Pericytes at the intersection between tissue regeneration and pathology

Computational evaluation of 1,2,3-triazole-based VEGFR-2 inhibitors: anti-angiogenesis potential and pharmacokinetic assessment

The vascular endothelial growth factor (VEGF) and its cell surface receptor, as well as the human VEGFR-2 domain kinase, are some of the signaling pathways that have received the most attention in this field. This study aimed to identify novel molecules as VEGFR-2 inhibitors using 3D-QSAR modeling based on 1,2,3-triazole. Docking studies and dynamic simulations were performed to analyze novel interactions with the inhibitors and validate the molecular docking, dynamic simulations, and ADMET analyses. The optimized CoMSIA/SEH model showed good statistical results, and molecular docking and molecular dynamics simulations demonstrated stability of M3 ligand with the receptor and provided insight into ligand-receptor interactions. The newly developed compounds performed well in ADMET evaluations and showed promising results using Lipinski's rule of five, suggesting that the molecule M3 could be a useful anti-angiogenesis agent. In conclusion, this study provides insights into the structure-activity relationship of VEGFR-2 inhibitors and identifies M3 as a potential new anti-angiogenesis drug. The methodology used in this study can be applied to other similar drug targets to discover new and potent inhibitors.

Mechanisms of muscle cells alterations and regeneration decline during aging

Skeletal muscles are essential for locomotion and body metabolism regulation. As muscles age, they lose strength, elasticity, and metabolic capability, leading to ineffective motion and metabolic derangement. Both cellular and extracellular alterations significantly influence muscle aging. Satellite cells (SCs), the primary muscle stem cells responsible for muscle regeneration, become exhausted, resulting in diminished population and functionality during aging. This decline in SC function impairs intercellular interactions as well as extracellular matrix production, further hindering muscle regeneration. Other muscle-resident cells, such as fibro-adipogenic progenitors (FAPs), pericytes, and immune cells, also deteriorate with age, reducing local growth factor activities and responsiveness to stress or injury. Systemic signaling, including hormonal changes, contributes to muscle cellular catabolism and disrupts muscle homeostasis. Collectively, these cellular and environmental components interact, disrupting muscle homeostasis and regeneration in advancing age. Understanding these complex interactions offers insights into potential regenerative strategies to mitigate age-related muscle degeneration.

Correlation between Periostin Expression and Pro-Angiogenic Factors in Non-Small-Cell Lung Carcinoma

The role of periostin (POSTN) in remodeling the microenvironment surrounding solid tumors and its effect on the tumor cells in non-small-cell lung carcinoma (NSCLC) have not yet been fully understood. The aim of this study was to determine the relationship between POSTN expression (in tumor cells [NSCLC cells] and the tumor stroma) and pro-angiogenic factors (CD31, CD34, CD105, and VEGF-A) and microvascular density (MVD) in NSCLC. In addition, these associations were analyzed in individual histological subtypes of NSCLC (SCC, AC, and LCC) and their correlations with clinicopathological factors and prognosis were examined. Immunohistochemistry using tissue microarrays (TMAs) was used to assess the expression of POSTN (in tumor cells and cancer-associated fibroblasts [CAFs]) and the pro-angiogenic factors. A significant positive correlation was found between the expression of POSTN (in cancer cells/CAFs) and the expression of the analyzed pro-angiogenic factors (CD31, CD34, CD105, and VEGF-A) and MVD in the entire population of patients with NSCLC and individual histological subtypes (AC, SCC). In addition, this study found that POSTN expression (in tumor cells/CAFs) increased with tumor size (pT), histopathological grade (G), and lymph-node involvement (pN). In addition, a high expression of POSTN (in tumor cells and CAFs) was associated with shorter survival among patients with NSCLC. In conclusion, a high expression of POSTN (in cancer cells and CAFs) may be crucial for angiogenesis and NSCLC progression and can constitute an independent prognostic factor for NSCLC.

The fate and role of the pericytes in myocardial diseases

The adult mammalian heart contains a large population of pericytes that play important roles in homeostasis and disease. In the normal heart, pericytes regulate microvascular permeability and flow. Myocardial diseases are associated with marked alterations in pericyte phenotype and function. This review manuscript discusses the role of pericytes in cardiac homeostasis and disease. Following myocardial infarction (MI), cardiac pericytes participate in all phases of cardiac repair. During the inflammatory phase, pericytes may secrete cytokines and chemokines and may regulate leukocyte trafficking, through formation of intercellular gaps that serve as exit points for inflammatory cells. Moreover, pericyte contraction induces microvascular constriction, contributing to the pathogenesis of 'no-reflow' in ischemia and reperfusion. During the proliferative phase, pericytes are activated by growth factors, such as transforming growth factor (TGF)-β and contribute to fibrosis, predominantly through secretion of fibrogenic mediators. A fraction of pericytes acquires fibroblast identity but contributes only to a small percentage of infarct fibroblasts and myofibroblasts. As the scar matures, pericytes form a coat around infarct neovessels, promoting stabilization of the vasculature. Pericytes may also be involved in the pathogenesis of chronic heart failure, by regulating inflammation, fibrosis, angiogenesis and myocardial perfusion. Pericytes are also important targets of viral infections (such as SARS-CoV2) and may be implicated in the pathogenesis of cardiac complications of COVID19. Considering their role in myocardial inflammation, fibrosis and angiogenesis, pericytes may be promising therapeutic targets in myocardial disease.

Glioblastoma Neurovascular Progenitor Orchestrates Tumor Cell Type Diversity

Glioblastoma (GBM) is the deadliest form of primary brain tumor with limited treatment options. Recent studies have profiled GBM tumor heterogeneity, revealing numerous axes of variation that explain the molecular and spatial features of the tumor. Here, we seek to bridge descriptive characterization of GBM cell type heterogeneity with the functional role of individual populations within the tumor. Our lens leverages a gene program-centric meta-atlas of published transcriptomic studies to identify commonalities between diverse tumors and cell types in order to decipher the mechanisms that drive them. This approach led to the discovery of a tumor-derived stem cell population with mixed vascular and neural stem cell features, termed a neurovascular progenitor (NVP). Following in situ validation and molecular characterization of NVP cells in GBM patient samples, we characterized their function in vivo. Genetic depletion of NVP cells resulted in altered tumor cell composition, fewer cycling cells, and extended survival, underscoring their critical functional role. Clonal analysis of primary patient tumors in a human organoid tumor transplantation system demonstrated that the NVP has dual potency, generating both neuronal and vascular tumor cells. Although NVP cells comprise a small fraction of the tumor, these clonal analyses demonstrated that they strongly contribute to the total number of cycling cells in the tumor and generate a defined subset of the whole tumor. This study represents a paradigm by which cell type-specific interrogation of tumor populations can be used to study functional heterogeneity and therapeutically targetable vulnerabilities of GBM.

Vascular remodelling in cardiovascular diseases: hypertension, oxidation, and inflammation

Optimal vascular structure and function are essential for maintaining the physiological functions of the cardiovascular system. Vascular remodelling involves changes in vessel structure, including its size, shape, cellular and molecular composition. These changes result from multiple risk factors and may be compensatory adaptations to sustain blood vessel function. They occur in diverse cardiovascular pathologies, from hypertension to heart failure and atherosclerosis. Dynamic changes in the endothelium, fibroblasts, smooth muscle cells, pericytes or other vascular wall cells underlie remodelling. In addition, immune cells, including macrophages and lymphocytes, may infiltrate vessels and initiate inflammatory signalling. They contribute to a dynamic interplay between cell proliferation, apoptosis, migration, inflammation, and extracellular matrix reorganisation, all critical mechanisms of vascular remodelling. Molecular pathways underlying these processes include growth factors (e.g., vascular endothelial growth factor and platelet-derived growth factor), inflammatory cytokines (e.g., interleukin-1β and tumour necrosis factor-α), reactive oxygen species, and signalling pathways, such as Rho/ROCK, MAPK, and TGF-β/Smad, related to nitric oxide and superoxide biology. MicroRNAs and long noncoding RNAs are crucial epigenetic regulators of gene expression in vascular remodelling. We evaluate these pathways for potential therapeutic targeting from a clinical translational perspective. In summary, vascular remodelling, a coordinated modification of vascular structure and function, is crucial in cardiovascular disease pathology.

Single-cell transcriptome analysis of cavernous tissues reveals the key roles of pericytes in diabetic erectile dysfunction

Erectile dysfunction (ED) affects a significant proportion of men aged 40-70 and is caused by cavernous tissue dysfunction. Presently, the most common treatment for ED is phosphodiesterase 5 inhibitors; however, this is less effective in patients with severe vascular disease such as diabetic ED. Therefore, there is a need for development of new treatment, which requires a better understanding of the cavernous microenvironment and cell-cell communications under diabetic condition. Pericytes are vital in penile erection; however, their dysfunction due to diabetes remains unclear. In this study, we performed single-cell RNA sequencing to understand the cellular landscape of cavernous tissues and cell type-specific transcriptional changes in diabetic ED. We found a decreased expression of genes associated with collagen or extracellular matrix organization and angiogenesis in diabetic fibroblasts, chondrocytes, myofibroblasts, valve-related lymphatic endothelial cells, and pericytes. Moreover, the newly identified pericyte-specific marker, Limb Bud-Heart (Lbh), in mouse and human cavernous tissues, clearly distinguishing pericytes from smooth muscle cells. Cell-cell interaction analysis revealed that pericytes are involved in angiogenesis, adhesion, and migration by communicating with other cell types in the corpus cavernosum; however, these interactions were highly reduced under diabetic conditions. Lbh expression is low in diabetic pericytes, and overexpression of LBH prevents erectile function by regulating neurovascular regeneration. Furthermore, the LBH-interacting proteins (Crystallin Alpha B and Vimentin) were identified in mouse cavernous pericytes through LC-MS/MS analysis, indicating that their interactions were critical for maintaining pericyte function. Thus, our study reveals novel targets and insights into the pathogenesis of ED in patients with diabetes.

Nanoparticles in tumor microenvironment remodeling and cancer immunotherapy

Cancer immunotherapy and vaccine development have significantly improved the fight against cancers. Despite these advancements, challenges remain, particularly in the clinical delivery of immunomodulatory compounds. The tumor microenvironment (TME), comprising macrophages, fibroblasts, and immune cells, plays a crucial role in immune response modulation. Nanoparticles, engineered to reshape the TME, have shown promising results in enhancing immunotherapy by facilitating targeted delivery and immune modulation. These nanoparticles can suppress fibroblast activation, promote M1 macrophage polarization, aid dendritic cell maturation, and encourage T cell infiltration. Biomimetic nanoparticles further enhance immunotherapy by increasing the internalization of immunomodulatory agents in immune cells such as dendritic cells. Moreover, exosomes, whether naturally secreted by cells in the body or bioengineered, have been explored to regulate the TME and immune-related cells to affect cancer immunotherapy. Stimuli-responsive nanocarriers, activated by pH, redox, and light conditions, exhibit the potential to accelerate immunotherapy. The co-application of nanoparticles with immune checkpoint inhibitors is an emerging strategy to boost anti-tumor immunity. With their ability to induce long-term immunity, nanoarchitectures are promising structures in vaccine development. This review underscores the critical role of nanoparticles in overcoming current challenges and driving the advancement of cancer immunotherapy and TME modification.

Progress of the study of pericytes and their potential research value in adenomyosis

Pericytes (PCs) are versatile cells integral to the microcirculation wall, exhibiting specific stem cell traits. They are essential in modulating blood flow, ensuring vascular permeability, maintaining homeostasis, and aiding tissue repair process. Given their involvement in numerous disease-related pathological and physiological processes, the regulation of PCs has emerged as a focal point of research. Adenomyosis is characterized by the presence of active endometrial glands and stroma encased by an enlarged and proliferative myometrial layer, further accompanied by fibrosis and new blood vessel formation. This distinct pathological condition might be intricately linked with PCs. This article comprehensively reviews the markers associated with PCs, their contributions to angiogenesis, blood flow modulation, and fibrotic processes. Moreover, it provides a comprehensive overview of the current research on adenomyosis pathophysiology, emphasizing the potential correlation and future implications regarding PCs and the development of adenomyosis.

Pericytes as the Orchestrators of Vasculature and Adipogenesis

Pericytes (PCs) are located surrounding the walls of small blood vessels, particularly capillaries and microvessels. In addition to their functions in maintaining vascular integrity, participating in angiogenesis, and regulating blood flow, PCs also serve as a reservoir for multi-potent stem/progenitor cells in white, brown, beige, and bone marrow adipose tissues. Due to the complex nature of this cell population, the identification and characterization of PCs has been challenging. A comprehensive understanding of the heterogeneity of PCs may enhance their potential as therapeutic targets for metabolic syndromes or bone-related diseases. This mini-review summarizes multiple PC markers commonly employed in lineage-tracing studies, with an emphasis on their contribution to adipogenesis and functions in different adipose depots under diverse metabolic conditions.

Assessment of the proliferative and angiogenic effects of the synthetic cannabinoid (R)-5-fluoro ADB on human cerebral microvascular endothelial cells

Objectives

The process of vascular formation, also known as angiogenesis, primarily relies on endothelial cell proliferation, migration, and invasion. In recent years, it has been discovered that synthetic cannabinoids (SCs) may potentially impact angiogenic processes within the body. We evaluated the impact of the synthetic cannabinoid (R)-5-Fluoro-ADB on the proliferation rate and angiogenesis in Human Cerebral Microvascular Endothelial Cells (hBMECs).

Materials and Methods

hBMECs were treated with (R)-5-Fluoro-ADB and investigated for cell viability, migration rate, and tube-like structure formation. Furthermore, angiogenic-related proteins including Angopoitein-1 and -2, and Vascular Endothelial Growth Factors (VEGF) were examined on mRNA and protein levels.

Results

The results showed a notable rise in the rate of proliferation (P-value<0.0001) of HBMECs induced by (R)-5-Fluoro-ADB. The angiogenic capacity of HBMECs was also enhanced between 0.001 μM to 1 μM (R)-5-Fluoro-ADB. Moreover, an increase in the levels of ANG-1, ANG-2, and VEGF mRNA and protein, as well as elevated phosphorylation rate of GSK-3β, were observed across various concentrations of (R)-5-Fluoro-ADB.

Conclusion

Our results suggest an innovative approach in pharmacology for addressing a range of conditions linked to angiogenesis. This approach involves precise targeting of both cannabinoid receptors type-1 and -2. To achieve this, specific agonists or antagonists of these receptors could be employed based on the particular characteristics of the diseases in question.

The therapeutic value of adipose-derived pericyte transplantation after intracerebral hemorrhage in rats

Intracerebral hemorrhage (ICH) is a devastating cerebrovascular associated with inflammation and BBB disruption. Pericytes plays a critical role in neurological diseases, while whether pericytes could be utilized to treat ICH remains to be elucidated. Here, we isolated CD146+CD34- pericytes from rat adipose tissues (ADPs). Fluorescence-activated cells maintained their cell morphology and differentiation potential and expressed pericytes markers (CD146, NG2, and PDGFRβ) but not endothelial markers (CD31, CD34, and CD45). ADPs transplantation improved the neuro-behavioral functions in ICH rats and resulted in decreased hematoma volume and neuron loss after ICH. Besides, ADPs graft restrained the infiltration of neutrophils and reactive microgliosis after ICH injury around the peri-hematoma area of rats, as evidenced by increased Iba1- and MPO immunoreactivity. The transplanted pericytes were covered on endothelial cells, and promoted angiogenesis and vascular basement membrane formation in the peri-hematoma area of ICH rats, as shown by double staining of PDGFRβ and CD31/CollagenIV. The decreased brain water content and Evans Blue leakage proved the protective role of ADPs graft on BBB permeability. Finally, transplanted ADPs increased the expression of VE-cadherin, ZO-1, and claudin-5, leading to stable endothelial cell-cell adhesion and tight junction. In conclusion, the transplantation of APDs improved neuronal after ICH, which involved different mechanisms including neuroinflammation regulation and BBB dysfunction recovery. Our results supported that ADPs might be the ideal cell type for ICH therapy and provided insights into the potential cell therapy for further ICH treatment.

Identification of potential angiogenic biomarkers in human follicular fluid for predicting oocyte maturity

Background

Angiogenesis in folliculogenesis contributes to oocyte developmental competence in natural and in vitro fertilization (IVF) cycles. Therefore, the identification of key angiogenic factors in follicular fluid (FF) during folliculogenesis is clinically significant and important for in vitro fertilization. This study aims to identify the key angiogenic factors in FF for predicting oocyte maturity during in vitro fertilization.

Materials and methods

Forty participants who received ovarian stimulation using a GnRH antagonist protocol in their first in vitro fertilization treatment were recruited. From each patient, two follicular samples (one preovulatory follicle, > 18 mm; one mid-antral follicle, < 14 mm) were collected without flushing during oocyte retrieval. In total, 80 FF samples were collected from 40 patients. The expression profiles of angiogenesis-related proteins in FF were analyzed via Luminex high-performance assays. Recorded patient data included antral follicle count, anti-müllerian hormone, age, and BMI. Serum samples were collected on menstrual cycle day 2, the trigger day, and the day of oocyte retrieval. Hormone concentrations including day 2 FSH/LH/E2/P4, trigger day E2/LH/P4, and retrieval day E2/LH/P4 were measured by chemiluminescence assay.

Results

Ten angiogenic factors were highly expressed in FF: eotaxin, Gro-α, IL-8, IP-10, MCP-1, MIG, PAI-1 (Serpin), VEGF-A, CXCL-6, and HGF. The concentrations of eotaxin, IL-8, MCP1, PAI-1, and VEGF-A were significantly higher in preovulatory follicles than those in mid-antral follicles, while the Gro-α and CXCL-6 expressional levels were lower in preovulatory than in mid-antral follicles (p < 0.05). Logistic regression and receiver operating characteristic (ROC) analysis revealed that VEGF-A, eotaxin, and CXCL-6 were the three strongest predictors of oocyte maturity. The combination of VEGF-A and CXCL-6 predicted oocyte maturity with a higher sensitivity (91.7%) and specificity (72.7%) than other combinations.

Conclusion

Our findings suggest that VEGF-A, eotaxin, and CXCL-6 concentrations in FF strongly correlate with oocyte maturity from the mid-antral to preovulatory stage. The combination of VEGF-A and CXCL-6 exhibits a relatively good prediction rate of oocyte maturity during in vitro fertilization.

Angiogenesis in abnormal uterine bleeding: a narrative review

BACKGROUND

Abnormal uterine bleeding (AUB) has a significant socioeconomic impact since it considerably impacts quality of life. Therapeutic options are frequently based on trial and error and do not target disease aetiology. Pathophysiological insight in this disease is required for the development of novel treatment options. If no underlying cause is found for the AUB (e.g. fibroids, adenomyosis, polyps), endometrial-AUB (AUB-E) is usually caused by a primary endometrium disorder. When AUB is induced by prescribed (exogenous) hormones, it is classified as iatrogenic-AUB (AUB-I). Considering vascular modulation and function, AUB-E and AUB-I both could potentially result from abnormal vascularization in the endometrium due to alterations in the process of angiogenesis and vascular maturation.

OBJECTIVE AND RATIONALE

We aim to investigate the fundamental role of angiogenesis and vascular maturation in patients with AUB and hypothesize that aberrant endometrial angiogenesis has an important role in the aetiology of both AUB-E and AUB-I, possibly through different mechanisms.

SEARCH METHODS

A systematic literature search was performed until September 2021 in the Cochrane Library Databases, Embase, PubMed, and Web of Science, with search terms such as angiogenesis and abnormal uterine bleeding. Included studies reported on angiogenesis in the endometrium of premenopausal women with AUB-E or AUB-I. Case reports, letters, reviews, editorial articles, and studies on AUB with causes classified by the International Federation of Gynecology and Obstetrics as myometrial, oncological, or infectious, were excluded. Study quality was assessed by risk of bias, using the Cochrane tool and the Newcastle-Ottawa Scale.

OUTCOMES

Thirty-five out of 2158 articles were included. In patients with AUB-E, vascular endothelial growth factor A and its receptors (1 and 2), as well as the angiopoietin-1:angiopoietin-2 ratio and Tie-1, were significantly increased. Several studies reported on the differential expression of other pro- and antiangiogenic factors in patients with AUB-E, suggesting aberrant vascular maturation and impaired vessel integrity. Overall, endometrial microvessel density (MVD) was comparable in patients with AUB-E and controls. Interestingly, patients with AUB-I showed a higher MVD and higher expression of proangiogenic factors when compared to controls, in particular after short-term hormone exposure. This effect was gradually lost after longer-term exposure, while alterations in vessel maturation were observed after both short- and long-term exposures.

WIDER IMPLICATIONS

AUB-E and AUB-I are most likely associated with aberrant endometrial angiogenesis and impaired vessel maturation. This review supports existing evidence that increased proangiogenic and decreased antiangiogenic factors cause impaired vessel maturation, resulting in more fragile and permeable vessels. This matches our hypothesis and these mechanisms appear to play an important role in the pathophysiology of AUB-E and AUB-I. Exploring the alterations in angiogenesis in these patients could provide treatment targets for AUB.

Cardiovascular research at the Heart of Clinical Science

Clinical Science was originally established as the journal Heart in 1909 by Sir Thomas Lewis and Sir James Mackenzie. Heart was an influential journal publishing cardiovascular research and was renamed Clinical Science in 1933 to attract broader research interests. Nevertheless, cardiovascular research contributions remain a foundational part of the journal to this day. This editorial provides historical perspective on the journal's cardiovascular origins and includes data related to cardiovascular publications from the past decade. Clinical Science is committed to publishing leading cardiovascular research from the field and looks forward to receiving your submission.

The impact of pericytes on the stability of microvascular networks in response to nanoparticles

Recapitulating the normal physiology of the microvasculature is pivotal in the development of more complex in-vitro models and organ-on-chip designs. Pericytes are an important component of the vasculature, promoting vessel stability, inhibiting vascular permeability and maintaining the vascular hierarchical architecture. The use of such co-culture for the testing of therapeutics and nanoparticle safety is increasingly considered for the validation of therapeutic strategies. This report presents the use of a microfluidic model for such applications. Interactions between endothelial cells and pericytes are first explored. We identify basal conditions required to form stable and reproducible endothelial networks. We then investigate interactions between endothelial cells and pericytes via direct co-culture. In our system, pericytes prevented vessel hyperplasia and maintained vessel length in prolonged culture (> 10 days). In addition, these vessels displayed barrier function and expression of junction markers associated with vessel maturation, including VE-cadherin, β-catenin and ZO-1. Furthermore, pericytes maintained vessel integrity following stress (nutrient starvation) and prevented vessel regression, in contrast to the striking dissociation of networks in endothelial monocultures. This response was also observed when endothelial/pericyte co-cultures were exposed to high concentrations of moderately toxic cationic nanoparticles used for gene delivery. This study highlights the importance of pericytes in protecting vascular networks from stress and external agents and their importance to the design of advanced in-vitro models, including for the testing of nanotoxicity, to better recapitulate physiological response and avoid false positives.

Thyroid Hormone Transporters MCT8 and OATP1C1 Are Expressed in Pyramidal Neurons and Interneurons in the Adult Motor Cortex of Human and Macaque Brain

Monocarboxylate transporter 8 (MCT8) and organic anion transporter polypeptide 1C1 (OATP1C1) are thyroid hormone (TH) transmembrane transporters that play an important role in the availability of TH for neural cells, allowing their proper development and function. It is important to define which cortical cellular subpopulations express those transporters to explain why MCT8 and OATP1C1 deficiency in humans leads to dramatic alterations in the motor system. By means of immunohistochemistry and double/multiple labeling immunofluorescence in adult human and monkey motor cortices, we demonstrate the presence of both transporters in long-projection pyramidal neurons and in several types of short-projection GABAergic interneurons in both species, suggesting a critical position of these transporters for modulating the efferent motor system. MCT8 is present at the neurovascular unit, but OATP1C1 is only present in some of the large vessels. Both transporters are expressed in astrocytes. OATP1C1 was unexpectedly found, only in the human motor cortex, inside the Corpora amylacea complexes, aggregates linked to substance evacuation towards the subpial system. On the basis of our findings, we propose an etiopathogenic model that emphasizes these transporters' role in controlling excitatory/inhibitory motor cortex circuits in order to understand some of the severe motor disturbances observed in TH transporter deficiency syndromes.

Cell Reprogramming for Regeneration and Repair of the Nervous System

A persistent barrier to the cure and treatment of neurological diseases is the limited ability of the central and peripheral nervous systems to undergo neuroregeneration and repair. Recent efforts have turned to regeneration of various cell types through cellular reprogramming of native cells as a promising therapy to replenish lost or diminished cell populations in various neurological diseases. This review provides an in-depth analysis of the current viral vectors, genes of interest, and target cellular populations that have been studied, as well as the challenges and future directions of these novel therapies. Furthermore, the mechanisms by which cellular reprogramming could be optimized as treatment in neurological diseases and a review of the most recent cellular reprogramming in vitro and in vivo studies will also be discussed.

Pro-angiogenic activity of isofuran

Isofurans (IsoFs) are a series of novel discovered lipid peroxidation products. This study focused on the investigation of angiogenic property of IsoF. MTT stain assay indicated that 1 μM IsoF had the most bioactivity in RBECs. IsoF significantly promoted cellular proliferation and migration and remarkably decreased staurosporine-induced apoptosis by TUNEL assay in the RBECs. It successfully up-regulated rat aortic vascularization and choroid explant sprouting, extracellular regulated protein kinases (ERK)1/2, and triggered calcium release. RT-PCR examination indicated that IsoF up-regulated tumor necrosis factor (TNF)α, angiopoietin-1 receptor (Tie2), and vascular endothelial growth factor (VEGF)-A, but did not interfere with caspase 2 and VEGF-C in the RBECs. IsoF has pro-angiogenic activity. Calcium release and ERK1/2 phosphorylation may be involved in the signaling of the IsoF-induced up-regulation of TNFα, Tie2, and VEGF-A, which could be the molecular mechanism of the pro-angiogenic activity of the IsoF.

The Role of Periostin in Angiogenesis and Lymphangiogenesis in Tumors

Simple Summary

Cancers are common diseases that affect people of all ages worldwide. For this reason, continuous attempts are being made to improve current therapeutic options. The formation of metastases significantly decreases patient survival. Therefore, understanding the mechanisms that are involved in this process seems to be crucial for effective cancer therapy. Cancer dissemination occurs mainly through blood and lymphatic vessels. As a result, many scientists have conducted a number of studies on the formation of new vessels. Many studies have shown that proangiogenic factors and the extracellular matrix protein, i.e., periostin, may be important in tumor angio- and lymphangiogenesis, thus contributing to metastasis formation and worsening of the prognosis.

Abstract

Periostin (POSTN) is a protein that is part of the extracellular matrix (ECM) and which significantly affects the control of intracellular signaling pathways (PI3K-AKT, FAK) through binding integrin receptors (αvβ3, αvβ5, α6β4). In addition, increased POSTN expression enhances the expression of VEGF family growth factors and promotes Erk phosphorylation. As a result, this glycoprotein controls the Erk/VEGF pathway. Therefore, it plays a crucial role in the formation of new blood and lymphatic vessels, which may be significant in the process of metastasis. Moreover, POSTN is involved in the proliferation, progression, migration and epithelial-mesenchymal transition (EMT) of tumor cells. Its increased expression has been detected in many cancers, including breast cancer, ovarian cancer, non-small cell lung carcinoma and glioblastoma. Many studies have shown that this protein may be an independent prognostic and predictive factor in many cancers, which may influence the choice of optimal therapy.

Central Nervous System Pericytes Contribute to Health and Disease

Successful neuroprotection is only possible with contemporary microvascular protection. The prevention of disease-induced vascular modifications that accelerate brain damage remains largely elusive. An improved understanding of pericyte (PC) signalling could provide important insight into the function of the neurovascular unit (NVU), and into the injury-provoked responses that modify cell-cell interactions and crosstalk. Due to sharing the same basement membrane with endothelial cells, PCs have a crucial role in the control of endothelial, astrocyte, and oligodendrocyte precursor functions and hence blood-brain barrier stability. Both cerebrovascular and neurodegenerative diseases impair oxygen delivery and functionally impair the NVU. In this review, the role of PCs in central nervous system health and disease is discussed, considering their origin, multipotency, functions and also dysfunction, focusing on new possible avenues to modulate neuroprotection. Dysfunctional PC signalling could also be considered as a potential biomarker of NVU pathology, allowing us to individualize therapeutic interventions, monitor responses, or predict outcomes.

Therapeutic Effect of Pericytes for Diabetic Wound Healing

Objective

Numerous attempts have been made to devise treatments for ischemic foot ulcer (IFU), which is one of the most severe and fatal consequences of diabetes mellitus (DM). Pericytes, which are perivascular multipotent cells, are of interest as a treatment option for IFU because they play a critical role in forming and repairing various tissues. In this study, we want to clarify the angiogenic potential of pericytes in DM-induced wounds.

Methods

We evaluated pericyte stimulation capability for tube formation, angiogenesis, and wound healing (cell migration) in human umbilical vein endothelial cells (HUVECs) with in-vivo and in-vitro models of high glucose conditions.

Results

When HUVECs were co-cultured with pericytes, their tube-forming capacity and cell migration were enhanced. Our diabetic mouse model showed that pericytes promote wound healing via increased vascularization.

Conclusion

The findings of this study indicate that pericytes may enhance wound healing in high glucose conditions, consequently making pericyte transplantation suitable for treating IFUs.

Glioma Pericytes Promote Angiogenesis by Producing Periostin

Glioma is the prevalent aggressive primary brain tumor, with a very poor prognosis. The absence of advanced understanding of the roles played by the cells within the glioma microenvironment limits the development of effective drugs. A recent study indicates that periostin expressed by pericytes is crucial for glioma angiogenesis. Here, we describe succinctly the results and implications of this discovery in what we know about pericytes within the glioma microenvironment. The emerging knowledge from this work will benefit the development of therapies for gliomas.

Defining Wound Healing Progression in Cetacean Skin: Characteristics of Full-Thickness Wound Healing in Fraser's Dolphins (Lagenodelphis hosei)

Simple Summary

Cutaneous wound healing is a complex and tightly regulated biological process to restore physiological and anatomic function. Current knowledge of cutaneous wound healing is mostly based on studies in laboratory animals and humans. The histological and immunological features of skin, for example, cutaneous thickness, cellular components, and immune response, are not identical among animal species, and these differences may lead to substantial effects in cutaneous wound healing. In field observation, large cutaneous wounds in cetaceans could heal without medical treatments. However, little is known about the underlying mechanisms, and there is no histological study on full-thickness wound healing in cetaceans. The current study characterizes the macroscopic and histological features of large full-thickness wound healing in Fraser’s dolphins (Lagenodelphis hosei). The differences of wound healing between cetaceans and terrestrial mammals were shown from the histological aspect, including rete and dermal ridge appearance, repigmentation, and adipose tissue regeneration. Better understanding of the mechanism of full-thickness wound healing in cetaceans will shed light on veterinary and human regenerative medicine, leading to novel therapies.

Abstract

Cetaceans are tight-skinned mammals that exhibit an extraordinary capacity to heal deep soft tissue injuries. However, essential information of large full-thickness wound healing in cetaceans is still lacking. Here, the stages of full-thickness wound healing were characterized in Fraser’s dolphins (Lagenodelphis hosei). The skin samples were collected from normal skin and full-thickness cookiecutter shark (Isistius brasiliensis)-bite wounds of stranded carcasses. We defined five stages of wound healing according to macroscopic and histopathological examinations. Wounds in Stage 1 and 2 were characterized by intercellular and intracellular edema in the epidermal cells near the wound edge, mixed inflammatory cell infiltration, and degradation of collagen fibers. In Stage 3 wounds, melanocytes, melanin granules, rete and dermal ridges were noticed in the neo-epidermis, and the adipose tissue in adjacent blubber was replaced by cells and fibers. Wounds in Stage 4 and 5 were characterized by gradual restoration of the normal skin architecture including rete and dermal ridges, collagen bundles, and adipose tissue. These phenomena were quite different from previous studies in terrestrial tight-skinned mammals, and therefore, further in-depth research into the mechanisms of dolphin wound healing would be needed to gain new insights into veterinary and human regenerative medicine.

Heterotypic Multicellular Spheroids as Experimental and Preclinical Models of Sprouting Angiogenesis

Sprouting angiogenesis is the common response of live tissues to physiological and pathological angiogenic stimuli. Its accurate evaluation is of utmost importance for basic research and practical medicine and pharmacology and requires adequate experimental models. A variety of assays for angiogenesis were developed, none of them perfect. In vitro approaches are generally less physiologically relevant due to the omission of essential components regulating the process. However, only in vitro models can be entirely non-xenogeneic. The limitations of the in vitro angiogenesis assays can be partially overcome using 3D models mimicking tissue O2 and nutrient gradients, the influence of the extracellular matrix (ECM), and enabling cell-cell interactions. Here we present a review of the existing models of sprouting angiogenesis that are based on the use of endothelial cells (ECs) co-cultured with perivascular or other stromal cells. This approach provides an excellent in vitro platform for further decoding of the cellular and molecular mechanisms of sprouting angiogenesis under conditions close to the in vivo conditions, as well as for preclinical drug testing and preclinical research in tissue engineering and regenerative medicine.

QSAR analysis of pyrimidine derivatives as VEGFR-2 receptor inhibitors to inhibit cancer using multiple linear regression and artificial neural network

BACKGROUND AND PURPOSE

In this study, the pharmacological activity of 33 compounds of furopyrimidine and thienopyrimidine as vascular endothelial growth factor receptor 2 (VEGFR-2) inhibitors to inhibit cancer was investigated. The most important angiogenesis inducer is VEGF endothelial growth factor, which exerts its activity by binding to two tyrosine kinase receptors called VEGFR-1 and VEGFR-2. Due to the critical role of VEGF in the pathological angiogenesis of this molecule, it is a valuable therapeutic target for anti-angiogenesis therapies.

EXPERIMENTAL APPROACH

After calculating descriptors using SPSS software and stepwise selection method, 5 descriptors were used for modeling in multiple linear regression (MLR) and artificial neural network (ANN). The calibration series and the test series in this study included 26 and 7 combinations, respectively.

FINDINGS/RESULTS

The performance evaluation of models was determined by the R2, RMSE, and Q2 statistic parameters. The R2 values of MLR and ANN models were 0.889 and 0.998, respectively. Also, the value of RMSE in the ANN model was lower and its Q2 value was higher than the MLR model.

CONCLUSION AND IMPLICATIONS

The results were evaluated by different statistical methods and it was concluded that the nonlinear neural network method is powerful to predict the pharmacological activity of similar compounds, and because of the complex and nonlinear relationships, the MLR was not capable of establishing a good model with high predictive power.

Skin trauma rapidly induces thermoregulatory plexus hyperemia, while an increased nutritive papillary capillary function can be detected after 24 h

OBJECTIVE

Clinical assessments and laser Doppler perfusion measurements (LDPM) of skin microcirculation have limited value, as they fail to capture events regulated by local metabolic needs at a papillary capillary level. This study aimed to examine the ability of computer-assisted video microscopy (CAVM) and diffuse reflectance spectroscopy (DRS) to assess skin nutritive perfusion-compared to LDPM.

METHODS

Healthy volunteers (n = 10) were examined after (≈1 and ≈24 h) an incision (5 × 1 mm) on the forearm, at 0.1 mm (only with CAVM), 2-3 mm, and 30 mm from the trauma.

RESULTS

No changes were detected by CAVM after ≈1 h. After ≈24 h, 0-1 mm from the trauma, both CAVM parameters were increased: functional capillary density (capillary crossings/mm, 11.8 ± 1.4 vs. 7.3 ± 1.2, p < .01) and capillary flow velocities (CFV, %capillaries with brisk flow, 10 ± 6.8 vs. 1 ± 1, p < .01). At a distance of 2-3 mm, only CFV was increased (6.2 ± 6.1 vs. 1 ± 1, p < .05). DRS and LDPM measurements increased 2-3 mm from the trauma line in relation to baseline after both ≈1 and ≈24 h, that is, with DRS (%microvascular oxygen saturation): 45.8 ± 7.4% (baseline), 70.0 ± 12.5% (≈1 h), and 73.1 ± 10.4% (≈24 h), p < .01 and with LDPM (a.u.): 7.2 ± 2.5 (baseline), 28.3 ± 18.7 (≈1 h), and 45.9 ± 16.3 (≈24 h), p < .01.

CONCLUSIONS

≈24 h after skin trauma, an increased function of the nutritive papillary capillaries can be detected by CAVM.

Telocytes in the Tumor Microenvironment

There are several theories explaining the communication between cells in the context of tumor development. Over the years, interactions between normal and transformed cells have been observed. Generally, all types of cells make equal contributions to the formation of the tumor microenvironment - a location of primary oncogenesis. To date, several studies have reported the role of telocytes in cancer development, and many publications have emphasized the direct and indirect involvement of telocytes in angiogenesis; signaling through the secretion of extracellular vesicles, growth factors, and bioactive molecules; fibrosis development and extracellular matrix production; tissue repair and regeneration; and immune responses. Considering the main components of the tumor microenvironment, we will discuss the features of telocytes and their possible involvement in local tissue homeostasis.

Pericytes: Intrinsic Transportation Engineers of the CNS Microcirculation

Pericytes in the brain are candidate regulators of microcirculatory blood flow because they are strategically positioned along the microvasculature, contain contractile proteins, respond rapidly to neuronal activation, and synchronize microvascular dynamics and neurovascular coupling within the capillary network. Analyses of mice with defects in pericyte generation demonstrate that pericytes are necessary for the formation of the blood-brain barrier, development of the glymphatic system, immune homeostasis, and white matter function. The development, identity, specialization, and progeny of different subtypes of pericytes, however, remain unclear. Pericytes perform brain-wide 'transportation engineering' functions in the capillary network, instructing, integrating, and coordinating signals within the cellular communicome in the neurovascular unit to efficiently distribute oxygen and nutrients ('goods and services') throughout the microvasculature ('transportation grid'). In this review, we identify emerging challenges in pericyte biology and shed light on potential pericyte-targeted therapeutic strategies.

Pericytes cross-talks within the tumor microenvironment

Cancer cells are embedded within the tumor microenvironment and interact dynamically with its components during tumor progression. Understanding the molecular mechanisms by which the tumor microenvironment components communicate is crucial for the success of therapeutic applications. Recent studies show, by using state-of-the-art technologies, including sophisticated in vivo inducible Cre/loxP mediated systems and CRISPR-Cas9 gene editing, that pericytes communicate with cancer cells. The arising knowledge on cross-talks within the tumor microenvironment will be essential for the development of new therapies against cancer. Here, we review recent progress in our understanding of pericytes roles within tumors.

Stem Cells from Human Exfoliated Deciduous Teeth (SHEDs) and Dental Pulp Stem Cells (DPSCs) Display a Similar Profile with Pericytes

Background

Pericytes play an important role in forming functional blood vessels and establishing stable and effective microcirculation, which is crucial for vascular tissue engineering. The slow ex vivo expansion rate, limited proliferative capacity, and variability of tissue-specific phenotypes would hinder experimental studies and clinical translation of primary pericytes. In this study, the angiogenic and pericyte functions of stem cells from human exfoliated deciduous teeth (SHEDs) and postnatal human dental pulp stem cells (DPSCs) were investigated.

Methods

Osteogenic and adipogenic induction assays were performed to evaluate the mesenchymal potential of SHEDs, DPSCs, and pericytes. An in vitro Matrigel angiogenesis assay was conducted to reveal the ability of SHEDs, DPSCs, and pericytes to stabilize vascular-like structures. Quantitative real-time polymerase chain reaction (RT-qPCR) was performed to evaluate mRNA expression. Flow cytometry, western blotting, and immunostaining were used to assess the protein expression. Wound healing and transwell assays were performed to evaluate the migration ability of SHEDs, DPSCs, and pericytes.

Results

The osteogenic and adipogenic induction assays showed that SHEDs, DPSCs, and pericytes exhibited similar stem cell characteristics. The mRNA expression levels of PDGFR-β, α-SMA, NG2, and DEMSIN in SHEDs and DPSCs cultured in EC medium were significantly higher than those in the control groups on day 7 (P < 0.05), but significantly higher than those in the pericytes group on day 14 (P < 0.05). Flow cytometry showed that high proportions of SHEDs and DPSCs were positive for various pericyte markers on day 7. The DPSCs, SHEDs, and pericytes displayed strong migration ability; however, there was no significant difference among the groups (P > 0.05).

Conclusion

The SHEDs and DPSCs display a profile similar to that of pericytes. Our study lays a solid theoretical foundation for the clinical use of dental pulp stem cells as a potential candidate to replace pericytes.

Lung Pericytes in Pulmonary Vascular Physiology and Pathophysiology

Pericytes are mesenchymal-derived mural cells localized within the basement membrane of pulmonary and systemic capillaries. Besides structural support, pericytes control vascular tone, produce extracellular matrix components, and cytokines responsible for promoting vascular homeostasis and angiogenesis. However, pericytes can also contribute to vascular pathology through the production of pro-inflammatory and pro-fibrotic cytokines, differentiation into myofibroblast-like cells, destruction of the extracellular matrix, and dissociation from the vessel wall. In the lung, pericytes are responsible for maintaining the integrity of the alveolar-capillary membrane and coordinating vascular repair in response to injury. Loss of pericyte communication with alveolar capillaries and a switch to a pro-inflammatory/pro-fibrotic phenotype are common features of lung disorders associated with vascular remodeling, inflammation, and fibrosis. In this article, we will address how to differentiate pericytes from other cells, discuss the molecular mechanisms that regulate the interactions of pericytes and endothelial cells in the pulmonary circulation, and the experimental tools currently used to study pericyte biology both in vivo and in vitro. We will also discuss evidence that links pericytes to the pathogenesis of clinically relevant lung disorders such as pulmonary hypertension, idiopathic lung fibrosis, sepsis, and SARS-COVID. Future studies dissecting the complex interactions of pericytes with other pulmonary cell populations will likely reveal critical insights into the origin of pulmonary diseases and offer opportunities to develop novel therapeutics to treat patients afflicted with these devastating disorders. © 2021 American Physiological Society. Compr Physiol 11:2227-2247, 2021.

Extracellular matrix remodeling associated with bleomycin-induced lung injury supports pericyte-to-myofibroblast transition

Of the many origins of pulmonary myofibroblasts, microvascular pericytes are a known source. Prior literature has established the ability of pericytes to transition into myofibroblasts, but provide limited insight into molecular cues that drive this process during lung injury repair and fibrosis. Fibronectin and RGD-binding integrins have long been considered pro-fibrotic factors in myofibroblast biology, and here we test the hypothesis that these known myofibroblast cues coordinate pericyte-to-myofibroblast transitions. Specifically, we hypothesized that αvβ3 integrin engagement on fibronectin induces pericyte transition into myofibroblastic phenotypes in the murine bleomycin lung injury model. Myosin Heavy Chain 11 (Myh11)-CreERT2 lineage tracing in transgenic mice allows identification of cells of pericyte origin and provides a robust tool for isolating pericytes from tissues for further evaluation. We used this murine model to track and characterize pericyte behaviors during tissue repair. The majority of Myh11 lineage-positive cells are positive for the pericyte surface markers, PDGFRβ (55%) and CD146 (69%), and display typical pericyte morphology with spatial apposition to microvascular networks. After intratracheal bleomycin treatment of mice, Myh11 lineage-positive cells showed significantly increased contractile and secretory markers, as well as αv integrin expression. According to RNASeq measurements, many disease and tissue-remodeling genesets were upregulated in Myh11 lineage-positive cells in response to bleomycin-induced lung injury. In vitro, blocking αvβ3 binding through cycloRGDfK prevented expression of the myofibroblastic marker αSMA relative to controls. In response to RGD-containing provisional matrix proteins present in lung injury, pericytes may alter their integrin profile.

Circulating Nestin-GFP+ Cells Participate in the Pathogenesis of Paracoccidioides brasiliensis in the Lungs

Multiple infectious diseases lead to impaired lung function. Revealing the cellular mechanisms involved in this impairment is crucial for the understanding of how the lungs shift from a physiologic to a pathologic state in each specific condition. In this context, we explored the pathogenesis of Paracoccidioidomycosis, which affects pulmonary functioning. The presence of cells expressing Nestin-GFP has been reported in different tissues, and their roles as tissue-specific progenitors have been stablished in particular organs. Here, we explored how Nestin-GFP⁺ cells are affected after lung infection by Paracoccidioides brasiliensis, a model of lung granulomatous inflammation with fibrotic outcome. We used Nestin-GFP transgenic mice, parabiosis surgery, confocal microscopy and flow cytometry to investigate the participation of Nestin-GFP⁺ cells in Paracoccidioides brasiliensis pathogenesis. We revealed that these cells increase in the lungs post-Paracoccidioides brasiliensis infection, accumulating around granulomas. This increase was due mainly to Nestin-GPF⁺ cells derived from the blood circulation, not associated to blood vessels, that co-express markers suggestive of hematopoietic cells (Sca-1, CD45 and CXCR4). Therefore, our findings suggest that circulating Nestin-GFP⁺ cells participate in the Paracoccidioides brasiliensis pathogenesis in the lungs.

Microphysiological Systems for Studying Cellular Crosstalk During the Neutrophil Response to Infection

Neutrophils are the primary responders to infection, rapidly migrating to sites of inflammation and clearing pathogens through a variety of antimicrobial functions. This response is controlled by a complex network of signals produced by vascular cells, tissue resident cells, other immune cells, and the pathogen itself. Despite significant efforts to understand how these signals are integrated into the neutrophil response, we still do not have a complete picture of the mechanisms regulating this process. This is in part due to the inherent disadvantages of the most-used experimental systems: in vitro systems lack the complexity of the tissue microenvironment and animal models do not accurately capture the human immune response. Advanced microfluidic devices incorporating relevant tissue architectures, cell-cell interactions, and live pathogen sources have been developed to overcome these challenges. In this review, we will discuss the in vitro models currently being used to study the neutrophil response to infection, specifically in the context of cell-cell interactions, and provide an overview of their findings. We will also provide recommendations for the future direction of the field and what important aspects of the infectious microenvironment are missing from the current models.

Role of Podoplanin-Positive Cells in Cardiac Fibrosis and Angiogenesis After Ischemia

New insights into the cellular and extra-cellular composition of scar tissue after myocardial infarction (MI) have been identified. Recently, a heterogeneous podoplanin-expressing cell population has been associated with fibrogenic and inflammatory responses and lymphatic vessel growth during scar formation. Podoplanin is a mucin-like transmembrane glycoprotein that plays an important role in heart development, cell motility, tumorigenesis, and metastasis. In the adult mouse heart, podoplanin is expressed only by cardiac lymphatic endothelial cells; after MI, it is acquired with an unexpected heterogeneity by PDGFRα-, PDGFRβ-, and CD34-positive cells. Podoplanin may therefore represent a sign of activation of a cohort of progenitor cells during different phases of post-ischemic myocardial wound repair. Podoplanin binds to C-type lectin-like receptor 2 (CLEC-2) which is exclusively expressed by platelets and a variety of immune cells. CLEC-2 is upregulated in CD11b^high cells, including monocytes and macrophages, following inflammatory stimuli. We recently published that inhibition of the interaction between podoplanin-expressing cells and podoplanin-binding cells using podoplanin-neutralizing antibodies reduces but does not fully suppress inflammation post-MI while improving heart function and scar composition after ischemic injury. These data support an emerging and alternative mechanism of interactome in the heart that, when neutralized, leads to altered inflammatory response and preservation of cardiac function and structure. The overarching objective of this review is to assimilate and discuss the available evidence on the functional role of podoplanin-positive cells on cardiac fibrosis and remodeling. A detailed characterization of cell-to-cell interactions and paracrine signals between podoplanin-expressing cells and the other type of cells that compose the heart tissue is needed to open a new line of investigation extending beyond the known function of these cells. This review attempts to discuss the role and biology of podoplanin-positive cells in the context of cardiac injury, repair, and remodeling.

Permeability of the Blood-Brain Barrier after Traumatic Brain Injury; Radiological Considerations

Traumatic brain injury (TBI) is a leading cause of death and disability, especially in young persons, and constitutes a major socioeconomic burden worldwide. It is regarded as the leading cause of mortality and morbidity in previously healthy young persons. Most of the mechanisms underpinning the development of secondary brain injury are consequences of disruption of the complex relationship between the cells and proteins constituting the neurovascular unit or a direct result of loss of integrity of the tight junctions (TJ) in the blood-brain barrier (BBB). A number of changes have been described in the BBB after TBI, including loss of TJ proteins, pericyte loss and migration, and altered expressions of water channel proteins at astrocyte end-feet processes. There is a growing research interest in identifying optimal biological and radiological biomarkers of severity of BBB dysfunction and its effects on outcomes after TBI. This review explores the microscopic changes occurring at the neurovascular unit, after TBI, and current radiological adjuncts for its evaluation in pre-clinical and clinical practice.

JAM2: A New Culprit at the Pathophysiology of Primary Familial Brain Calcification

Primary familial brain calcification (PFBC) is an uncommon degenerative neurological disease that can be hereditary or sporadic, and manifests equally in both sexes and at any age. Several studies initially identified variants in four different genes as the cause of the disorder, all with an autosomal dominant inheritance pattern: SLC20A2, PDGFRB, PDGFB and XPR1. However, there have been reports of the involvement of additional genes in the autosomal recessive inheritance pattern, such as MYORG and more recently JAM2, suggesting that the deregulation of the neurovascular unit (NVU) is important in the pathogenesis of PFBC. The recent study by Schottlaender and collaborators (2020) has added new data to foster these analyses and to enable a better understanding of this underdiagnosed and intriguing neuropsychiatric condition. A great challenge now is to design a model that explains how different pathways might lead to similar neuroimaging findings but with variable clinical outcome, and with marked severity in cases linked to MYORG and JAM2. Currently available databases of detailed gene expression in different vascular cell types from the mouse brain could be used to explore a possible integrative model.

Neural crest cell-derived pericytes act as pro-angiogenic cells in human neocortex development and gliomas

Central nervous system diseases involving the parenchymal microvessels are frequently associated with a ‘microvasculopathy’, which includes different levels of neurovascular unit (NVU) dysfunction, including blood–brain barrier alterations. To contribute to the understanding of NVU responses to pathological noxae, we have focused on one of its cellular components, the microvascular pericytes, highlighting unique features of brain pericytes with the aid of the analyses carried out during vascularization of human developing neocortex and in human gliomas. Thanks to their position, centred within the endothelial/glial partition of the vessel basal lamina and therefore inserted between endothelial cells and the perivascular and vessel-associated components (astrocytes, oligodendrocyte precursor cells (OPCs)/NG2-glia, microglia, macrophages, nerve terminals), pericytes fulfil a central role within the microvessel NVU. Indeed, at this critical site, pericytes have a number of direct and extracellular matrix molecule- and soluble factor-mediated functions, displaying marked phenotypical and functional heterogeneity and carrying out multitasking services. This pericytes heterogeneity is primarily linked to their position in specific tissue and organ microenvironments and, most importantly, to their ontogeny. During ontogenesis, pericyte subtypes belong to two main embryonic germ layers, mesoderm and (neuro)ectoderm, and are therefore expected to be found in organs ontogenetically different, nonetheless, pericytes of different origin may converge and colonize neighbouring areas of the same organ/apparatus. Here, we provide a brief overview of the unusual roles played by forebrain pericytes in the processes of angiogenesis and barriergenesis by virtue of their origin from midbrain neural crest stem cells. A better knowledge of the ontogenetic subpopulations may support the understanding of specific interactions and mechanisms involved in pericyte function/dysfunction, including normal and pathological angiogenesis, thereby offering an alternative perspective on cell subtype-specific therapeutic approaches.

TGFβ1 induces in-vitro and ex-vivo angiogenesis through VEGF production in human ovarian follicular fluid-derived granulosa cells during in-vitro fertilization cycle

A growing body of evidence indicates that angiogenesis in folliculogenesis contributes to oocyte developmental competence in natural and in-vitro fertilization (IVF) cycle of animals. Among the known angiogenic factors, vascular endothelial growth factor (VEGF) has an important role involved in angiogenesis. However, its expression level and regulatory mechanism in ovarian follicular fluid (FF) in patients undergoing IVF with controlled ovarian stimulation (COS) remains to be explored. In this study, the primary cultured human ovarian follicular granulosa cells (GCs) were prepared from FF and their identity was characterized by the presence of the GC specific markers. The transforming growth factor β1 (TGFβ1) was found to induce a significant increase in VEGF mRNA level and protein expression/secretion in GCs. In line with these observations, TGFβ1 could be detected in the ovarian FF, ranging from about 400 to 2000 pg/mL among three IVF patient groups with different patient's serum Anti-Müllerian hormone level. The cellular signaling analysis revealed that TGFβ1 induced VEGF production through TGFβ receptor (TGFβR), Smad2/3, PI3 K/AKT, and JNK1/2-related signaling pathways. Finally, in a functional study, the TGFβ1-primed GC VEGF secretion promoted in-vitro angiogenesis in vascular endothelial cells and ex-vivo vessel sprouting in aortic ring. Taken together, we demonstrated here that TGFβ1 expressed in ovarian FF is an inducer for promoting VEGF production in follicular GCs through TGFβR-mediated signaling pathways and the released VEGF subsequently leads to angiogenesis. This possibly contributes to oocyte developmental competence in folliculogenesis of IVF patients with a COS protocol.

Neural crest cell-derived pericytes act as pro-angiogenic cells in human neocortex development and gliomas

Central nervous system diseases involving the parenchymal microvessels are frequently associated with a ‘microvasculopathy’, which includes different levels of neurovascular unit (NVU) dysfunction, including blood–brain barrier alterations. To contribute to the understanding of NVU responses to pathological noxae, we have focused on one of its cellular components, the microvascular pericytes, highlighting unique features of brain pericytes with the aid of the analyses carried out during vascularization of human developing neocortex and in human gliomas. Thanks to their position, centred within the endothelial/glial partition of the vessel basal lamina and therefore inserted between endothelial cells and the perivascular and vessel-associated components (astrocytes, oligodendrocyte precursor cells (OPCs)/NG2-glia, microglia, macrophages, nerve terminals), pericytes fulfil a central role within the microvessel NVU. Indeed, at this critical site, pericytes have a number of direct and extracellular matrix molecule- and soluble factor-mediated functions, displaying marked phenotypical and functional heterogeneity and carrying out multitasking services. This pericytes heterogeneity is primarily linked to their position in specific tissue and organ microenvironments and, most importantly, to their ontogeny. During ontogenesis, pericyte subtypes belong to two main embryonic germ layers, mesoderm and (neuro)ectoderm, and are therefore expected to be found in organs ontogenetically different, nonetheless, pericytes of different origin may converge and colonize neighbouring areas of the same organ/apparatus. Here, we provide a brief overview of the unusual roles played by forebrain pericytes in the processes of angiogenesis and barriergenesis by virtue of their origin from midbrain neural crest stem cells. A better knowledge of the ontogenetic subpopulations may support the understanding of specific interactions and mechanisms involved in pericyte function/dysfunction, including normal and pathological angiogenesis, thereby offering an alternative perspective on cell subtype-specific therapeutic approaches.

Cancer-Associated Fibroblast-Induced Resistance to Chemotherapy and Radiotherapy in Gastrointestinal Cancers

In the past few decades, the role of cancer-associated fibroblasts (CAFs) in resistance to therapies for gastrointestinal (GI) cancers has emerged. Clinical studies focusing on GI cancers have revealed that the high expression of CAF-related molecules within tumors is significantly correlated with unfavorable therapeutic outcomes; however, the exact mechanisms whereby CAFs enhance resistance to chemotherapy and radiotherapy in GI cancers remain unclear. The cells of origin of CAFs in GI cancers include normal resident fibroblasts, mesenchymal stem cells, endothelial cells, pericytes, and even epithelial cells. CAFs accumulated within GI cancers produce cytokines, chemokines, and growth factors involved in resistance to therapies. CAF-derived exosomes can be engaged in stroma-related resistance to treatments, and several non-coding RNAs, such as miR-92a, miR-106b, CCAL, and H19, are present in CAF-derived exosomes and transferred to GI cancer cells. The CAF-induced desmoplastic reaction interferes with drug delivery to GI cancer cells, evoking resistance to chemotherapy. However, due to the heterogeneity of CAFs in GI cancers, identifying the exact mechanism underlying CAF-induced resistance may be difficult. Recent advancements in single-cell "omics" technologies could offer clues for revealing the specific subtypes and biomarkers related to resistance.

Emerging Role of Pericytes and Their Secretome in the Heart

Pericytes, as mural cells covering microvascular capillaries, play an essential role in vascular remodeling and maintaining vascular functions and blood flow. Pericytes are crucial participants in the physiological and pathological processes of cardiovascular disease. They actively interact with endothelial cells, vascular smooth muscle cells (VSMCs), fibroblasts, and other cells via the mechanisms involved in the secretome. The secretome of pericytes, along with diverse molecules including proinflammatory cytokines, angiogenic growth factors, and the extracellular matrix (ECM), has great impacts on the formation, stabilization, and remodeling of vasculature, as well as on regenerative processes. Emerging evidence also indicates that pericytes work as mesenchymal cells or progenitor cells in cardiovascular regeneration. Their capacity for differentiation also contributes to vascular remodeling in different ways. Previous studies primarily focused on the roles of pericytes in organs such as the brain, retina, lung, and kidney; very few studies have focused on pericytes in the heart. In this review, following a brief introduction of the origin and fundamental characteristics of pericytes, we focus on pericyte functions and mechanisms with respect to heart disease, ending with the promising use of cardiac pericytes in the treatment of ischemic heart failure.

Ultrasound-guided percutaneous needle tenotomy (PNT) alone versus PNT plus platelet-rich plasma injection for the treatment of chronic tendinosis: A randomized controlled trial

BACKGROUND

Tendinosis is a chronic degenerative condition. Current research suggests both percutaneous needle tenotomy (PNT) and leukocyte-rich platelet-rich plasma (LR-PRP) may be effective treatments for chronic tendinosis, but no studies have assessed the effectiveness of PNT alone versus PNT with intratendinous LR-PRP for multiple tendon types in a single study.

OBJECTIVE

To assess the efficacy of PNT versus PNT + LR-PRP to treat chronic tendinosis.

STUDY DESIGN

Double-blind, randomized, controlled comparative treatment study.

SETTING

Primary academic institution.

PARTICIPANTS

A convenience sample of 40 participants who had chronic tendinosis (rotator cuff, wrist extensor, wrist flexor, hip abductor, proximal hamstring, patellar, or Achilles) confirmed via ultrasound, failed conservative treatment, and did not have tendon tears, known coagulopathy, or systemic illnesses.

INTERVENTIONS

Participants were randomly assigned to PNT (n = 19) or PNT + LR-PRP (n = 21). Participants and outcomes assessors were blinded to treatment assignments. PNT was performed with 20-30 passes of a 22-gauge needle under ultrasound guidance, with 1% lidocaine given outside the tendon. LR-PRP was processed from whole blood (30-60 mL) and injected into the affected tendon using the same PNT technique.

MAIN OUTCOME MEASURES

Primary outcome was current numerical rating scale pain at 6 weeks. Secondary outcomes were average pain, function, general well-being, and sleep quality at 6, 52, and 104 weeks.

RESULTS

Baseline characteristics were similar between groups. Overall, there were no significant differences between groups over time for any of the outcomes (P > .05). Between-group analyses showed significantly lower current and average pain after PNT compared to PNT + LR-PRP at 6 weeks (estimated-mean [SE]: 3.1[0.4] vs. 4.6[0.6], P = .04; 3.4[0.4] vs. 4.9[0.5], P = .03) only. Adverse event rates were low (PNT-3.9%; PNT + LR-PRP-5.0%) and related primarily to postprocedural pain and inflammation.

CONCLUSIONS

Although pain scores were lower after PNT compared to PNT + LR-PRP at 6 weeks, there were no between-group differences in outcomes at 52 or 104 weeks.

Current status of cardiac regenerative medicine; An update on point of view to cell therapy application

Cardiovascular diseases (CVDs) are the leading cause of death globally. Because of the economic and social burden of acute myocardial infarction and its chronic consequences in surviving patients, understanding the pathophysiology of myocardial infarction injury is a major priority for cardiovascular research. MI is defined as cardiomyocytes death caused by an ischemic that resulted from the apoptosis, necrosis, necroptosis, and autophagy. The phases of normal repair following MI including inflammatory, proliferation, and maturation. Normal repair is slow and inefficient generally so that other treatments are required. Because of difficulties, outcomes, and backwashes of traditional therapies including coronary artery bypass grafting, balloon angioplasty, heart transplantation, and artificial heart operations, the novel strategy in the treatment of MI, cell therapy, was newly emerged. In cell therapy, a new population of cells has created that substitute with damaged cells. Different types of stem cell and progenitor cells have been shown to improve cardiac function through various mechanisms, including the formation of new myocytes, endothelial cells, and vascular smooth muscle cells. Bone marrow- and/or adipose tissue-derived mesenchymal stem cells, embryonic stem cells, autologous skeletal myoblasts, induced pluripotent stem cells, endothelial progenitor cells, cardiac progenitor cells and cardiac pericytes considered as a source for cell therapy. In this study, we focused on the point of view of the cell sources.

Regulation of tumor microenvironment for pancreatic cancer therapy

Pancreatic cancer (PC) is one kind of the most lethal malignancies worldwide, owing to its insidious symptoms, early metastases, and negative responses to current therapies. With an increasing understanding of pathology, the tumor microenvironment (TME) plays a significant role in ineffective treatment and poor prognosis of PC. Thus, a growing number of studies have focused on whether components of the TME could be effective targets for PC therapy. Biomaterials have been widely applied in cancer therapy, and numerous organic or inorganic biomaterials for TME regulation have been developed to inhibit the growth and metastasis of PC, as well as reverse therapeutic resistance. In this review, we discuss various biomaterials utilized to treat PC based on different components of the TME, including, but not limited to, extracellular matrix (ECM), abnormal tumor vascularization, and tumor-associated immune cells, as well as other unconventional therapeutic strategies. Besides, the perspectives on the underlying future of theranostic nanomedicines for PC therapy are also presented.

The aging transcriptome and cellular landscape of the human lung in relation to SARS-CoV-2

Age is a major risk factor for severe coronavirus disease-2019 (COVID-19). Here, we interrogate the transcriptional features and cellular landscape of the aging human lung. By intersecting these age-associated changes with experimental data on SARS-CoV-2, we identify several factors that may contribute to the heightened severity of COVID-19 in older populations. The aging lung is transcriptionally characterized by increased cell adhesion and stress responses, with reduced mitochondria and cellular replication. Deconvolution analysis reveals that the proportions of alveolar type 2 cells, proliferating basal cells, goblet cells, and proliferating natural killer/T cells decrease with age, whereas alveolar fibroblasts, pericytes, airway smooth muscle cells, endothelial cells and IGSF21+ dendritic cells increase with age. Several age-associated genes directly interact with the SARS-CoV-2 proteome. Age-associated genes are also dysregulated by SARS-CoV-2 infection in vitro and in patients with severe COVID-19. These analyses illuminate avenues for further studies on the relationship between age and COVID-19.

CXCL3 Signaling in the Tumor Microenvironment

Cancer progression is driven, to a large extent, by the action of immune cells that have been recruited to tumor sites through interactions between chemokines and their receptors. Chemokines of the CXC subfamily are secreted by both tumor and non-tumor cells within the microenvironment of the tumor, where they induce either antitumor or protumor activity that fosters either clearance or progression of the tumor, respectively. Understanding the nature of these interactions is important to envisage novel approaches targeting the essential components of the tumor microenvironment, increasing the odds for favorable patient outcomes. In this chapter we describe the involvement of the chemokine (C-X-C motif) ligand 3 (CXCL3) in the human tumor microenvironment and its effects on immune and non-immune cells. Because of the limited data on the CXCL3 signaling in the tumor microenvironment, we extend the review to other members of the CXC subfamily of chemokines. This review also addresses the future trends or directions for therapeutic interventions that target signaling pathways used by these molecules in the tumor microenvironment.