Permeability Of Blood Vessels Research Articles

Sialyl Lewis X decorated integrin α3 on small extracellular vesicles promotes metastasis of bladder cancer via enhancing vascular permeability.

The permeability of blood vessels plays a crucial role in the spread of cancer cells, facilitating their metastasis at distant sites. Small extracellular vesicles (sEVs) are known to contribute to the metastasis of various cancers by crossing the blood vessel wall. However, the role of abnormal glycoconjugates on sEVs in tumor blood vessels remains unclear. Our study found elevated levels of fucosyltransferase VII (FUT7) and its product sialyl Lewis X (sLeX) in muscle-invasive bladder cancer (BLCA), with high levels of sLeX promoting the growth and invasion of BLCA cells. Further investigation revealed that sLeX was enriched in sEVs derived from BLCA. sLeX-decorated sEVs increased blood vessel permeability by disrupting the tight junctions of human umbilical vein endothelial cells (HUVECs). Using the glycoproteomics approach, we identified integrin α3 (ITGA3) as a sLeX-bearing glycoprotein in BLCA cells and their sEVs. Mechanically, sLeX modification stabilized ITGA3 by preventing its degradation in lysosomes. sEVs carrying sLeX-modified ITGA3 can be effectively internalized by HUVECs, leading to a decrease in the expression of tight junction protein. Conversely, silencing ITGA3 in sLeX-decorated sEVs restored tight junction proteins and reduced blood vessel permeability by inhibiting the MAPK pathway. Moreover, sLeX-modification of ITGA3 at Asn 265 in HUVECs promoted occludin dephosphorylation at Ser/Thr residues, followed by inducing its importin α1-mediated nuclear translocation, which resulted in the disruption of tight junctions. Our findings suggest a potential strategy for disrupting the formation of a metastatic microenvironment and preventing the spread of malignant bladder cancer.

Effect of Egyptian spitting cobra Naja nubiae crude venom on immunogenic activity of rats

Snakes show defensive activities, often counting visual or auditory displays against an aggressor. The study observed what happens to rats administered subcutaneously sub-lethal doses of crude venom Naja nubiae. The pro-inflammatory cytokines, such as tumor necrosis alpha (TNF-α) and interleukin-6 (IL-6), as well as the anti-inflammatory cytokines such as interleukin-10 (IL-10), and inflammatory mediator's prostaglandin E-2 (PG-E2), were evaluated. Vascular permeability (VP) was employed to assess how leaky or permeable blood vessels are in various tissues and organs, including the rat peritoneal cavity and lymphoid organs. Lymphoid organs' histological alterations brought on by Nubiae venom. The study found that the two venom doses—1/4 and 1/2 LD50—induced high levels of inflammatory activity as evidenced by the production of inflammatory cytokines. These findings demonstrated that venom enhanced innate immunity through specifically increased T helper cells, IL-6, TNF-α, IL-10, and PG-E2. The results reveal whether the venom has an immunomodulatory effect and promotes inflammation. The data have a substantial impact on the development of new drugs and treatments for inflammatory conditions.

Methylprednisolone alleviates lung injury in sepsis by regulating miR-151-5p/USP38 pathway

BackgroundAcute lung injury (ALI) is manifested by increased blood vessel permeability within the lungs and subsequent impairment of alveolar gas exchange. Methylprednisolone (MP) is commonly used as a treatment for ALI to reduce inflammation, yet its molecular mechanism remains unclear. This study aims to explore the underlying mechanisms of MP on ALI in a model induced by lipopolysaccharide (LPS). Material and MethodsThe proliferation, viability, apoptosis, and miR-151-5p expression of alveolar type II epithelial cells (AECII) were detected using the cell EdU assay, Annexin V/PI Apoptosis Kit, counting kit-8 (CCK-8) assay, and RT-qPCR. Western blot analysis was used to detect the Usp38 protein level. IL-6 and TNF-α were measured by ELISA. The combination of miR-151-5p and USP38 was determined by chromatin immunoprecipitation (ChIP)-PCR and dual-luciferase reporter assay. ResultsMP greatly improved pulmonary function in vivo, reduced inflammation, and promoted the proliferation of the alveolar type II epithelial cells (AECII) in vitro. By comparing the alterations of microRNAs in lung tissues between MP treatment and control groups, we found that miR-151-5p exhibited a significant increase after LPS-treated AECII, but decreased after MP treatment. Confirmed by a luciferase reporter assay, USP38, identified as a downstream target of miR-151-5p, was found to increase after MP administration. Inhibition of miR-151-5p or overexpression of USP38 in AECII significantly improved the anti-inflammatory, anti-apoptotic, and proliferation-promotive effects of MP. ConclusionIn summary, our data demonstrated that MP alleviates the inflammation and apoptosis of AECII induced by LPS, and promotes the proliferation of AECII partially via miR-151-5p suppression and subsequent USP38 activation.

Distal Immunization and Systemic Cytokines Establish a Transient Immune Alert State in the Intestine.

Conventionally, immune responses are studied in the context of inflamed tissues and their corresponding draining lymph nodes (LNs). However, little is known about the effects of systemic inflammatory signals generated during local inflammation on distal tissues and nondraining LNs. Using a mouse model of cutaneous immunization, we found that systemic inflammatory stimuli triggered a rapid and selective distal response in the small intestine and the mesenteric LN (mesLN). This consisted of increased permeability of intestinal blood vessels and lymphatic drainage of bloodborne solutes into the mesLN, enhanced activation and migration of intestinal dendritic cells, as well as amplified T cell responses in the mesLNs to systemic but not orally derived Ags. Mechanistically, we found that the small intestine endothelial cells preferentially expressed molecules involved in TNF-α signaling and that TNF-α blockade markedly diminished distal intestinal responses to cutaneous immunization. Together, these findings reveal that the intestinal immune system is rapidly and selectively activated in response to inflammatory cues regardless of their origin, thus identifying an additional layer of defense and enhanced surveillance of a key barrier organ at constant risk of pathogen encounter.

Hypersensitive blood vessels in Clarkson disease.

Idiopathic systemic capillary leak syndrome (ISCLS) is a rare, recurrent condition with dramatically increased blood vessel permeability and, therefore, induction of systemic edema, which may lead to organ damage and death. In this issue of the JCI, Ablooglu et al. showed that ISCLS vessels were hypersensitive to agents known to increase vascular permeability, using human biopsies, cell culture, and mouse models. Several endothelium-specific proteins that regulate endothelial junctions were dysregulated and thereby compromised the vascular barrier. These findings suggest that endothelium-intrinsic dysregulation underlies hyperpermeability and implicate the cytoplasmic serine/threonine protein phosphatase 2A (PP2A) as a potential drug target for the treatment of ISCLS.

The mechanical ventilation guided by electrical impedance tomography in acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a common and critical clinical condition characterized by diffuse damage to the lung interstitium, alveoli, and increased permeability of pulmonary blood vessels. CT can be used to assess the imaging features, severity, and prediction of ARDS, but it requires patient transportation to the CT room and is only a static examination. Electrical impedance tomography (EIT) is an increasingly widely used monitoring tool in clinical applications in recent years. It enables continuous real-time assessment of lung ventilation distribution at the bedside and has high clinical value in optimizing mechanical ventilation parameters for critically ill patients. This article introduces the basic principles of EIT and how to better utilize EIT technology to guide mechanical ventilation treatment for ARDS patients.

Transmembrane Protein TMEM230, Regulator of Glial Cell Vascular Mimicry and Endothelial Cell Angiogenesis in High-Grade Heterogeneous Infiltrating Gliomas and Glioblastoma.

High-grade gliomas (HGGs) and glioblastoma multiforme (GBM) are characterized by a heterogeneous and aggressive population of tissue-infiltrating cells that promote both destructive tissue remodeling and aberrant vascularization of the brain. The formation of defective and permeable blood vessels and microchannels and destructive tissue remodeling prevent efficient vascular delivery of pharmacological agents to tumor cells and are the significant reason why therapeutic chemotherapy and immunotherapy intervention are primarily ineffective. Vessel-forming endothelial cells and microchannel-forming glial cells that recapitulate vascular mimicry have both infiltration and destructive remodeling tissue capacities. The transmembrane protein TMEM230 (C20orf30) is a master regulator of infiltration, sprouting of endothelial cells, and microchannel formation of glial and phagocytic cells. A high level of TMEM230 expression was identified in patients with HGG, GBM, and U87-MG cells. In this study, we identified candidate genes and molecular pathways that support that aberrantly elevated levels of TMEM230 play an important role in regulating genes associated with the initial stages of cell infiltration and blood vessel and microchannel (also referred to as tumor microtubule) formation in the progression from low-grade to high-grade gliomas. As TMEM230 regulates infiltration, vascularization, and tissue destruction capacities of diverse cell types in the brain, TMEM230 is a promising cancer target for heterogeneous HGG tumors.

Abstract 6659: Oncolytic herpes simplex virus expressing XCL1 and FLT3L modulate the intratumoral immune response and improve the anti-tumor efficacy in a metastatic breast tumor model

Abstract Patients with metastatic breast cancer (MBC) have a dismal prognosis, with a 5-year survival rate of only 26%. The inadequate infiltration of immune cells targeting the tumor microenvironment (TME) is a key factor contributing to this low survival rate. Immune effector cells, including CD8+ cytotoxic T cells, NKT cells, and NK cells, play a crucial role in targeting tumor cells. The activation of immune effector cells relies on the presence of conventional type I dendritic cells (cDC1), which present tumor-specific antigenic peptides on their surface. Recent studies have identified the chemokine XCL1 and growth factor FLT3L as critical factors involved in the intratumoral recruitment and expansion of dendritic cells. To enhance the activity of cDC1 in the TME we designed an oncolytic herpes simplex virus (oHSV) expressing XCL1 and FLT3L. The recombinant oHSV, rQ1-XF, was generated by incorporating LoxP sites into the viral genome through recombination with a carrier plasmid carrying the polycistronic cassette. To enhance the intratumoral penetration of oHSV injected intravenously in primary tumors and MBC lesions in the lung, we employed the cancer drug ganetespib, which can increase the permeability of tumor blood vessels. In comparison to untreated mice, ganetespib combined with rQ1-XF reduced the size of primary tumors and induced a short but significant increase in the survival of mice. Additionally, compared to the ganetespib alone treatment, ganetespib combined with rQ1-XF reduced MBC burden in the lung. The flow cytometry analysis of immune cells revealed an increased infiltration of CD11c+CD11b- dendritic cells in primary tumors treated with oHSV combination therapy compared to the ganetespib only control. A similar trend was also observed in CD4 T cells and CD8 T cells in primary tumors. As expected, there was a negative correlation between tumor burden and the infiltration of CD4+ T cells and CD8+ T cells in primary tumors. Ganetespib combined with oHSV also reduced the infiltration of CD4+ regulatory T cells (Tregs) in primary tumors, however the number of Tregs increased with primary tumor size as well as tumor burden in the lung. This could potentially lead to reduced efficacy of tumor-infiltrating dendritic cells in activating effector T cells in tumors treated with ganetespib and rQ1-XF. Moreover, the combination therapy did not yield significant alterations in the populations of DCs, CD4+ T cells, and CD8+ T cells in lungs with metastatic lesions. Further studies are underway to investigate whether the depletion of Treg cells in combination with rQ1-XF enhances effector T cell activation against metastatic breast tumor cells. The findings of this study will provide valuable insights into the effectiveness of using XCL1 and FLT3L-armed oncolytic viruses in patients with MBC. Citation Format: Himanshu Soni, Liqun Gu, Sylvie Roberge, Heena Kumra, Hiroshi Nakashima, E. Antonio Chiocca, Yves Boucher. Oncolytic herpes simplex virus expressing XCL1 and FLT3L modulate the intratumoral immune response and improve the anti-tumor efficacy in a metastatic breast tumor model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6659.

Age-dependent loss of HAPLN1 erodes vascular integrity via indirect upregulation of endothelial ICAM1 in melanoma.

Melanoma, the most lethal form of skin cancer, often has worse outcomes in older patients. We previously demonstrated that an age-related decrease in the secreted extracellular matrix (ECM) protein HAPLN1 has a role in slowing melanoma progression. Here we show that HAPLN1 in the dermal ECM is sufficient to maintain the integrity of melanoma-associated blood vessels, as indicated by increased collagen and VE-cadherin expression. Specifically, we show that HAPLN1 in the ECM increases hyaluronic acid and decreases endothelial cell expression of ICAM1. ICAM1 phosphorylates and internalizes VE-cadherin, a critical determinant of vascular integrity, resulting in permeable blood vessels. We found that blocking ICAM1 reduces tumor size and metastasis in older mice. These results suggest that HAPLN1 alters endothelial ICAM1expression in an indirect, matrix-dependent manner. Targeting ICAM1 could be a potential treatment strategy for older patients with melanoma, emphasizing the role of aging in tumorigenesis.

Tumor-derived exosomal ADAM17 promotes pre-metastatic niche formation by enhancing vascular permeability in colorectal cancer

BackgroundHematological metastasis has been recognized as a crucial factor contributing to the high rates of metastasis and mortality observed in colorectal cancer (CRC). Notably, exosomes derived from cancer cells participate in the formation of CRC pre-metastatic niches; however, the mechanisms underlying their effects are largely unknown. While our preliminary research revealed the role of exosome-derived disintegrin and metalloproteinase 17 (ADAM17) in the early stages of CRC metastasis, the role of exosomal ADAM17 in CRC hematogenous metastasis remains unclear.MethodsIn the present study, we isolated and purified exosomes using ultracentrifugation and identified exosomal proteins through quantitative mass spectrometry. In vitro, co-culture assays were conducted to evaluate the impact of exosomal ADAM17 on the permeability of the blood vessel endothelium. Vascular endothelial cell resistance, the cell index, membrane protein separation, flow cytometry, and immunofluorescence were employed to investigate the mechanisms underlying exosomal ADAM17-induced vascular permeability. Additionally, a mouse model was established to elucidate the role of exosomal ADAM17 in the modulation of blood vessel permeability and pre-metastatic niche formation in vivo.ResultsOur clinical data indicated that ADAM17 derived from the circulating exosomes of patients with CRC could serve as a blood-based biomarker for predicting metastasis. The CRC-derived exosomal ADAM17 targeted vascular endothelial cells, thus enhancing vascular permeability by influencing vascular endothelial cadherin cell membrane localization. Moreover, exosomal ADAM17 mediated the formation of a pre-metastatic niche in nude mice by inducing vascular leakage, thereby promoting CRC metastasis. Nonetheless, ADAM17 selective inhibitors effectively reduced CRC metastasis in vivo.ConclusionsOur results suggest that exosomal ADAM17 plays a pivotal role in the hematogenous metastasis of CRC. Thus, this protein may serve as a valuable blood-based biomarker and potential drug target for CRC metastasis intervention.

A Case Report Intravitreal Anti VEGF Bevacizumab on Patient with Hypertension Retinopathy and Exudative Retinal Detachment

Introduction : To present a case of intravitreal anti VEGF bevacizumab function on patient with hypertension retinopathy and exudative retinal detachment.
 Case Illustration : A 29 years old man presented with chief complaint blurry vision with visual acuity 1/60 on both eyes. History of hypertension sinced one year ago and already got hemodialisa treatment twice a week sinced 6 months ago. Ophthalmic examination showed decreased vision on both eyes and posterior segment both eyes we can find macular star and papil edema. Patient had diagnosed with hypertension retinopathy scheie 4 and exudative retinal detachment both eyes.
 Discussion : Hypertension will cause blood vessels to become damage in the form of sclerosis, thickening of blood vessel walls, and plasma leakage. Hypertension retinopathy acts as predictor of systemic morbidity and mortality due to organ target damage. Regulating systemic disease like blood pressure to become normal will improve clinical signs of hypertension retinopathy. Administration of anti-VEGF intravitreal injection therapy like bevacizumab can improve permeability of blood vessels in retina and decreased volume of exudate in retina. Visual acuity for this patient will improve to become 4/60 for both eyes.
 Conclusion : Uncontrolled hypertension can lead to organ target damage, which one of that was eyes. Hypertension retinopathy can make complications like exudative retinal detachment if the blood pressure still uncontrolled. Management of exudative retinal detachment caused by hypertension retinopathy was giving intravitreal anti VEGF injection in eyes to repair breakdown of blood retinal barrier, and the blood pressure must be well controlled to maintain permeability of blood retinal barrier.

Glucagon Enhances Chemotherapy Efficacy By Inhibition of Tumor Vessels in Colorectal Cancer.

Chemotherapy is widely used to treat colorectal cancer (CRC). Despite its substantial benefits, the development of drug resistance and adverse effects remain challenging. This study aimed to elucidate a novel role of glucagon in anti-cancer therapy. In a series of in vitro experiments, glucagon inhibited cell migration and tube formation in both endothelial and tumor cells. In vivo studies demonstrated decreased tumor blood vessels and fewer pseudo-vessels in mice treated with glucagon. The combination of glucagon and chemotherapy exhibited enhanced tumor inhibition. Mechanistic studies demonstrated that glucagon increased the permeability of blood vessels, leading to a pronounced disruption of vessel morphology. Signaling pathway analysis identified a VEGF/VEGFR-dependent mechanism whereby glucagon attenuated angiogenesis through its receptor. Clinical data analysis revealed a positive correlation between elevated glucagon expression and chemotherapy response. This is the first study to reveal a role for glucagon in inhibiting angiogenesis and vascular mimicry. Additionally, the delivery of glucagon-encapsulated PEGylated liposomes to tumor-bearing mice amplified the inhibition of angiogenesis and vascular mimicry, consequently reinforcing chemotherapy efficacy. Collectively, the findings demonstrate the role of glucagon in inhibiting tumor vessel network and suggest the potential utility of glucagon as a promising predictive marker for patients with CRC receiving chemotherapy.

Vasoinhibin's Apoptotic, Inflammatory, and Fibrinolytic Actions Are in a Motif Different From Its Antiangiogenic HGR Motif.

Vasoinhibin, a proteolytic fragment of the hormone prolactin, inhibits blood vessel growth (angiogenesis) and permeability, stimulates the apoptosis and inflammation of endothelial cells, and promotes fibrinolysis. The antiangiogenic and antivasopermeability properties of vasoinhibin were recently traced to the HGR motif located in residues 46 to 48 (H46-G47-R48), allowing the development of potent, orally active, HGR-containing vasoinhibin analogues for therapeutic use against angiogenesis-dependent diseases. However, whether the HGR motif is also responsible for the apoptotic, inflammatory, and fibrinolytic properties of vasoinhibin has not been addressed. Here, we report that HGR-containing analogues are devoid of these properties. Instead, the incubation of human umbilical vein endothelial cells with oligopeptides containing the sequence HNLSSEM, corresponding to residues 30 to 36 of vasoinhibin, induced apoptosis, nuclear translocation of NF-κB, expression of genes encoding leukocyte adhesion molecules (VCAM1 and ICAM1) and proinflammatory cytokines (IL1B, IL6, and TNF), and adhesion of peripheral blood leukocytes. Also, intravenous or intra-articular injection of HNLSSEM-containing oligopeptides induced the expression of Vcam1, Icam1, Il1b, Il6, and Tnf in the lung, liver, kidney, eye, and joints of mice and, like vasoinhibin, these oligopeptides promoted the lysis of plasma fibrin clots by binding to plasminogen activator inhibitor-1 (PAI-1). Moreover, the inhibition of PAI-1, urokinase plasminogen activator receptor, or NF-κB prevented the apoptotic and inflammatory actions. In conclusion, the functional properties of vasoinhibin are segregated into 2 different structural determinants. Because apoptotic, inflammatory, and fibrinolytic actions may be undesirable for antiangiogenic therapy, HGR-containing vasoinhibin analogues stand as selective and safe agents for targeting pathological angiogenesis.

Therapeutic effect of folic acid combined with decitabine on diabetic mice.

To evaluate the therapeutic effect of folic acid combined with decitabine on diabetic mice. The diabetic model of db/db mice were randomly divided into model group, folic acid group, decitabine group, folic acid combined with decitabine group, and C57 mice as normal control group. The density of retinal blood vessels and retinal thickness were detected by fundus photography and optical coherence tomography, respectively. Pathological changes of retina were observed by hematoxylin-eosin (HE) staining. The homocysteine (Hcy) in serum was detected by enzyme linked immunosorbent assay (ELISA). TdT-mediated dUTP nick-end labeling (TUNEL) was used to detect apoptosis in retinal tissue. Evans blue dye was used to detect the permeability of retinal blood vessels. The platelet endothelial cell adhesion molecule-1 (CD31) and vascular endothelial growth factor receptor (VEGFR) protein were detected by Western blot. The 3-nitrotyrosine (3-NT) and 4-hydroxynonanine (4-HNE) were detected by immunohistochemistry. The density of retinal blood vessels, retinal thickness, retinal vascular permeability and the proportion of apoptotic cells of retinal tissue in the model group increased significantly than control group (P<0.05). The Hcy in serum and the levels of CD31, VEGFR, 3-NT, and 4-HNE in retinal tissue increased significantly in the model group (P<0.01). Folic acid and decitabine both reversed these changes significantly, and the combination of the folic acid and decitabine worked best. The combination of folic acid and decitabine has a more significant protective effect on the retina in diabetic mice.

Calamity Of Secondary Dengue Virus Followed By Climatic Changes.

Madam, This is to bring your attention to a long-standing issue despite several activities devised to curb it. Being aware of the effect of drastic climatic changes, developing countries like Pakistan should remain alert about the emergence of infectious outbreaks. The stagnant water after heavy rainfall and flood is a ground for the breeding of dengue vector called Aedes aegypti mosquitoes. The virus is transmitted from one person to another through these mosquitoes. Lately, the surge in the cases of dengue virus was due to massive flooding in Pakistan in 2022. A total of 25932 cases were reported and 62 deaths were recorded during the dengue outbreak during the flood crisis of 2022[1]. Dengue virus comprises of four serotypes 1, 2, 3, and 4. A person infected by a distinct serotype of the virus gains immunity against it and future infection by the same DENV will not affect the person’s health but infection by a heterogenous serotype causes secondary infection in the form of dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS). Expansive capillary leakage in DHF due to an increase in the permeability of blood vessels can turn on a shock state called DSS. This deprivation of blood to highly functional organs like the brain, kidney, and heart puts them at risk of multi-organ failure [2]. The seasonal surge of secondary infection puts a burden on hospitals as the patient requires vigilant inpatient hospital care. The patient's health deteriorates further because of self-treatment at home with local herbs and over-the-counter (OTC) drugs [3]. As modern medicine is focused more on prevention than treatment, the need for the approval of the use of the dengue vaccine on high-risk individuals in an endemic country like Pakistan should be considered. The DENGVAXIA is a well-tolerated vaccine protecting against all the serotypes and is approved for use in individuals 9 to 45 years who are previously infected by the dengue virus in the past. [4] The vaccine will restrain the rise in DHF and DSS cases as it is for high-risk individuals who are already infected in the past thus curbing the incidence of secondary infection. Many endemic countries like the Philippines and Brazil have already taken a step against secondary dengue by granting the license of DENGVAXIA [5]. As Pakistan is developing country, approving the license for DENGVAXIA should be considered.

OR2806 Levosulpiride-Induced Hyperprolactinemia For The Treatment Of Diabetic Macular Edema: A Phase 2 Pilot Clinical Trial

Abstract Disclosure: C. Clapp: None. C.D. Núñez-Amaro: None. M. López: None. E. Adán-Castro: None. M. Robles Osorio: None. R. García-Franco: None. M. García-Roa: None. Y. Villalpando: None. P. Ramírez-Neria: None. N. Pineiro: None. J.F. Rubio-Mijangos: None. J. Sánchez: None. G. Ramirez-Hernandez: None. L. Siqueiros-Márquez: None. N. Díaz-Lezama: None. E. López-Star: None. T. Bertsch: None. G. Martínez de la Escalera: None. J. Triebel: None. Vasoinhibin is a fragment of prolactin that inhibits the permeability and growth of blood vessels. The prokinetic dopamine D2 receptor blocker, levosulpiride, elevates the circulating levels of prolactin and the accumulation of vasoinhibin in the vitreous of patients with proliferative diabetic retinopathy (PDR) (1) suggesting clinical benefits due to the vascular properties of vasoinhibin. Here, we describe the 2-month results of a phase 2 clinical trial (2) investigating the biological activity of levosulpiride in center-involving diabetic macular edema (DME). This prospective, randomized, double-masked, dual-center, placebo-controlled, pilot study was carried out in individuals (aged 40 to 69 years) with DME involving the center of the macula and best-corrected visual acuity (BCVA) between 58 and 16 ETDRS letters at 4 m (20/16 to 20/100 Snellen equivalent) or with PDR undergoing elective pars plana vitrectomy. Oral treatment (TID) with levosulpiride or placebo was for 8 weeks in DME patients or for the 1 week before vitrectomy in PDR patients. Primary outcome measures included changes from baseline in BCVA, central foveal thickness (CFT), and mean macular volume (MMV) every 2 weeks for 8 weeks in placebo- (17 patients, 18 eyes) and levosulpiride- (17 patients, 22 eyes) treated DME groups; whereas vitreous levels of vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) were primary outcomes in PDR patients after placebo (18 patients) or levosulpiride (18 patients). Starting at 4 weeks, levosulpiride improved changes from baseline in BCVA (P &amp;lt; 0.037), CFT (P &amp;lt; 0.013), and MMV (P &amp;lt; 0.002) compared to placebo. At 8 weeks, the proportion of eyes gaining &amp;gt;5 letters (41% vs. 28%), loosing &amp;gt; 21 μm in CFT (55% vs. 28%), and dropping &amp;gt; 0.06 mm3 in MMV (65% vs. 29%) were higher in levosulpiride vs placebo. The overall grading of visual (BCVA) and structural parameters (CFT, MMV, OCT macula image, fundoscopy, and fluorescein angiography) showed improvement with levosulpiride (P = 0.029). Levosulpiride reduced VEGF (P = 0.025) and PlGF (P= 0.008) levels in the vitreous of PDR patients. There were no apparent adverse side-effects. In conclusion, oral levosulpiride administration for 8 weeks improved visual and structural outcomes in patients with center involving DME by mechanisms that may include intraocular upregulation of vasoinhibin and downregulation of VEGF and PlGF. Larger clinical trials evaluating long-term efficacy and safety are warranted. Reference: (1) Núñez-Amaro et al., Transl Vis Sci Technol. 2020 Aug 17;9(9):27. (2) www.clinicaltrials.gov, ID: NCT03161652; Supported by UNAM grant 405PC. Presentation: Sunday, June 18, 2023

Endothelial Dysfunction in Cardiorenal Conditions: Implications of Endothelial Glucocorticoid Receptor-Wnt Signaling.

The endothelium constitutes the innermost lining of the blood vessels and controls blood fluidity, vessel permeability, platelet aggregation, and vascular tone. Endothelial dysfunction plays a key role in initiating a vascular inflammatory cascade and is the pivotal cause of various devastating diseases in multiple organs including the heart, lung, kidney, and brain. Glucocorticoids have traditionally been used to combat vascular inflammation. Endothelial cells express glucocorticoid receptors (GRs), and recent studies have demonstrated that endothelial GR negatively regulates vascular inflammation in different pathological conditions such as sepsis, diabetes, and atherosclerosis. Mechanistically, the anti-inflammatory effects of GR are mediated, in part, through the suppression of Wnt signaling. Moreover, GR modulates the fatty acid oxidation (FAO) pathway in endothelial cells and hence can influence FAO-mediated fibrosis in several organs including the kidneys. This review summarizes the relationship between GR and Wnt signaling in endothelial cells and the effects of the Wnt pathway in different cardiac and renal diseases. Available data suggest that GR plays a significant role in restoring endothelial integrity, and research on endothelial GR-Wnt interactions could facilitate the development of novel therapies for many cardiorenal conditions.

Interaction Between Blood Vasculatures and Lymphatic Vasculatures During Inflammation.

Physiological activity cannot be regulated without the blood and lymphatic vasculatures, which play complementary roles in maintaining the body's homeostasis and immune responses. Inflammation is the body's initial response to pathological injury and is responsible for protecting the body, removing damaged tissues, and restoring and maintaining homeostasis in the body. A growing number of researches have shown that blood and lymphatic vessels play an essential role in a variety of inflammatory diseases. In the inflammatory state, the permeability of blood vessels and lymphatic vessels is altered, and angiogenesis and lymphangiogenesis subsequently occur. The blood vascular and lymphatic vascular systems interact to determine the development or resolution of inflammation. In this review, we discuss the changes that occur in the blood vascular and lymphatic vascular systems of several organs during inflammation, describe the different scenarios of angiogenesis and lymphangiogenesis at different sites of inflammation, and demonstrate the prospect of targeting the blood vasculature and lymphatic vasculature systems to limit the development of inflammation and promote the resolution of inflammation in inflammatory diseases.

BIOL-08. RADIATION DRIVES METASTASIS IN MEDULLOBLASTOMA THROUGH AN INFLAMMATORY PROCESS

Abstract Current treatment for medulloblastoma is comprised of surgery, radiotherapy (RT) and/or chemotherapy. Although the primary tumor is controlled with this approach, recurrent metastatic disease is ubiquitously fatal. However, little is known about the biology of metastatic recurrences in medulloblastoma. In the present study, we observe across 3 non-overlapping cohorts of infant medulloblastoma that patients recur locally without focal RT and metastatically after focal RT. Using 3 independent murine flank xenograft medulloblastoma models, we found that the incidence of leptomeningeal metastasis was significantly increased in mice that received RT compared to sham controls. We have also found a significant increase in viable circulating tumor cells after RT. Our multi-omics (bulk RNA-seq, scRNA-seq and proteo/phosphoproteomics) approach using immunocompetent sporadic medulloblastoma models treated with RT showed activation of the innate inflammatory response through the overexpression of chemokines, cytokines and activation of immune cell types. In situ analysis of protein expression after RT showed a gradual increase in the abundance of macrophages, neutrophils and dendritic cells after RT, suggesting increased permeability and cell trafficking across the blood brain barrier. Applying live intravital microscopy using a low molecular weight vascular dye (150kDa), we observed a striking increase in blood vessel permeability in RT vs sham-treated brain tumors. Our observations support a model where RT drives metastasis through inflammation. To test this, we applied lipopolysaccharide (LPS), an inflammation inducing treatment, to a sporadic murine medulloblastoma model which significantly increased the metastatic burden. We then treated a xenograft model with dexamethasone in combination with RT, which resulted in total abrogation of metastatic dissemination compared to RT alone. Collectively, our findings suggest that while external beam irradiation is an effective and essential treatment for medulloblastoma, it may facilitate metastatic dissemination through an inflammation-induced process. These findings can help inform potential approaches to prevent disseminated relapsed disease.

Activin A Limits VEGF-Induced Permeability via VE-PTP.

The clinical success of neutralizing vascular endothelial growth factor (VEGF) has unequivocally identified VEGF as a driver of retinal edema that underlies a variety of blinding conditions. VEGF is not the only input that is received and integrated by the endothelium. For instance, the permeability of blood vessels is also regulated by the large and ubiquitously expressed transforming growth factor beta (TGF-β) family. In this project, we tested the hypothesis that members of the TGF-β family influence the VEGF-mediated control of the endothelial cell barrier. To this end, we compared the effect of bone morphogenetic protein-9 (BMP-9), TGF-β1, and activin A on the VEGF-driven permeability of primary human retinal endothelial cells. While BMP-9 and TGF-β1 had no effect on VEGF-induced permeability, activin A limited the extent to which VEGF relaxed the barrier. This activin A effect was associated with the reduced activation of VEGFR2 and its downstream effectors and an increased expression of vascular endothelial tyrosine phosphatase (VE-PTP). Attenuating the expression or activity of VE-PTP overcame the effect of activin A. Taken together, these observations indicate that the TGF-β superfamily governed VEGF-mediated responsiveness in a ligand-specific manner. Furthermore, activin A suppressed the responsiveness of cells to VEGF, and the underlying mechanism involved the VE-PTP-mediated dephosphorylation of VEGFR2.