Notch regulates vascular collagen IV basement membrane through modulation of lysyl hydroxylase 3 trafficking

Mucosal bleeding while on venovenous extracorporeal membrane oxygenation in the setting of vitamin C deficiency

A major complication with extracorporeal membrane oxygenation (ECMO) is bleeding which can occur in up to 40% of cases and can be life-threatening. Minor bleeding may be overlooked and under-reported. While some of the underlying mechanisms such as platelet injury and anticoagulation therapy have been identified, several other factors are still under-researched. Here, we describe a unique case of a subtle mucosal membrane bleeding that is found to be associated with vitamin C deficiency while on treatment with ECMO. Investigating vitamin C levels may be useful in understanding causes of bleeding in some patients on ECMO therapy, particularly if there are risk factors for malnutrition.

Loss of cell junctional components and matrix alterations drive cell desquamation and fibrotic changes in Idiopathic Pulmonary Fibrosis

The distal bronchioles in Idiopathic Pulmonary Fibrosis (IPF) exhibit histopathological abnormalities such as bronchiolization, peribronchiolar fibrosis and honeycomb cysts that contribute to the overall architectural remodeling of lung tissue seen in the disease. Here we describe an additional histopathologic finding of epithelial desquamation in patients with IPF, wherein epithelial cells detach from the basement membrane of the distal bronchioles. To understand the mechanism driving this pathology, we performed spatial transcriptomics of the epithelial cells and spatial proteomics of the basement membrane of the distal bronchioles from IPF patients and patients with no prior history of lung disease. Our findings reveal a downregulation of cell junctional components, upregulation of epithelial-mesenchymal transition signatures and dysregulated basement membrane matrix in IPF distal bronchioles, facilitating epithelial desquamation. Further, functional assays identified regulation between Collagen IV in the matrix, and the junctional genes JUP and PLEC , that is crucial for maintaining distal bronchiolar homeostasis. In IPF, this balanced regulation between matrix and cell-junctions is disrupted, leading to loss of epithelial adhesion, peribronchiolar fibrosis and epithelial desquamation. Overall, our study suggests that in IPF the interplay between the loss of cell junctions and a dysregulated matrix results in desquamation of distal bronchiolar epithelium and lung remodeling, exacerbating the disease.

One Sentence Summary

Two-way regulation of cell junctional proteins and matrix proteins drives cellular desquamation and fibrosis in the distal bronchioles of patients with Idiopathic Pulmonary Fibrosis.

Dihydrotestosterone Augments the Angiogenic and Migratory Potential of Human Endothelial Progenitor Cells by an Androgen Receptor-Dependent Mechanism

Endothelial progenitor cells (EPCs) play a critical role in cardiovascular regeneration. Enhancement of their native properties would be highly beneficial to ensuring the proper functioning of the cardiovascular system. As androgens have a positive effect on the cardiovascular system, we hypothesized that dihydrotestosterone (DHT) could also influence EPC-mediated repair processes. To evaluate this hypothesis, we investigated the effects of DHT on cultured human EPCs' proliferation, viability, morphology, migration, angiogenesis, gene and protein expression, and ability to integrate into cardiac tissue. The results showed that DHT at different concentrations had no cytotoxic effect on EPCs, significantly enhanced the cell proliferation and viability and induces fast, androgen-receptor-dependent formation of capillary-like structures. DHT treatment of EPCs regulated gene expression of androgen receptors and the genes and proteins involved in cell migration and angiogenesis. Importantly, DHT stimulation promoted EPC migration and the cells' ability to adhere and integrate into murine cardiac slices, suggesting it has a role in promoting tissue regeneration. Mass spectrometry analysis further highlighted the impact of DHT on EPCs' functioning. In conclusion, DHT increases the proliferation, migration, and androgen-receptor-dependent angiogenesis of EPCs; enhances the cells' secretion of key factors involved in angiogenesis; and significantly potentiates cellular integration into heart tissue. The data offer support for potential therapeutic applications of DHT in cardiovascular regeneration and repair processes.

Evoked Weibel-Palade Body Exocytosis Modifies the Endothelial Cell Surface by Releasing a Substrate-Selective Phosphodiesterase

Weibel Palade bodies (WPB) are lysosome-related secretory organelles of endothelial cells. Commonly known for their main cargo, the platelet and leukocyte receptors von-Willebrand factor (VWF) and P-selectin, WPB play a crucial role in hemostasis and inflammation. Here, the authors identify the glycerophosphodiester phosphodiesterase domain-containing protein 5 (GDPD5) as a WPB cargo protein and show that GDPD5 is transported to WPB following uptake from the plasma membrane via an unique endocytic transport route. GDPD5 cleaves GPI-anchored, plasma membrane-resident proteins within their GPI-motif, thereby regulating their local activity. The authors identify a novel target of GDPD5 , the complement regulator CD59, and show that it is released from the endothelial surface by GDPD5 following WPB exocytosis. This results in increased deposition of complement components and can enhance local inflammatory and thrombogenic responses. Thus, stimulus-induced WPB exocytosis can modify the endothelial cell surface by GDPD5-mediated selective release of a subset of GPI-anchored proteins.

Amelioration of Tumor-promoting Microenvironment via Vascular Remodeling and CAF Suppression Using E7130: Biomarker Analysis by Multimodal Imaging Modalities

E7130 is a novel anticancer agent created from total synthetic study of the natural compound norhalichondrin B. In addition to inhibiting microtubule dynamics, E7130 also ameliorates tumor-promoting aspects of the tumor microenvironment (TME) by suppressing cancer-associated fibroblasts (CAF) and promoting remodeling of tumor vasculature. Here, we demonstrate TME amelioration by E7130 using multi-imaging modalities, including multiplexed mass cytometry [cytometry by time-of-flight (CyTOF)] analysis, multiplex IHC analysis, and MRI. Experimental solid tumors characterized by large numbers of CAFs in TME were treated with E7130. E7130 suppressed LAP-TGFβ1 production, a precursor of TGFβ1, in CAFs but not in cancer cells; an effect that was accompanied by a reduction of circulating TGFβ1 in plasma. To our best knowledge, this is the first report to show a reduction of TGFβ1 production in TME. Furthermore, multiplex IHC analysis revealed reduced cellularity and increased TUNEL-positive apoptotic cells in E7130-treated xenografts. Increased microvessel density (MVD) and collagen IV (Col IV), an extracellular matrix (ECM) component associated with endothelial cells, were also observed in the TME, and plasma Col IV levels were also increased by E7130 treatment. MRI revealed increased accumulation of a contrast agent in xenografts. Moreover, diffusion-weighted MRI after E7130 treatment indicated reduction of tumor cellularity and interstitial fluid pressure. Overall, our findings strongly support the mechanism of action that E7130 alters the TME in therapeutically beneficial ways. Importantly, from a translational perspective, our data demonstrated MRI as a noninvasive biomarker to detect TME amelioration by E7130, supported by consistent changes in plasma biomarkers.

Deep learning-based automated pipeline for blood vessel detection and distribution analysis in multiplexed prostate cancer images

Introduction: Prostate cancer is a highly heterogeneous disease, presenting varying levels of aggressiveness and response to treatment. Angiogenesis is one of the hallmarks of cancer, providing oxygen and nutrient supply to tumors. Micro vessel density has previously been correlated with higher Gleason score and poor prognosis. Manual segmentation of blood vessels (BVs) In microscopy images is challenging, time consuming and may be prone to inter-rater variabilities. In this study, an automated pipeline is presented for BV detection and distribution analysis in multiplexed prostate cancer images. Methods: A deep learning model was trained to segment BVs by combining CD31, CD34 and collagen IV images. In addition, the trained model was used to analyze the size and distribution patterns of BVs in relation to disease progression in a cohort of prostate cancer patients (N = 215). Results: The model was capable of accurately detecting and segmenting BVs, as compared to ground truth annotations provided by two reviewers. The precision (P), recall (R) and dice similarity coefficient (DSC) were equal to 0.93 (SD 0.04), 0.97 (SD 0.02) and 0.71 (SD 0.07) with respect to reviewer 1, and 0.95 (SD 0.05), 0.94 (SD 0.07) and 0.70 (SD 0.08) with respect to reviewer 2, respectively. BV count was significantly associated with 5-year recurrence (adjusted p = 0.0042), while both count and area of blood vessel were significantly associated with Gleason grade (adjusted p = 0.032 and 0.003 respectively). Discussion: The proposed methodology is anticipated to streamline and standardize BV analysis, offering additional insights into the biology of prostate cancer, with broad applicability to other cancers.

Arf6 is required for endocytosis and filamentous actin assembly during angiogenesis in vitro

OBJECTIVE

Endocytosis is a process vital to angiogenesis and vascular homeostasis. In pathologies where supraphysiological growth factor signaling underlies disease etiology, such as in diabetic retinopathy and solid tumors, strategies to limit chronic growth factor signaling by way of blunting endocytic processes have been shown to have tremendous clinical value. ADP ribosylation factor 6 (Arf6) is a small GTPase that promotes the assembly of actin necessary for clathrin-mediated and clathrin-independent endocytosis. In its absence, growth factor signaling is greatly diminished, which has been shown to ameliorate pathological signaling input in diseased vasculature. However, it is less clear if there are bystander effects related to loss of Arf6 on angiogenic behaviors. Our goal was to provide an analysis of Arf6's function in angiogenic endothelium, focusing on its role in actin and endocytosis as well as sprouting morphogenesis.

METHODS

Primary endothelial cells were cultured in both 2D and 3D environments. Here, endothelial cells were fixed and stained for various proteins or transfected with fluorescently-tagged constructs for live-cell imaging.

RESULTS

We found that Arf6 localized to both filamentous actin and sites of endocytosis in two-dimensional culture. Loss of Arf6 distorted both apicobasal polarity and reduced the total cellular filamentous actin content, which may be the primary driver underlying gross sprouting dysmorphogenesis in its absence.

CONCLUSIONS

Our findings highlight that endothelial Arf6 is a potent mediator of both actin regulation and endocytosis and is required for proper sprout formation.

Pathological angiogenesis: mechanisms and therapeutic strategies

In multicellular organisms, angiogenesis, the formation of new blood vessels from pre-existing ones, is an essential process for growth and development. Different mechanisms such as vasculogenesis, sprouting, intussusceptive, and coalescent angiogenesis, as well as vessel co-option, vasculogenic mimicry and lymphangiogenesis, underlie the formation of new vasculature. In many pathological conditions, such as cancer, atherosclerosis, arthritis, psoriasis, endometriosis, obesity and SARS-CoV-2(COVID-19), developmental angiogenic processes are recapitulated, but are often done so without the normal feedback mechanisms that regulate the ordinary spatial and temporal patterns of blood vessel formation. Thus, pathological angiogenesis presents new challenges yet new opportunities for the design of vascular-directed therapies. Here, we provide an overview of recent insights into blood vessel development and highlight novel therapeutic strategies that promote or inhibit the process of angiogenesis to stabilize, reverse, or even halt disease progression. In our review, we will also explore several additional aspects (the angiogenic switch, hypoxia, angiocrine signals, endothelial plasticity, vessel normalization, and endothelial cell anergy) that operate in parallel to canonical angiogenesis mechanisms and speculate how these processes may also be targeted with anti-angiogenic or vascular-directed therapies.

Arf6 Regulates Endocytosis and Angiogenesis by Promoting Filamentous Actin Assembly

Clathrin-mediated endocytosis (CME) is a process vital to angiogenesis as well as general vascular homeostasis. In pathologies where supraphysiological growth factor signaling underlies disease etiology, such as in diabetic retinopathy and solid tumors, strategies to limit chronic growth factor signaling by way of CME have been shown to have tremendous clinical value. ADP ribosylation factor 6 (Arf6) is a small GTPase that promotes the assembly of actin necessary for CME. In its absence, growth factor signaling is greatly diminished, which has been shown to ameliorate pathological signaling input in diseased vasculature. However, it is less clear if there are bystander effects related to loss of Arf6 on angiogenic behaviors. Our goal was to provide a analysis of Arf6’s function in angiogenic endothelium, focusing on its role in lumenogenesis as well as its relation to actin and CME. We found that Arf6 localized to both filamentous actin and sites of CME in 2-dimensional culture. Loss of Arf6 distorted both apicobasal polarity and reduced the total cellular filamentous actin content, and this may be the primary driver underlying gross dysmorphogenesis during angiogenic sprouting in its absence. Our findings highlight that endothelial Arf6 is a potent mediator of both actin regulation and CME.

Mucopolysaccharidoses and the blood-brain barrier

Mucopolysaccharidoses comprise a set of genetic diseases marked by an enzymatic dysfunction in the degradation of glycosaminoglycans in lysosomes. There are eight clinically distinct types of mucopolysaccharidosis, some with various subtypes, based on which lysosomal enzyme is deficient and symptom severity. Patients with mucopolysaccharidosis can present with a variety of symptoms, including cognitive dysfunction, hepatosplenomegaly, skeletal abnormalities, and cardiopulmonary issues. Additionally, the onset and severity of symptoms can vary depending on the specific disorder, with symptoms typically arising during early childhood. While there is currently no cure for mucopolysaccharidosis, there are clinically approved therapies for the management of clinical symptoms, such as enzyme replacement therapy. Enzyme replacement therapy is typically administered intravenously, which allows for the systemic delivery of the deficient enzymes to peripheral organ sites. However, crossing the blood-brain barrier (BBB) to ameliorate the neurological symptoms of mucopolysaccharidosis continues to remain a challenge for these large macromolecules. In this review, we discuss the transport mechanisms for the delivery of lysosomal enzymes across the BBB. Additionally, we discuss the several therapeutic approaches, both preclinical and clinical, for the treatment of mucopolysaccharidoses.

Rab35 governs apicobasal polarity through regulation of actin dynamics during sprouting angiogenesis

In early blood vessel development, trafficking programs, such as those using Rab GTPases, are tasked with delivering vesicular cargo with high spatiotemporal accuracy. However, the function of many Rab trafficking proteins remain ill-defined in endothelial tissue; therefore, their relevance to blood vessel development is unknown. Rab35 has been shown to play an enigmatic role in cellular behaviors which differs greatly between tissue-type and organism. Importantly, Rab35 has never been characterized for its potential contribution in sprouting angiogenesis; thus, our goal was to map Rab35’s primary function in angiogenesis. Our results demonstrate that Rab35 is critical for sprout formation; in its absence, apicobasal polarity is entirely lost in vitro and in vivo. To determine mechanism, we systematically explored established Rab35 effectors and show that none are operative in endothelial cells. However, we find that Rab35 partners with DENNd1c, an evolutionarily divergent guanine exchange factor, to localize to actin. Here, Rab35 regulates actin polymerization through limiting Rac1 and RhoA activity, which is required to set up proper apicobasal polarity during sprout formation. Our findings establish that Rab35 is a potent brake of actin remodeling during blood vessel development.

The promiscuous GTPase Rab35 has been shown to be involved in many important cellular functions. In this article, Francis et al. illustrate how Rab35 acts as a critical brake to actin remodeling during sprouting angiogenesis and how it is necessary for proper blood vessel development.

[JAG1 promotes migration, invasion, and adhesion of triple-negative breast cancer cells by promoting angiogenesis]

OBJECTIVE

To investigate the effect of JAG1 on the malignant phenotype of triple-negative breast cancer (TNBC) and its role in angiogenesis in breast cancer microenvironment.

METHODS

The expressions of Notch molecules were detected in human TNBC 231 and 231B cells using RT-qPCR. Five female nude mice were inoculated with 231 cells and another 5 with 231B cells into the mammary fat pads, and 4-6 weeks later, the tumors were collected for immunohistochemical and immunofluorescence tests. 231 cells and 231B cells were treated with recombinant JAG (rJAG) protein and DAPT, respectively, and changes in their malignant phenotypes were assessed using CCK-8 assay, Hoechst 33258 staining, wound healing assay, Transwell chamber assay and endothelial cell adhesion assay. Western blotting was used to detect the changes in the expressions of proteins related with the malignant phenotypes of 231 and 231B cells. The effects of conditioned medium (CM) derived from untreated 231 and 231 B cells, rJAG1-treated 231 cells and DAPT-treated 231B cells on proliferation and tube formation ability of cultured human umbilical vein endothelial cells (HUVECs) were evaluated using CCK-8 assay and tube-forming assay.

RESULTS

The expression of JAG1 was higher in 231B cells than in 231 cells (P < 0.05). Tumor 231B showed higher expression of VEGFA and CD31. Compared with 231-Blank group, the migration, invasion and adhesion of 231 cells in 231-rJAG1 were significantly enhanced (P < 0.05). Protein levels of Twist1 and Snail increased (P < 0.01), anti-apoptotic protein Bcl-2 increased (P < 0.05), while DAPT inhibited the related phenomena and indicators of 231B. The 231-rJAG1-CM increased the cell number and tubule number of HUVEC (P < 0.05).

CONCLUSION

JAG1 may affect the malignant phenotype of TNBC and promote angiogenesis in the tumor microenvironment.

Discovering the Potential of Natural Antioxidants in Age-Related Macular Degeneration: A Review

Age-related macular degeneration (AMD) is a multifactorial disease associated with anatomical changes in the inner retina. Despite tremendous advances in clinical care, there is currently no cure for AMD. This review aims to evaluate the published literature on the therapeutic roles of natural antioxidants in AMD. A literature search of PubMed, Web of Science and Google Scholar for peer-reviewed articles published between 1 January 2011 and 31 October 2021 was undertaken. A total of 82 preclinical and 18 clinical studies were eligible for inclusion in this review. We identified active compounds, carotenoids, extracts and polysaccharides, flavonoids, formulations, vitamins and whole foods with potential therapeutic roles in AMD. We evaluated the integral cellular signaling pathways including the activation of antioxidant pathways and angiogenesis pathways orchestrating their mode of action. In conclusion, we examined the therapeutic roles of natural antioxidants in AMD which warrant further study for application in clinical practice. Our current understanding is that natural antioxidants have the potential to improve or halt the progression of AMD, and tailoring therapeutics to the specific disease stages may be the key to preventing irreversible vision loss.

Shooting at Moving and Hidden Targets-Tumour Cell Plasticity and the Notch Signalling Pathway in Head and Neck Squamous Cell Carcinomas

Head and Neck Squamous Cell Carcinoma (HNSCC) is often aggressive, with poor response to current therapies in approximately 40-50% of the patients. Current therapies are restricted to operation and irradiation, often combined with a small number of standard-of-care chemotherapeutic drugs, preferentially for advanced tumour patients. Only very recently, newer targeted therapies have entered the clinics, including Cetuximab, which targets the EGF receptor (EGFR), and several immune checkpoint inhibitors targeting the immune receptor PD-1 and its ligand PD-L1. HNSCC tumour tissues are characterized by a high degree of intra-tumour heterogeneity (ITH), and non-genetic alterations that may affect both non-transformed cells, such as cancer-associated fibroblasts (CAFs), and transformed carcinoma cells. This very high degree of heterogeneity likely contributes to acquired drug resistance, tumour dormancy, relapse, and distant or lymph node metastasis. ITH, in turn, is likely promoted by pronounced tumour cell plasticity, which manifests in highly dynamic and reversible phenomena such as of partial or hybrid forms of epithelial-to-mesenchymal transition (EMT), and enhanced tumour stemness. Stemness and tumour cell plasticity are strongly promoted by Notch signalling, which remains poorly understood especially in HNSCC. Here, we aim to elucidate how Notch signal may act both as a tumour suppressor and proto-oncogenic, probably during different stages of tumour cell initiation and progression. Notch signalling also interacts with numerous other signalling pathways, that may also have a decisive impact on tumour cell plasticity, acquired radio/chemoresistance, and metastatic progression of HNSCC. We outline the current stage of research related to Notch signalling, and how this pathway may be intricately interconnected with other, druggable targets and signalling mechanisms in HNSCC.