D-Peptide analogues of Boc-Phe-Leu-Phe-Leu-Phe-COOH induce neovascularization via endothelial N-formyl peptide receptor 3

The N-formyl peptide receptors: much more than chemoattractant receptors. Relevance in health and disease

Pattern Recognition Receptors (PRRs) are a superfamily of receptors that detect molecular structures typical for pathogens and damaged cells and play a crucial role in the proper function of the innate immune system. A particular subgroup of membrane-bound PRRs is represented by the N-formyl peptide receptors (FPRs) that consist of transmembrane G-protein coupled receptors involved in inflammatory responses. FPRs were initially described in immune cells as transducers of chemotactic signals in phagocytes that react to tissue injury. Subsequently, FPRs were also identified in a wide variety of cell types, including cancer cells. Beyond broad cellular distribution, FPRs are also characterized by the ability to bind a variety of ligands with different chemical and biological properties, ranging from natural peptides to synthetic compounds. The binding of FPRs to specific agonists induces a cascade of functional biological events, such as cell proliferation, migration, angiogenesis, and oxidative stress. From all this evidence, it becomes clear that FPRs are multifaceted receptors involved in several pathophysiological processes associated with inflammation. In this review, we provide a comprehensive molecular description of structure-function relationship of FPRs and their pivotal role in the host defense, highlighting the regulatory functions in both the initiation and resolution of inflammation. In addition to their activity as PRRs during innate immune response, we focus on their involvement in pathological conditions, including chronic inflammatory disease, neurodegenerative disorders, and cancer, with special emphasis on FPR targeting as promising therapeutic strategies in the era of precision medicine.

Exploring Tryptophan-based Short Peptides: Promising Candidate for Anticancer and Antimicrobial Therapies

BACKGROUND

Ultra-short peptides are essential therapeutic agents due to their heightened selectivity and reduced toxicity. Scientific literature documents the utilization of dipeptides, tripeptides, and tetrapeptides as promising agents for combating cancer. We have created a range of tryptophan-based peptides derived from literature sources in order to assess their potential as anticancer drugs.

METHODS

We present the results of our study on the antibacterial and anticancer effectiveness of 10 ultra-short peptides that were produced utilizing microwave-assisted solid phase peptide synthesis. The synthesized peptides underwent screening for in vitro antibacterial activity using the agar dilution method.

RESULTS

HPLC, LC-MS, 1H NMR, and 13C NMR spectroscopy were used to analyze the synthesized peptides. In tests using the HeLa and MCF-7 cell lines, the synthesized peptides' anticancer efficacy was assessed. The study found that two peptides showed potential median inhibitory concentration (IC50) values of 3.9±0.13 μM and 1.8±0.09 μM, respectively, and showed more activity than the reference medication doxorubicin.

CONCLUSION

The antibacterial activity of synthesized peptides 3b and 4b was found to be better than the other synthetic peptides. MIC value of roughly 5-50 μg/mL for peptides 3a, 4c, and 4d showed strong antifungal activity against Candida albicans. The synthesized peptides were also evaluated for their anticancer activity against HeLa and MCF-7 cell lines, and found that peptides 3e and 4e were more potent than other peptides against doxorubicin.

Neuroprotective Action of Humanin and Humanin Analogues: Research Findings and Perspectives

Humanin is a 24-mer peptide first reported in the early 2000s as a new neuroprotective/cytoprotective factor rescuing neuronal cells from death induced by various Alzheimer's disease-associated insults. Nowadays it is known that humanin belongs to the novel class of the so-called mitochondrial-derived peptides (which are encoded by mitochondrial DNA) and has been shown to exert beneficial cytoprotective effects in a series of in vitro and/or in vivo experimental models of human diseases, including not only neurodegenerative disorders but other human diseases as well (e.g., age-related macular degeneration, cardiovascular diseases, or diabetes mellitus). This review article is focused on the presentation of recent in vitro and in vivo research results associated with the neuroprotective action of humanin as well as of various, mainly synthetic, analogues of the peptide; moreover, the main mode(s)/mechanism(s) through which humanin and humanin analogues may exert in vitro and in vivo regarding neuroprotection have been reported. The prospects of humanin and humanin analogues to be further investigated in the frame of future research endeavors against neurodegenerative/neural diseases have also been briefly discussed.

Molecular mechanism of VEGF and its role in pathological angiogenesis

Over the last seven decades, a significant scientific contribution took place in the delineation of the implications of vascular endothelial-derived growth factor (VEGF) in the processes of angiogenesis. Under pathological conditions, mainly in response to hypoxia or ischemia, elevated VEGF levels promote vascular damage and the growth of abnormal blood vessels. Indeed, the development of VEGF biology has revolutionized our understanding of its role in pathological conditions. Hence, targeting VEGF or VEGF-mediated molecular pathways could be an excellent therapeutic strategy for managing cancers and intraocular neovascular disorders. Although anti-VEGF therapies, such as monoclonal antibodies and small-molecule tyrosine kinase inhibitors, have limited clinical efficacy, they can still significantly improve the overall survival rate. This thus demands further investigation through the development of alternative strategies in the management of VEGF-mediated pathological angiogenesis. This review article focuses on the recent developments toward the delineation of the functional biology of VEGF and the role of anti-VEGF strategies in the management of tumor and eye pathologies. Moreover, therapeutic angiogenesis, an exciting frontier for the treatment of ischemic disorders, is highlighted in this review, including wound healing.

Molecular mechanisms of coronary microvascular endothelial dysfunction in diabetes mellitus: focus on mitochondrial quality surveillance

Coronary microvascular endothelial dysfunction is both a culprit and a victim of diabetes, and can accelerate diabetes-related microvascular and macrovascular complications by promoting vasoconstrictive, pro-inflammatory and pro-thrombotic responses. Perturbed mitochondrial function induces oxidative stress, disrupts metabolism and activates apoptosis in endothelial cells, thus exacerbating the progression of coronary microvascular complications in diabetes. The mitochondrial quality surveillance (MQS) system responds to stress by altering mitochondrial metabolism, dynamics (fission and fusion), mitophagy and biogenesis. Dysfunctional mitochondria are prone to fission, which generates two distinct types of mitochondria: one with a normal and the other with a depolarized mitochondrial membrane potential. Mitochondrial fusion and mitophagy can restore the membrane potential and homeostasis of defective mitochondrial fragments. Mitophagy-induced decreases in the mitochondrial population can be reversed by mitochondrial biogenesis. MQS abnormalities induce pathological mitochondrial fission, delayed mitophagy, impaired metabolism and defective biogenesis, thus promoting the accumulation of unhealthy mitochondria and the activation of mitochondria-dependent apoptosis. In this review, we examine the effects of MQS on mitochondrial fitness and explore the association of MQS disorders with coronary microvascular endothelial dysfunction in diabetes. We also discuss the potential to treat diabetes-related coronary microvascular endothelial dysfunction using novel MQS-altering drugs.

Mitofusin-2 Enhances Mitochondrial Contact With the Endoplasmic Reticulum and Promotes Diabetic Cardiomyopathy

Diabetic cardiomyopathy has been associated with mitochondrial damage. Mitochondria–endoplasmic reticulum (ER) contact is an important determinant of mitochondrial function and ER homeostasis. We therefore investigated whether hyperglycemia can damage the mitochondria by increasing their contact with the ER in cardiomyocytes. We found that hyperglycemia induced mitochondria–ER contact in cardiomyocytes, as evidenced by the increased MMM1, MDM34, and BAP31 expressions. Interestingly, the silencing of Mfn2 reduced the cooperation between the mitochondria and the ER in cardiomyocytes. Mfn2 silencing improved cardiomyocyte viability and function under hyperglycemic conditions. Additionally, the silencing of Mfn2 markedly attenuated the release of calcium from the ER to the mitochondria, thereby preserving mitochondrial metabolism in cardiomyocytes under hyperglycemic conditions. Mfn2 silencing reduced mitochondrial reactive oxygen species production, which reduced mitochondria-dependent apoptosis in hyperglycemia-treated cardiomyocytes. Finally, Mfn2 silencing attenuated ER stress in cardiomyocytes subjected to high-glucose stress. These results demonstrate that Mfn2 promotes mitochondria–ER contact in hyperglycemia-treated cardiomyocytes. The silencing of Mfn2 sustained mitochondrial function, suppressed mitochondrial calcium overload, prevented mitochondrial apoptosis, and reduced ER stress, thereby enhancing cardiomyocyte survival under hyperglycemic conditions.

Identification of FPR3 as a Unique Biomarker for Targeted Therapy in the Immune Microenvironment of Breast Cancer

Although research into immunotherapy is growing, its use in the treatment of breast cancer remains limited. Thus, identification and evaluation of prognostic biomarkers of tissue microenvironments will reveal new immune-based therapeutic strategies for breast cancer. Using an in silico bioinformatic approach, we investigated the tumor microenvironmental and genetic factors related to breast cancer. We calculated the Immune score, Stromal score, Estimate score, Tumor purity, TMB (Tumor mutation burden), and MATH (Mutant-allele tumor heterogeneity) of Breast cancer patients from the Cancer Genome Atlas (TCGA) using the ESTIMATE algorithm and Maftools. Significant correlations between Immune/Stromal scores with breast cancer subtypes and tumor stages were established. Importantly, we found that the Immune score, but not the Stromal score, was significantly related to the patient's prognosis. Weighted correlation network analysis (WGCNA) identified a pattern of gene function associated with Immune score, and that almost all of these genes (388 genes) are significantly upregulated in the higher Immune score group. Protein-protein interaction (PPI) network analysis revealed the enrichment of immune checkpoint genes, predicting a good prognosis for breast cancer. Among all the upregulated genes, FPR3, a G protein-coupled receptor essential for neutrophil activation, is the sole factor that predicts poor prognosis. Gene set enrichment analysis analysis showed FRP3 upregulation synergizes with the activation of many pathways involved in carcinogenesis. In summary, this study identified FPR3 as a key immune-related biomarker predicting a poor prognosis for breast cancer, revealing it as a promising intervention target for immunotherapy.

Coronary Endothelium No-Reflow Injury Is Associated with ROS-Modified Mitochondrial Fission through the JNK-Drp1 Signaling Pathway

Coronary artery no-reflow is a complex problem in the area of reperfusion therapy, and the molecular mechanisms underlying coronary artery no-reflow injury have not been fully elucidated. In the present study, we explored whether oxidative stress caused damage to coronary endothelial cells by inducing mitochondrial fission and activating the JNK pathway. The hypoxia/reoxygenation (H/R) model was induced in vitro to mimic coronary endothelial no-reflow injury, and mitochondrial fission, mitochondrial function, and endothelial cell viability were analyzed using western blotting, quantitative polymerase chain reaction (qPCR), enzyme-linked immunosorbent assay (ELISA), and immunofluorescence. Our data indicated that reactive oxygen species (ROS) were significantly induced upon H/R injury, and this was followed by decreased endothelial cell viability. Mitochondrial fission was induced and mitochondrial bioenergetics were impaired in cardiac endothelial cells after H/R injury. Neutralization of ROS reduced mitochondrial fission and protected mitochondrial function against H/R injury. Our results also demonstrated that ROS stimulated mitochondrial fission via JNK-mediated Drp1 phosphorylation. These findings indicate that the ROS-JNK-Drp1 signaling pathway may be one of the molecular mechanisms underlying endothelial cell damage during H/R injury. Novel treatments for coronary no-reflow injury may involve targeting mitochondrial fission and the JNK-Drp1 signaling pathway.

Simultaneously characterization of tumoral angiogenesis and vasculogenesis in stem cell-derived teratomas

Tumor neovascularization may occur via both angiogenic and vasculogenic events. In order to investigate the vessel formation during tumor growth, we developed a novel experimental model that takes into account the differentiative and tumorigenic properties of Embryonic Stem cells (ESCs). Leukemia Inhibitory Factor-deprived murine ESCs were grafted on the top of the chick embryo chorionallantoic membrane (CAM) in ovo. Cell grafts progressively grew, forming a vascularized mass within 10 days. At this stage, the grafts are formed by cells with differentiative features representative of all three germ layers, thus originating teratomas, a germinal cell tumor. In addition, ESC supports neovascular events by recruiting host capillaries from surrounding tissue that infiltrates the tumor mass. Moreover, immunofluorescence studies demonstrate that perfused active blood vessels within the tumor are of both avian and murine origin because of the simultaneous occurrence of angiogenic and vasculogenic events. In conclusion, the chick embryo ESC/CAM-derived teratoma model may represent a useful approach to investigate both vasculogenic and angiogenic events during tumor growth and for the study of natural and synthetic modulators of the two processes.

COVID-19 and pneumonia: a role for the uPA/uPAR system

Here, we highlight recent findings on the urokinase plasminogen activator (uPA)/uPA receptor (uPAR) system that suggest its potential role as a main orchestrator of fatal progression to pulmonary, kidney, and heart failure in patients with coronavirus. Patients with prolonged background inflammation can present aberrant inflammatory reactions, well recognized as the main factors that can result in death and probably sustained by a dysregulated uPA/uPAR system. SuPAR, the soluble form of uPAR, represents a biomarker of disease progression, and its levels correlate well with comorbidities associated with the death of patients with coronavirus. New drugs that regulate the uPA/uPAR system could help treat the severe complications of highly pathogenic human coronaviruses (hCoVs), including pandemic coronavirus 2019 (COVID-19).