PECAM-1: a multi-functional molecule in inflammation and vascular biology

Fibroblast activation in response to TGFβ1 is modulated by co-culture with endothelial cells in a vascular organ-on-chip platform

Background: Tissue fibrosis is a major healthcare burden that affects various organs in the body for which no effective treatments exist. An underlying, emerging theme across organs and tissue types at early stages of fibrosis is the activation of pericytes and/or fibroblasts in the perivascular space. In hepatic tissue, it is well known that liver sinusoidal endothelial cells (EC) help maintain the quiescence of stellate cells, but whether this phenomenon holds true for other endothelial and perivascular cell types is not well studied. Methods: The goal of this work was to develop an organ-on-chip microvascular model to study the effect of EC co-culture on the activation of perivascular cells perturbed by the pro-fibrotic factor TGFβ1. A high-throughput microfluidic platform, PREDICT96, that was capable of imparting physiologically relevant fluid shear stress on the cultured endothelium was utilized. Results: We first studied the activation response of several perivascular cell types and selected a cell source, human dermal fibroblasts, that exhibited medium-level activation in response to TGFβ1. We also demonstrated that the PREDICT96 high flow pump triggered changes in select shear-responsive factors in human EC. We then found that the activation response of fibroblasts was significantly blunted in co-culture with EC compared to fibroblast mono-cultures. Subsequent studies with conditioned media demonstrated that EC-secreted factors play at least a partial role in suppressing the activation response. A Luminex panel and single cell RNA-sequencing study provided additional insight into potential EC-derived factors that could influence fibroblast activation. Conclusion: Overall, our findings showed that EC can reduce myofibroblast activation of perivascular cells in response to TGFβ1. Further exploration of EC-derived factors as potential therapeutic targets in fibrosis is warranted.

Characterization of human stem cell-derived hepatic stellate cells and liver sinusoidal endothelial cells during extended in vitro culture

Background: There is a significant need for predictive and stable in vitro human liver representations for disease modeling and drug testing. Hepatic stellate cells (HSCs) and liver sinusoidal endothelial cells (LSECs) are important non-parenchymal cell components of the liver and are hence of relevance in a variety of disease models, including hepatic fibrosis. Pluripotent stem cell- (PSC-) derived HSCs (scHSCs) and LSECs (scLSECs) offer an attractive alternative to primary human material; yet, the suitability of scHSCs and scLSECs for extended in vitro modeling has not been characterized. Methods: In this study, we describe the phenotypic and functional development of scHSCs and scLSECs during 14 days of 2D in vitro culture. Cell-specific phenotypes were evaluated by cell morphology, immunofluorescence, and gene- and protein expression. Functionality was assessed in scHSCs by their capacity for intracellular storage of vitamin A and response to pro-fibrotic stimuli induced by TGF-β. scLSECs were evaluated by nitric oxide- and factor VIII secretion as well as endocytic uptake of bioparticles and acetylated low-density lipoprotein. Notch pathway inhibition and co-culturing scHSCs and scLSECs were separately tested as options for enhancing long-term stability and maturation of the cells. Results and Conclusion: Both scHSCs and scLSECs exhibited a post-differentiation cell type-specific phenotype and functionality but deteriorated during extended culture with PSC line-dependent variability. Therefore, the choice of PSC line and experimental timeframe is crucial when designing in vitro platforms involving scHSCs and scLSECs. Notch inhibition modestly improved long-term monoculture in a cell line-dependent manner, while co-culturing scHSCs and scLSECs provides a strategy to enhance phenotypic and functional stability.

FITC-Labeled RGD Peptides as Novel Contrast Agents for Functional Fluorescent Angiographic Detection of Retinal and Choroidal Neovascularization

The development of choroidal neovascularization (CNV) is a crucial factor in the pathophysiology and prognosis of exudative age-related macular degeneration (AMD). Therefore, the detection of CNV is essential for establishing an appropriate diagnosis and treatment plan. Current ophthalmic imaging techniques, such as fundus fluorescent angiography and optical coherence tomography, have limitations in accurately visualizing CNV lesions and expressing CNV activity, owing to issues such as excessive dye leakage with pooling and the inability to provide functional information. Here, using the arginine-glycine-aspartic acid (RGD) peptide's affinity for integrin α_vβ₃, which is expressed in the neovascular endothelial cells in ocular tissues, we propose the use of fluorescein isothiocyanate (FITC)-labeled RGD peptide as a novel dye for effective molecular imaging of CNV. FITC-labeled RGD peptides (FITC-RGD₂), prepared by bioconjugation of one FITC molecule with two RGD peptides, demonstrated better visualization and precise localization of CNV lesions than conventional fluorescein dyes in laser-induced CNV rodent models, as assessed using various imaging techniques, including a commercially available clinical fundus camera (Optos). These results suggest that FITC-RGD₂ can serve as an effective novel dye for the diagnosis of neovascular retinal diseases, including AMD, by enabling early detection and treatment of disease occurrence and recurrence after treatment.

Improving Diastolic and Microvascular Function in Heart Transplantation with Donation after Circulatory Death

The impact of the machine perfusion of donation after circulatory death (DCD) hearts with the novel Custodiol-N solution on diastolic and coronary microvascular dysfunction is unknown. Porcine DCD-hearts were maintained four hours by perfusion with normothermic blood (DCD-B), hypothermic Custodiol (DCD-C), or Custodiol-N (DCD-CN), followed by one hour of reperfusion with fresh blood, including microvascular and contractile evaluation. In another group (DCD group), one hour of reperfusion, including microvascular and contractile evaluation, was performed without a previous maintenance period (all groups N = 5). We measured diastolic function with a balloon catheter and microvascular perfusion by Laser-Doppler-Technology, resulting in Laser-Doppler-Perfusion (LDP). We performed immunohistochemical staining and gene expression analysis. The developed pressure was improved in DCD-C and DCD-CN. The diastolic pressure decrement (DCD-C: -1093 ± 97 mmHg/s; DCD-CN: -1703 ± 329 mmHg/s; DCD-B: -690 ± 97 mmHg/s; p < 0.05) and relative LDP (DCD-CN: 1.42 ± 0.12; DCD-C: 1.11 ± 0.13; DCD-B: 1.22 ± 0.27) were improved only in DCD-CN. In DCD-CN, the expression of eNOS increased, and ICAM and VCAM decreased. Only in DCD-B compared to DCD, the pathways involved in complement and coagulation cascades, focal adhesion, fluid shear stress, and the IL-6 and IL-17 pathways were upregulated. In conclusion, machine perfusion with Custodiol-N improves diastolic and microvascular function and preserves the microvascular endothelium of porcine DCD-hearts.

Cooperative sensing of mitochondrial DNA by ZBP1 and cGAS promotes cardiotoxicity

Mitochondrial DNA (mtDNA) is a potent agonist of the innate immune system; however, the exact immunostimulatory features of mtDNA and the kinetics of detection by cytosolic nucleic acid sensors remain poorly defined. Here, we show that mitochondrial genome instability promotes Z-form DNA accumulation. Z-DNA binding protein 1 (ZBP1) stabilizes Z-form mtDNA and nucleates a cytosolic complex containing cGAS, RIPK1, and RIPK3 to sustain STAT1 phosphorylation and type I interferon (IFN-I) signaling. Elevated Z-form mtDNA, ZBP1 expression, and IFN-I signaling are observed in cardiomyocytes after exposure to Doxorubicin, a first-line chemotherapeutic agent that induces frequent cardiotoxicity in cancer patients. Strikingly, mice lacking ZBP1 or IFN-I signaling are protected from Doxorubicin-induced cardiotoxicity. Our findings reveal ZBP1 as a cooperative partner for cGAS that sustains IFN-I responses to mitochondrial genome instability and highlight ZBP1 as a potential target in heart failure and other disorders where mtDNA stress contributes to interferon-related pathology.

Aging disrupts gene expression timing during muscle regeneration

Skeletal muscle function and regenerative capacity decline during aging, yet factors driving these changes are incompletely understood. Muscle regeneration requires temporally coordinated transcriptional programs to drive myogenic stem cells to activate, proliferate, fuse to form myofibers, and to mature as myonuclei, restoring muscle function after injury. We assessed global changes in myogenic transcription programs distinguishing muscle regeneration in aged mice from young mice by comparing pseudotime trajectories from single-nucleus RNA sequencing of myogenic nuclei. Aging-specific differences in coordinating myogenic transcription programs necessary for restoring muscle function occur following muscle injury, likely contributing to compromised regeneration in aged mice. Differences in pseudotime alignment of myogenic nuclei when comparing aged with young mice via dynamic time warping revealed pseudotemporal differences becoming progressively more severe as regeneration proceeds. Disruptions in timing of myogenic gene expression programs may contribute to incomplete skeletal muscle regeneration and declines in muscle function as organisms age.

Neuroinflammatory and Metabolomic Temporal Dynamics Following Wood Smoke Inhalation

Smoke from wildland fires has been shown to produce neuroinflammation in preclinical models, characterized by neural infiltrations of neutrophils and monocytes, as well as altered neurovascular endothelial phenotypes. To address the longevity of such outcomes, the present study examined the neuroinflammatory and metabolomic temporal dynamics after inhalation exposures from biomass-derived smoke. 2-month-old female C57BL/6J mice were exposed to wood smoke every other day for two weeks at an average exposure concentration of 0.5mg/m 3 . Subsequent serial euthanasia occurred at 1-, 3-, 7-, 14-, and 28-days post-exposure. Flow cytometry of right hemispheres revealed two endothelial populations of PECAM (CD31), high and medium expressors, with wood smoke inhalation causing an increased proportion of PECAM Hi . These populations of PECAM Hi and PECAM Med were associated with an anti-inflammatory and pro-inflammatory response, respectively, and their inflammatory profiles were largely resolved by the 28-day mark. However, activated microglial populations (CD11b + /CD45 low ) remained higher in wood smoke-exposed mice than controls at day 28. Infiltrating neutrophil populations decreased to levels below controls by day 28. However, the MHC-II expression of the peripheral immune infiltrate remained high, and the population of neutrophils retained an increased expression of CD45, Ly6C, and MHC-II. Utilizing an unbiased approach examining the metabolomic alterations, we observed notable hippocampal perturbations in neurotransmitter and signaling molecules like glutamate, quinolinic acid, and 5-α-dihydroprogesterone. Utilizing a targeted panel designed to explore the aging-associated NAD + metabolic pathway, wood smoke exposure drove fluctuations and compensations across the 28-day time course, ending with decreased hippocampal NAD + abundance at day 28. Summarily, these results indicate a highly dynamic neuroinflammatory environment, with potential resolution extending past 28 days, the implications of which may include long-term behavioral changes, systemic and neurological sequalae directly associated wtith wildfire smoke exposure.

Placental diabesity: placental VEGF and CD31 expression according to pregestational BMI and gestational weight gain in women with gestational diabetes

PURPOSE

The aim of this study is to investigate the placental expression of VEGF and CD31 in pregnancies complicated by gestational diabetes (GDM) and the influence of pregestational BMI and gestational weight gain (GWG) on this expression.

METHODS

We prospectively enrolled pregnant women with diagnosis of GDM and healthy controls who delivered in our Center between December 2016 and May 2017. Patients were grouped according to the presence of GDM and we compared pregnancy characteristics, placental VEGF and CD31 expression between the cases and controls. Immunochemistry analysis was performed to assess biomarkers positivity. Positivity of biomarkers was assessed in a dichotomic fashion with positivity set at 5% for VEGF and 1% for CD31.

RESULTS

39 patients matched inclusion criteria, 29 (74.3%) women with GDM and 10 (25.7%) healthy controls. Immunochemistry analysis showed that VEGF was more expressed in placentas from women with GDM compared to controls (21/29, 72.4% vs 2/10, 20%; p = 0.007), and CD31 was more expressed in placentas from women with GDM compared to controls (6/29, 20.7% vs 0/10, 0%; risk difference 0.2). VEGF positivity was associated with the presence of GDM (aOR 22.02, 95% CI 1.13-428.08, p = 0.04), pregestational BMI (aOR 1.53, 1.00-2.34, p = 0.05) and GWG (aOR 1.47, 95% CI 1.03-2.11, p = 0.03). CD31 positivity was associated with the pregestational BMI (aOR 1.47, 95% CI 1.00-2.17, p = 0.05) and with the gestational weight gain (aOR 1.32, 95% CI 1.01-1.72, p = 0.04).

CONCLUSION

Pregnancies complicated by GDM are characterized by increased placental expression of VEGF and CD31, and the expression of these markers is also independently associated to maternal increased pregestational BMI and GWG, defining the concept of "placental diabesity".

Single cell sequencing of the mouse anterior palate reveals mesenchymal heterogeneity

BACKGROUND

Cleft palate is one of the most prevalent birth defects. Mice are useful for studying palate development because of their morphological and genetic similarities to humans. In mice, palate development occurs between embryonic days (E)11.5 to 15.5. Single cell transcriptional profiles of palate cell populations have been a valuable resource for the craniofacial research community, but we lack a single cell transcriptional profile for anterior palate at E13.5, at the transition from proliferation to shelf elevation.

RESULTS

A detailed single cell RNA sequencing analysis reveals heterogeneity in expression profiles of the cell populations of the E13.5 anterior palate. Hybridization chain reaction RNA fluorescent in situ hybridization (HCR RNA FISH) reveals epithelial populations segregate into layers. Mesenchymal populations spatially segregate into four domains. One of these mesenchymal populations expresses ligands and receptors distinct from the rest of the mesenchyme, suggesting that these cells have a unique function. RNA velocity analysis shows two terminal cell states that contribute to either the proximal or distal palatal regions emerge from a single progenitor pool.

CONCLUSION

This single cell resolution expression data and detailed analysis from E13.5 anterior palate provides a powerful resource for mechanistic insight into secondary palate morphogenesis for the craniofacial research community.

Identification of TNFα-mediated inflammation as potential pathological marker and therapeutic target for calcification progress of congenital bicuspid aortic valve

BACKGROUD

Congenital bicuspid aortic valve (cBAV) develops calcification and stenotic obstruction early compared with degenerative tricuspid aortic valve (dTAV), which requires surgical intervention. Here we report a comparative study of patients with cBAV or dTAV to identify risk factors associated with the rapid development of calcified bicuspid valves.

METHODS

A total of 69 aortic valves (24 dTAV and 45 cBAV) were collected at the time of surgical aortic valve replacement for comparative clinical characteristics. Ten samples were randomly selected from each group for histology, pathology, and inflammatory factors expression and comparison analyses. OM-induced calcification in porcine aortic valve interstitial cell cultures were prepared for illustrating the underlying molecular mechanisms about calcification progress of cBAV and dTAV.

RESULTS

We found that cBAV patients have increased cases of aortic valve stenosis compared with dTAV patients. Histopathological examinations revealed increased collagens deposition, neovascularization and infiltrations by inflammatory cells, especially T-lymphocytes and macrophages. We identified that tumor necrosis factor α (TNFα) and its regulated inflammatory cytokines are upregulated in cBAV. Further in vitro study indicated that TNFα-NFκB and TNFα-GSK3β pathway accelerate aortic valve interstitial cells calcification, while inhibition of TNFα significantly delays this process.

CONCLUSION

The finding of intensified TNFα-mediated inflammation in the pathological cBAV advocates the inhibition of TNFα as a potential treatment for patients with cBAV by alleviating the progress of inflammation-induced valve damage and calcification.

Identification of hub genes and immune infiltration in ulcerative colitis using bioinformatics

Ulcerative colitis (UC) is a chronic inflammatory disease of the intestine, whose pathogenesis is not fully understood. Given that immune infiltration plays a key role in UC progression, our study aimed to assess the level of immune cells in UC intestinal mucosal tissues and identify potential immune-related genes. The GSE65114 UC dataset was downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) between healthy and UC tissues were identified using the "limma" package in R, while their Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were determined with the clusterProfiler package. Protein-protein interaction network analysis and visualization were performed with STRING and Cytoscape. Immune cell infiltration was calculated with CIBERSORT. The relationship between hub genes and immune-infiltrated cells in UC was determined by Pearson correlation. A total of 206 DEGs were identified, of which 174 were upregulated and 32 downregulated. GO and KEGG functional classification indicated DEG enrichment in immune response pathways, including Toll-like receptor signaling, IL-17 signaling, and immune system process and chemokine signaling. 13 hub genes were identified. Infiltration matrix analysis of immune cells showed abundant plasma cells, memory B cells, resting CD4 memory T cells, γδ T cells, M0 and M1 macrophages, and neutrophils in UC intestinal tissues. Correlation analysis revealed 13 hub genes associated with immune-infiltrated cells in UC. 13 hub genes associated with immune-infiltrated cells in UC were identified; they included CXCL13, CXCL10, CXCL9, CXCL8, CCL19, CTLA4, CCR1, CD69, CD163, IL7R, PECAM1, TLR8 and TLR2. These genes could potentially serve as markers for the diagnosis and treatment of UC.

Mouse Spinal Cord Vascular Transcriptome Analysis Identifies CD9 and MYLIP as Injury-Induced Players

Traumatic spinal cord injury (SCI) initiates a cascade of cellular events, culminating in irreversible tissue loss and neuroinflammation. After the trauma, the blood vessels are destroyed. The blood-spinal cord barrier (BSCB), a physical barrier between the blood and spinal cord parenchyma, is disrupted, facilitating the infiltration of immune cells, and contributing to a toxic spinal microenvironment, affecting axonal regeneration. Understanding how the vascular constituents of the BSCB respond to injury is crucial to prevent BSCB impairment and to improve spinal cord repair. Here, we focus our attention on the vascular transcriptome at 3- and 7-days post-injury (dpi), during which BSCB is abnormally leaky, to identify potential molecular players that are injury-specific. Using the mouse contusion model, we identified Cd9 and Mylip genes as differentially expressed at 3 and 7 dpi. CD9 and MYLIP expression were injury-induced on vascular cells, endothelial cells and pericytes, at the injury epicentre at 7 dpi, with a spatial expression predominantly at the caudal region of the lesion. These results establish CD9 and MYLIP as two new potential players after SCI, and future studies targeting their expression might bring promising results for spinal cord repair.

Emerging of a new CD3+CD31HCD184+ tang cell phenothype in Sjögren’s syndrome induced by microencapsulated human umbilical cord matrix-derived multipotent stromal cells

Background

Sjögren’s syndrome (SS) is an autoimmune disease hallmarked by infiltration and destruction of exocrine glands. Currently, there is no therapy that warrants full recovery of the affected tissues. Umbilical cord-derived multipotent stromal cells, microincapsulated in an endotoxin-free alginate gel (CpS-hUCMS), were shown to modulate the inflammatory activity of PBMCs in SS patients in vitro, through release of soluble factors (TGFβ1, IDO1, IL6, PGE2, VEGF). These observations led us to set up the present study, aimed at defining the in vitro effects of CpS-hUCMS on pro- and anti-inflammatory lymphocyte subsets involved in the pathogenesis of SS.

Methods and results

Peripheral blood mononuclear cells (PBMCs) upon collection from SS patients and matched healthy donors, were placed in co-culture with CpS-hUCMS for five days. Cellular proliferation and T- (Tang, Treg) and B- (Breg, CD19+) lymphocyte subsets were studied by flow cytometry, while Multiplex, Real-Time PCR, and Western Blotting techniques were employed for the analysis of transcriptome and secretome. IFNγ pre-treated hUCMS were assessed with a viability assay and Western Blotting analysis before co-culture. After five days co-culture, CpS-hUCMS induced multiple effects on PBMCs, with special regard to decrease of lymphocyte proliferation, increase of regulatory B cells and induction of an angiogenic T cell population with high expression of the surface marker CD31, that had never been described before in the literature.

Conclusion

We preliminarily showed that CpS-hUCMS can influence multiple pro- and anti-inflammatory pathways that are deranged in SS. In particular, Breg raised and a new Tang phenothype CD3+CD31HCD184+ emerged. These results may considerably expand our knowledge on multipotent stromal cell properties and may open new therapeutic avenues for the management of this disease, by designing ad hoc clinical studies.

Extracellular vesicles and atherosclerotic peripheral arterial disease

Atherogenesis involves a complex multifactorial process including chronic inflammation that requires the participation of several cell types and molecules. In addition to their role in vascular homeostasis, extracellular vesicles also appear to play an important role in atherogenesis, including monocyte transmigration and foam cell formation, SMC proliferation and migration, leukocyte transmigration, and thrombosis. Peripheral arterial disease, a major form of peripheral vascular disease, is characterized by structural or functional impairment of peripheral arterial supply, often secondary to atherosclerosis. Elevated levels of extracellular vesicles have been demonstrated in patients with peripheral arterial disease and implicated in the development of atherosclerosis within peripheral vascular beds. However, extracellular vesicles also appear capable of delivering cargo with atheroprotective effects. This capability has been exploited in vesicles engineered to carry content capable of neovascularization, suggesting potential for therapeutic angiogenesis. This dual capacity holds substantial promise for diagnosis and therapy, including possibly limb- and life-saving options for peripheral arterial disease management.

The impact of Allgower-Donati suture pattern and postoperative sweet foods on wound suture breakage in experimental rats

Background

Wound gnawing and/or scratching in rats often occurs in experimental models, causing suture breakage and wound dehiscence, and consequently affecting experimental results and wasting resources. This study aimed to investigate the impact of the combined postoperative use of the Allgower-Donati (A-D) suture pattern and sweet foods on suture breakage, inflammation, and healing in wounds.

Materials and methods

Sprague Dawley (SD) rats (n = 48) were treated for linear wounds on the back by four procedures: simple suture, simple suture with postoperative sweet foods, A-D suture, and A-D suture with postoperative sweet foods. Additionally, CD68 immunofluorescence and CD31 immunohistochemistry were used to analyze wound inflammation and vascularization, respectively, on postoperative day 7. Sirius red staining was used to assess collagen deposition on postoperative day 14.

Results

Gnawing and scratching of wound sutures were significantly reduced in treated rats (P < 0.01). Neovascularization and collagen deposition were significantly increased (P < 0.001), and inflammatory responses were significantly reduced (P < 0.001) in animals receiving AD sutures and postoperative sweet foods. CD31/CD68 analyses showed that A-D suture and postoperative sweet foods regulated wound angiogenesis and attenuated wound inflammation.

Conclusions

Sweet food provision after A-D suture union surgery could reduce wound gnawing and/or scratching, suture breakage, incisional dehiscence, wound inflammation, and promote wound healing in rats.

Core genes in lung adenocarcinoma identified by integrated bioinformatic analysis

This study aims to identify potential core genes of lung adenocarcinoma (LUAD). Three datasets (GSE32863, GSE43458, and GSE116959) were retrieved from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) between LUAD and normal tissues were filtrated by GEO2R tool. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed via Metascape database. The protein-protein interaction (PPI) network was constructed and core genes were identified using STRING and Cytoscape. Core genes expressions and their relevant clinical characteristics were performed via Oncomine and UALCAN databases respectively. The correlation between core genes and immune infiltrates was investigated by TIMER database. Kaplan-Meier plotter was performed for survival analysis. The signal pathway network of core genes was mapped by KEGG Mapper analysis tool. In this study, ten core genes were significantly related to overall survival (OS) of LUAD patients, which can provide clues for prognosis of LUAD.

PAK4 inhibition improves PD1 blockade immunotherapy in prostate cancer by increasing immune infiltration

Antitumor immunity requires lymphocytes to localize to the tumor. Prostate cancers (PCs) are immunologically cold and tend to lack T-cell infiltration. Most advanced PCs are insensitive to PD1 blockade therapies. Using syngeneic RM1 prostate tumors, p21-activated kinase-4 (PAK4) knockdown (KD) and pharmacological inhibition was assessed in C57BL/6J mice treated with PD1 antibodies (αPD1). RNASeq was used to characterize the immune response in the tumor. Immunohistochemistry, flow cytometry, and in vivo blocking studies confirmed the role of cell surface proteins in the generation of immune responses. In The Cancer Genome Atlas, PAK4 expression was inversely correlated with immune cell infiltration. PAK4 expression was controlled by the androgen receptor and its pioneering factor, FOXA1. PAK4 KD increased CD8⁺ T-cell infiltration and expression of IFNγ response genes. PAK4 KD also upregulated angiogenesis and endothelial cell adhesion molecules in the tumor microenvironment, contributing to CD8⁺ lymphocyte recruitment. Pharmacological inhibition of PAK4 made PC more responsive to immunotherapy with αPD1. A decrease in PAK4 activity increases immune activation and vascularity, which increases CD8⁺ lymphocyte infiltration into the tumor. Therefore, targeting PAK4 may improve the response of human PC to immunotherapy.

PGRMC1 Ablation Protects from Energy-Starved Heart Failure by Promoting Fatty Acid/Pyruvate Oxidation

Heart failure (HF) is an emerging epidemic with a high mortality rate. Apart from conventional treatment methods, such as surgery or use of vasodilation drugs, metabolic therapy has been suggested as a new therapeutic strategy. The heart relies on fatty acid oxidation and glucose (pyruvate) oxidation for ATP-mediated contractility; the former meets most of the energy requirement, but the latter is more efficient. Inhibition of fatty acid oxidation leads to the induction of pyruvate oxidation and provides cardioprotection to failing energy-starved hearts. One of the non-canonical types of sex hormone receptors, progesterone receptor membrane component 1 (Pgrmc1), is a non-genomic progesterone receptor associated with reproduction and fertility. Recent studies revealed that Pgrmc1 regulates glucose and fatty acid synthesis. Notably, Pgrmc1 has also been associated with diabetic cardiomyopathy, as it reduces lipid-mediated toxicity and delays cardiac injury. However, the mechanism by which Pgrmc1 influences the energy-starved failing heart remains unknown. In this study, we found that loss of Pgrmc1 inhibited glycolysis and increased fatty acid/pyruvate oxidation, which is directly associated with ATP production, in starved hearts. Loss of Pgrmc1 during starvation activated the phosphorylation of AMP-activated protein kinase, which induced cardiac ATP production. Pgrmc1 loss increased the cellular respiration of cardiomyocytes under low-glucose conditions. In isoproterenol-induced cardiac injury, Pgrmc1 knockout resulted in less fibrosis and low heart failure marker expression. In summary, our results revealed that Pgrmc1 ablation in energy-deficit conditions increases fatty acid/pyruvate oxidation to protect against cardiac damage via energy starvation. Moreover, Pgrmc1 may be a regulator of cardiac metabolism that switches the dominance of glucose-fatty acid usage according to nutritional status and nutrient availability in the heart.

Antinociceptive Effects of Aaptamine, a Sponge Component, on Peripheral Neuropathy in Rats

Aaptamine, a natural marine compound isolated from the sea sponge, has various biological activities, including delta-opioid agonist properties. However, the effects of aaptamine in neuropathic pain remain unclear. In the present study, we used a chronic constriction injury (CCI)-induced peripheral neuropathic rat model to explore the analgesic effects of intrathecal aaptamine administration. We also investigated cellular angiogenesis and lactate dehydrogenase A (LDHA) expression in the ipsilateral lumbar spinal cord after aaptamine administration in CCI rats by immunohistofluorescence. The results showed that aaptamine alleviates CCI-induced nociceptive sensitization, allodynia, and hyperalgesia. Moreover, aaptamine significantly downregulated CCI-induced vascular endothelial growth factor (VEGF), cluster of differentiation 31 (CD31), and LDHA expression in the spinal cord. Double immunofluorescent staining showed that the spinal VEGF and LDHA majorly expressed on astrocytes and neurons, respectively, in CCI rats and inhibited by aaptamine. Collectively, our results indicate aaptamine's potential as an analgesic agent for neuropathic pain. Furthermore, inhibition of astrocyte-derived angiogenesis and neuronal LDHA expression might be beneficial in neuropathy.

Innate immune dysfunction and neuroinflammation in autism spectrum disorder (ASD)

Autism spectrum disorder (ASD) is a highly heterogeneous neurodevelopmental disorder characterized by communication and social behavior deficits. The presence of restricted and repetitive behaviors often accompanies these deficits, and these characteristics can range from mild to severe. The past several decades have seen a significant rise in the prevalence of ASD. The etiology of ASD remains unknown; however, genetic and environmental risk factors play a role. Multiple hypotheses converge to suggest that neuroinflammation, or at least the interaction between immune and neural systems, may be involved in the etiology of some ASD cases or groups. Repeated evidence of innate immune dysfunction has been seen in ASD, often associated with worsening behaviors. This evidence includes data from circulating myeloid cells and brain resident macrophages/microglia in both human and animal models. This comprehensive review presents recent findings of innate immune dysfunction in ASD, including aberrant innate cellular function, evidence of neuroinflammation, and microglia activation.

The matricellular protein CCN3 supports lung endothelial homeostasis and function

Aberrant vascular remodeling contributes to the progression of many aging-associated diseases, including idiopathic pulmonary fibrosis (IPF), where heterogeneous capillary density, endothelial transcriptional alterations, and increased vascular permeability correlate with poor disease outcomes. Thus, identifying disease-driving mechanisms in the pulmonary vasculature may be a promising strategy to limit IPF progression. Here, we identified Ccn3 as an endothelial-derived factor that is upregulated in resolving but not in persistent lung fibrosis in mice, and whose function is critical for vascular homeostasis and repair. Loss and gain of function experiments were carried out to test the role of CCN3 in lung microvascular endothelial function in vitro through RNAi and the addition of recombinant human CCN3 protein, respectively. Endothelial migration, permeability, proliferation, and in vitro angiogenesis were tested in cultured human lung microvascular endothelial cells (ECs). Loss of CCN3 in lung ECs resulted in transcriptional alterations along with impaired wound-healing responses, in vitro angiogenesis, barrier integrity as well as an increased profibrotic activity through paracrine signals, whereas the addition of recombinant CCN3 augmented endothelial function. Altogether, our results demonstrate that the matricellular protein CCN3 plays an important role in lung endothelial function and could serve as a promising therapeutic target to facilitate vascular repair and promote lung fibrosis resolution.

Characterization of large extracellular vesicles (L-EV) derived from human regulatory macrophages (Mreg): novel mediators in wound healing and angiogenesis?

BACKGROUND

Large extracellular vesicles (L-EV) with a diameter between 1 and 10 µm are released by various cell types. L-EV contain and transport active molecules which are crucially involved in cell to cell communication. We have shown that secretory products of human regulatory macrophages (Mreg) bear pro-angiogenic potential in-vitro and our recent findings show that Mreg cultures also contain numerous large vesicular structures similar to L-EV with so far unknown characteristics and function.

AIM OF THIS STUDY

To characterize the nature of Mreg-derived L-EV (L-EV_Mreg) and to gain insights into their role in wound healing and angiogenesis.

METHODS

Mreg were differentiated using blood monocytes from healthy donors (N = 9) and L-EV_Mreg were isolated from culture supernatants by differential centrifugation. Characterization of L-EV_Mreg was performed by cell/vesicle analysis, brightfield/transmission electron microscopy (TEM), flow cytometry and proteome profiling arrays. The impact of L-EV_Mreg on wound healing and angiogenesis was evaluated by means of scratch and in-vitro tube formation assays.

RESULTS

Mreg and L-EV_Mreg show an average diameter of 13.73 ± 1.33 µm (volume: 1.45 ± 0.44 pl) and 7.47 ± 0.75 µm (volume: 0.22 ± 0.06 pl) respectively. Flow cytometry analyses revealed similarities between Mreg and L-EV_Mreg regarding their surface marker composition. However, compared to Mreg fewer L-EV_Mreg were positive for CD31 (P < 0.01), CD206 (P < 0.05), CD103 (P < 0.01) and CD45 (P < 0.05). Proteome profiling suggested that L-EV_Mreg contain abundant amounts of pro-angiogenic proteins (i.e. interleukin-8, platelet factor 4 and serpin E1). From a functional point of view L-EV_Mreg positively influenced in-vitro wound healing (P < 0.05) and several pro-angiogenic parameters in tube formation assays (all segment associated parameters, P < 0.05; number of meshes, P < 0.05).

CONCLUSION

L-EV_Mreg with regenerative and pro-angiogenic potential can be reproducibly isolated from in-vitro cultured human regulatory macrophages. We propose that L-EV_Mreg could represent a putative therapeutic option for the treatment of chronic wounds and ischemia-associated diseases.

Cytological, molecular, cytogenetic, and physiological characterization of a novel immortalized human enteric glial cell line

Enteric glial cells (EGCs), the major components of the enteric nervous system (ENS), are implicated in the maintenance of gut homeostasis, thereby leading to severe pathological conditions when impaired. However, due to technical difficulties associated with EGCs isolation and cell culture maintenance that results in a lack of valuable in vitro models, their roles in physiological and pathological contexts have been poorly investigated so far. To this aim, we developed for the first time, a human immortalized EGC line (referred as ClK clone) through a validated lentiviral transgene protocol. As a result, ClK phenotypic glial features were confirmed by morphological and molecular evaluations, also providing the consensus karyotype and finely mapping the chromosomal rearrangements as well as HLA-related genotypes. Lastly, we investigated the ATP- and acetylcholine, serotonin and glutamate neurotransmitters mediated intracellular Ca²⁺ signaling activation and the response of EGCs markers (GFAP, SOX10, S100β, PLP1, and CCL2) upon inflammatory stimuli, further confirming the glial nature of the analyzed cells. Overall, this contribution provided a novel potential in vitro tool to finely characterize the EGCs behavior under physiological and pathological conditions in humans.

Endothelial Responses to Curvature-Induced Flow Patterns in Engineered Cerebral Aneurysms

Hemodynamic factors have long been associated with clinical outcomes in the treatment of cerebral aneurysms. Computational studies of cerebral aneurysm hemodynamics have provided valuable estimates of the mechanical environment experienced by the endothelium in both the parent vessel and aneurysmal dome walls and have correlated them with disease state. These computational-clinical studies have recently been correlated with the response of endothelial cells (EC) using either idealized or patient-specific models. Here, we present a robust workflow for generating anatomic-scale aneurysm models, establishing luminal cultures of ECs at physiological relevant flow profiles, and comparing EC responses to curvature mediated flow. We show that flow patterns induced by parent vessel curvature produce changes in wall shear stress (WSS) and wall shear stress gradients (WSSG) that are correlated with differences in cell morphology and cellular protein localization. Cells in higher WSS regions align better with the flow and display strong Notch1-extracellular domain (ECD) polarization, while, under low WSS, differences in WSSG due to curvature change were associated with less alignment and attenuation of Notch1-ECD polarization in ECs of the corresponding regions. These proof-of-concept results highlight the use of engineered cellularized aneurysm models for connecting computational fluid dynamics to the underlying endothelial biology that mediates disease.

Increased Caveolin-2 Expression in Brain Endothelial Cells Promotes Age-Related Neuroinflammation

Aging is a major risk factor for common neurodegenerative diseases. Although multiple molecular, cellular, structural, and functional changes occur in the brain during aging, the involvement of caveolin-2 (Cav-2) in brain ageing remains unknown. We investigated Cav-2 expression in brains of aged mice and its effects on endothelial cells. The human umbilical vein endothelial cells (HUVECs) showed decreased THP-1 adhesion and infiltration when treated with Cav-2 siRNA compared to control siRNA. In contrast, Cav-2 overexpression increased THP-1 adhesion and infiltration in HUVECs. Increased expression of Cav-2 and iba-1 was observed in brains of old mice. Moreover, there were fewer iba-1-positive cells in the brains of aged Cav-2 knockout (KO) mice than of wild-type aged mice. The levels of several chemokines were higher in brains of aged wild-type mice than in young wild-type mice; moreover, chemokine levels were significantly lower in brains of young mice as well as aged Cav-2 KO mice than in their wild-type counterparts. Expression of PECAM1 and VE-cadherin proteins increased in brains of old wild-type mice but was barely detected in brains of young wild-type and Cav-2 KO mice. Collectively, our results suggest that Cav-2 expression increases in the endothelial cells of aged brain, and promotes leukocyte infiltration and age-associated neuroinflammation.

RNF213 Loss-of-Function Promotes Angiogenesis of Cerebral Microvascular Endothelial Cells in a Cellular State Dependent Manner

Enhanced and aberrant angiogenesis is one of the main features of Moyamoya disease (MMD) pathogenesis. The ring finger protein 213 (RNF213) and the variant p.R4810K have been linked with higher risks of MMD and intracranial arterial occlusion development in east Asian populations. The role of RNF213 in diverse aspects of the angiogenic process, such as proliferation, migration and capillary-like formation, is well-known but has been difficult to model in vitro. To evaluate the effect of the RNF213 MMD-associated gene on the angiogenic activity, we have generated RNF213 knockout in human cerebral microvascular endothelial cells (hCMEC/D3-RNF213^-/-) using the CRISPR-Cas9 system. Matrigel-based assay and a tri-dimensional (3D) vascularized model using the self-assembly approach of tissue engineering were used to assess the formation of capillary-like structures. Quite interestingly, this innovative in vitro model of MMD recapitulated, for the first time, disease-associated pathophysiological features such as significant increase in angiogenesis in confluent endothelial cells devoid of RNF213 expression. These cells, grown to confluence, also showed a pro-angiogenic signature, i.e., increased secretion of soluble pro-angiogenic factors, that could be eventually used as biomarkers. Interestingly, we demonstrated that that these MMD-associated phenotypes are dependent of the cellular state, as only noted in confluent cells and not in proliferative RNF213-deficient cells.

Histological Methods to Assess Skeletal Muscle Degeneration and Regeneration in Duchenne Muscular Dystrophy

Duchenne muscular dystrophy (DMD) is a progressive disease caused by the loss of function of the protein dystrophin. This protein contributes to the stabilisation of striated cells during contraction, as it anchors the cytoskeleton with components of the extracellular matrix through the dystrophin-associated protein complex (DAPC). Moreover, absence of the functional protein affects the expression and function of proteins within the DAPC, leading to molecular events responsible for myofibre damage, muscle weakening, disability and, eventually, premature death. Presently, there is no cure for DMD, but different treatments help manage some of the symptoms. Advances in genetic and exon-skipping therapies are the most promising intervention, the safety and efficiency of which are tested in animal models. In addition to in vivo functional tests, ex vivo molecular evaluation aids assess to what extent the therapy has contributed to the regenerative process. In this regard, the later advances in microscopy and image acquisition systems and the current expansion of antibodies for immunohistological evaluation together with the development of different spectrum fluorescent dyes have made histology a crucial tool. Nevertheless, the complexity of the molecular events that take place in dystrophic muscles, together with the rise of a multitude of markers for each of the phases of the process, makes the histological assessment a challenging task. Therefore, here, we summarise and explain the rationale behind different histological techniques used in the literature to assess degeneration and regeneration in the field of dystrophinopathies, focusing especially on those related to DMD.

Pralatrexate mediates effective killing of gemcitabine-resistant pancreatic cancer: role of mTOR/4E-BP1 signal pathway

Gemcitabine is the first-line chemotherapeutic agent for pancreatic cancer. However, gemcitabine-resistance frequently leads to poor prognosis. Exploring new chemotherapeutic agents is important for patients with gemcitabine-resistant pancreatic cancer. In this study, we established a new acquired gemcitabine-resistant pancreatic cancer cell line BxPC-GEM-20 from parental BxPC-3. We found that pralatrexate significantly inhibited the growth of BxPC-GEM-20. The half-maximal inhibitory concentration of pralatrexate on BxPC-GEM-20 cell was about 3.43 ± 0.25 nM. Pralatrexate was found to effectively inhibit the clonal growth of BxPC-GEM-20 cell. Additionally, pralatrexate at 20 mg/kg had an excellent tumor inhibitory effect with an inhibitory rate of 76.92% in vivo. This pralatrexate therapy showed good safety profile that with little to no additional influence on the hepatic, renal function as well as body weight changes in nude mice. Pralatrexate was confirmed to prevent cells from entering the G2/M phase, leading to the promotion of apoptosis and autophagy. Further analysis demonstrated that the reduced phosphorylation of mTOR played a significant role in the tumor cell damage caused by pralatrexate. Pralatrexate effectively inhibited the mTOR/4E-BP1 pathway. Activation of mTOR pathway can further obstruct the repressive effect of pralatrexate on gemcitabine-resistant pancreatic cancer. In summary, pralatrexate induces effective inhibition of gemcitabine-resistant pancreatic cancer. This may lead to the expansion of pralatrexate's application and offer benefit to gemcitabine-resistant pancreatic cancer patients in the future.

Response to Matters Arising: Characterization of placental fetal macrophages

Chen et al.¹ published a report that casts doubt on our main finding from a recent article.² Although we acknowledge the importance of their observations, we are reserved about whether their observations would invalidate our conclusions that placental fetal macrophages are generated de novo via placental hemogenic endothelium. This Matters Arising response paper addresses the Chen et al.¹ Matters Arising paper published concurrently in Developmental Cell.

Organotypic stromal cells impact endothelial cell transcriptome in 3D microvessel networks

Endothelial cells line all major blood vessels and serve as integral regulators of many functions including vessel diameter, cellular trafficking, and transport of soluble mediators. Despite similar functions, the phenotype of endothelial cells is highly organ-specific, yet our understanding of the mechanisms leading to organ-level differentiation is incomplete. We generated 3D microvessel networks by combining a common naïve endothelial cell with six different stromal cells derived from the lung, skin, heart, bone marrow, pancreas, and pancreatic cancer. Single cell RNA-Seq analysis of the microvessel networks reveals five distinct endothelial cell populations, for which the relative proportion depends on the stromal cell population. Morphologic features of the organotypic vessel networks inversely correlate with a cluster of endothelial cells associated with protein synthesis. The organotypic stromal cells were each characterized by a unique subpopulation of cells dedicated to extracellular matrix organization and assembly. Finally, compared to cells in 2D monolayer, the endothelial cell transcriptome from the 3D in vitro heart, skin, lung, and pancreas microvessel networks are more similar to the in vivo endothelial cells from the respective organs. We conclude that stromal cells contribute to endothelial cell and microvessel network organ tropism, and create an endothelial cell phenotype that more closely resembles that present in vivo.

Cytokine Adsorber Use during DCD Heart Perfusion Counteracts Coronary Microvascular Dysfunction

Microvascular dysfunction (MVD) in cardiac allografts is associated with an impaired endothelial function in the coronary microvasculature. Ischemia/reperfusion injury (IRI) deteriorates endothelial function. Hearts donated after circulatory death (DCD) are exposed to warm ischemia before initiating ex vivo blood perfusion (BP). The impact of cytokine adsorption during BP to prevent MVD in DCD hearts is unknown. In a porcine DCD model, we assessed the microvascular function of hearts after BP with (DCD-BPCytoS, n = 5) or without (DCD-BP, n = 5) cytokine adsorption (CytoSorb®). Microvascular autoregulation was assessed by increasing the coronary perfusion pressure, while myocardial microcirculation was measured by Laser-Doppler-Perfusion (LDP). We analyzed the immunoreactivity of arteriolar oxidative stress markers nitrotyrosine and 4-hydroxy-2-nonenal (HNE), endothelial injury indicating cell adhesion molecules CD54, CD106 and CD31, and eNOS. We profiled the concentration of 13 cytokines in the perfusate. The expression of 84 genes was determined and analyzed using machine learning and decision trees. Non-DCD hearts served as a control for the gene expression analysis. Compared to DCD-BP, relative LDP was improved in the DCD-BPCytoS group (1.51 ± 0.17 vs. 1.08 ± 0.17). Several pro- and anti-inflammatory cytokines were reduced in the DCD-BPCytoS group. The expression of eNOS significantly increased, and the expression of nitrotyrosine, HNE, CD54, CD106, and CD31, markers of endothelial injury, majorly decreased in the DCD-BPCytoS group. Three genes allowed exact differentiation between groups; regulation of HIF1A enabled differentiation between perfusion (DCD-BP, DCD-BPCytoS) and non-perfusion groups. CAV1 allowed differentiation between BP and BPCytoS. The use of a cytokine adsorption device during BP counteracts preload-dependent MVD and preserves the microvascular endothelium by preventing oxidative stress and IRI of coronary arterioles of DCD hearts.

Tumor Progression Locus 2 Protects against Acute Respiratory Distress Syndrome in Influenza A Virus-Infected Mice

Excessive inflammation in patients with severe influenza disease may lead to acute lung injury that results in acute respiratory distress syndrome (ARDS). ARDS is associated with alveolar damage and pulmonary edema that severely impair gas exchange, leading to hypoxia. With no existing FDA-approved treatment for ARDS, it is important to understand the factors that lead to virus-induced ARDS development to improve prevention, diagnosis, and treatment. We have previously shown that mice deficient in the serine-threonine mitogen-activated protein kinase, Tpl2 (MAP3K8 or COT), succumb to infection with a typically low-pathogenicity strain of influenza A virus (IAV; HKX31, H3N2 [x31]). The goal of the current study was to evaluate influenza A virus-infected Tpl2-/- mice clinically and histopathologically to gain insight into the disease mechanism. We hypothesized that Tpl2-/- mice succumb to IAV infection due to development of ARDS-like disease and pulmonary dysfunction. We observed prominent signs of alveolar septal necrosis, hyaline membranes, pleuritis, edema, and higher lactate dehydrogenase (LDH) levels in the lungs of IAV-infected Tpl2-/- mice compared to wild-type (WT) mice from 7 to 9 days postinfection (dpi). Notably, WT mice showed signs of regenerating epithelium, indicative of repair and recovery, that were reduced in Tpl2-/- mice. Furthermore, biomarkers associated with human ARDS cases were upregulated in Tpl2-/- mice at 7 dpi, demonstrating an ARDS-like phenotype in Tpl2-/- mice in response to IAV infection. IMPORTANCE This study demonstrates the protective role of the serine-threonine mitogen-activated protein kinase, Tpl2, in influenza virus pathogenesis and reveals that host Tpl2 deficiency is sufficient to convert a low-pathogenicity influenza A virus infection into severe influenza disease that resembles ARDS, both histopathologically and transcriptionally. The IAV-infected Tpl2-/- mouse thereby represents a novel murine model for studying ARDS-like disease that could improve our understanding of this aggressive disease and assist in the design of better diagnostics and treatments.

Personalized risk predictor for acute cellular rejection in lung transplant using soluble CD31

We evaluated the contribution of artificial intelligence in predicting the risk of acute cellular rejection (ACR) using early plasma levels of soluble CD31 (sCD31) in combination with recipient haematosis, which was measured by the ratio of arterial oxygen partial pressure to fractional oxygen inspired (PaO₂/FiO₂) and respiratory SOFA (Sequential Organ Failure Assessment) within 3 days of lung transplantation (LTx). CD31 is expressed on endothelial cells, leukocytes and platelets and acts as a "peace-maker" at the blood/vessel interface. Upon nonspecific activation, CD31 can be cleaved, released, and detected in the plasma (sCD31). The study included 40 lung transplant recipients, seven (17.5%) of whom experienced ACR. We modelled the plasma levels of sCD31 as a nonlinear dependent variable of the PaO₂/FiO₂ and respiratory SOFA over time using multivariate and multimodal models. A deep convolutional network classified the time series models of each individual associated with the risk of ACR to each individual in the cohort.

Effect of Co-culture of mesenchymal stem cell and glomerulus endothelial cell to promote endothelialization under optimized perfusion flow rate in whole renal ECM scaffold

In recent era, many researches on implantable bio-artificial organs has been increased owing to large gap between donors and receivers. Comprehensive organ based researches on perfusion culture for cell injury using different flow rate have not been conducted at the cellular level. The present study investigated the co-culture of rat glomerulus endothelial cell (rGEC) and rat bone marrow mesenchymal stem cells (rBMSC) to develop micro vascularization in the kidney scaffolds culturing by bioreactor system. To obtain kidney scaffold, extracted rat kidneys were decellularized by 1% sodium dodecyl sulfate (SDS), 1% triton X-100, and distilled water. Expanded rGECs were injected through decellularized kidney scaffold artery and cultured using bioreactor system. Vascular endothelial cells adhered and proliferated on the renal ECM scaffold in the bioreactor system for 3, 7 and 14 days. Static, 1 ​ml/min and 2 ​ml/min flow rates (FR) were tested and among them, 1 ​ml/min flow rate was selected based on cell viability, glomerulus character, inflammation/endothelialization proteins expression level. However, the flow injury was still existed on primary cell cultured at vessel in kidney scaffold. Therefore, co-culture of rGEC ​+ ​rBMSC found suitable to possibly solve this problem and resulted increased cell proliferation and micro-vascularization in the glomerulus, reducing inflammation and cell death which induced by flow injury. The optimized perfusion rate under rGEC ​+ ​rBMSC co-culture conditions resulted in enhanced endocellularization to make ECM derived implantable renal scaffold and might be useful as a way of treatment of the acute renal failure.

Inflammatory profile of convalescent plasma to treat COVID: Impact of amotosalen/UVA pathogen reduction technology

Blood products in therapeutic transfusion are now commonly acknowledged to contain biologically active constituents during the processes of preparation. In the midst of a worldwide COVID-19 pandemic, preliminary evidence suggests that convalescent plasma may lessen the severity of COVID-19 if administered early in the disease, particularly in patients with profound B-cell lymphopenia and prolonged COVID-19 symptoms. This study examined the influence of photochemical Pathogen Reduction Treatment (PRT) using amotosalen‐HCl and UVA light in comparison with untreated control convalescent plasma (n= 72 – paired samples) - cFFP, regarding soluble inflammatory factors: sCD40L, IFN-alpha, IFN-beta, IFN-gamma, IL-1 beta, IL-6, IL-8, IL-10, IL-18, TNF-alpha and ex-vivo inflammatory bioactivity on endothelial cells. We didn’t observe significant modulation of the majority of inflammatory soluble factors (8 of 10 molecules tested) pre- or post-PRT. We noted that IL-8 concentrations were significantly decreased in cFFP with PRT, whereas the IL-18 concentration was increased by PRT. In contrast, endothelial cell release of IL-6 was similar whether cFFP was pre-treated with or without PRT. Expression of CD54 and CD31 in the presence of cFFP were similar to control levels, and both were significant decreased in when cFFP had been pre-treated by PRT. It will be interesting to continue investigations of IL-18 and IL-8, and the physiopathological effect of PRT- treated convalescent plasma and in clinical trials. But overall, it appears that cFFP post-PRT were not excessively pro-inflammatory. Further research, including a careful clinical evaluation of CCP-treated patients, will be required to thoroughly define the clinical relevance of these findings.

Executable models of immune signaling pathways in HIV-associated atherosclerosis

Atherosclerosis (AS)-associated cardiovascular disease is an important cause of mortality in an aging population of people living with HIV (PLWH). This elevated risk has been attributed to viral infection, anti-retroviral therapy, chronic inflammation, and lifestyle factors. However, the rates at which PLWH develop AS vary even after controlling for length of infection, treatment duration, and for lifestyle factors. To investigate the molecular signaling underlying this variation, we sequenced 9368 peripheral blood mononuclear cells (PBMCs) from eight PLWH, four of whom have atherosclerosis (AS+). Additionally, a publicly available dataset of PBMCs from persons before and after HIV infection was used to investigate the effect of acute HIV infection. To characterize dysregulation of pathways rather than just measuring enrichment, we developed the single-cell Boolean Omics Network Invariant Time Analysis (scBONITA) algorithm. scBONITA infers executable dynamic pathway models and performs a perturbation analysis to identify high impact genes. These dynamic models are used for pathway analysis and to map sequenced cells to characteristic signaling states (attractor analysis). scBONITA revealed that lipid signaling regulates cell migration into the vascular endothelium in AS+ PLWH. Pathways implicated included AGE-RAGE and PI3K-AKT signaling in CD8+ T cells, and glucagon and cAMP signaling pathways in monocytes. Attractor analysis with scBONITA facilitated the pathway-based characterization of cellular states in CD8+ T cells and monocytes. In this manner, we identify critical cell-type specific molecular mechanisms underlying HIV-associated atherosclerosis using a novel computational method.

The potential applications of microparticles in the diagnosis, treatment, and prognosis of lung cancer

Microparticles (MPs) are 100–1000 nm heterogeneous submicron membranous vesicles derived from various cell types that express surface proteins and antigenic profiles suggestive of their cellular origin. MPs contain a diverse array of bioactive chemicals and surface receptors, including lipids, nucleic acids, and proteins, which are essential for cell-to-cell communication. The tumour microenvironment (TME) is enriched with MPs that can directly affect tumour progression through their interactions with receptors. Liquid biopsy, a minimally invasive test, is a promising alternative to tissue biopsy for the early screening of lung cancer (LC). The diverse biomolecular information from MPs provides a number of potential biomarkers for LC risk assessment, early detection, diagnosis, prognosis, and surveillance. Remodelling the TME, which profoundly influences immunotherapy and clinical outcomes, is an emerging strategy to improve immunotherapy. Tumour-derived MPs can reverse drug resistance and are ideal candidates for the creation of innovative and effective cancer vaccines. This review described the biogenesis and components of MPs and further summarised their main isolation and quantification methods. More importantly, the review presented the clinical application of MPs as predictive biomarkers in cancer diagnosis and prognosis, their role as therapeutic drug carriers, particularly in anti-tumour drug resistance, and their utility as cancer vaccines. Finally, we discussed current challenges that could impede the clinical use of MPs and determined that further studies on the functional roles of MPs in LC are required.

Regulation of CCL2 by EZH2 affects tumor-associated macrophages polarization and infiltration in breast cancer

Tumor associated macrophages (TAMs) play an important role in tumorigenesis, development and anti-cancer drug therapy. However, very few epigenetic compounds have been elucidated to affect tumor growth by educating TAMs in the tumor microenvironment (TME). Herein, we identified that EZH2 performs a crucial role in the regulation of TAMs infiltration and protumoral polarization by interacting with human breast cancer (BC) cells. We showed that EZH2 inhibitors-treated BC cells induced M2 macrophage polarization in vitro and in vivo, while EZH2 knockdown exhibited the opposite effect. Mechanistically, inhibition of EZH2 histone methyltransferase alone by EZH2 inhibitors in breast cancer cells could reduce the enrichment of H3K27me3 on CCL2 gene promoter, elevate CCL2 transcription and secretion, contributing to the induction of M2 macrophage polarization and recruitment in TME, which reveal a potential explanation behind the frustrating results of EZH2 inhibitors against breast cancer. On the contrary, EZH2 depletion led to DNA demethylation and subsequent upregulation of miR-124-3p level, which inhibited its target CCL2 expression in the tumor cells, causing arrest of TAMs M2 polarization. Taken together, these data suggested that EZH2 can exert opposite regulatory effects on TAMs polarization through its enzymatic or non-enzymatic activities. Our results also imply that the effect of antitumor drugs on TAMs may affect its therapeutic efficacy, and the combined application with TAMs modifiers should be warranted to achieve great clinical success.

Comparison of mechanisms of angiostasis caused by the anti-inflammatory steroid 5α-tetrahydrocorticosterone versus conventional glucocorticoids

5α-Tetrahydrocorticosterone (5αTHB) is an effective topical anti-inflammatory agent in mouse, with less propensity to cause skin thinning and impede new blood vessel growth compared with corticosterone. Its anti-inflammatory effects were not prevented by RU38486, a glucocorticoid receptor antagonist, suggesting alternative mechanisms. The hypothesis that 5αTHB directly inhibits angiogenesis to a lesser extent than hydrocortisone was tested, focussing on glucocorticoid receptor mediated actions. New vessel growth from aortae from C57BL/6 male mice was monitored in culture, in the presence of 5αTHB, hydrocortisone (mixed glucocorticoid/mineralocorticoid receptor agonist) or the selective glucocorticoid receptor agonist dexamethasone. Transcript profiles were studied, as was the role of the glucocorticoid receptor, using the antagonist, RU38486. Ex vivo, 5αTHB suppressed vessel growth from aortic rings, but was less potent than hydrocortisone (EC50 2512 nM 5αTHB, versus 762 nM hydrocortisone). In contrast to conventional glucocorticoids, 5αTHB did not alter expression of genes related to extracellular matrix integrity or inflammatory signalling, but caused a small increase in Per1 transcript, and decreased transcript abundance of Pecam1 gene. RU38486 did not antagonise the residual effects of 5αTHB to suppress vessel growth or regulate gene expression, but modified effects of dexamethasone. 5αTHB did not alter expression of glucocorticoid-regulated genes Fkbp51 and Hsd11b1, unlike hydrocortisone and dexamethasone. In conclusion, compared with hydrocortisone, 5αTHB exhibits limited suppression of angiogenesis, at least directly in blood vessels and probably independent of the glucocorticoid receptor. Discriminating the mechanisms employed by 5αTHB may provide the basis for the development of novel safer anti-inflammatory drugs for topical use.

Serum of Post-COVID-19 Syndrome Patients with or without ME/CFS Differentially Affects Endothelial Cell Function In Vitro

A proportion of COVID-19 reconvalescent patients develop post-COVID-19 syndrome (PCS) including a subgroup fulfilling diagnostic criteria of Myalgic encephalomyelitis/Chronic Fatigue Syndrome (PCS/CFS). Recently, endothelial dysfunction (ED) has been demonstrated in these patients, but the mechanisms remain elusive. Therefore, we investigated the effects of patients’ sera on endothelia cells (ECs) in vitro. PCS (n = 17), PCS/CFS (n = 13), and healthy controls (HC, n = 14) were screened for serum anti-endothelial cell autoantibodies (AECAs) and dysregulated cytokines. Serum-treated ECs were analysed for the induction of activation markers and the release of small molecules by flow cytometry. Moreover, the angiogenic potential of sera was measured in a tube formation assay. While only marginal differences between patient groups were observed for serum cytokines, AECA binding to ECs was significantly increased in PCS/CFS patients. Surprisingly, PCS and PCS/CFS sera reduced surface levels of several EC activation markers. PCS sera enhanced the release of molecules associated with vascular remodelling and significantly promoted angiogenesis in vitro compared to the PCS/CFS and HC groups. Additionally, sera from both patient cohorts induced the release of molecules involved in inhibition of nitric oxide-mediated endothelial relaxation. Overall, PCS and PCS/CFS patients′ sera differed in their AECA content and their functional effects on ECs, i.e., secretion profiles and angiogenic potential. We hypothesise a pro-angiogenic effect of PCS sera as a compensatory mechanism to ED which is absent in PCS/CFS patients.

Preclinical anti-angiogenic and anti-cancer activities of BAY1143269 in glioblastoma via targeting oncogenic protein expression

Glioblastoma angiogenesis is critical for tumor growth, making it an appealing target for treatment development. BAY1143269 is a novel inhibitor of mitogen-activated protein kinase interacting serine/threonine-protein kinase 1 (MKN1) and has potent anti-cancer activity. We identified BAY1143269 as an angiogenesis inhibitor, by in vitro and in vivo glioblastoma angiogenesis models. BAY1143269 inhibited the capillary network formation of glioblastoma microvascular endothelial cells (GMECs), particularly the early stage of tubular structure formation. It also inhibited migration and proliferation, and induced apoptosis of GMECs isolated from glioblastoma patients. We found that BAY1143269 acted on GMECs by suppressing the eukaryotic translation initiation factor 4E (eIF4E) and eIF4E-mediated expression of oncogenic proteins, including those involved in cell cycle, epithelial-mesenchymal transition (EMT), and pro-survival. In addition, BAY1143269 suppressed eIF4E phosphorylation, inhibited proliferation, and induced apoptosis of glioblastoma cells. Interestingly, it reduced vascular endothelial growth factor (VEGF) level in tumor cells and culturing medium, demonstrating the inhibitory effect of BAY1143269 on tumor proangiogenic microenvironment. We finally challenged BAY1143269 on the glioblastoma xenograft mice model and observed a significant tumor growth reduction without toxicity in mice receiving oral BAY1143269. Immunoblotting analysis demonstrated significantly less phosphorylated-eIF4E (p-eIF4E), cluster of differentiation 31 (CD31) (microvascular endothelial cell marker), and VEGF in tumors from drug-treated mice. In summary, the inhibition of glioblastoma angiogenesis with BAY1143269 may provide an alternative approach for anti-glioblastoma therapy.

Associations between antenatal maternal asthma status and placental DNA methylation

INTRODUCTION

Maternal asthma in pregnancy is associated with adverse perinatal and child health outcomes; however, mechanisms are poorly understood.

METHODS

The PRogramming of Intergenerational Stress Mechanisms (PRISM) prospective pregnancy cohort characterized asthma history during pregnancy via questionnaires and quantified placental DNAm using the Illumina Infinium HumanMethylation450 BeadChip. We performed epigenome-wide association analyses (n = 223) to estimate associations between maternal active or inactive asthma, as compared to never asthma, and placental differentially methylated positions (DMPs) and differentially variable positions (DVPs). Models adjusted for maternal pre-pregnancy body mass index, smoking status, parity, age and education level and child sex. P-values were FDR-adjusted.

RESULTS

One hundred and fifty-nine (71.3%) pregnant women reported no history of asthma (never asthma), 15 (6.7%) reported inactive, and 49 (22%) reported active antenatal asthma. Women predominantly self-identified as Black/Hispanic Black [88 (39.5%)] and Hispanic/non-Black [42 (18.8%)]. We identified 10 probes at FDR<0.05 and 4 probes at FDR<0.10 characterized by higher variability in maternal active asthma compared to never asthma mapping to GPX3, LHPP, PECAM1, ATAD3C, and ARHGEF4 and 2 probes characterized by lower variation mapping to CHMP4A and C5orf24. Amongst women with inactive asthma, we identified 52 probes, 41 at FDR<0.05 and an additional 11 at FDR <0.10, with higher variability compared to never asthma; BMP4, LHPP, PHYHIPL, and ZSCAN23 were associated with multiple DVPs. No associations were observed with DMPs.

DISCUSSION

We observed alterations in placental DNAm in women with antenatal asthma, as compared to women without a history of asthma. Further research is needed to understand the impact on fetal development.

Peripheral blood derived endothelial colony forming cells as suitable cell source for pre-endothelialization of arterial vascular grafts under dynamic flow conditions

In regenerative medicine, autologous peripheral blood derived endothelial colony forming cells (PB-derived ECFC) represent a promising source of endothelial cells (EC) for pre-endothelialization of arterial tissue engineered vascular grafts (TEVG) since they are readily attainable, can easily be isolated and possess a high proliferation potential. The aim of this study was to compare the phenotype of PB-derived ECFC with arterial and venous model cells such as human aortic endothelial cells (HAEC) and human umbilical vein endothelial cells (HUVEC) under dynamic cell culture conditions to find a suitable cell source of EC for pre-endothelialization. In this study PB-derived ECFC were cultivated over 24 h under a high pulsatile shear stress (20 dyn/cm², 1 Hz) and subsequently analyzed. ECFC oriented and elongated in the direction of flow and expressed similar anti-thrombotic and endothelial differentiation markers compared to HAEC. There were significant differences observable in gene expression levels of CD31, CD34 and NOTCH4 between ECFC and HUVEC. These results therefore suggest an arterial phenotype for PB-derived ECFC both under static and flow conditions, and this was supported by NOTCH4 protein expression profiles. ECFC also significantly up-regulated gene expression levels of anti-thrombotic genes such as krueppel-like factor 2, endothelial nitric oxide synthase 3 and thrombomodulin under shear stress cultivation as compared to static conditions. Dynamically cultured PB-derived ECFC therefore may be a promising cell source for pre-endothelialization of arterial TEVGs.

PECAM-1 Is Down-Regulated in γδT Cells during Remission, but Up-Regulated in Relapse of Multiple Sclerosis

Introduction. PECAM-1 and NKRP1A are both involved in the vascular transmigration of T lymphocytes. Vascular transmigration is a crucial process in multiple sclerosis pathogenesis. Methods and aim. The current paper presents an analysis of PECAM-1 and NKRP1A expression on γδ T cells. Expression of PECAM-1 and NKRP1A on subsets of γδ T cells was performed with flow cytometry. Results. Based on the flow cytometry data, PECAM1 was slightly differentially modulated on γδ T cells—it was up-regulated during relapse, but down-regulated during remission. Moreover, a significant downregulation of CD3 expression was noted on γδ T cells from MS patients, most notably during relapse. Conclusions. This may be a sign of the overall activation of γδ T cells in the course of multiple sclerosis.

Monitoring Wound Healing with Topically Applied Optical NanoFlare mRNA Nanosensors

An effective wound management strategy needs accurate assessment of wound status throughout the whole healing process. This can be achieved by examining molecular biomarkers including proteins, DNAs, and RNAs. However, existing methods for quantifying these biomarkers such as immunohistochemistry and quantitative polymerase chain reaction are usually laborious, resource-intensive, and disruptive. This article reports the development and utilization of mRNA nanosensors (i.e., NanoFlare) that are topically applied on cutaneous wounds to reveal the healing status through targeted and semi-quantitative examination of the mRNA biomarkers in skin cells. In 2D and 3D in vitro models, the efficacy and efficiency of these nanosensors are demonstrated in revealing the dynamic changes of mRNA biomarkers for different stages of wound development. In mouse models, this platform permits the tracking and identification of wound healing stages and a normal and diabetic wound healing process by wound healing index in real time.

Single Cell RNA Sequencing Reveals Deep Homology of Dental Cell Types Across Vertebrates

Like most mammals, humans replace their teeth once throughout their lives and have limited regenerative capabilities. In contrast, mice continually renew tissues lost due to gnawing through a well characterized population of stem cells on the labial surface of the incisor. Most non-mammalian vertebrates replace teeth throughout life; the cellular and molecular mechanisms of successional tooth replacement are largely unknown. Here we use single nuclei RNA sequencing (snRNA-seq) of replacement teeth and adjacent oral lamina in Lake Malawi cichlids, species with lifelong whole–tooth replacement, to make two main discoveries. First, despite hundreds of millions of years of evolution, we demonstrate conservation of cell type gene expression across vertebrate teeth (fish, mouse, human). Second, we used an approach that combines marker gene expression and developmental potential of dental cells to uncover the transcriptional signature of stem-like cells in regenerating teeth. Our work underscores the importance of a comparative framework in the study of vertebrate oral and regenerative biology.

PECAM EMPs regulate apoptosis in pulmonary microvascular endothelial cells in COPD by activating the Akt signaling pathway

INTRODUCTION

Endothelial microparticles (EMPs) are partly associated with the progress of chronic obstructive pulmonary disease (COPD). We sought to measure the levels of EMPs in COPD patients and in human pulmonary microvascular endothelial cells (HPMECs) exposed to cigarette smoking extract (CSE) to elucidate the potential mechanisms of their action.

METHODS

We obtained prospectively blood EMPs from 30 stable COPD patients and 20 non-COPD volunteers. EMP subpopulations were determined by flow cytometry in platelet-free plasma according to the expression of membrane specific antigens. Cell growth, proliferation, apoptosis and the expression of protein kinase B (Akt) in HPMECs after exposure to PECAM EMPs were assessed. After intervention with an antioxidant (Eukarion-134, EUK-134), apoptosis and the expression of Akt in HPMECs were also measured.

RESULTS

Unlike those of MCAM EMPs, VE-cadherin, PECAM and E-selectin EMP values were significantly higher in the stable COPD patients than in the non-COPD volunteers (p<0.05). Only PECAM EMPs were higher in HPMECs exposed to CSE (p<0.05). Further, in vitro studies showed that the apoptosis rate and expression of cleaved caspase 3/9 in HPMECs increased in a dose- and time-independent manner with PECAM EMPs. The expression of phospho-Akt (p-Akt) decreased in a time-independent manner with PECAM EMPs (p<0.05). Compared with the control group, the early apoptosis rate of HPMECs was higher, and the expression of p-Akt was lower in both the PECAM EMP group and EUK-134 + PECAM EMP group (p<0.05). The apoptosis rate declined markedly, and the expression of p-Akt was higher in the EUK-134 + PECAM EMP group, compared with the PECAM EMPs group (p<0.05).

CONCLUSIONS

The present results suggest that PECAM EMPs positively regulate apoptosis in HPMECs in COPD, likely by decreasing Akt phosphorylation and can be protected by antioxidants.

Vascular alterations impede fragile tolerance to pregnancy in type 1 diabetes

OBJECTIVE

To determine the impact of autoimmunity in the absence of glycemic alterations on pregnancy in type 1 diabetes (T1D).

DESIGN

Because nonobese diabetic (NOD) mice experience autoimmunity before the onset of hyperglycemia, we studied pregnancy outcomes in prediabetic NOD mice using flow cytometry and enzyme-linked immunosorbent assays. Once we determined that adverse events in pregnancy occurred in euglycemic mice, we performed an exploratory study using electronic health records to better understand pregnancy complications in humans with T1D and normal hemoglobin A1c levels.

SETTING

University Medical Center.

PATIENT(S)/ANIMAL(S)

Nonobese diabetic mice and electronic health records from Vanderbilt University Medical Center.

INTERVENTION(S)

Nonobese diabetic mice were administered 200 μg of an anti-interleukin 6 (IL-6) antibody every other day starting on day 5 of gestation.

MAIN OUTCOME MEASURE(S)

Changes in the number of abnormal and reabsorbed pups in NOD mice and odds of vascular complications in pregnancy in T1D in relation to A1c.

RESULT(S)

Prediabetic NOD mice had increased adverse pregnancy outcomes compared with nonautoimmune mice; blockade of IL-6, which was secreted by endothelial cells, decreased the number of reabsorbed and abnormal fetuses. Similarly, vascular complications were increased in pregnant patients with T1D across all A1c values.

CONCLUSION(S)

The vascular secretion of IL-6 drives adverse pregnancy outcomes in prediabetic NOD mice. Pregnant patients with T1D have increased vascular complications even with normal hemoglobin A1cs, indicating a potential effect of autoimmunity on the placental vasculature.

Targeting vascular inflammation through emerging methods and drug carriers

Acute inflammation is a common dangerous component of pathogenesis of many prevalent conditions with high morbidity and mortality including sepsis, thrombosis, acute respiratory distress syndrome (ARDS), COVID-19, myocardial and cerebral ischemia-reperfusion, infection, and trauma. Inflammatory changes of the vasculature and blood mediate the course and outcome of the pathology in the tissue site of insult, remote organs and systemically. Endothelial cells lining the luminal surface of the vasculature play the key regulatory functions in the body, distinct under normal vs. pathological conditions. In theory, pharmacological interventions in the endothelial cells might enable therapeutic correction of the overzealous damaging pro-inflammatory and pro-thrombotic changes in the vasculature. However, current agents and drug delivery systems (DDS) have inadequate pharmacokinetics and lack the spatiotemporal precision of vascular delivery in the context of acute inflammation. To attain this level of precision, many groups design DDS targeted to specific endothelial surface determinants. These DDS are able to provide specificity for desired tissues, organs, cells, and sub-cellular compartments needed for a particular intervention. We provide a brief overview of endothelial determinants, design of DDS targeted to these molecules, their performance in experimental models with focus on animal studies and appraisal of emerging new approaches. Particular attention is paid to challenges and perspectives of targeted therapeutics and nanomedicine for advanced management of acute inflammation.

Spatial transcriptomic profiles of mouse uterine microenvironments at pregnancy day 7.5†

Uterine dysfunctions lead to fertility disorders and pregnancy complications. Normal uterine functions at pregnancy depend on crosstalk among multiple cell types in uterine microenvironments. Here, we performed the spatial transcriptomics and single-cell RNA-seq assays to determine local gene expression profiles at the embryo implantation site of the mouse uterus on pregnancy day 7.5 (D7.5). The spatial transcriptomic annotation identified 11 domains of distinct gene signatures, including a mesometrial myometrium, an anti-mesometrial myometrium, a mesometrial decidua enriched with natural killer cells, a vascular sinus zone for maternal vessel remodeling, a fetal-maternal interface, a primary decidual zone, a transition decidual zone, a secondary decidual zone, undifferentiated stroma, uterine glands, and the embryo. The scRNA-Seq identified 12 types of cells in the D7.5 uterus including three types of stromal fibroblasts with differentiated and undifferentiated markers, one cluster of epithelium including luminal and glandular epithelium, mesothelium, endothelia, pericytes, myelomonocytic cell, natural killer cells, and lymphocyte B. These single-cell RNA signatures were then utilized to deconvolute the cell-type compositions of each individual uterine microenvironment. Functional annotation assays on spatial transcriptomic data revealed uterine microenvironments with distinguished metabolic preferences, immune responses, and various cellular behaviors that are regulated by region-specific endocrine and paracrine signals. Global interactome among regions is also projected based on the spatial transcriptomic data. This study provides high-resolution transcriptome profiles with locality information at the embryo implantation site to facilitate further investigations on molecular mechanisms for normal pregnancy progression.