Molecular Mechanisms Associated with ROS-Dependent Angiogenesis in Lower Extremity Artery Disease

A novel class of potent antiangiogenic and antioxidant pyrazoles: synthesis, bioactivity, docking and ADMET studies

Aim: Angiogenesis is the hallmark of cancer progression driven by VEGF/VEGFR-2 signalling pathway, inhibition of which could be a solution to tackle the progression of tumour cells and thus arresting their growth.Materials & methods: A novel class of pyrazoles was synthesized using arginine and dibromo ketones. Antiangiogenic activity was performed by in vivo yolk sac method. Antioxidant activity was evaluated by hydroxyl and superoxide radical scavenging assays. Docking studies were performed to determine the pyrazoles' binding potential with VEGFR-2 receptor and VEGF tyrosine kinase. ADMET properties were calculated using SwissADME and admetSAR for drug-likeness.Results: Compounds 5a-e showed significant antiangiogenic effects. Compound 5f exhibited effective hydroxyl and superoxide radical scavenging activities. Docking results confirmed the potential binding efficiency with VEGFR-2 receptor over VEGF tyrosine kinase, thus, functioning as competitive-inhibitors. ADMET studies revealed that the compounds possess favourable drug-like qualities.Conclusion: This study presents a novel class of pyrazoles as promising antioxidant and antiangiogenic agents with favourable drug-likeness properties.

Microneedle system for tissue engineering and regenerative medicines: a smart and efficient therapeutic approach

The global demand for an enhanced quality of life and extended lifespan has driven significant advancements in tissue engineering and regenerative medicine. These fields utilize a range of interdisciplinary theories and techniques to repair structurally impaired or damaged tissues and organs, as well as restore their normal functions. Nevertheless, the clinical efficacy of medications, materials, and potent cells used at the laboratory level is always constrained by technological limitations. A novel platform known as adaptable microneedles has been developed to address the abovementioned issues. These microneedles offer a solution for the localized distribution of various cargos while minimizing invasiveness. Microneedles provide favorable patient compliance in clinical settings due to their effective administration and ability to provide a painless and convenient process. In this review article, we summarized the most recent development of microneedles, and we started by classifying various microneedle systems, advantages, and fundamental properties. Subsequently, it provides a comprehensive overview of different types of microneedles, the material used to fabricate microneedles, the fundamental properties of ideal microneedles, and their applications in tissue engineering and regenerative medicine, primarily focusing on preserving and restoring impaired tissues and organs. The limitations and perspectives have been discussed by concluding their future therapeutic applications in tissue engineering and regenerative medicines.

Reversion of the Inflammatory Markers in Patients With Chronic Limb-Threatening Ischemia

BACKGROUND

Peripheral artery disease is characterized by an intense inflammatory process that can be associated with a higher mortality rate, particularly in chronic limb-threatening ischemia (CLTI). This study aims to compare the evolution of inflammatory markers between patients with claudication with those with CLTI at 3, 6, and 12 months.

METHODS AND RESULTS

An observational, single-center, and prospective study was conducted. A total of 119 patients with peripheral artery disease (65 with claudication and 54 with CLTI) were observed and inflammatory markers collected at admission and 3, 6, and 12 months. At admission, patients with CLTI, when compared with patients with claudication, had significantly higher serum levels of C-reactive protein and fibrinogen (positive acute-phase proteins) and lower serum level of albumin, total cholesterol, and high-density lipoprotein (negative acute-phase proteins): C-reactive protein (g/dL), 2.90 (25th-75th percentile, 2.90-4.90) versus 6.80 (25th-75th percentile, 2.90-53.26) (P=0.000); fibrinogen (mg/dL), 293.00 (25th-75th percentile, 269.25-349.00) versus 415.50 (25th-75th percentile, 312.00-615.75) (P=0.000); total cholesterol (mg/dL), 161.79±95% [152.74-170.85] versus 146.42%±95% [135.30-157.53] (P=0.034); high-density lipoprotein (mg/dL), 50.00 (25th-75th percentile, 41.00-60.00) versus 37.00 (25th-75th percentile, 30.00-45.50) (P=0.000); albumin (g/dL): 4.00 (25th-75th percentile, 3.70-4.20) versus 3.60 (25th-75th percentile, 3.10-4.00) (P=0.003). The association between CLTI and total cholesterol was lost after adjusting for confounders. Three months after the resolution of the CLTI, there was an increase in the levels of negative acute-phase proteins and a decrease in positive acute-phase proteins. These inflammatory proteins did not register an evolution in patients with claudication. The differences in the inflammatory proteins between groups disappeared at 6 months.

CONCLUSIONS

CLTI has an inflammatory environment that can be partially reverted after resolution of the ischemic process, emphasizing the importance of timely intervention.

Association between homocysteine level and length of stay in patients with lower extremity atherosclerotic disease: a retrospective cohort study

OBJECTIVES

Homocysteine (Hcy) level has been widely identified as a risk factor associated with adverse outcomes in patients with lower extremity atherosclerotic disease (LEAD). However, there are still some knowledge gaps in research on the association between Hcy level and downstream adverse outcomes, such as length of stay (LOS). This study aims to explore whether and to what extent Hcy level is associated with LOS in patients with LEAD.

DESIGN

Retrospective cohort study.

SETTING

China.

PARTICIPANTS, PRIMARY AND SECONDARY OUTCOMES

We conducted a retrospective cohort study of 748 patients from inpatients with LEAD between January 2014 and November 2021 at the First Hospital of China Medical University in China. We used a slew of generalised linear models to evaluate the association between Hcy level and LOS.

RESULTS

The patients' median age was 68 years and 631 (84.36%) were males. A dose-response curve with an inflection point at 22.63 µmol/L was observed between Hcy level and LOS after the adjustment of potential confounders. LOS increased before Hcy level reached the inflection point (β: 0.36; 95% CI: 0.18 to 0.55; p<0.001).ConclusionOur results show that an Hcy level <22.63 µmol/L is associated with increased LOS in patients with LEAD, which was independent of some other risk factors. This might shed light on how Hcy can be used as a key marker in the comprehensive management of patients with LEAD during hospitalisation.

In Vitro and In Vivo Characterization Methods for Evaluation of Modern Wound Dressings

Chronic wound management represents a major challenge in the healthcare sector owing to its delayed wound-healing process progression and huge financial burden. In this regard, wound dressings provide an appropriate platform for facilitating wound healing for several decades. However, adherent traditional wound dressings do not provide effective wound healing for highly exudating chronic wounds and need the development of newer and innovative wound dressings to facilitate accelerated wound healing. In addition, these dressings need frequent changing, resulting in more pain and discomfort. In order to overcome these issues, a wide range of affordable and innovative modern wound dressings have been developed and explored recently to accelerate and improve the wound healing process. However, a comprehensive understanding of various in vitro and in vivo characterization methods being utilized for the evaluation of different modern wound dressings is lacking. In this context, an overview of modern dressings and their complete in vitro and in vivo characterization methods for wound healing assessment is provided in this review. Herein, various emerging modern wound dressings with advantages and challenges have also been reviewed. Furthermore, different in vitro wound healing assays and in vivo wound models being utilized for the evaluation of wound healing progression and wound healing rate using wound dressings are discussed in detail. Finally, a summary of modern wound dressings with challenges and the future outlook is highlighted.

Noninvasive Evaluation of Angiogenesis and Therapeutic Response after Hindlimb Ischemia with an Integrin-Targeted Tracer by PET

Background

Peripheral arterial disease (PAD) can severely compromise limb vitality and function. Angiogenesis plays an important role in healing of ischemic lesions. Radiolabeled RGD (Arg-Gly-Asp) peptides specifically targeting α v β 3 integrin are promising tracers for imaging angiogenesis. In this study, we investigated the application of a one-step labeled RGD in evaluation of angiogenesis and therapy response in a mouse model of hindlimb ischemia (HI) by positron emission tomography (PET).

Methods

HI was induced by ablation of the femoral artery in mice. PET imaging using 18F-AlF-NOTA-PRGD2 (18F-PRGD2) tracer was performed at day 0 (pre-surgery) and days 3, 7, 14, and 21 after surgery to evaluate hindlimb angiogenesis longitudinally and noninvasively. The control peptide RAD (Arg-Ala-Asp) labeled with a similar procedure and a block agent were used to confirm the specific binding of 18F-PRGD2 to α v β 3 integrin. Ex vivo CD31 staining was performed to detect angiogenesis. In addition, the angiogenic therapy response was monitored with 18F-PRGD2 tracer and immunofluorescence staining to confirm the imaging data.

Results

The successful establishment of HI model was confirmed by ultrasound imaging and laser doppler perfusion imaging (LDPI). Specific binding of 18F-PRGD2 to α v β 3 integrin was validated by minimal tracer uptake of the control peptide RAD and significant decrease of tracer accumulation when a block agent was added. Local accumulation of 18F-RRGD2 in ischemic hindlimb was detected as early as 3 days and reached a peak at 7 days after surgery. The temporal change of focal tracer uptake was positively correlated with the pattern of vascular density. Moreover, vascular endothelial growth factor (VEGF) treatment increased the tracer uptake and enhanced angiogenesis, which is consistent with integrin β 3 expression.

Conclusions

PET imaging of a one-step labeled tracer 18F-PRGD2 targeted to α v β 3 integrin allows longitudinal monitoring of ischemia-induced angiogenesis and noninvasive assessment of VEGF treatment response in a mouse model of hindlimb ischemia. The simple synthesis procedure and in vivo performance of this PET tracer enables the feasibility of future clinical translation in ischemic cardiovascular diseases.

Advances in neovascularization after diabetic ischemia

With the high incidence of diabetes around the world, ischemic complications cause a serious influence on people's production and living. Neovascularization plays a significant role in its development. Therefore, neovascularization after diabetic ischemia has aroused attention and has become a hot spot in recent years. Neovascularization is divided into angiogenesis represented by atherosclerosis and arteriogenesis characterized by coronary collateral circulation. When mononuclear macrophages successively migrate to the ischemia anoxic zone after ischemia or hypoxia, they induce the secretion of cytokines, such as vascular endothelial growth factor and hypoxia-inducible factor, activate signaling pathways such as classic Wnt and phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt) pathways, trigger oxidative stress response, activate endothelial progenitor cells or enter the glycolysis or lactic acid process and promote the formation of new blood vessels, remodeling them into mature blood vessels and restoring blood supply. However, the hypoglycemic condition has different impacts on neovascularization. Consequently, this review aimed to introduce the mechanisms of neovascularization after diabetic ischemia, increase our un-derstanding of diabetic ischemic complications and their therapies and provide more treatment options for clinical practice and effectively relieve patients' pain. It is believed that in the near future, neovascularization will bring more benefits and hope to patients with diabetes.

P311 promotes type II transforming growth factor-β receptor mediated fibroblast activation and granulation tissue formation in wound healing

Background

P311, a highly conserved 8 kDa intracellular protein, has recently been reported to play an important role in aggravating hypertrophic scaring by promoting the differentiation and secretion of fibroblasts. Nevertheless, how P311 regulates the differentiation and function of fibroblasts to affect granulation tissue formation remains unclear. In this work, we studied the underlying mechanisms via which P311 affects fibroblasts and promotes acute skin wound repair.

Methods

To explore the role of P311, both in vitro and in vivo wound-healing models were used. Full-thickness skin excisional wounds were made in wild-type and P311^-/- C57 adult mice. Wound healing rate, re-epithelialization, granulation tissue formation and collagen deposition were measured at days 3, 6 and 9 after skin injury. The biological phenotypes of fibroblasts, the expression of target proteins and relevant signaling pathways were examined both in vitro and in vivo.

Results

P311 could promote the proliferation and differentiation of fibroblasts, enhance the ability of myofibroblasts to secrete extracellular matrix and promote cell contraction, and then facilitate the formation of granulation tissue and eventually accelerate skin wound closure. Importantly, we discovered that P311 acts via up-regulating the expression of type II transforming growth factor-β receptor (TGF-βRII) in fibroblasts and promoting the activation of the TGF-βRII-Smad signaling pathway. Mechanistically, the mammalian target of rapamycin signaling pathway is closely implicated in the regulation of the TGF-βRII-Smad pathway in fibroblasts mediated by P311.

Conclusions

P311 plays a critical role in activation of the TGF-βRII-Smad pathway to promote fibroblast proliferation and differentiation as well as granulation tissue formation in the process of skin wound repair.

Nerve growth factor and post-infarction cardiac remodeling

The prevalence of sudden death from chronic heart failure and cardiac arrhythmias caused by myocardial infarction is a complex problem in cardiology. Post-infarction cardiac remodeling occurs after myocardial infarction. This compensatory-adaptive reaction, regulated by mechanical, neurohumoral and genetic factors, includes the structural and functional changes of cardiomyocytes, stromal elements and extracellular matrix, geometry and architectonics of the left ventricular cavity. Adverse left ventricular remodeling is associated with heart failure and increased mortality. The concept of post-infarction cardiac remodeling is an urgent problem, since the mechanisms of development and progression of adverse post-infarction changes in the myocardium are completely unexplored. In recent years, the scientist attention has been focused on neurotrophic factors involved in the sympathetic nervous system and the vascular system remodeling after myocardial infarction. Nerve growth factor (NGF) is a protein from the neurotrophin family that is essential for the survival and development of sympathetic and sensory neurons, which also plays an important role in vasculogenesis. Acute myocardial infarction and heart failure are characterized by changes in the expression and activity of neurotrophic factors and their receptors, affecting the innervation of the heart muscle, as well as having a direct effect on cardiomyocytes, endothelial and smooth muscle vascular cells. The identification of the molecular mechanisms involved in the interactions between cardiomyocytes and neurons, as well as the study of the effects of NGF in the cardiovascular system, will improve understanding of the cardiac remodeling mechanism. This review summarizes the available scientific information (2019–2021) about mechanisms of the link between post-infarction cardiac remodeling and NGF functions.

Update on the pathophysiology and medical treatment of peripheral artery disease

Approximately 6% of adults worldwide have atherosclerosis and thrombosis of the lower limb arteries (peripheral artery disease (PAD)) and the prevalence is rising. PAD causes leg pain, impaired health-related quality of life, immobility, tissue loss and a high risk of major adverse events, including myocardial infarction, stroke, revascularization, amputation and death. In this Review, I describe the pathophysiology, presentation, outcome, preclinical research and medical management of PAD. Established treatments for PAD include antithrombotic drugs, such as aspirin and clopidogrel, and medications to treat dyslipidaemia, hypertension and diabetes mellitus. Randomized controlled trials have demonstrated that these treatments reduce the risk of major adverse events. The drug cilostazol, exercise therapy and revascularization are the current treatment options for the limb symptoms of PAD, but each has limitations. Novel therapies to promote collateral and new capillary growth and treat PAD-related myopathy are under investigation. Methods to improve the implementation of evidence-based medical management, novel drug therapies and rehabilitation programmes for PAD-related pain, functional impairment and ischaemic foot disease are important areas for future research.

A regenerative approach to the pharmacological management of hard-to-heal wounds

A wound is considered hard-to-heal when, despite the appropriate clinical analysis and intervention, the wound area reduces by less than a third at four weeks and complete healing fails to occur within 12 weeks. The most prevalent hard-to-heal wounds are associated with underlying metabolic diseases or vascular insufficiency and include arterial, venous, pressure and diabetic foot ulcers. Their common features include an abnormal immune response and extended inflammatory phase, a subdued proliferation phase due to cellular insufficiencies and finally an almost non-existent remodeling phase. Advances in wound care technology, tested in both pre-clinical models and clinical trials, have paved the way for improved treatment options, focused on regeneration. These interventions have been shown to limit the extent of ongoing inflammatory damage, decrease bacterial load, promote angiogenesis and deposition of granulation tissue, and stimulate keratinocyte migration thereby promoting re-epithelialization in these wounds. The current review discusses these hard-to-heal wounds in the context of their underlying pathology and potential of advanced treatment options, which if applied promptly as a standard of care, could reduce morbidity, promote quality of life, and alleviate the burden on a strained health system.

Expression Profile of Genes Encoding Proteins Involved in Regulation of Vasculature Development and Heart Muscle Morphogenesis-A Transcriptomic Approach Based on a Porcine Model

Despite significant advances in treatment of acute coronary syndromes (ACS) many subjects still develop heart failure due to significantly reduced ejection fraction. Currently, there are no commonly available treatment strategies that replace the infarcted/dysfunctional myocardium. Therefore, understanding the mechanisms that control the regeneration of the heart muscle is important. The development of new coronary vessels plays a pivotal role in cardiac regeneration. Employing microarray expression assays and RT-qPCR validation expression pattern of genes in long-term primary cultured cells isolated form the right atrial appendage (RAA) and right atrium (RA) was evaluated. After using DAVID software, it indicated the analysis expression profiles of genes involved in ontological groups such as: “angiogenesis”, “blood vessel morphogenesis”, “circulatory system development”, “regulation of vasculature development”, and “vasculature development” associated with the process of creation new blood vessels. The performed transcriptomic comparative analysis between two different compartments of the heart muscle allowed us to indicate the presence of differences in the expression of key transcripts depending on the cell source. Increases in culture intervals significantly increased expression of SFRP2, PRRX1 genes and some other genes involved in inflammatory process, such as: CCL2, IL6, and ROBO1. Moreover, the right atrial appendage gene encoding lysyl oxidase (LOX) showed much higher expression compared to the pre-cultivation state.