Effects of endothelin-1 on fibroblasts from type 2 diabetic patients: Possible role in wound healing and tissue repair

Endothelin-1 (ET-1) promotes the contractile ability of fibroblasts, essential for wound closure and reconstitution of the dermis. Wound healing is impaired in type 2 diabetic patients (D). We compared the effect of ET-1 on proliferative transforming growth factor (TGFbeta(1)) expression, fibronectin and laminin release), differentiative [alpha-smooth muscle actin (alpha-SMA) expression] and inflammatory [monocyte chemo-attractant protein (MCP-1) and interleukin-6 (IL-6) expression] responses in skin fibroblasts of healthy subjects (C) and D, testing the relative role of ET(A) and ET(B) receptors in mediating these responses. ET-1 did not influence TGFbeta(1), fibronectin or laminin production. alpha-SMA was more abundant and more stimulated in D, as well as MCP-1 and IL-6 expression and release. These effects were prevented by BMS-182874, selective antagonist of ET(A), more abundant than ET(B) in both cell strains and whose expression rose more in D than C upon stimulation with ET-1. This peculiar pattern of responses to ET-1, presumably acquired during the chronic in vivo exposure to hyperglycemia along the natural history of the disease, may partially explain the increased susceptibility of D to chronic ulcerations.     

The Dark Side of Extracellular ATP in Kidney Diseases

Intracellular ATP is the most vital source of cellular energy for biologic systems, whereas extracellular ATP is a multifaceted mediator of several cell functions via its interaction, in an autocrine or paracrine manner, with P2 purinergic receptors expressed on the cell surface. These ionotropic and metabotropic P2 purinergic receptors modulate a variety of physiologic events upon the maintenance of a highly sensitive “set point,” the derangement of which may lead to the development of key pathogenic mechanisms during acute and chronic diseases. Growing evidence suggests that extracellular ATP signaling via P2 purinergic receptors may be involved in different renal pathologic conditions. For these reasons, investigators and pharmaceutical companies are actively exploring novel strategies to antagonize or block these receptors with the goal of reducing extracellular ATP production or accelerating extracellular ATP clearance. Targeting extracellular ATP signaling, particularly through the P2X₇ receptor, has considerable translational potential, given that novel P2X₇-receptor inhibitors are already available for clinical use (e.g., CE224,535, AZD9056, and GSK1482160). This review summarizes the current evidence regarding the involvement of extracellular ATP and its P2 purinergic receptor–mediated signaling in physiologic and pathologic processes in the kidney; potential therapeutic options targeting extracellular ATP purinergic receptors are analyzed as well.     

Metformin Benefits: Another Example for Alternative Energy Substrate Mechanism?

Since the UK Prospective Diabetes Study (UKPDS), metformin has been considered the first-line medication for patients with newly diagnosed type 2 diabetes. Though direct evidence from specific trials is still lacking, several studies have suggested that metformin may protect from diabetes- and nondiabetes-related comorbidities, including cardiovascular, renal, neurological, and neoplastic diseases. In the past few decades, several mechanisms of action have been proposed to explain metformin’s protective effects, none being final. It is certain, however, that metformin increases lactate production, concentration, and, possibly, oxidation. Once considered a mere waste product of exercising skeletal muscle or anaerobiosis, lactate is now known to act as a major energy shuttle, redistributed from production sites to where it is needed. Through the direct uptake and oxidation of lactate produced elsewhere, all end organs can be rapidly supplied with fundamental energy, skipping glycolysis and its possible byproducts. Increased lactate production (and consequent oxidation) could therefore be considered a positive mechanism of action of metformin, except when, under specific circumstances, metformin and lactate become excessive, increasing the risk of lactic acidosis. We are proposing that, rather than considering metformin-induced lactate production as dangerous, it could be considered a mechanism through which metformin exerts its possible protective effect on the heart, kidneys, and brain and, to some extent, its antineoplastic action.     

Enlarged approach to the anterior cervical spine.

In this report a new enlarged approach to the anterior cervical spine is presented. A 66-year-old female, having a large C3-C4-C5 chordoma, recurrent after surgery and following radiotherapy, underwent a surgical resection. The approach allows a wide retraction of the nasopharynx, oropharynx and larynx from the midline, only sacrificing the superior laryngeal nerve on one side. Its continuity can be re-established later by adopting the stent in tube technique. The approach we used presents all the risks of infection common in trans-oral approaches. For this reason, closure of the pharynx in two layers must be meticulous and watertight and reinforced by using a myofascial sternocleidomastoid flap, according to the tracheoesophageal fistula closure technique. A correct alignment of the tongue, the pre-plating of the mandible and the correct suture of the vermillion border guarantee excellent cosmetic and functional results.     

Adipocytokines mark insulin sensitivity in euthyroid Hashimoto’s patients

The relationship between inflammation, Hashimoto’s thyroiditis (HT) and insulin resistance is still controversial. In this regard, a pretty complete evaluation of adipocytokines levels in patients with HT has not been performed so far. We assessed retinol binding protein-4 (RBP4), adipocyte-fatty acid binding protein (A-FABP), neutrophil gelatinase–associated lipocalin (NGAL) and tumor necrosis factor-α (TNFα) levels in 93 euthyroid HT patients and 51 healthy controls (CTL), also evaluating the possible correlation between adipocytokines levels and markers of insulin resistance. No significant differences between HT patients and CTL in fasting plasma glucose and insulin levels, and HOMA index were observed. HT patients had significantly higher RBP4, NGAL and A-FABP levels than CTL, while TNFα levels did not differ between the two groups. In HT patients, RBP4 was significantly related with fT3 and fT4 levels, while A-FABP with fT4 only. Moreover, in HT patients, either RBP4 or A-FABP was directly associated with plasma insulin and HOMA index. Circulating levels of these adipocytokines were not influenced by the presence of antithyroid peroxidase or antithyroglobulin autoantibodies or only one of them, neither by autoantibodies titer. In conclusion, euthyroid HT patients are characterized by a peculiar inflammatory response of the adipose tissue, apparently related to an early reduction in insulin sensitivity and to serum thyroid hormone levels, although within the normal range. These results suggest that HT patients with high RBP4 and A-FABP levels might deserve a particular attention, being potentially more exposed to develop insulin resistance and increased cardiovascular risk.     

Metal cementless prosthesis for vertebral body replacement of metastatic malignant disease of the cervical spine

Sixteen patients affected with metastatic malignant disease of the cervical spine underwent cervical vertebral body replacement with an original metal cementless prosthesis. In all cases there was immediate spine stability postoperatively and pain relief. All patients were able to walk within a few days postoperatively without any rigid external support. Follow-up roentgenograms have shown nonprosthetic mobilization.     

Antihypertensive treatment and multifactorial approach for renal protection in diabetes

Type 2 diabetes is reaching epidemic proportions throughout the world, representing the most common cause of ESRD. Early identification of renal impairment associated with diabetes and initiation of renoprotective therapy are imperative. High BP, dyslipidemia, long duration of diabetes, and poor glycemic control are important risk factors; their modification, renal function monitoring, and combined therapies are the current integrated approaches to treat patients with diabetic kidney disease. Strong evidence suggests that achieving target BP goals via inhibition of the renin-angiotensin-aldosterone system confers significant renal protection for diabetic patients. Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers lower BP and reduce both the progression of renal damage and adverse cardiovascular events; some important renoprotective actions seem to be independent of the antihypertensive effect. Stringent quality of glycemic control is another key point to prevent onset of nephropathy or slow its progression. Evidence from basic research and clinical trials indicates that hypolipidemic drugs, mainly statins, contribute to modulate the progression of renal damage in diabetes; their use should be considered in any patient with diabetes. Smoking cessation may slow nephropathy progression; given the additional health benefits of stopping smoking, this advice is an important part of the strategy of diabetic nephropathy treatment and prevention. In conclusion, a target-driven, long-term, intensified intervention aimed at multiple risk factors should be recommended in patients with diabetes to preserve their kidney function.