications as interrelated may well facilitate early detection of microvascular disease. Despite good long-term glycaemic and blood pressure control, diabetes remains a major cause of blindness, renal failure and amputations. As the incidence of diabetes continues to rise, the burden of diabetic microvascular complications will increase in future, hence the need for early detection. Considering the microvascular complications of diabetes as related, and enquiring proactively about complications, may well facilitate early detection of microvascular disease

Characterization of an Immortalized Human Microglial Cell Line as a Tool for the Study of Diabetic Retinopathy

The complexity of the retinal structure reflects on the difficulty to describe its composite cell interactions. Microglia is responsible for the immune reaction to inflammatory stimuli during diabetic retinopathy (DR), but most studies still use rodent cells. We characterized a commercially available immortalized human microglial line and tested its susceptibility to inflammation, to study the interactions between the neuro-vascular retinal portions in species-specific models. After checking the expression of microglial markers, we tried lipopolysaccharide (LPS) stimulation and several pro-inflammatory cocktails to select the best combination able to induce a significant M1 (inflammatory) response. We measured M1 induction through the expression of pro- and anti-inflammatory molecules and performed morphologic and functional assays. Marker expression confirmed the human microglial derivation of these cells. Differently from rodents, LPS did not induce a M1 profile. The best pro-inflammatory stimulus was an interleukin-1β + tumor necrosis factor-α + interferon-γ cocktail, which induced morphology changes and increased proliferation, apoptosis, migration, reactive oxygen species, and the expression of inflammatory cytokines and miRNAs. In conclusion, this microglial line proved potentially useful to investigate the cascade of events leading to DR. In perspective, co-culture models involving microvascular cells will help in the understanding of multifaceted interactions of the neurovascular unit