PDGFRB Research Articles

A germline PDGFRB splice site variant associated with infantile myofibromatosis and resistance to imatinib

Infantile myofibromatosis is characterized by the development of myofibroblastic tumors in young children. In most cases, the disease is caused by somatic gain-of-function variants in platelet-derived growth factor (PDGF) receptor beta (PDGFRB). Here, we reported a novel germline intronic PDGFRB variant, c.2905-8G>A, in 6 unrelated infants with multifocal myofibromatosis and their relatives. We performed constitutional and tumor DNA and RNA sequencing to identify novel variants, which were subsequently characterized in cellular assays. All patients had multiple skin nodules, 4 had bone lesions, and 2 had aggressive disease with bowel obstruction. The c.2905-8G>A substitution creates an alternative acceptor splice site in intron 21, inserting 2 codons in the PDGFRB transcript. Functional studies revealed that the splice change induced a partial loss of function, contrasting with previously described variants. In 4 tumor samples, we identified a second somatic hit at position Asp850 in PDGFRB exon 18, triggering constitutive receptor activation and resistance to imatinib. In addition to vinblastine and methotrexate, 2 patients received imatinib without objective response. One of them switched to dasatinib with concomitant improvement. This splice-site PDGFRB variant favors the development of myofibroma, featuring an acquired oncogenic variant in the same gene and resistance to targeted therapy.

Stromal PDGFR-beta expression is a prognostic factor in high-grade serous ovarian cancer patients but is it also predictive for response to antiangiogenic treatment?

ObjectiveIn advanced ovarian cancer, the majority of patients receive anti-angiogenic treatment with bevacizumab. However, its use is often associated with severe side effects, and not all patients benefit from the therapy. Currently, there are no reliable biomarkers to predict response to treatment. Given their role as key regulators of angiogenesis, platelet-derived growth factor receptor-beta (PDGFR-beta) and vascular endothelial growth factor receptor-2 (VEGFR-2) are promising candidates for predictive biomarkers. This study evaluates their potential.MethodsPDGFR-beta and VEGFR-2 expression was evaluated using immunohistochemistry in a tissue microarray assay including 391 ovarian tissue samples. Correlation analyses with clinical and histopathological parameters were performed in a homogeneous cohort of 199 high grade serous ovarian cancer samples (HGSOC).ResultsIn HGSOC, strong stromal PDGFR-beta expression was associated with significantly shorter overall survival compared to weak/moderate expression. The impact of stromal PDGFR-beta expression on patient survival was however not restricted to the subgroup of patients receiving therapy with bevacizumab, and therefore cannot be considered as a predictive factor. For VEGFR-2, no or weak protein expression was found in the majority of the tumor samples. Survival analyses showed a more favorable prognosis with no or weak VEGFR-2 expression.ConclusionsHigh stromal expression levels of PDGFR-beta correlate with shorter overall survival in HGSOC. Thus, stromal PDGFR-beta might serve as a prognostic biomarker. No predictive effect in response to bevacizumab therapy could be attributed.

Novel PDGFRB Gene Fusions in Two Cases of Infantile Myofibromatosis.

Infantile myofibromatosis (IM) comprises a wide clinical spectrum, ranging from solitary or multicentric lesions to generalized life-threatening forms. IM is mostly linked to germline or somatic heterozygous mutations in the PDGFRβ tyrosine kinase, encoded by the PDGFRB gene. Treatments for IM range from wait and see approach to systemic chemotherapy, according to the clinical context. Targeted therapies, such as tyrosine kinase inhibitors (TKIs) like Imatinib, show promise in treating IM lesions with PDGFRB gain-of-function mutations. Here, we report the first evidence of two sporadic, multifocal IM with PDGFRB gene fusions. RNA sequencing analysis revealed two novel fusion transcripts involving the protein kinase domain of PDGFRB, with UBE2I and FN1 genes, respectively. Although gene fusions are frequent and potent oncogenic drivers in soft-tissue neoplasia, fusion genes involving PDGFRB have not previously been linked to IM. DNA-based NGS panel testing may not detect chromosomal rearrangements, such as translocations, emphasizing the critical role of comprehensive molecular profiling, including RNA sequencing, in diagnosing and managing children with IM.

Interleukin 8-CXCR2-mediated neutrophil extracellular trap formation in biliary atresia associated with neutrophil extracellular trap-induced stellate cell activation.

Biliary atresia (BA) entails an inflammatory sclerosing lesion of the biliary tree, with prominent fibrosis in infancy. Previous studies revealed that neutrophil-activating IL-8 and neutrophil extracellular traps (NETs) positively correlated with bilirubin and the risk of liver transplant. The aims of this study were to determine the mechanism of NET formation (NETosis) in BA and whether NETs induce stellate cell activation. BA and other liver disease control plasma and tissue were obtained at diagnosis and transplant. Elastase, NETs, and IL-8 were quantified by ELISA for plasma and by immunohistochemistry for liver tissue. FACS analysis of neutrophils co-cultured with BA or control plasma measured BA-specific NETosis. Stellate cell activation from co-culture studies of stellate cells with NETs was measured by real-time quantitative PCR, ELISA, and FACS. Liver neutrophils and NETs, and plasma elastase, NETs, and IL-8, were significantly increased in BA at diagnosis and transplant. Normal neutrophils co-cultured with BA plasma had increased NETosis and activation of CXCR2, an IL-8 receptor; CXCR2 inhibition decreased NET production. Immunohistochemistry identified increased NET expression of profibrogenic tissue factor and IL-17. NETs co-cultured with stellate cells resulted in stellate cell activation based on increased ACTA2 and COL1A1 mRNA, collagen protein, and cell surface expression of actin, collagen1A, and platelet-derived growth factor receptor-beta. Patients with BA have persistent IL-8-CXCR2-mediated NETosis that correlates with biomarkers of injury and fibrosis, and NETs induce stellate cell activation, suggesting a role for NETs in the immunopathogenesis of disease. Future investigations should focus on therapeutic agents that inhibit NETs in BA.

Cancer-type somatic mutations in saccular cerebral aneurysms.

Intracranial aneurysms (IAs) are a major cause of subarachnoidal hemorrhage (SAH) which can have a significant morbidity and mortality. The processes underlying the aneurysm development remains unclear. We performed whole exome sequencing of DNA derived from 20 saccular cerebral aneurysms of 20 patients, followed by somatic variant calling. Eleven (55%) of the 20 patients had detectable nonsynonymous somatic mutations and in total, 48 mutations were detected in the aneurysm samples. The mutations were highly enriched in cancer-related genes and 77% were predictably deleterious. A p.Tyr562Asp somatic mutation was detected in the PDGFRB gene; somatic mutations at the same codon have been reported in fusiform cerebral aneurysms. These results widen the concept on the role of somatic mutations in cerebral aneurysms, indicating their possible role in the more common saccular aneurysm, similarly to the rarer fusiform aneurysm.

Multiple allostery in the regulation of PDGFR beta kinase activities.

Platelet-derived growth factor receptor beta (PDGFRβ), a type III receptor tyrosine kinase (RTK) with a featured kinase insert, regulates important cellular functions. Dysregulation of PDGFRβ is associated with cardiovascular and fibrosis diseases. Thus, its kinase activity needs to be precisely regulated under physiological conditions. Early studies demonstrated that its kinase is autoinhibited by its juxtamembrane segment and activated by transphosphorylation. However, additional mechanisms are required for the comprehensive regulation of the receptor kinase. Herein, we provide evidence that dimerization of activated kinases, autoinhibition by the kinase insert, and dimerization of inactive kinase, all contribute to the regulation of the receptor kinase. Moreover, we find such multiple allosteric regulation is also conserved in other type III RTKs, including colony stimulating factor 1 receptor (CSF1R). Impaired allosteric regulation of CSF1R is associated with malfunctions of microglia and demyelination of neurons in hereditary diffuse leukoencephalopathy with spheroids (HDLS).

Immuno-Histochemical Analysis of PDGFRβ in OSCC: Clinical Significance and Prospects for Targeted Therapy

The most prominent and key cells in cancer development are fibroblasts, known as cancer-associated fibroblasts. Limited data available on Head and Neck Cancer showed the presence of platelet-derived growth factor receptor beta as the most prevalent marker. Furthermore, therapies can be targeted against this receptor for the treatment of cancer. Objectives: To evaluate the expression of Platelet-derived growth factor receptor beta as a specific marker of cancer-associated fibroblasts in different grades of oral squamous cell carcinoma through immunohistochemistry. Methods: This descriptive study included 51 cases of squamous cell carcinoma of the head and neck region. Platelet-derived growth factor receptor beta expression was assessed based on the extent and intensity of immune-labelling in a tumor. SPSS was used to determine the association between the grade of tumor and Platelet-derived growth factor receptor beta expression. Results: Mean age was found as 53.65 + 17.15 years and there were 30 (58.8%) male and 21 (41.2%) female. The most commonly affected sites were glottis and supra-glottis areas accounting for 18.9% of total cases followed by the tongue which accounts for 13.2% of cases. The majority of the patients 34 (66.7%) patients had an intermediate grade of squamous cell carcinoma. In most cases, the degree of staining was strongest, with intermediate-grade tumors exhibiting the highest platelet-derived growth factor receptor beta staining. Conclusions: It was concluded that platelet-derived growth factor receptor beta emerges as a promising tumor marker in head and

PDGFRB promotes dedifferentiation and pulmonary metastasis through rearrangement of cytoskeleton under hypoxic microenvironment in osteosarcoma

Osteosarcoma (OS) cells commonly suffer from hypoxia and dedifferentiation, resulting in poor prognosis. We plan to identify the role of hypoxia on dedifferentiation and the associated cellular signaling. We performed sphere formation assays and determined spheroid cells as dedifferentiated cells by detecting stem cell-like markers. RNAi assay was used to explore the relationship between hypoxia inducible factor 1 subunit alpha (HIF1A) and platelet derived growth factor receptor beta (PDGFRB). We obtained PDGFRB knockdown and overexpression cells through lentiviral infection experiments and detected the expression of PDGFRB, p-PDGFRB, focal adhesion kinase (FAK), p-FAK, phosphorylated myosin light chain 2 (p-MLC2), and ras homolog family member A (RhoA) in each group. The effects of PDGFRB on cytoskeleton rearrangement and cell adhesion were explored by immunocytochemistry. Wound-healing experiments, transwell assays, and animal trials were employed to investigate the effect of PDGFRB on OS cell metastasis both in vitro and in vivo. Dedifferentiated OS cells were found to exhibit high expression of HIF1A and PDGFRB, and HIF1A upregulated PDGFRB, subsequently activated RhoA, and increased the phosphorylation of MLC2. PDGFRB also enhanced the phosphorylation of FAK. The OS cell morphology and vinculin distribution were altered by PDGFRB. PDGFRB promoted cell dedifferentiation and had a significant impact on the migration and invasion abilities of OS cells in vitro. In addition, PDGFRB increased pulmonary metastasis of OS cells in vivo. Our results demonstrated that HIF1A up-regulated PDGFRB under hypoxic conditions, and PDGFRB regulated the actin cytoskeleton, a process likely linked to the activation of RhoA and the phosphorylation of, thereby promoting OS dedifferentiation and pulmonary metastasis.

Neurovascular unit, neuroinflammation and neurodegeneration markers in brain disorders.

Neurovascular unit (NVU) inflammation via activation of glial cells and neuronal damage plays a critical role in neurodegenerative diseases. Though the exact mechanism of disease pathogenesis is not understood, certain biomarkers provide valuable insight into the disease pathogenesis, severity, progression and therapeutic efficacy. These markers can be used to assess pathophysiological status of brain cells including neurons, astrocytes, microglia, oligodendrocytes, specialized microvascular endothelial cells, pericytes, NVU, and blood-brain barrier (BBB) disruption. Damage or derangements in tight junction (TJ), adherens junction (AdJ), and gap junction (GJ) components of the BBB lead to increased permeability and neuroinflammation in various brain disorders including neurodegenerative disorders. Thus, neuroinflammatory markers can be evaluated in blood, cerebrospinal fluid (CSF), or brain tissues to determine neurological disease severity, progression, and therapeutic responsiveness. Chronic inflammation is common in age-related neurodegenerative disorders including Alzheimer's disease (AD), Parkinson's disease (PD), and dementia. Neurotrauma/traumatic brain injury (TBI) also leads to acute and chronic neuroinflammatory responses. The expression of some markers may also be altered many years or even decades before the onset of neurodegenerative disorders. In this review, we discuss markers of neuroinflammation, and neurodegeneration associated with acute and chronic brain disorders, especially those associated with neurovascular pathologies. These biomarkers can be evaluated in CSF, or brain tissues. Neurofilament light (NfL), ubiquitin C-terminal hydrolase-L1 (UCHL1), glial fibrillary acidic protein (GFAP), Ionized calcium-binding adaptor molecule 1 (Iba-1), transmembrane protein 119 (TMEM119), aquaporin, endothelin-1, and platelet-derived growth factor receptor beta (PDGFRβ) are some important neuroinflammatory markers. Recent BBB-on-a-chip modeling offers promising potential for providing an in-depth understanding of brain disorders and neurotherapeutics. Integration of these markers in clinical practice could potentially enhance early diagnosis, monitor disease progression, and improve therapeutic outcomes.

Suppressing PDGFRβ Signaling Enhances Myocyte Fusion to Promote Skeletal Muscle Regeneration.

Muscle cell fusion is critical for forming and maintaining multinucleated myotubes during skeletal muscle development and regeneration. However, the molecular mechanisms directing cell-cell fusion are not fully understood. Here, we identify platelet-derived growth factor receptor beta (PDGFRβ) signaling as a key modulator of myocyte fusion in adult muscle cells. Our findings demonstrate that genetic deletion of Pdgfrβ enhances muscle regeneration and increases myofiber size, whereas PDGFRβ activation impairs muscle repair. Inhibition of PDGFRβ activity promotes myonuclear accretion in both mouse and human myotubes, whereas PDGFRβ activation stalls myotube development by preventing cell spreading to limit fusion potential. Transcriptomics analysis show that PDGFRβ signaling cooperates with TGFβ signaling to direct myocyte size and fusion. Mechanistically, PDGFRβ signaling requires STAT1 activation, and blocking STAT1 phosphorylation enhances myofiber repair and size during regeneration. Collectively, PDGFRβ signaling acts as a regenerative checkpoint and represents a potential clinical target to rapidly boost skeletal muscle repair.

Identification of potential bioactive phytochemicals for the inhibition of platelet-derived growth factor receptor β: a structure-based approach for cancer therapy.

Platelet-derived growth factor receptor beta (PDGFRβ) belongs to the receptor tyrosine kinase (RTK) protein family and is implicated in several disorders such as hematopoietic, glial, and soft-tissue cancer, non-cancerous disorders, including skeletal defects, brain calcification, and vascular anomalies. The research on small molecule inhibitors targeting PDGFRβ in cancer treatment has seen promising developments, but significant gaps remain. PDGFRβ, receptor tyrosine kinase, is overexpressed in various cancers and plays an important role in tumor progression, making it a potential therapeutic target. However, despite advances in identifying and characterizing PDGFRβ inhibitors, few have progressed to clinical trials, and the mechanistic details of PDGFRβ's interactions with small molecule inhibitors are still not fully understood. Moreover, the specificity and selectivity of these inhibitors remain challenging, as off-target effects can lead to unwanted toxicity. In this investigation, two compounds, Genostrychnine and Chelidonine, were discovered that help inhibit the kinase activity of PDGFRβ. These small molecules were identified by employing various parameters involved in the drug discovery process, such as Lipinski's rule of five (RO5), 2D similarity search and 3D pharmacophore-based virtual screening followed by MD simulation studies. The identified molecules were found to be effective and significantly bound with the PDGFRβ kinase domain. Overall, our findings demonstrate that these small drug-like compounds can be beneficial tools in studying the properties of PDGFRβ and can play a crucial role in the therapeutic development of cancers and other associated diseases.

Galectin-3 inhibition reduces fibrotic scarring and promotes functional recovery after spinal cord injury in mice

BackgroundIn the context of spinal cord injury (SCI), infiltrating macrophages assume prominence as the primary inflammatory cells within the lesion core, where the fibrotic scar is predominantly orchestrated by platelet-derived growth factor receptor beta (PDGFRβ+) fibroblasts. Galectin-3, a carbohydrate-binding protein of the lectin family, is notably expressed by infiltrating hematogenous macrophages and mediates cell-cell interactions. Although Galectin-3 has been shown to contribute to the endocytic internalization of PDGFRβ in vitro, its specific role in driving fibrotic scar formation after SCI has not been determined.MethodsWe employed a crush mid-thoracic (T10) SCI mouse model. Galectin-3 inhibition after SCI was achieved through intrathecal injection of the Galectin-3 inhibitor TD139 or in situ injection of lentivirus carrying Galectin-3-shRNA (Lv-shLgals3). A fibrosis-induced mice model was established by in situ injection of platelet-derived growth factor D (PDGFD) or recombinant Galectin-3 (rGalectin-3) into the uninjured spinal cord. Galectin-3 internalization experiments were conducted in PDGFRβ+ fibroblasts cocultured in conditioned medium in vitro.ResultsWe identified the spatial and temporal correlation between macrophage-derived Galectin-3 and PDGFRβ in fibroblasts from 3 to 56 days post-injury (dpi). Administration of TD139 via intrathecal injection or in situ injection of Lv-shLgals3 effectively mitigated fibrotic scar formation and extracellular matrix deposition within the injured spinal cord, leading to better neurological outcomes and function recovery after SCI. Furthermore, the fibrosis-inducing effects of exogenous PDGFD in the uninjured spinal cord could be blocked by TD139. In vitro experiments further demonstrated the ability of PDGFRβ+ fibroblasts to internalize Galectin-3, with Galectin-3 inhibition resulting in reduced PDGFRβ expression.ConclusionsOur finding underscores the pivotal role of macrophage-derived Galectin-3 in modulating the sustained internalized activation of PDGFRβ within fibroblasts, providing a novel mechanistic insight into fibrotic scarring post-SCI.

A-170 Hypereosinophilic Syndrome and t(5;15): Case Report and Literature Review

Abstract Background Hypereosinophilic syndrome (HES) is a myeloproliferative disorder characterized by persistent eosinophilia (absolute eosinophil count >1,500/mm3), classified into primary/clonal, reactive and idiopathic. After ruling out secondary causes of eosinophilia (parasitic infections, allergic conditions, vasculitis and collagenosis, drugs, eosinophilic lung disease, allergic gastroenteritis and metabolic conditions such as adrenal insufficiency), the main hypotheses become oncohematological diseases. Main entities to consider are myeloid/lymphoid neoplasms associated with eosinophilia and rearrangement of PDGFRA, FDGFRB, FGFR1 or PCM1-JAK2 and chronic eosinophilic leukemia. Conventional and molecular cytogenetics are the basis for classification and diagnosis of various hematological malignancies. This report describes a rare case of HES with t(5;15) (q33;q22). Methods A 29-year-old male patient was admitted with leukocytosis with the following exams: hemoglobin 6.5g/dL, hematocrit 21.7%, platelets 71,000/mm3, leukocytes 56,190/mm3 (60% neutrophils with a left shift to pro-myelocyte; 6% monocytes and 24% eosinophils), DHL 277 U/L, B12 vitamin 932 pg/mL, folic acid 1.72ng/mL, ferritin 913ng/mL. Non-reactive results were detected for antinuclear antibody, rheumatoid Factor, HIV, hepatitis B and C, syphilis and chagas disease. Bone marrow was hypercellular for age with absolute granulocytic predominance (G:E ratio 64:1) and eosinophilia (38%) in all maturational stages without dysplasia. Bone marrow flow cytometry did not detect neither increases in blasts nor anomalous immunophenotype. Bone marrow biopsy demonstrated 99% cellularity with normal blasts. Cytogenetics with translocation between the long arms of chromosome 5 and 15 in 15 of 20 metaphases analyzed - 46,XY,t(5;15)(q33;q22). No other molecular tests were available for this patient. Results In the case described t(5;15)(q33;q22) was found, which may be related to the TP53BP1::PDGFRB gene rearrangement. This breakpoint generates a chimeric oncoprotein similar to other tyrosine kinase fusions responsive to Imatinib. 53BP1 is a cellular DNA damage response component that binds wild type (non-mutant) p53. Oncogenesis occurs since the coiled-coil domains of TP53BP1 can mediate the homodimerization of PDGFRB and the constitutive activation of its tyrosine kinase activity; on the other hand, the DNA damage response of TP53BP1 may be disrupted. Gene rearrangements involving PDGFRA and FDGFRB are associated with response to tyrosine kinase inhibitors. Elevated vitamin B12 is a common finding in myeloproliferations with eosinophilia due to the increased production of haptocorrins, which binds to vitamin B12 in serum and in other tissues. Conclusions To our knowledge, in the literature there is only one described case of Myeloproliferative Neoplasia with Eosinophilia related to t(5;15)(q33;q22).

The effectiveness of edible bird's nest in lowering VEGF, CD31, and PDGFR-β levels in diabetic retinopathy in rats with type 1 diabetes.

Diabetic eye disease, known as diabetic retinopathy (DR), is one of the problems that can arise from having high blood sugar for an extended period. This study aimed to investigate the effect of the edible bird's nest (EBN) on retinal angiogenesis in diabetic rats. The 50 rats were separated into five different groups, each containing 10 rats: control, diabetes (DM), bird's nest-fed diabetes (75 mg/kg Body weight; BW), (EBN 75), (150 mg/kg BW) (EBN 150), and glyburide (GR) for an eight-week study. H&E and Masson's trichrome staining were utilized to investigate the retinal tissue and vascular changes. The immunofluorescence study was used to detect angiogenic protein expression. The vascular corrosion cast/SEM method was also used to evaluate capillary plexus formation within the retinal layer. From histological studies, DM rats have thinning of the retinal layer. Remarkably, the retinal vessels displayed dilations resembling ruptured blood vessels. The expression of vascular endothelial growth factor (VEGF) (30.51±2.62), cluster of differentiation 31 (CD31) (28.18±0.22), and platelet-derived growth factor receptor beta (PDGFR-β) (141.67±0.97) were increased. EBN 75 exhibited some small improvements in their blood vessels and eye tissue. At a dose of 150 mg/kg BW, EBN proved to be more effective. There was a significant decrease in VEGF and CD31 expression compared with the diabetic group (p<0.001 and p<0.01, respectively). These studies have demonstrated that EBN can lower the growth levels of VEGF, CD31, and PDGFR-β, which results in a decrease in angiogenesis and a recovery from a variety of diabetic retinopathy-related diseases.

The Value of PDGFRβ-Based Score in Predicting Liver Fibrosis Stage in Egyptian Patients with NAFLD and Viral Liver Disease

Abstract Background Multiple therapeutic efforts have focused on Platelet Derived Growth Factor Receptor beta (PDGFRB) because of its association with hepatic stellate cell activation in liver fibrosis. Yet, its potential as a diagnostic tool is essentially unexplored. Objective This research was done to assess the value of the sPDGFRβ based-score in predicting liver fibrosis stages in Egyptian patients with NAFLD and viral liver disease in correlation with NAFLD fibrosis score and Fibro-scan. Methods In this case-control study, patients with liver fibrosis/cirrhosis related to viral hepatitis and non-alcoholic fatty liver disease (NAFLD) were categorized according to the degree of fibrosis detected by Fibro-scan, and their circulating PDGFRB levels were compared. The diagnostic roles of PDGFRβ as an individual blood parameter or combined with other metabolic parameters were assessed and compared to previously validated clinical fibrosis scores Fib-4, APRI, and AST/ALT ratio in both groups of patients and to NAFLD fibrosis score in NAFLD patients. Findings Patients with advanced fibrosis showed the greatest rise in sPDGFRB compared to those with absent or mild fibrosis. Combining sPDGFRB-levels with platelet counts and albumin levels into a new diagnostic algorithm, the PRTA-score, improved the accuracy of sPDGFRB-levels in predicting fibrosis; the score generated a predictive value that was higher than Fib-4, APRI, and AST/ALT in NAFLD and viral liver disease, and higher than the NAFLD fibrosis score in the NAFLD group. Finally, we used case-control research to verify the diagnostic significance of sPDGFRB levels and the PRTA-score in identifying severe liver fibrosis in NAFLD and viral hepatitis. Interpretation This research concluded that patients with viral hepatitis and non-alcoholic fatty liver disease (NAFLD).may benefit from the PRTA-score since it is an effective method for diagnosing advanced liver fibrosis

Abstract P435: PROTEIN KINASE MODULATION IN THE INVESTIGATION OF ANGIOTENSIN-CONVERTING ENZYME AS A SIGNALING PATHWAY.

The Renin-Angiotensin System (RAS) is a hormonal cascade intricately involved in regulating hydro electrolyte homeostasis and blood pressure control. The Angiotensin II peptide (ANGII) is the main and most potent biologically active product within this system, which is produced by the action of Angiotensin Converting Enzyme (ACE) on Angiotensin I. Dysregulation of the RAS is an important factor in the pathogenesis and progression of cardiovascular diseases and diabetes. Furthermore, ACE inhibitors (iECA) havebeen associated with the activation of signaling pathways, thus implicating ACE as a signal transducer molecule. This study aims to elucidate the significance of signaling pathways triggered by ACE and proteins that are differentially regulated when CHO-ECA cells are stimulated with ACE inhibitors. At approximately 80% confluency, the cells were deprived of serum and then stimulated with captopril (1μM) or enalapril (1μM) or vehicle for 2 and 5 minutes (n=10 in each group), to discerning the influence of sulfhydryl and carboxyl radicals. CHO-ECA cells were cultured for Kinase Array assay analysis using the Phospho-kinase Array Kit. This assay demonstrated that some pathways were positively modulated after captopril treatment after 2 minutes (AMPKa1, HSP27, Akt 1/2/3 T308) and after 5 (STATa/b, HSP60, b-Catenin). Some kinases were negatively modulated by captopril treatment (p53, PLC-γ1, Pyk2, eNOS). Conversely, treatment with enalapril modulated proteins differently at both treatment times. Some phospho-protein kinases were positively modulated in 2 minutes, such as PLC γ1, PYK2, and Yes, and others were positively modulated in 5 minutes (EGFR, GSK-3α/β, Lyn, PDGF Rβ, STAT 5a/b, WNK1 and STAT3 S2). The kinases AKT 1/2/3 T308, AKT 1/2/3 S743, CREB, Chk-2, c-Jun, JNK1/2/3, Lck, p38α, STAT3 Y705, β-Catenin were positively modulated in 2 and 5 minutes. The kinases eNOS, ERK1/2, GSK-3β, HSP27, p53 S15, p53 S46, MSK1/2, p70 S6 T389, p70 S6 T421/S424, PRAS40, Src, RSK1/2, RSK1/2/3, STAT1 and HSP60 were negatively modulated at 2 and 5 minutes. In conclusion, our findings augmented the current understanding of kinases modulated by captopril or enalapril, after ACE binding, highlighting the multifaceted role of ACE. Therefore, it can suggest that ACE may be a candidate to act not only as an enzyme but also as a signaling receptor and transducer protein.

Single-cell analysis reveals the implication of vascular endothelial cell-intrinsic ANGPT2 in human intracranial aneurysm.

While previous single-cell RNA sequencing (scRNA-seq) studies have attempted to dissect intracranial aneurysm (IA), the primary molecular mechanism for IA pathogenesis remains unknown. Here, we uncovered the alterations of cellular compositions, especially the transcriptome changes of vascular endothelial cells (ECs), in human IA. We performed scRNA-seq to compare the cell atlas of sporadic IA and the control artery. The transcriptomes of 43,462 cells were profiled for further analysis. In general, IA had increased immune cells (T/NK cells, B cells, myeloid cells, mast cells, neutrophils) and fewer vascular cells (ECs, vascular smooth muscle cells and fibroblasts). Based on the obtained high-quantity and high-quality EC data, we found genes associated with angiogenesis in ECs from IA patients. By EC-specific expression of candidate genes in vivo, we observed the involvement of angpt2a in causing cerebral vascular abnormality. Furthermore, an IA zebrafish model mimicking the main features of human IA was generated through targeting pdgfrb gene, and knockdown of angpt2a alleviated the vascular dilation in the IA zebrafish model. By performing a landscape view of the single-cell transcriptomes of IA and the control artery, we contribute to a deeper understanding of the cellular composition and the molecular changes of ECs in IA. The implication of angiogenic regulator ANGPT2 in IA formation and progression, provides a novel potential therapeutical target for IA interventions.

The utility of pentraxin 3 and platelet-derived growth factor receptor beta as non-invasive biomarkers for prediction of cardiovascular risk in MAFLD patients

BackgroundMetabolic-associated fatty liver disease (MAFLD) has emerged as the predominant form of chronic liver disease globally linked with heightened cardiovascular disease (CVD) risk, the leading cause of mortality among affected individuals.AimThis study aims to assess serum PTX3 (pentraxin 3) and platelet-derived growth factor receptor beta (PDGFRβ) as potential non-invasive biomarkers for predicting cardiovascular risk (CVR) in MAFLD patients.MethodA case–control investigation encompassing 84 MAFLD patients without prior CVD history and 30 age- and gender-matched healthy controls was conducted. Both cohorts underwent comprehensive laboratory and radiological evaluations. CVR was evaluated through common carotid artery intima-media thickness (IMT), Framingham risk score, and QRISK 2 score. The efficacy of two ELISA biomarkers PTX3 and PDGFRβ was examined for correlation with CVR in MAFLD patients.ResultsMAFLD patients displayed significantly heightened levels of PTX3 and PDGFβ compared to healthy controls (P < 0.001, P = 0.016, respectively). PDGFβ exhibited a notably positive correlation with the Framingham score (P = 0.016), while no significant correlation was observed with pentraxin 3 (P = 0.061). Univariate and multivariate analyses identified diabetes mellitus (DM) (P < 0.001*), hypertension (P = 0.005), visceral fat (P < 0.001*), waist/hip circumference (P = 0.04), and PDGFβ (P = 0.03) as robust predictors of CVR, with PTX3 demonstrating limited prognostic utility.ConclusionPDGFβ emerged as a promising early non-invasive predictor of CVR in MAFLD patients, highlighting its potential role in guiding tailored preventive interventions, while PTX3 exhibited a modest impact warranting further investigation.

Assessing blood-brain barrier dysfunction and its association with Alzheimer’s pathology, cognitive impairment and neuroinflammation

BackgroundBlood-brain barrier (BBB) alterations may contribute to AD pathology through various mechanisms, including impaired amyloid-β (Aβ) clearance and neuroinflammation. Soluble platelet-derived growth factor receptor beta (sPDGFRβ) has emerged as a potential biomarker for BBB integrity. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) offers a direct assessment of BBB permeability. However, the relationship between BBB dysfunction, cognitive impairment, and AD pathology remains unclear, with inconsistent findings in the literature.MethodsWe conducted a cross-sectional study using data from the DELCODE and DESCRIBE cohorts to investigate BBB dysfunction in participants with normal cognition (NC), mild cognitive impairment (MCI), and AD dementia. BBB function was assessed using DCE-MRI and sPDGFRβ levels in cerebrospinal fluid and AD biomarkers Aβ and tau were measured. In a subset of patients, the CSF/plasma-ratio of albumin (QAlb) as a standard marker of BBB integrity and markers of neuroinflammation were analyzed.Results91 participants (NC: 44, MCI: 21, AD: 26) were included in the analysis. The average age was 74.4 years, 42% were female. Increased hippocampal BBB disruption was observed in the AD-group (Ktrans: 0.55 × 10− 3 min− 1 ± 0.74 × 10− 3 min− 1) but not the MCI-group (Ktrans: 0.177 × 10− 3 min− 1 ± 0.22 × 10− 3 min− 1), compared to the NC group (Ktrans: 0.19 × 10− 3 min− 1 ± 0.37 × 10− 3 min− 1, p < .01). sPDGFRβ was not significantly different between the cognitive groups. However, sPDGFRβ levels were significantly associated with age (r = .33, p < .01), independent of vascular risk factors. Further, sPDGFRβ showed significant positive associations with soluble Aβ levels (Aβ40: r = .57, p < .01; Aβ42: r = .39, p < .01) and YKL-40 (r = .53, p < .01), a marker of neuroinflammation. sPDGFRβ/DCE-MRI was not associated with overall AD biomarker positivity or APOE-status.ConclusionIn dementia, but not MCI, hippocampal BBB disruption was observed. sPDGFRβ increased with age and was associated with neuroinflammation independent of cognitive impairment. The association between Aβ and sPDGFRβ may indicate a bidirectional relationship reflecting pericytes’ clearance of soluble Aβ and/or vasculotoxic properties of Aβ.

Remodeling of tumor microenvironment by extracellular matrix protein 1a differentially regulates ovarian cancer metastasis

We previously reported that extracellular matrix protein 1 isoform a (ECM1a) promotes epithelial ovarian cancer (EOC) through autocrine signaling by binding to cell surface receptors αXβ2. However, the role of ECM1a as a secretory molecule in the tumor microenvironment is rarely reported. In this study, we constructed murine Ecm1-knockout mice and human ECM1a-knockin mice and further generated orthotopic or peritoneal xenograft tumor models to mimic the different metastatic stages of EOC. We show that ECM1a induces oncogenic metastasis of orthotopic xenograft tumors, but inhibits early-metastasis of peritoneal xenograft tumors. ECM1a remodels extracellular matrices (ECM) and promotes remote metastases by recruiting and transforming bone marrow mesenchymal stem cells (BMSCs) into platelet-derived growth factor receptor beta (PDGFRβ+) cancer-associated fibroblasts (CAFs) and facilitating the secretion of angiopoietin-like protein 2 (ANGPTL2). Competing with ECM1a, ANGPTL2 also binds to integrin αX through the P1/P2 peptides, resulting in negative effects on BMSC differentiation. Collectively, this study reveals the dual functions of ECM1a in remodeling of TME during tumor progression, emphasizing the complexity of EOC phenotypic heterogeneity and metastasis.