Study of the association of adrenomedullin and basic-fibroblast growth factors with the peripheral arterial blood flow and endothelial dysfunction biomarkers in type 2 diabetic patients with peripheral vascular insufficiency

Adrenomedullin, transcriptionally regulated by vitamin D receptors, alleviates atherosclerosis in mice through suppressing AMPK-mediated endothelial ferroptosis

PURPOSE

Vitamin D receptors (VDR) play important roles in cardiovascular, immune, metabolic and other functions. Activation of VDR may help improve endothelial dysfunction, atherosclerosis, vascular calcification, and cardiac hypertrophy. However, the specific target genes and mechanisms of VDR in improving Human Umbilical Vein Endothelial Cell (HUVEC) functions remain unclear. This study aims to investigate the function and mechanism of VDR in HUVECs.

METHODS

Endothelial dysfunction cell model was constructed by oxidized low-density lipoprotein (ox-LDL). An animal model of atherosclerosis was established in male homozygous Apoe-/- mice (6 weeks) on a high fat diet for 6 weeks. The relationship between VDR and adrenomedullin (ADM) was studied by bioinformatics analysis, ChIP, and luciferase reporter gene analysis. Endothelial cell function was evaluated by Transwell migration and Tube Formation tests. Ferroptosis was detected by measuring intracellular iron content, levels of oxidative stress markers, and ferroptosis related proteins.

RESULTS

Overexpression of VDR in HUVECs inhibits ox-LDL-induced endothelial dysfunction and ferroptosis. VDR binds to the ADM promoter sequence and regulates the transcription of ADM. Inhibition of ADM promotes ox-LDL-induced endothelial dysfunction and ferroptosis. ADM regulates ox-LDL-induced endothelial dysfunction and ferroptosis through the AMPK signaling pathway. Overexpression of VDR in Apoe-/- mice inhibited lipid deposition and plaque area in atherosclerotic mice.

CONCLUSION

VDR inhibits ox-LDL-induced endothelial dysfunction and ferroptosis by regulating ADM transcription and acting on AMPK signaling pathway. Overexpression of VDR in Apoe-/- mice reduced lipid deposition and plaque area in the thoracic aorta of atherosclerotic mice.

Sustained Activation of CLR/RAMP Receptors by Gel-Forming Agonists

Background: Adrenomedullin (ADM), adrenomedullin 2 (ADM2), and CGRP family peptides are important regulators of vascular vasotone and integrity, neurotransmission, and fetoplacental development. These peptides signal through CLR/RAMP1, 2, and 3 receptors, and protect against endothelial dysfunction in disease models. As such, CLR/RAMP receptor agonists are considered important therapeutic candidates for various diseases. Methods and Results: Based on the screening of a series of palmitoylated chimeric ADM/ADM2 analogs, we demonstrated a combination of lipidation and accommodating motifs at the hinge region of select peptides is important for gaining an enhanced receptor-activation activity and improved stimulatory effects on the proliferation and survival of human lymphatic endothelial cells when compared to wild-type peptides. In addition, by serendipity, we found that select palmitoylated analogs self-assemble to form liquid gels, and subcutaneous administration of an analog gel led to the sustained presence of the peptide in the circulation for >2 days. Consistently, subcutaneous injection of the analog gel significantly reduced the blood pressure in SHR rats and increased vasodilation in the hindlimbs of adult rats for days. Conclusions: Together, these data suggest gel-forming adrenomedullin analogs may represent promising candidates for the treatment of various life-threatening endothelial dysfunction-associated diseases such as treatment-resistant hypertension and preeclampsia, which are in urgent need of an effective drug.

The co-activator-associated arginine methyltransferase 1 (CARM1) gene is overexpressed in type 2 diabetes

PURPOSE

We examined the expression of a panel of epigenetic enzymes catalyzing histone tails post-transcriptional modifications, together with effectors of metabolic and inflammatory alterations, in type 2 diabetes.

METHODS

Cross-sectional, case-control study of 21 people with type 2 diabetes and 21 matched controls. Total RNA was extracted from white cells and reverse transcribed. PCR primer assays for 84 key genes encoding enzymes known to modify genomic DNA and histones were performed. Western blot was performed on lysates using primary antibodies for abnormally expressed enzymes. Hormones and cytokines were measured by multiplex kits. A Bayesian network was built to investigate the relationships between epigenetic, cytokine, and endocrine variables.

RESULTS

Co-activator-associated aRginine Methyltransferase 1 (CARM1) expression showed a five-fold higher median value, matched by higher protein levels, among patients who also had increased GIP, IL-4, IL-7, IL-13, IL-17, FGF basic, G-CSF, IFN-γ, and TNFα and decreased IP-10. In a Bayesian network approach, CARM1 expression showed a conditional dependence on diabetes, but was independent of all other variables nor appeared to influence any.

CONCLUSIONS

Increased CARM1 expression in type 2 diabetes suggests that epigenetic mechanisms are altered in human diabetes. The impact of lifestyle and pharmacological treatment on regulation of this enzyme should be further investigated.

A pro-angiogenic degradable Mg-poly(lactic-co-glycolic acid) implant combined with rhbFGF in a rat limb ischemia model

Site-specific controlled release of exogenous angiogenic growth factors, such as recombinant human basic fibroblast growth factor (rhbFGF), has become a promising approach to improve peripheral vascular disease. Here, we have developed an implant composed of spiral magnesium (Mg) and a coating made using poly(lactic-co-glycolic acid) (PLGA) with encapsulated rhbFGF (Mg-PLGA-rhbFGF). The encapsulated protein could release continually for 4weeks with well preserved bioactivity. We compared the angiogenic effect produced by Mg-PLGA-rhbFGF with that of a PLGA implant loaded with rhbFGF (PLGA-rhbFGF). The incorporation of Mg in the implant raised the microclimate pH in the polymer, which preserved the stability of rhbFGF. Mg-PLGA-rhbFGF exhibited advantages over PLGA-rhbFGF implant in terms of a cytocompatibility evaluation. An in vivo angiogenesis test further confirmed the efficacy of released rhbFGF. HE, CD31 and α-SMA staining revealed that the controlled release of rhbFGF from the Mg-PLGA-rhbFGF implant was superior in promoting angiogenesis compared with that of the PLGA-rhbFGF implant. Four weeks post-implantation, the capillary density of the Mg-PLGA-rhbFGF group was significantly higher than that of the PLGA-rhbFGF, control and the normal group (p<0.05, p<0.01 and p<0.01, respectively). Furthermore, the limb blood perfusion ratios of the Mg-PLGA-rhbFGF and PLGA-rhbFGF groups were dramatically increased, at 99.1±2.9% and 80.7±3.2%, respectively, whereas the ischemic limb did not recover in the control group. The biocompatibility of the implants was also evaluated. In conclusion, Mg-PLGA-based, sustained local delivery of rhbFGF promotes post-ischemic angiogenesis and blood flow recovery. The results suggest potential therapeutic usefulness of Mg-PLGA-rhbFGF for tissue ischemia.

STATEMENT OF SIGNIFICANCE

Magnesium (Mg)-based implant has been already used in patients with critical limb ischemia. Site-specific controlled release of recombinant human basic fibroblast growth factor (rhbFGF), has become a promising approach to improve peripheral vascular disease. We report here on a novel combination implant composed of spiral magnesium and a coating made using poly(lactic-co-glycolic acid) (PLGA) with encapsulated rhbFGF (Mg-PLGA-rhbFGF). The preparation method does not involve any complex processes and results in a high encapsulation efficiency (approximately 100%). The degradation of metal Mg raise the microclimate pH in the PLGA polymer, which could well preserve the bioactivity of rhbFGF incorporated in the implant. Mg-PLGA-based, sustained local delivery of rhbFGF promotes post-ischemic angiogenesis and blood flow recovery in rat limb ischemic model. This work marks the first report for controlled release of rhbFGF in combination with metal Mg, and suggests potential therapeutic usefulness of Mg-PLGA-rhbFGF for tissue ischemia.

Blood levels of pro-inflammatory and anti-inflammatory cytokines during an oral glucose tolerance test in patients with symptoms suggesting reactive hypoglycemia

We evaluated the impact of postprandial glycemia on blood levels of pro-inflammatory and anti-inflammatory cytokines during an oral glucose tolerance test in non-diabetic patients with symptoms suggesting reactive hypoglycemia. Eleven patients with clinical symptoms suggesting reactive hypoglycemia received an oral glucose solution (75 g) Blood was collected at 0 (baseline), 30, 60, 120 and 180 min after glucose ingestion and the plasma concentrations of interferon-α (IFN-α), interferon-γ (IFN-γ), interleukin-1 receptor antagonist (IL-1RA), interleukin 2 (IL-2), interleukin-2 receptor (IL-2R), interleukin 4 (IL-4), interleukin 6 (IL-6), interleukin 8 (IL-8), interleukin 10 (IL-10), interleukin-12 (IL-12), interleukin 13 (IL-13), interleukin 15 (IL-15), interleukin 17 (IL-17), IFN-γ inducible protein 10 (IP-10), monocyte chemotactic protein 1 (MCP1), monokine induced by IFN-γ (MIG), macrophage inflammatory protein-1α (MIP-1α), interleukin-1β (IL-1β), colony stimulating factor (G-CSF), granulocyte-macrophage CSF (GM-CSF), basic fibroblast growth factor (FGF-basic), eotaxin, tumor necrosis factor α (TNFα), epidermal growth factor (EGF), hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF), macrophage inflammatory protein-1α (MIP-1α), and 1β (MIP-1β) were evaluated. Overall, glycemic levels increased, reached its maximum at 30 min (phase 1), returned to baseline levels at 120 min (phase 2), followed by a mild hypoglycemia at 180 min (phase 3). During phase 1, cytokine blood levels were maintained. However, we observed a synchronous fall (P<0.05) in the concentrations of pro-inflammatory (IL-15, IL-17, MCP-1) and anti-inflammatory cytokines (FGF-basic, IL-13, IL-1RA) during phase 2. Furthermore, a simultaneous rise (P<0.05) of pro-inflammatory (IL-2, IL-5, IL-17) and anti-inflammatory cytokines (IL-4, IL-1RA, IL-2R, IL-13, FGF-basic) occurred during phase 3. Thus, mild acute hypoglycemia but not a physiological increase of glycemia was associated with increased blood levels of anti-inflammatory and pro-inflammatory cytokines.

Aqueous humour concentrations of TGF-β, PLGF and FGF-1 and total retinal blood flow in patients with early non-proliferative diabetic retinopathy

PURPOSE

To correlate angiogenic cytokines in the aqueous humour with total retinal blood flow in subjects with type 2 diabetes with non-proliferative diabetic retinopathy (NPDR).

METHODS

A total of 17 controls and 16 NPDR patients were recruited into the study. Aqueous humour was collected at the start of cataract surgery to assess the concentration of 14 angiogenic cytokines. Aqueous humour was analysed using the suspension array method. Six images were acquired to assess total retinal blood flow (TRBF) using the prototype RTVue^™ Doppler Fourier domain optical coherence tomography (Doppler FD-OCT) (Optovue, Inc., Fremont, CA) using a double circular scan protocol, 1 month postsurgery. At the same visit, forearm blood was collected to determine glycosylated haemoglobin (A1c).

RESULTS

Transforming growth factor beta (TGF-β1, TGF-β2) and PLGF were increased while FGF-1 was reduced in NPDR compared to controls (Bonferroni corrected, p < 0.003 for all). Total retinal blood flow (TRBF) was significantly reduced in the NPDR group compared to controls (33.1 ± 9.9 versus 43.3 ± 5.3 μl/min, p = 0.002). Aqueous FGF-1 significantly correlated with TRBF in the NPDR group (r = 0.71, p = 0.01; r²  = 0.51). In a multiple regression analysis, A1c was found to be a significant predictor of aqueous TGF-β1 and FGF-1 (p = 0.018 and p = 0.020, respectively).

CONCLUSION

Aqueous angiogenic cytokines (TGF-β1, TGF-β2 and PLGF) were elevated in conjunction with a reduction in TRBF in patients with NPDR compared to controls. Non-invasive measurement of TRBF may be useful for predicting aqueous FGF-1 levels and severity of vasculopathy in DR.

Current and Emerging Technology for Continuous Glucose Monitoring

Diabetes has become a leading cause of death worldwide. Although there is no cure for diabetes, blood glucose monitoring combined with appropriate medication can enhance treatment efficiency, alleviate the symptoms, as well as diminish the complications. For point-of-care purposes, continuous glucose monitoring (CGM) devices are considered to be the best candidates for diabetes therapy. This review focuses on current growth areas of CGM technologies, specifically focusing on subcutaneous implantable electrochemical glucose sensors. The superiority of CGM systems is introduced firstly, and then the strategies for fabrication of minimally-invasive and non-invasive CGM biosensors are discussed, respectively. Finally, we briefly outline the current status and future perspective for CGM systems.

Analysis of Serum Endothelial Cell-Specific Molecule 1 (Endocan) Level in Type 2 Diabetes Mellitus With Acute ST-Segment Elevation Myocardial Infarction and its Correlation

Endothelial cell-specific molecule 1 (ESM-1; endocan) is expressed by endothelial cells, and it can be overexpressed in diabetic patients. However, little is known concerning diabetic patients with acute ST-segment elevation myocardial infarction (STEMI). Therefore, we assessed serum ESM-1 level in patients having type 2 diabetes mellitus (T2DM) STEMI; 72 patients with DM (38 with and 34 without vascular disease) and 33 individuals as a control group were included. There was a significant difference in serum ESM-1 level between the T2DM group and the control group ( P = .03). There was also a significant difference in serum ESM-1 level between the T2DM with STEMI group and newly diagnosed T2DM group without vascular disease ( P = .01). In patients with T2DM, serum ESM-1 levels correlated positively with high-sensitivity C-reactive protein levels and the neutrophil to lymphocyte ratio ( r = .321, P = .006 and r = .320, P = .006). Our findings suggest that serum ESM-1 level may be a novel endothelial dysfunction biomarker and it may be related to vascular disease in T2DM.

Whole blood glucose analysis based on smartphone camera module

Complementary metal oxide semiconductor (CMOS) image sensors have received great attention for their high efficiency in biological applications. The present work describes a CMOS image sensor-based whole blood glucose monitoring system through a point-of-care (POC) approach. A simple poly-ethylene terephthalate (PET) chip was developed to carry out the enzyme kinetic reaction at various concentrations (110–586 mg∕dL) of mouse blood glucose. In this technique, assay reagent is immobilized onto amine functionalized silica (AFSiO2) nanoparticles as an electrostatic attraction in order to achieve glucose oxidation on the chip. The assay reagent immobilized AFSiO2 nanoparticles develop a semi-transparent reaction platform, which is technically a suitable chip to analyze by a camera module. The oxidized glucose then produces a green color according to the glucose concentration and is analyzed by the camera module as a photon detection technique; the photon number decreases when the glucose concentration increases. The combination of these components, the CMOS image sensor and enzyme immobilized PET film chip, constitute a compact, accurate, inexpensive, precise, digital, highly sensitive, specific, and optical glucose-sensing approach for POC diagnosis.