Circulating endothelial progenitor cells in type 1 diabetic patients with erectile dysfunction

Therapeutic Effects of Proanthocyanidins on Diabetic Erectile Dysfunction in Rats

The rising occurrence of erectile dysfunction related to diabetes mellitus (DMED) has led to the creation of new medications. Proanthocyanidins (PROs) is a potential agent for DMED. In this study, the DMED rat model was established using streptozotocin (STZ) and erectile function was assessed using apomorphine (APO) in rats. Following this, the rats were subjected to oral treatment with PRO. Then, we evaluated the influence of PROs on DMED rats. The findings suggest that PROs significantly enhance erectile function in DMED rats. PROs modulated glucose and lipid metabolism in DMED rats by decreasing blood glucose and lipid levels while increasing liver glycogen and serum insulin levels. Furthermore, PROs enhanced vascular endothelial function in DMED rats by augmenting nitric oxide (NO) levels and reducing the levels of endothelin-1 (ET-1) and lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1). Additionally, PROs have been shown to elevate testosterone (T) levels, mitigate pathological testicular damage, and enhance sperm concentration and survival rates. Finally, the core targets were screened using network pharmacology, followed by validation through molecular docking, enzyme-linked immunoassay (ELISA), and real-time PCR methodologies. Our findings imply that PROs may treat DMED by elevating AKT1 levels while concurrently diminishing CASP3 levels, thereby effectively regulating the PI3K-Akt signaling pathway. Overall, these results support using PROs as a potential candidate for the treatment of DMED.

Associations between Erectile Dysfunction and Vascular Parameters: A Systematic Review and Meta-Analysis

PURPOSE

Erectile dysfunction (ED) is associated with several vascular disorders, but the associations between ED and vascular parameters are still unclear.

MATERIALS AND METHODS

We analyzed and synthesized a comprehensive range of studies from PubMed, Web of Science, and Scopus regarding the associations between ED and the following measures: ankle-brachial index (ABI), pulse wave velocity (PWV), intima-media thickness (IMT), nitrate-mediated dilation (NMD), flow-mediated dilation (FMD), augmentation index (AI), endothelial progenitor cells (EPCs) and other vascular parameters. Subgroup analysis was conducted according to specific types of parameters. Study quality was assessed by using the Newcastle-Ottawa Scale. Sensitivity analysis was conducted to confirm the robustness of the pooled results.

RESULTS

Fifty-seven studies with 7,312 individuals were included. Twenty-eight studies were considered to be high-quality. ED patients had a 0.11 mm higher IMT (95% confidence interval [CI]: 0.07, 0.15), a 2.86% lower FMD (95% CI: -3.56, -2.17), a 2.34% lower NMD (95% CI: -3.37, -1.31), a 2.83% higher AI (95% CI: 0.02, 5.63), a 1.11 m/s higher PWV (95% CI: 0.01, 2.21), and a 0.72% lower percentage of EPCs (95% CI: -1.19, -0.24) compared to those without ED. However, ABI was similar between ED patients and non-ED individuals. According to sensitivity analysis, the pooled results were robust.

CONCLUSIONS

Our study confirmed the associations between ED and several vascular parameters and highlighted the importance of prevention and management of vascular and endothelial dysfunction in ED patients.

Evaluating the Impact of Continuous Glucose Monitoring on Erectile Dysfunction in Type 1 Diabetes: A Focus on Reducing Glucose Variability and Inflammation

Type 1 diabetes (T1D) severely impairs metabolic control and can lead to erectile dysfunction (ED) through hyperglycemia-induced vascular damage, autonomic neuropathy, and psychological distress. This review examines the role of continuous glucose monitoring (CGM) in ameliorating ED by addressing glucose variability and inflammation. A comprehensive analysis of studies and clinical trials was conducted to evaluate the impact of CGM on metabolic control, inflammatory responses, and vascular health in patients with T1D. Evidence suggests that CGM systems significantly stabilize blood glucose levels and reduce hyper- and hypoglycemic episodes that contribute to endothelial dysfunction and ED. CGM's real-time feedback helps patients optimize metabolic control, improve vascular health, and reduce inflammation. CGM has the potential to redefine ED management in patients with T1D by improving glycemic control and reducing the physiological stressors that cause ED, potentially improving quality of life and sexual health. Further research is warranted to explore the specific benefits of CGM for ED management.

Global prevalence of erectile dysfunction and its associated risk factors among men with type 1 diabetes: a systematic review and meta-analysis

Various observational studies have examined the prevalence and determinants of erectile dysfunction (ED) in men with type 1 diabetes across different geographical areas. Nevertheless, a comprehensive systematic review and meta-analysis to consolidate the worldwide prevalence and risk factors remains lacking. Hence, the primary study objective was to perform an extensive systematic review and meta-analysis that specifically examined ED prevalence and determinants in men with type 1 diabetes. A thorough exploration was conducted by examining electronic databases, such as PubMed, Embase, and Web of Science. The general ED prevalence and a 95% confidence interval (CI) in men with type 1 diabetes were summarized. The relevant risk factors were analyzed by deriving a comprehensive odds ratio (OR) from merging the ORs using fixed- or random-effects models. The sources of heterogeneity were investigated using subgroup analyses and meta-regression. This systematic review and meta-analysis included 19 articles involving 3788 men with type 1 diabetes. The meta-analysis revealed that men with type 1 diabetes had a combined ED prevalence of 42.5% (95% CI: 34.3%-50.8%). This prevalence showed significant heterogeneity (I2 = 96.2%, P < 0.01). Meta-regression revealed that age (P = 0.016) and type 1 diabetes duration (P = 0.004) were significant causes of heterogeneity. Furthermore, the ED risk in men with type 1 diabetes was significantly influenced by age, type 1 diabetes duration, body mass index, glycated hemoglobin (HbA1c), retinopathy, and smoking habits (all P < 0.05). In summary, this systematic review and meta-analysis revealed a significant prevalence of ED in men with type 1 diabetes, highlighting the importance of clinicians addressing concerns regarding ED in this specific group of individuals.

Change in Circulating Levels of Endothelial Progenitor Cells and Sexual Function in Women With Type 1 Diabetes

CONTEXT

Endothelial progenitor cells (EPCs), which are involved in the mechanisms of vascular repair and sexual function, are decreased in diabetic women compared with general population.

OBJECTIVE

This work aimed to investigate the circulating levels of EPCs and the change in sexual function during the menstrual cycle in women with type 1 diabetes (T1DM) compared with healthy women.

METHODS

This case-control observational study was conducted at the Unit of Endocrinology and Metabolic Diseases at University Hospital "Luigi Vanvitelli'' of Naples. Participants included 36 women with T1DM and 64 age-matched healthy controls. EPCs were quantified by flow cytometry and sexual function was assessed using the Female Sexual Function Index (FSFI) and the Female Sexual Distress Scale. All assessments were made at the follicular, ovulatory, and luteal phases of the same menstrual cycle. Main outcome measures included differences in EPCs levels and sexual function between patients and controls.

RESULTS

Compared with controls, women with T1DM showed significantly lower levels of both CD34 + (P < .001) and CD34 + CD133 + cells (P < .001) in the ovulatory phase, and CD34 + KDR + cells both in the ovulatory phase and in the luteal phase (P < .001 for both). Diabetic women showed significantly lower total FSFI scores and higher FSDS score than control women in all phases of the menstrual cycle. FSFI total score was predicted by both CD34 + CD133 + and CD34 + KDR + cells in the follicular phase, CD34 + and CD34 + KDR + CD133 + cells in the ovulatory phase, and CD34 + KDR + and CD34 + KDR + CD133 + cells in the luteal phase.

CONCLUSION

Women with T1DM show lower levels of EPCs during the menstrual cycle compared with controls. EPCs count predicts sexual function in this selected population.

Combined Transplantation of Adipose Tissue-Derived Stem Cells and Endothelial Progenitor Cells Improve Diabetic Erectile Dysfunction in a Rat Model

Erectile dysfunction (ED) is a common complication in men suffered with diabetic mellitus. Stem cell transplantation is a promising strategy for the treatment of diabetic ED (DED). In this study, we evaluated whether combined transplantation of adipose tissue-derived stem cells (ADSCs) and endothelial progenitor cells (EPCs) could improve the erectile function of the DED rat model. DED rats were induced via intraperitoneal injection of streptozotocin (50 mg/kg), and ED was screened by apomorphine (100 mg/kg). DED rats were divided into 4 groups (n = 14 each): DED, ADSC, EPC, and ADSC/EPC group. Another 14 age-matched male SD rats with normal erectile function were served as the normal group. The normal group and the DED group were received intracavernous injection with phosphate-buffered saline (PBS). And the other groups were received intracavernous injection with ADSCs (1 × 10⁶), EPCs (1 × 10⁶), and ADSCs/EPCs (0.5 × 10⁶/0.5 × 10⁶), respectively. The total intracavernous pressure (ICP) and mean arterial pressure (MAP) were recorded at day 28 after injection. The endothelium, smooth muscle, and penile dorsal nerves were assessed within cavernoursal tissue. On day 28 after injection, the ADSC/EPC group displayed more significantly enhanced ICP and ICP/MAP than the DED or ADSC or EPC group (p < 0.05). Immunofluorescent analysis and western blot demonstrated that the improvement of erectile function in the ADSC/EPC5 group was associated with increased expression of endothelial marker (CD31) and the correction of eNOS-cGMP-NO signaling. More 5-ethynyl-2′-deoxyuridine- (EdU-) positive EPCs could be found lining in the cavernous endothelial layer in the ADSC/EPC group than the EPC group, which was attributed to the paracrine of vascular endothelial growth factor (VEGF) and stromal-derived factor-1 (SDF-1) by ADSCs. Combined transplantation of ADSCs and EPCs has a synergic effect in repairing the endothelial function of DED rats, and the underlying mechanism might be the paracrine of VEGF and SDF-1 by ADSCs, which improves the recruitment and proliferation of EPCs in the cavernosum.

Phase I and registry study of autologous bone marrow concentrate evaluated in PDE5 inhibitor refractory erectile dysfunction

Background

Bone marrow mononuclear cells have been successfully utilized for numerous regenerative purposes. In the current study, patients suffering from erectile dysfunction (ED) unresponsive to phosphodiesterase 5 inhibitors were administered autologous bone marrow concentrate delivered intracavernously utilizing a point of care FDA cleared medical device.

Methods

A total of 40 patients were treated in the primary trial and 100 in the clinical registry, with the longest follow up of 12 months.

Results

Minimal treatment associated adverse effects where observed related to short term bruising at the site of harvest or injection. No long-term adverse events were noted related to the intervention. Mean improvements in IIEF-5 score were 2 in the Caverstem 1.0 low dose group, 3 in the high dose Caverstem 1.0 group and 9 in the Caverstem 2.0 group. Furthermore, improvements peaked by 3 months and maintained at 6 months follow-up.

Conclusion

These data support the safety and efficacy of point of care, minimally to non-manipulated, non-expanded bone marrow concentrate for the treatment of ED.

Trial registration Funded by Creative Medical Health, Inc.; Clinicaltrials.gov number: NCT03699943; https://clinicaltrials.gov/ct2/show/NCT03699943?term=caverstem&rank=1; initially registered December 12, 2015.

Endothelium as a Therapeutic Target in Diabetes Mellitus: From Basic Mechanisms to Clinical Practice

Endothelium plays an essential role in human homeostasis by regulating arterial blood pressure, distributing nutrients and hormones as well as providing a smooth surface that modulates coagulation, fibrinolysis and inflammation. Endothelial dysfunction is present in Diabetes Mellitus (DM) and contributes to the development and progression of macrovascular disease, while it is also associated with most of the microvascular complications such as diabetic retinopathy, nephropathy and neuropathy. Hyperglycemia, insulin resistance, hyperinsulinemia and dyslipidemia are the main factors involved in the pathogenesis of endothelial dysfunction. Regarding antidiabetic medication, metformin, gliclazide, pioglitazone, exenatide and dapagliflozin exert a beneficial effect on Endothelial Function (EF); glimepiride and glibenclamide, dipeptidyl peptidase-4 inhibitors and liraglutide have a neutral effect, while studies examining the effect of insulin analogues, empagliflozin and canagliflozin on EF are limited. In terms of lipid-lowering medication, statins improve EF in subjects with DM, while data from short-term trials suggest that fenofibrate improves EF; ezetimibe also improves EF but further studies are required in people with DM. The effect of acetylsalicylic acid on EF is dose-dependent and lower doses improve EF while higher ones do not. Clopidogrel improves EF, but more studies in subjects with DM are required. Furthermore, angiotensin- converting-enzyme inhibitors /angiotensin II receptor blockers improve EF. Phosphodiesterase type 5 inhibitors improve EF locally in the corpus cavernosum. Finally, cilostazol exerts favorable effect on EF, nevertheless, more data in people with DM are required.

Insights into Endothelial Progenitor Cells: Origin, Classification, Potentials, and Prospects

With the discovery of endothelial progenitor cells (EPCs) in the late 1990s, a paradigm shift in the concept of neoangiogenesis occurred. The identification of circulating EPCs in peripheral blood marked the beginning of a new era with enormous potential in the rapidly transforming regenerative field. Overwhelmed with the revelation, researchers across the globe focused on isolating, defining, and interpreting the role of EPCs in various physiological and pathological conditions. Consequently, controversies emerged regarding the isolation techniques and classification of EPCs. Nevertheless, the potential of using EPCs in tissue engineering as an angiogenic source has been extensively explored. Concomitantly, the impact of EPCs on various diseases, such as diabetes, cancer, and cardiovascular diseases, has been studied. Within the limitations of the current knowledge, this review attempts to delineate the concept of EPCs in a sequential manner from the speculative history to a definitive presence (origin, sources of EPCs, isolation, and identification) and significance of these EPCs. Additionally, this review is aimed at serving as a guide for investigators, identifying potential research gaps, and summarizing our current and future prospects regarding EPCs.

From inflammation to sexual dysfunctions: a journey through diabetes, obesity, and metabolic syndrome

Metabolic diseases are associated with chronic low-grade inflammation, which has been indicated as a potential mediator of endothelial dysfunction and cardiovascular disease. Visceral adiposity is thought to be the starting condition of the inflammatory state through the release of inflammatory cytokines, including TNF-alpha, CRP, and IL-6, which in turn promote endothelial dysfunction, endothelial expression of chemokines (IL-1) and adhesion molecules (ICAM-1, VCAM-1, and P-selectin), and the inhibition of anti-atherogenic factors (adiponectin). Obesity, metabolic diseases, and diabetes, all conditions characterized by abdominal fat, are well-recognized risk factors for sexual dysfunction in both sexes. Evidence from randomized-controlled trials supports the association between inflammatory milieau and erectile dysfunction in men suffering from metabolic diseases, whereas, in women, this has to be confirmed in further studies. A healthy lifestyle based on dietary pattern with high content of whole grain, fruit, nuts and seeds, and vegetables and low in sodium and saturated fatty acids plus regular physical activity may help to modulate the pro-inflammatory state associated with metabolic diseases and the related burden of sexual dysfunctions.

Gender-differences in glycemic control and diabetes related factors in young adults with type 1 diabetes: results from the METRO study

PURPOSE

To describe gender differences concerning glycemic control, cardiovascular risk factors, diabetic complications, concomitant pathologies, and circulating endothelial progenitor cells (EPCs), in a population of young adults with type 1 diabetes.

METHODS

We collected data from 300 consecutively patients (168 males and 132 females), aged 18-30 years, among those admitted at Diabetes Unit of University of Campania "Luigi Vanvitelli" (Naples, Italy) from March 2012 to January 2017. Circulating levels of seven EPCs phenotypes were determined by flow cytometry.

RESULTS

As compared to men, women with type 1 diabetes had a significantly higher HbA1c levels (%, 8.4 ± 1.3 vs. 8.1 ± 1.3, P = 0.020), body mass index (Kg/m², 24.8 ± 4.2 vs. 23.9 ± 3.9, P = 0.034), HDL-cholesterol (mg/dL, 61.7 ± 13.7 vs. 54.7 ± 13.9, P < 0.001), and a lower count of both CD133+KDR+ and CD34+KDR+CD133+ EPCs (P = 0.022, P < 0.001, respectively). A higher proportion of women had overweight/obesity, and thyroiditis; smoking and sexual dysfunctions were more prevalent in men than in women.

CONCLUSIONS

Young adults with type 1 diabetes present gender differences with regard to glycemic control, prevalence of some cardiovascular risk factors, sexual dysfunctions and circulating levels of EPCs, most often to the detriment of women.

Treatment of diabetes mellitus-induced erectile dysfunction using endothelial progenitor cells genetically modified with human telomerase reverse transcriptase

The efficacy of treatments for diabetes mellitus-induced erectile dysfunction (DMED) is quite poor, and stem cell therapy is emerging as a useful method. In this study, we used endothelial progenitor cells (EPCs) overexpressing human telomerase reverse transcriptase (hTERT) for the treatment of DMED. Rat EPCs were transfected with hTERT (EPCs-hTERT). EPCs-hTERT secreted more growth factors and demonstrated enhanced proliferation and resistance to oxidative stress. Twenty-four male DMED rats were subjected to four treatments: DMED (DMED group), EPCs (EPCs group), EPCs transduced with control lentivirus (EPC-control group) and EPCs-hTERT (EPCs-hTERT group). A group of healthy rats were used as the normal control group. The erectile function in the EPCs-hTERT group was markedly increased compared with the EPCs and EPCs-control groups. The EPCs-hTERT group exhibited more growth factors, smooth muscle content and retained stem cells in penile tissues. The degree of apoptosis and collagen/smooth muscle ratio in penile tissues of the EPCs-hTERT group was considerably reduced. Endothelial nitric oxide synthase (eNOS) expression increased significantly in the EPCs-hTERT group. Taken together, these data showed that the enhanced paracrine effect, resistance to oxidative stress and proliferation of EPCs-hTERT may contribute to the improvements of erectile function in DMED rats.

[Treatment by stem cell therapy of erectile dysfunction of diabetic origin: State of the art]

PURPOSE

Review of various publications on stem cell therapy to treat erectile dysfunction of diabetic origin.

MATERIAL AND METHODS

Bibliographic search in PUBMED performed using the keywords cell therapy strain/erectile dysfunction associated with diabetes. Among the 51 articles obtained from the PUBMED research, we selected 16 articles for their specificity of studying erectile dysfunction (DE) related to diabetes.

RESULTS

Different types of stem cells have been studied: adipose derived mesenchymal stem cells/bone marrow derived mesenchymal stem cells as well as progenitor endothelial cells. The experimental protocols are quite similar from one study to the next with nevertheless some specifications concerning the studied cells and the monitoring of the latter. Intracavernous pressure (ICP) measured after the injection of stem cells into the corpus cavernosum was always significantly higher than the control populations. The addition of certain growth factors to stem cells by gene transfection improve the efficacy of the cells. No ideal tracking markers of the cells have been identified.

CONCLUSION

The positive effect of the injection of stem cells on the ICP belongs to the cellular trans-differentiation effect but especially to the paracrine effects which have not yet been completely elucidated.

Ginsenoside Rg1 nanoparticle penetrating the blood-brain barrier to improve the cerebral function of diabetic rats complicated with cerebral infarction

Diabetic cerebral infarction is with poorer prognosis and high rates of mortality. Ginsenoside Rg1 (Rg1) has a wide variety of therapeutic values for central nervous system (CNS) diseases for the neuron protective effects. However, the blood–brain barrier (BBB) restricts Rg1 in reaching the CNS. In this study, we investigated the therapeutic effects of Rg1 nanoparticle (PHRO, fabricated with γ-PGA, L-PAE (H), Rg1, and OX26 antibody), targeting transferrin receptor, on the diabetes rats complicated with diabetic cerebral infarction in vitro and in vivo. Dynamic light scattering analysis shows the average particle size of PHRO was 79±18 nm and the polydispersity index =0.18. The transmission electron microscope images showed that all NPs were spherical in shape with diameters of 89±23 nm. PHRO released Rg1 with sustained release manner and could promote the migration of cerebrovascular endothelial cells and tube formation and even penetrated the BBB in vitro. PHRO could penetrate the BBB with high concentration in brain tissue to reduce the cerebral infarction volume and promote neuronal recovery in vivo. PHRO was promising to be a clinical treatment of diabetes mellitus with cerebral infarction.

Combination of low-energy shock-wave therapy and bone marrow mesenchymal stem cell transplantation to improve the erectile function of diabetic rats

Stem cell transplantation and low-energy shock-wave therapy (LESWT) have emerged as potential and effective treatment protocols for diabetic erectile dysfunction. During the tracking of transplanted stem cells in diabetic erectile dysfunction models, the number of visible stem cells was rather low and decreased quickly. LESWT could recruit endogenous stem cells to the cavernous body and improve the microenvironment in diabetic cavernous tissue. Thus, we deduced that LESWT might benefit transplanted stem cell survival and improve the effects of stem cell transplantation. In this research, 42 streptozotocin-induced diabetic rats were randomized into four groups: the diabetic group (n = 6), the LESWT group (n = 6), the bone marrow-derived mesenchymal stem cell (BMSC) transplantation group (n = 15), and the combination of LESWT and BMSC transplantation group (n = 15). One and three days after BMSC transplantation, three rats were randomly chosen to observe the survival numbers of BMSCs in the cavernous body. Four weeks after BMSC transplantation, the following parameters were assessed: the surviving number of transplanted BMSCs in the cavernous tissue, erectile function, real-time polymerase chain reaction, and penile immunohistochemical assessment. Our research found that LESWT favored the survival of transplanted BMSCs in the cavernous body, which might be related to increased stromal cell-derived factor-1 expression and the enhancement of angiogenesis in the diabetic cavernous tissue. The combination of LESWT and BMSC transplantation could improve the erectile function of diabetic erectile function rats more effectively than LESWT or BMSC transplantation performed alone.

Dietary Strategies Implicated in the Prevention and Treatment of Metabolic Syndrome

Metabolic syndrome (MetS) is established as the combination of central obesity and different metabolic disturbances, such as insulin resistance, hypertension and dyslipidemia. This cluster of factors affects approximately 10%-50% of adults worldwide and the prevalence has been increasing in epidemic proportions over the last years. Thus, dietary strategies to treat this heterogenic disease are under continuous study. In this sense, diets based on negative-energy-balance, the Mediterranean dietary pattern, n-3 fatty acids, total antioxidant capacity and meal frequency have been suggested as effective approaches to treat MetS. Furthermore, the type and percentage of carbohydrates, the glycemic index or glycemic load, and dietary fiber content are some of the most relevant aspects related to insulin resistance and impaired glucose tolerance, which are important co-morbidities of MetS. Finally, new studies focused on the molecular action of specific nutritional bioactive compounds with positive effects on the MetS are currently an objective of scientific research worldwide. The present review summarizes some of the most relevant dietary approaches and bioactive compounds employed in the treatment of the MetS to date.

Modulating putative endothelial progenitor cells for the treatment of endothelial dysfunction and cardiovascular complications in diabetes

Diabetes induces a decrease in the number and function of different pro-angiogenic cell types generically designated as putative endothelial progenitor cells (EPC), which encompasses cells from myeloid origin that act in a paracrine fashion to promote angiogenesis and putative "true" EPC that contribute to endothelial replacement. This not only compromises neovasculogenesis in ischemic tissues but also impairs, at an early stage, the reendotheliziation process at sites of injury, contributing to the development of endothelial dysfunction and cardiovascular complications. Hyperglycemia, insulin resistance and dyslipidemia promote putative EPC dysregulation by affecting the SDF-1/CXCR-4 and NO pathways and the p53/SIRT1/p66Shc axis that contribute to their mobilization, migration, homing and vasculogenic properties. To optimize the clinical management of patients with hypoglycemic agents, statins and renin-angiotensin system inhibitors, which display pleiotropic effects on putative EPC, is a first step to improve their number and angiogenic potential but specific strategies are needed. Among them, mobilizing therapies based on G-CSF, erythropoietin or CXCR-4 antagonism have been developed to increase putative EPC number to treat ischemic diseases with or without prior cell isolation and transplantation. Growth factors, genetic and pharmacological strategies are also evaluated to improve ex vivo cultured EPC function before transplantation. Moreover, pharmacological agents increasing in vivo the bioavailability of NO and other endothelial factors demonstrated beneficial effects on neovascularization in diabetic ischemic models but their effects on endothelial dysfunction remain poorly evaluated. More experiments are warranted to develop orally available drugs and specific agents targeting p66Shc to reverse putative EPC dysfunction in the expected goal of preventing endothelial dysfunction and diabetic cardiovascular complications.

Vasculogenesis and Diabetic Erectile Dysfunction: How Relevant Is Glycemic Control?

Erectile dysfunction (ED) is a complication of diabetes, condition responsible for causing endothelial dysfunction (EDys) and hampering repair mechanisms. However, scarce information is available linking vasculogenesis mediated by Endothelial Progenitor Cells (EPCs) and diabetes-associated ED. Furthermore, it remains to be elucidated if glycemic control plays a role on EPCs functions, EPCs modulators, and penile vascular health. We evaluated the effects of diabetes and insulin therapy on bone marrow (BM) and circulating EPCs, testosterone, and systemic/penile Stromal Derived Factor-1 alpha (SDF-1α) expression. Male Wistar rats were divided into groups: age-matched controls, 8-weeks streptozotocin-induced type 1 diabetics, and insulin-treated 8-weeks diabetics. EPCs were identified by flow cytometry for CD34/CD133/VEGFR2/CXCR4 antigens. Systemic SDF-1α and testosterone levels were evaluated by ELISA. Penile SDF-1α protein expression was assessed, in experimental and human diabetic cavernosal samples, by immunohistochemical techniques. Diabetic animals presented a reduction of BM-derived EPCs and an increase in putative circulating endothelial cells (CECs) sloughed from vessels wall. These alterations were rescued by insulin therapy. In addition, glycemic control promoted an increase in systemic testosterone and SDF-1α levels, which were significantly decreased in animals with diabetes. SDF-1α protein expression was reduced in experimental and human cavernosal diabetic samples, an effect prevented by insulin in treated animals. Insulin administration rescued the effects of diabetes on BM function, CECs levels, testosterone, and plasmatic/penile SDF-1α protein expression. This emphasizes the importance of glycemic control in the prevention of diabetes-induced systemic and penile EDys, by the amelioration of endothelial damage, and increase in protective pathways. J. Cell. Biochem. 118: 82-91, 2017. © 2016 Wiley Periodicals, Inc.

Reducing glucose variability with continuous subcutaneous insulin infusion increases endothelial progenitor cells in type 1 diabetes: an observational study

Circulating endothelial progenitor cells (EPCs) are involved in the repairing mechanisms of vascular damage. Glucose variability may contribute to the development of chronic vascular complications of diabetes. We evaluated whether reducing glucose variability with continuous subcutaneous insulin infusion (CSII) would increase circulating levels of EPCs in type 1 diabetes. The study population consisted of 106 type 1 diabetic patients: 41 subjects considered eligible for CSII completed a 6-month follow-up. Sixty-five patients on intensified insulin therapy with multiple daily injections served as control group. Seven EPCs phenotypes were assessed by flow cytometry, and glucose variability by mean amplitude of glycemic excursions (MAGE). Both CD34+KDR+ [difference between groups 32.0, 95 % CI (19.6-44.4) number/10(6) cells, P < 0.001] and CD34+KDR+CD133+ [12.5 (5.5-19.5), P < 0.001)] cell count increased at endpoint in the CSII group, associated with a reduction of MAGE [-1.1 (-2.1 to -0.1), P = 0.026]. No changes occurred in the control group. In multivariate analyses, changes in MAGE were independently associated with changes in both CD34+KDR+ (P = 0.019) and CD34+KDR+CD133+ (P = 0.022) cell count. Reducing glucose variability with CSII in type 1 diabetes increases circulating EPCs levels, suggesting a novel mechanism of vascular damage by oscillating glucose.

Molecular mechanisms associated with diabetic endothelial-erectile dysfunction

Erectile dysfunction (ED) is a common complication of diabetes, affecting up to 75% of all diabetic men. Although the aetiology of diabetic ED is multifactorial, endothelial dysfunction is recognized as a mainstay in the pathophysiology of the disease. Endothelial dysfunction is induced by the detrimental actions of high glucose levels and increased oxidative stress on endothelial cells that make up the vascular lining. Besides directly injuring the endothelium, diabetes might also hamper vascular repair mechanisms of angiogenesis and vasculogenesis. These states exacerbate and maintain endothelial dysfunction, impairing vasorelaxation events and cavernosal blood perfusion, which are crucial for normal erectile function.