Contribution of cell death signaling to blood vessel formation

Engineering injectable hyaluronic acid-based adhesive hydrogels with anchored PRP to pattern the micro-environment to accelerate diabetic wound healing

Diabetic wounds remain a global challenge due to disordered wound healing led by inflammation, infection, oxidative stress, and delayed proliferation. Therefore, an ideal wound dressing for diabetic wounds not only needs tissue adhesiveness, injectability, and self-healing properties but also needs a full regulation of the microenvironment. In this work, adhesive wound dressings (HA-DA/PRP) with injectability were fabricated by combining platelet rich plasma (PRP) and dopamine-modified-hyaluronic acid (HA-DA). The engineered wound dressings exhibited tissue adhesiveness, rapid self-healing, and shape adaptability, thereby enhancing stability and adaptability to irregular wounds. The in vitro experiments demonstrated that HA-DA/PRP adhesives significantly promoted fibroblast proliferation and migration, attributed to the loaded PRP. The adhesives showed antibacterial properties against both gram-positive and negative bacteria. Moreover, in vitro experiments confirmed that HA-DA/PRP adhesives effectively mitigated oxidative stress and inflammation. Finally, HA-DA/PRP accelerated the healing of diabetic wounds by inhibiting bacterial growth, promoting granulation tissue regeneration, accelerating neovascularization, facilitating collagen deposition, and modulating inflammation through inducing M1 to M2 polarization, in an in vivo model of infected diabetic wounds. Overall, HA-DA/PRP adhesives with the ability to comprehensively regulate the microenvironment in diabetic wounds may provide a novel approach to expedite the diabetic wounds healing in clinic.

Characterization of PANoptosis-related genes and the immune landscape in moyamoya disease

Moyamoya disease (MMD) is a cerebrovascular narrowing and occlusive condition characterized by progressive stenosis of the terminal portion of the internal carotid artery and the formation of an abnormal network of dilated, fragile perforators at the base of the brain. However, the role of PANoptosis, an apoptotic mechanism associated with vascular disease, has not been elucidated in MMD. In our study, a total of 40 patients' genetic data were included, and a total of 815 MMD-related differential genes were screened, including 215 upregulated genes and 600 downregulated genes. Among them, DNAJA3, ESR1, H19, KRT18 and STK3 were five key genes. These five key genes were associated with a variety of immune cells and immune factors. Moreover, GSEA (gene set enrichment analysis) and GSVA (gene set variation analysis) showed that the different expression levels of the five key genes affected multiple signaling pathways associated with MMD. In addition, they were associated with the expression of MMD-related genes. Then, based on the five key genes, a transcription factor regulatory network was constructed. In addition, targeted therapeutic drugs against MMD-related genes were obtained by the Cmap drug prediction method: MST-312, bisacodyl, indirubin, and tropanyl-3,5-dimethylbenzoate. These results suggest that the PANoptosis-related genes may contribute to the pathogenesis of MMD through multiple mechanisms.

Identification of a new gene signature for prognostic evaluation in cervical cancer: based on cuproptosis-associated angiogenesis and multi-omics analysis

Patients with recurrent or metastatic cervical cancer are in urgent need of novel prognosis assessment or treatment approaches. In this study, a novel prognostic gene signature was discovered by utilizing cuproptosis-related angiogenesis (CuRA) gene scores obtained through weighted gene co-expression network analysis (WGCNA) of The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets. To enhance its reliability, the gene signature was refined by integrating supplementary clinical variables and subjected to cross-validation. Meanwhile, the activation of the VEGF pathway was inferred from an analysis of cell-to-cell communication, based on the expression of ligands and receptors in cell transcriptomic datasets. High-CuRA patients had less infiltration of CD8 + T cells and reduced expression of most of immune checkpoint genes, which indicated greater difficulty in immunotherapy. Lower IC50 values of imatinib, pazopanib, and sorafenib in the high-CuRA group revealed the potential value of these drugs. Finally, we verified an independent prognostic gene SFT2D1 was highly expressed in cervical cancer and positively correlated with the microvascular density. Knockdown of SFT2D1 significantly inhibited ability of the proliferation, migration, and invasive in cervical cancer cells. CuRA gene signature provided valuable insights into the prediction of prognosis and immune microenvironment of cervical cancer, which could help develop new strategies for individualized precision therapy for cervical cancer patients.

YTHDF2-mediated regulations bifurcate BHPF-induced programmed cell deaths

N6-methyladenosine (m6A) is a critical regulator in the fate of RNA, but whether and how m6A executes its functions in different tissues remains largely obscure. Here we report downregulation of a crucial m6A reader, YTHDF2, leading to tissue-specific programmed cell deaths (PCDs) upon fluorene-9-bisphenol (BHPF) exposure. Currently, Bisphenol A (BPA) substitutes are widely used in plastic manufacturing. Interrogating eight common BPA substitutes, we detected BHPF in 14% serum samples of pregnant participants. In a zebrafish model, BHPF caused tissue-specific PCDs triggering cardiac and vascular defects. Mechanistically, BHPF-mediated downregulation of YTHDF2 reduced YTHDF2-facilitated translation of m6A-gch1 for cardiomyocyte ferroptosis, and decreased YTHDF2-mediated m6A-sting1 decay for caudal vein plexus (CVP) apoptosis. The two distinct YTHDF2-mediated m6A regulations and context-dependent co-expression patterns of gch1/ythdf2 and tnfrsf1a/ythdf2 contributed to YTHDF2-mediated tissue-specific PCDs, uncovering a new layer of PCD regulation. Since BHPF/YTHDF2-medaited PCD defects were also observed in mammals, BHPF exposure represents a potential health threat.

TMEM215 Prevents Endothelial Cell Apoptosis in Vessel Regression by Blunting BIK-Regulated ER-to-Mitochondrial Ca Influx

BACKGROUND

In developmental and pathological tissues, nascent vessel networks generated by angiogenesis require further pruning/regression to delete nonfunctional endothelial cells (ECs) by apoptosis and migration. Mechanisms underlying EC apoptosis during vessel pruning remain elusive. TMEM215 (transmembrane protein 215) is an endoplasmic reticulum-located, 2-pass transmembrane protein. We have previously demonstrated that TMEM215 knockdown in ECs leads to cell death, but its physiological function and mechanism are unclear.

METHODS

We characterized the role and mechanism of TMEM215 in EC apoptosis using human umbilical vein endothelial cells by identifying its interacting proteins with immunoprecipitation-mass spectrometry. The physiological function of TMEM215 in ECs was assessed by establishing a conditional knockout mouse strain. The role of TMEM215 in pathological angiogenesis was evaluated by tumor and choroidal neovascularization models. We also tried to evaluate its translational value by delivering a Tmem215 small interfering RNA (siRNA) using nanoparticles in vivo.

RESULTS

TMEM215 knockdown in ECs induced apoptotic cell death. We identified the chaperone BiP as a binding partner of TMEM215, and TMEM215 forms a complex with and facilitates the interaction of BiP (binding immunoglobin protein) with the BH (BCL-2 [B-cell lymphoma 2] homology) 3-only proapoptotic protein BIK (BCL-2 interacting killer). TMEM215 knockdown triggered apoptosis in a BIK-dependent way and was abrogated by BCL-2. Notably, TMEM215 knockdown increased the number and diminished the distance of mitochondria-associated endoplasmic reticulum membranes and increased mitochondrial calcium influx. Inhibiting mitochondrial calcium influx by blocking the IP3R (inositol 1,4,5-trisphosphate receptor) or MCU (mitochondrial calcium uniporter) abrogated TMEM215 knockdown-induced apoptosis. TMEM215 expression in ECs was induced by physiological laminar shear stress via EZH2 downregulation. In EC-specific Tmem215 knockout mice, induced Tmem215 depletion impaired the regression of retinal vasculature characterized by reduced vessel density, increased empty basement membrane sleeves, and increased EC apoptosis. Moreover, EC-specific Tmem215 ablation inhibited tumor growth with disrupted vasculature. However, Tmem215 ablation in adult mice attenuated lung metastasis, consistent with reduced Vcam1 expression. Administration of nanoparticles carrying Tmem215 siRNA also inhibited tumor growth and choroidal neovascularization injury.

CONCLUSIONS

TMEM215, which is induced by blood flow-derived shear stress via downregulating EZH2, protects ECs from BIK-triggered mitochondrial apoptosis mediated by calcium influx through mitochondria-associated ER membranes during vessel pruning, thus providing a novel target for antiangiogenic therapy.

The potential effect of leptin co-administration on photodynamic damage using quail chorioallantoic membrane model

BACKGROUND

The chorioallantoic membrane (CAM) of the Japanese quail is an excellent model for studying photodynamic therapy (PDT) due to its rich vascularization. PDT is used not only in oncological treatment but also in infectious diseases, or psoriasis, where it yields significant advantages. This treatment also has its limitations, such as burning, itching, erythema, redness, swelling, and delayed wound healing. The aim of this study was to analyse the potentially protective properties of the tissue hormone leptin during PDT.

METHODS

Japanese quail embryos incubated ex ovo were used in this experiment. On the 9th day of embryonic development, leptin (5 μg) and photosensitiser hypericin (79 μM) were topically applied, followed by irradiation. The effect of leptin co-administration was evaluated from CAM images and histological structure analysis, histological samples, and qPCR, where the expression of genes involved in angiogenesis, apoptosis, and oxidative stress was monitored.

RESULTS

We observed vascular damage in all experimental groups, the highest damage was found after the application of hypericin without leptin coadministration. Histological analysis confirmed the protective effect of leptin. qPCR analysis presented differences in FREK gene expression, but also in genes involved in oxidative stress like SOD, NRF-1, NRF-2, and GPX7. The application of leptin significantly reduced the expression of apoptosis regulatory proteins CASP3, cytochrome C, and APAF1.

CONCLUSIONS

Our results in the CAM model suggest a possible protective effect of leptin to prevent PDT damage and aid in the subsequent regeneration of target tissues after antimicrobial PDT.

The role of blood flow in vessel remodeling and its regulatory mechanism during developmental angiogenesis

Vessel remodeling is essential for a functional and mature vascular network. According to the difference in endothelial cell (EC) behavior, we classified vessel remodeling into vessel pruning, vessel regression and vessel fusion. Vessel remodeling has been proven in various organs and species, such as the brain vasculature, subintestinal veins (SIVs), and caudal vein (CV) in zebrafish and yolk sac vessels, retina, and hyaloid vessels in mice. ECs and periendothelial cells (such as pericytes and astrocytes) contribute to vessel remodeling. EC junction remodeling and actin cytoskeleton dynamic rearrangement are indispensable for vessel pruning. More importantly, blood flow has a vital role in vessel remodeling. In recent studies, several mechanosensors, such as integrins, platelet endothelial cell adhesion molecule-1 (PECAM-1)/vascular endothelial cell (VE-cadherin)/vascular endothelial growth factor receptor 2 (VEGFR2) complex, and notch1, have been shown to contribute to mechanotransduction and vessel remodeling. In this review, we highlight the current knowledge of vessel remodeling in mouse and zebrafish models. We further underline the contribution of cellular behavior and periendothelial cells to vessel remodeling. Finally, we discuss the mechanosensory complex in ECs and the molecular mechanisms responsible for vessel remodeling.

Remodeling of the Platynereis Musculature during Sexual Maturation

BACKGROUND

The external transformations associated with sexual maturation in Platynereis dumerilii (Audouin and Milne Edwards) are well studied, whereas the internal changes along the body axis have not been systematically analyzed. Therefore, we examined muscle morphology in body regions located anterior or posterior to the prospective atokous/epitokous border to generate a structural basis for internal transformations.

RESULTS

All dorsal and ventral longitudinal muscles were significantly reduced in size and density after sexual maturation and strongly atrophied, with the greatest decrease in the anterior segments of females. Despite the general reduction in size throughout the longitudinal muscles, we found a specific degradation mechanism for the posterior segments, which were characterized by the formation of secondary bundle-like fibrous structures. In addition, we observed a profound remodeling of the transversal muscles in the posterior segments of both sexes, apparently resulting in excessive thickening of these muscles. Accordingly, the entire transversal muscle complex was severely swollen and ultrastructurally characterized by a greatly increased number of mitochondria. As a possible trigger for this remodeling, we discovered an enormous number of small, blind-ending blood vessels that completely penetrated the longitudinal and transversal muscles in posterior segments. In addition, both the number of visceral muscles as well as their coelothelial covering were reduced during sexual maturation.

CONCLUSIONS

We hypothesize that a possible reason for the secondary bundling of the longitudinal fibers, as well as the difference in size of the posterior transversal muscles, could be the high degree of posterior vascularization. The different degree of muscle remodeling thus depends on segmental affiliation and reflects the tasks in the motility of the different body regions after maturation. The strongest atrophy was found in the anterior segments, while signs of redifferentiation were encountered in posterior segments, supported by the vigorous growth of vessels supplying the transformed epitokous parapodia and associated muscles, which allows rapid swimming during swarming and gamete release.

In situ photo-crosslinked adhesive hydrogel loaded with mesenchymal stem cell-derived extracellular vesicles promotes diabetic wound healing

The delayed healing of diabetic wounds is directly affected by the disturbance of wound microenvironment, resulting from persistent inflammation, insufficient angiogenesis, and impaired cell functions. Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) showed considerable therapeutic potential in diabetic wound healing. However, the low retention rate of MSC-EVs at wound sites hampers their efficacy. For skin wounds exposed to the outer environment, using a hydrogel with tissue adhesiveness under a moist wound condition is a promising strategy for wound healing. In this study, we modified methacryloyl-modified gelatin (GelMA) hydrogel with catechol motifs of dopamine to fabricate a GelMA-dopamine hydrogel. EVs isolated from MSCs were applied in the synthesized GelMA-dopamine hydrogel to prepare a GelMA-dopamine-EV hydrogel. The results demonstrated that the newly formed GelMA-dopamine hydrogel possessed improved properties of softness, adhesiveness, and absorptive capacity, as well as high biocompatibility in the working concentration (15% w/v). In addition, MSC-EVs were verified to promote cell migration and angiogenesis in vitro. In the skin wound model of diabetic rats, the GelMA-dopamine-EV hydrogel exerted prominent wound healing efficacy estimated by collagen deposition, skin appendage regeneration, and the expression of IL-6, CD31, and TGF-β. In conclusion, this combination of MSC-EVs and the modified hydrogel not only accelerates wound closure but also promotes skin structure normalization by rescuing the homeostasis of the healing microenvironment of diabetic wounds, which provides a potential approach for the treatment of diabetic wounds.

Klotho promotes AMPK activity and maintains renal vascular integrity by regulating the YAP signaling pathway

The development and formation of mammalian blood vessels are closely related to the regulation of signal transduction pathways. Klotho/AMPK and YAP/TAZ signaling pathways are closely related to angiogenesis, but the internal relationship between them is not clear. In this study, we found that Klotho heterozygous deletion mice (Klotho^+/- mice) had obvious thickening of the renal vascular wall, obvious enlargement of vascular volume, and significant proliferation and pricking of vascular endothelial cells. Western blot showed that the expression levels of total YAP protein, p-YAP protein (Ser127 and Ser397), p-MOB1, MST1, LATS1, and SAV1 in renal vascular endothelial cells were significantly lower in Klotho^+/- mice than in wild-type mice. Knockdown of endogenous Klotho in HUVECs accelerated their ability to divide and form vascular branches in the extracellular matrix. Meanwhile, the results of CO-IP western blot showed that the expression of LATS1 and p-LATS1 interacting with AMPK protein decreased significantly, and the ubiquitination level of YAP protein also decreased significantly in vascular endothelial cells of kidney tissue of Klotho^+/- mice. Subsequently, continuous overexpression of exogenous Klotho protein in Klotho heterozygous deficient mice effectively reversed the abnormal renal vascular structure by weakening the expression of the YAP signal transduction pathway. Therefore, we confirmed that Klotho and AMPKα proteins were highly expressed in vascular endothelial cells of adult mouse tissues and organs; this resulted in a phosphorylation modification of YAP protein, closed the activity of the YAP/TAZ signal transduction pathway, and inhibited the growth and proliferation of vascular endothelial cells. When Klotho was absent, the phosphorylation modification of YAP protein by AMPKα was inhibited, resulting in the activation of the YAP/TAZ signal transduction pathway and finally inducing the excessive proliferation of vascular endothelial cells.

Endogenous SO2 Controls Cell Apoptosis: The State-of-the-Art

SO2, previously known as the product of industrial waste, has recently been proven to be a novel gasotransmitter in the cardiovascular system. It is endogenously produced from the metabolism pathway of sulfur-containing amino acids in mammalians. Endogenous SO2 acts as an important controller in the regulation of many biological processes including cardiovascular physiological and pathophysiological events. Recently, the studies on the regulatory effect of endogenous SO2 on cell apoptosis and its pathophysiological significance have attracted great attention. Endogenous SO2 can regulate the apoptosis of vascular smooth muscle cells, endothelial cells, cardiomyocytes, neuron, alveolar macrophages, polymorphonuclear neutrophils and retinal photoreceptor cells, which might be involved in the pathogenesis of hypertension, pulmonary hypertension, myocardial injury, brain injury, acute lung injury, and retinal disease. Therefore, in the present study, we described the current findings on how endogenous SO2 is generated and metabolized, and we summarized its regulatory effects on cell apoptosis, underlying mechanisms, and pathophysiological relevance.