Vascular Research Articles

Study on the antihypertensive mechanism of acupuncture at "Renying" (ST9) and "Zusanli" (ST36) via gastrin/cholecystokinin B receptors

To observe the effect of acupuncture on serum gastrin content and urinary sodium excretion in spontaneously hypertensive rat (SHR), so as to explore its potential mechanism in the treatment of hypertension. Thirty-two male SHRs were randomly divided into model, hydrochlorothiazide, acupuncture and sham acupuncture groups, with 8 rats in each group, and 8 male Wistar-kyoto rats were taken as the control group. Rats in the hydrochlorothiazide group received gavage of hydrochlorothiazide solution (10 mg·kg-1·d-1), once daily for 4 weeks. Acupuncture was applied to bilateral "Renying" (ST9) and "Zusanli" (ST36) or non-acupoint on both sides for rats in the acupuncture and sham acupuncture groups, with manual stimulation every 10 minutes for a total of 20 minutes, once a day for a total of 4 weeks. The systolic blood pressure of the tail-artery was measured before and 1, 2, 3, and 4 weeks after the intervention. HE staining was used to observe the pathological changes in renal tissue. Serum gastrin contents were detected using enzyme-linked immunosorbent assay (ELISA). Urinary sodium content was measured by atomic absorption spectrometry. The expression levels of cholecystokinin B receptor (CCKBR) and Na+/K+-ATPase proteins in renal tissue were detected by Western blot, and the mRNA expression levels of CCKBR and the α1 subunit of Na+/K+- ATPase (ATP1A1) were detected by fluorescence quantitative PCR. Compared with the control group, the systolic blood pressure of the tail artery in the model group were increased significantly before intervention and at the 1st, 2nd, 3rd and 4th weeks of intervention (P<0.05). Before intervention, the 24 h urine volume of the model, hydrochlorothiazide, acupuncture and sham acupuncture groups were decreased significantly (P<0.05). After intervention, the 24 h urine volume and urinary sodium excretion in the model group were significantly decreased (P<0.05)；the expression levels of CCKBR protein and mRNA in renal tissue were significantly decreased (P<0.05)；the expression levels of Na+/K+-ATPase protein and ATP1A1 mRNA were significantly increased (P<0.05)；the glomerulus was mildly congested with a small amount of lymphocyte infiltration. Compared with the model group, the systolic blood pressure of the tail artery in the hydrochlorothiazide and the acupuncture groups were decreased significantly at the 2nd, 3rd and 4th weeks of intervention (P<0.05)；the 24 h urine volume and urinary sodium excretion in the hydrochlorothiazide and the acupuncture groups were significantly increased (P<0.05)；the serum gastrin content and the expression levels of CCKBR protein and mRNA in renal tissue were significantly increased (P<0.05)；the expression levels of Na+/K+-ATPase protein and ATP1A1 mRNA were significantly decreased (P<0.05)；there were no obvious pathological changes in renal tissue. A small number of lymphocyte focal infiltration around blood vessels was observed in the kidney tissue of the sham acupuncture group. Acupuncture can significantly reduce the tail artery systolic blood pressure of SHR, which may be related to its effect in increasing serum gastrin content and CCKBR expression, inhibiting sodium pump reabsorption, thus promoting urinary sodium excretion.

A Study on Lymph Node Distribution in the Main Lymph Node Area for Left-sided Colon Cancer.

In advanced left-sided colorectal cancer, cutting the root of the inferior mesenteric artery (IMA) branching from the aorta is recommended for complete lymph node dissection. However, this procedure sometimes causes severe complications. This study aimed to elucidate the lymph nodes' distribution around the IMA and identify the most critical sites for lymph node dissection. This study included 30 consecutive patients with left-sided colorectal cancer who underwent curative resection with main lymph node dissection in a single institution between January and June of 2022. The mesenteric sections (main lymph nodes, IMA, left colic artery [LCA], and inferior mesenteric vein) were removed from the surgically excised specimen. Subsequently, whole-tissue sections were prepared and stained with hematoxylin and eosin. The positional relationships between each blood vessel and respective lymph nodes were then assessed using the pathological findings. The main lymph nodes were identified in 26 out of 30 patients. The total number of dissected lymph nodes per patient was 0-30 (average: 5.3), and the median distance from the IMA to the main lymph node was 7.61 mm (1.87-43.26 mm). Dividing the lymph nodes into segments, we found 18%, 46%, and 36% of the lymph nodes in the proximal, middle, and distal segments, respectively. Additionally, all lymph nodes were found outside of the IMA sheath surrounding each arterial wall. In left-sided colorectal cancer, the main lymph nodes are mostly located around the LCA bifurcation, which may be essential to ensure main lymph node dissection for advanced stage cases.

Cellular Characteristics and Protein Signatures of Human Adipose Tissues from Donors With or Without Advanced Coronary Artery Disease

Background/Objectives: Perivascular adipose tissue (PVAT) exerts a paracrine effect on blood vessels and our objective was to understand PVAT molecular signatures related to cardiovascular disease. Methods: We studied two groups: those undergoing mitral valve repair/replacement (VR, n = 16) and coronary artery bypass graft (CABG, n = 38). VR donors did not have coronary artery disease, whereas CABG donors had advanced coronary artery disease. Clinical and tissue pathologies and proteomics from adipose tissue were assessed. Results: Donors undergoing VR had a lower body mass index (p = 0.01), HbA1C (p = 0.0023), and incidence of diabetes (p = 0.022) compared to CABG. VR donors were overall healthier, with higher cardiac function compared to CABG donors, based on ejection fraction. Although adipose histopathology between groups was not markedly different, PVAT had smaller and more adipocytes compared to subcutaneous adipose tissues. These differences were validated by whole specimen automated morphological analysis, and anisotropy analysis showed small (2.8–7.5 μm) and large (22.8–64.4 μm) scale differences between perivascular and subcutaneous adipose tissue from CABG donors, and small scale changes (2.8–7.5 μm) between perivascular and subcutaneous adipose tissue from VR donors. Distinct protein signatures in PVAT and subcutaneous adipose tissue include those involved in secretion, exosomes and vesicles, insulin resistance, and adipocyte identity. Comparing PVAT and subcutaneous adipose tissue from CABG donors, there were 82 significantly different proteins identified with log fold change ≥ 0.3 or ≤−0.3 (p &lt; 0.05). Using this threshold, there were 36 differences when comparing PVAT and subcutaneous adipose tissue from VR donors, 58 differences when comparing PVAT from CABG or VR donors, and 55 when comparing subcutaneous adipose tissue from CABG vs. VR donors. Conclusions: Routine histopathology cannot differentiate between PVAT from donors with or without coronary artery disease, but multiscale anisotropy analysis discriminated between these populations. Our mass spectrometry analysis identified a cohort of proteins that distinguish between adipose depots, and are also associated with the presence or absence of coronary artery disease.

Enhancing bevacizumab efficacy in a colorectal tumor mice model using dextran-coated albumin nanoparticles.

Bevacizumab is a monoclonal antibody (mAb) that prevents the growth of new blood vessels and is currently employed in the treatment of colorectal cancer (CRC). However, like other mAb, bevacizumab shows a limited penetration in the tumors, hampering their effectiveness and inducing adverse reactions. The aim of this work was to design and evaluate albumin-based nanoparticles, coated with dextran, as carriers for bevacizumab in order to promote its accumulation in the tumor and, thus, improve its antiangiogenic activity. These nanoparticles (B-NP-DEX50) displayed a mean size of about 250nm and a payload of about 110µg/mg. In a CRC mice model, these nanoparticles significantly reduced tumor growth and increased tumor doubling time, tumor necrosis and apoptosis more effectively than free bevacizumab. At the end of study, bevacizumab plasma levels were higher in the free drug group, while tumor levels were higher in the B-NP-DEX50 group (2.5-time higher). In line with this, the biodistribution study revealed that nanoparticles accumulated in the tumor core, potentially improving therapeutic efficacy while reducing systemic exposure. In summary, B-NP-DEX can be an adequate alternative to improve the therapeutic efficiency of biologically active molecules, offering a more specific biodistribution to the site of action.

Vascular and nerve biomarkers in thigh skin biopsies differentiate painful from painless diabetic peripheral neuropathy

BackgroundIdentifying distinct mechanisms and biomarkers for painful diabetic peripheral neuropathy (DPN) is required for advancing the treatment of this major global unmet clinical need. We previously provided evidence in calf skin biopsies that disproportion between reduced sensory small nerve fibers and increased blood vessels may distinguish painful from non-painful DPN. We proposed that overexposure of the reduced nerve fibers in DPN to increased hypoxemia-induced vasculature and related algogenic factors, e.g., nerve growth factor (NGF), leads to neuropathic pain. To further investigate this proposed mechanism, we have now studied more proximal thigh skin biopsies, to see if the same disproportion between increased vasculature and decreased nerve fibers generally differentiates painful DPN from painless DPN.MethodsA total of 28 subjects with type 2 diabetes (T2DM) and 13 healthy volunteers (HV) underwent detailed clinical and neurophysiological assessments, based on the neuropathy composite score of the lower limbs [NIS(LL)] plus 7 tests. T2DM subjects were subsequently divided into three groups: painful DPN (n = 15), painless DPN (n = 7), and no DPN (n = 6). All subjects underwent skin punch biopsy from the upper lateral thigh 20 cm below the anterior iliac spine.ResultsSkin biopsies showed decreased PGP 9.5-positive intraepidermal nerve fiber (IENF) density in both painful DPN (p &amp;lt; 0.0001) and painless DPN (p = 0.001). Vascular marker von Willebrand Factor (vWF) density was markedly increased in painful DPN vs. other groups, including painless DPN (p = 0.01). There was a resulting significant decrease in the ratio of intraepidermal nerve fiber density to vasculature and PGP9.5 to vWF, in painful DPN vs. painless DPN (p = 0.05). These results were similar in pattern to those observed in these HV and T2DM groups previously in distal calf biopsies; however, the increase in vWF was much higher and nerve fiber density much lower in the calf than thigh for painful DPN. Thigh skin vWF density was significantly correlated with several metabolic (waist/hip ratio, HbA1c), clinical (e.g., pain score), and neurophysiological measures.ConclusionThis study supports our proposal that increased dermal vasculature, and its disproportionate ratio to reduced nociceptors, may help differentiate painful DPN from painless DPN. This disproportion is greater in the distal calf than the proximal thigh skin; hence, neuropathic pain in DPN is length-dependent and first localized to the distal lower limbs, mainly feet.

Vascular Chemerin from PVAT contributes to Norepinephrine and Serotonin-Induced Vasoconstriction and Vascular Stiffness in a Sex-Dependent Manner.

The adipokine chemerin supports normal blood pressure and contributes to adiposity-associated hypertension, evidenced by falls in mean arterial pressure in Dahl SS rats given an antisense oligonucleotide against chemerin. In humans, circulating chemerin is positively associated with hypertension and aortic stiffness. Mechanisms of chemerin's influence on vascular health and disease remain unknown. We identified chemerin production in the vasculature-the blood vessel and its perivascular adipose tissue (PVAT). Here, using RNAScope®, QPCR, isometric contractility, high frequency ultrasound imaging, and western blot in the Dahl SS rat, we test the hypothesis that endogenous chemerin amplifies agonist-induced vasoconstriction through Chemerin1 and that chemerin drives aortic stiffness in the thoracic aorta. CMKLR1 (Chemerin1) expression was higher in the media, and Rarres2 (chemerin) expression was higher in the PVAT. Chemerin1 antagonism via selective inhibitor CCX832 reduced maximal contraction to norepinephrine (NE) and serotonin (5-HT), but not angiotensin II, in isolated thoracic aorta (PVAT intact) from male Dahl SS rat. In females, CCX832 did not alter contraction to NE or 5-HT. Male, but not female, genetic chemerin knockout Dahl SS rats had lower aortic arch pulse wave velocity than wild types, indicating chemerin's role in aortic stiffness. Aortic PVAT from females expressed less chemerin protein than males, suggesting PVAT as the primary source of active chemerin. We show that chemerin made by the PVAT amplifies NE and 5-HT-induced contraction and potentially induces aortic stiffening in a sex-dependent manner, highlighting the potential for chemerin to be a key factor in blood pressure control and aortic stiffening.

The Detection of Chlamydia pneumoniae, Helicobacter pylori and Cytomegalovirus in Non-Atherosclerotic Arteries of Patients with Coronary Artery Disease

Atherosclerotic coronary artery disease (ACAD) is a major cause of global morbidity and mortality, characterized as an inflammatory process due to damage to blood vessel walls by risk factors like aging, hyperlipidemia, hypertension, smoking, and diabetes. Infectious agents, including Chlamydia pneumoniae (Cpn), Cytomegalovirus (CMV), and Helicobacter pylori (HP), have been implicated in ACAD’s pathophysiology. A study with 56 subjects undergoing coronary artery bypass grafting (CABG) aimed to detect Cpn, CMV, and HP DNA in unaffected artery segments and explore associations with disease progression and inflammation markers. The study found infectious agents’ DNA in 21.4% of samples, HP in eight samples, and CMV and Cpn in four samples each. Significant correlations were observed between HP and overweight or obese subjects, as well as between the presence of infectious agents and inflammation marker values. An association between HP and renal function was also noted. The findings reaffirm previous discoveries of infectious agents in non-clinically affected arteries used as CABG grafts. Correlations identified between the presence of HP, CMV, and Cpn DNA in grafts and several biomarkers of inflammation and obesity emphasize the potential role of these infectious agents in ACAD pathogenesis.

Establishing Local Diagnostic Reference Levels for Head Computed Tomography Examinations

Background/Objectives: Head Computed Tomography (CT) is an essential diagnostic tool for identifying brain pathologies and visualizing blood vessels. However, CT exposes patients to ionizing radiation, making it necessary to establish local diagnostic reference levels (DRLs) to ensure patient safety. This study aimed to establish DRLs for head CT scans and assess the influence of patient characteristics on radiation dose. Methods: A retrospective analysis was conducted on 2043 non-contrast and 488 contrast-enhanced head CT scans performed between 1 July 2023 and 31 March 2024 using a SIEMENS SOMATOM Definition Edge machine. Computed Tomography Dose Index (CTDIvol) and Dose-Length Product (DLP) values were analyzed, with DRLs set at the 75th percentile. The influence of gender, height, and weight on radiation dose was also evaluated. Results: The DRL for both non-contrast and contrast-enhanced scans was 58.18 mGy for CTDIvol and 1018.11 mGy·cm for DLP per acquisition. Total DLP was 2046.09 mGy·cm for contrast-enhanced and 1027.99 mGy·cm for non-contrast scans. No significant correlation was found between patient characteristics and radiation dose, allowing for a uniform DRL to be established. Conclusions: Uniform DRLs were successfully established for head CT scans, ensuring safe radiation doses for both non-contrast and contrast-enhanced studies. The lack of correlation between patient-specific factors and dose supports the use of standardized DRLs, contributing to optimized radiation safety in head CT diagnostics.

Phagocytic activity and proinflammatory activation potential of smooth muscle cells of the Tunica intima of human aorta under experimental conditions

The aorta is the largest blood vessel in the body, which reaches a diameter of about 3 cm and is responsible for transporting oxygen-enriched arterial blood from the heart to tissues and organs. The aortic wall consists of three layers: the inner Tunica intima, the middle Tunica media and the outer Tunica adventitia. The layers of the aortic wall have a diverse cellular composition and include smooth muscle cells (SMCs), fibroblasts, endothelial cells, etc. Functional disorders in the cells of the intima of the human aorta can lead to various cardiovascular diseases (СVD), such as aneurysm and, as a result, dissection or rupture of the thoracic aorta. The cellular and molecular mechanisms of CVD development remain not fully understood, therefore, the study of the functional characteristics of various cell populations that make up the human aorta is an urgent task today. The aim is to evaluate the inflammatory response formed by cells that are part of the Tunica intima of the human aorta during phagocytosis of latex particles and internalization of low-density lipoproteins (LDL) to study their role in the development of aneurysms. The experiments were performed on smooth muscle cells (SMCs) isolated from the intima of the human aorta in patients with aneurysm. Phagocytic activity was studied by adding latex beads to the SMCs of Tunica intima, the ability to internalize LDL was evaluated using the BDP 630/650 dye and a biochemical method, the assessment of the ability to pro- and anti-inflammatory activation was studied using enzyme-linked immunosorbent assay (ELISA). Our results demonstrated that the absorption of latex beads and LDL stimulates the activation of interleukin secretion by smooth muscle cells that are part of the Tunica intima of the aorta, namely the proinflammatory cytokines IL-6 and IL-8. This fact may indicate that in the conditions of the body, the human aortic intima SMCs phenotype may switch from contractile to secretory or macrophage-like, which indicates the participation of this phenotypic cell transition in the process of aneurysm development.

NIK Is a Mediator of Inflammation and Intimal Hyperplasia in Endothelial Denudation-Induced Vascular Injury

Neointimal hyperplasia is the main cause of vascular graft failure in the medium term. NFκB is a key mediator of inflammation that is activated during neointimal hyperplasia following endothelial injury. However, the molecular mechanisms involved in NFκB activation are poorly understood. NFκB may be activated through canonical (transient) and non-canonical (persistent) pathways. NFκB-inducing kinase (NIK, MAP3K14) is the upstream kinase of the non-canonical pathway. We have now explored the impact of NIK deficiency on neointimal hyperplasia following guidewire-induced endothelial cell injury and on local inflammation by comparing NIK activity–deficient alymphoplasia mice (NIKaly/aly) with control wild-type (NIK+/+) mice. Guidewire-induced endothelial cell injury caused neointimal hyperplasia and luminal stenosis and upregulated the local expression of NIK and the NFκB target chemokines monocyte chemoattractant protein-1 (MCP-1/CCL2) and chemokine ligand 5 (RANTES/CCL5). Immunohistochemistry disclosed the infiltration of the media and intima by F4/80 positive macrophages. The intima/media ratio and percentage of stenosis were milder in the NIKaly/aly than in the NIK+/+ mice. Additionally, the gene expression for MCP-1 and RANTES was lower and F4/80+ cell infiltration was milder in the NIKaly/aly than in the NIK+/+ mice. Finally, circulating MCP-1 levels were lower in the NIKaly/aly than in the NIK+/+ mice, reflecting milder systemic inflammation. In conclusion, NIK is a driver of vascular wall inflammation and stenosis following guidewire-induced endothelial cell injury. NIK targeting may be a novel therapeutic approach to limit arterial stenosis following endothelial cell injury.

Research Progress of Pulsed Radiofrequency in the Treatment of Shoulder Pain

The shoulder is one of the most complex anatomical structures in the body, consisting of bones, muscles, tendons, bursae, joint capsules, nerves, and blood vessels. Shoulder pain is one of the most common musculoskeletal syndromes clinically, according to statistics, the prevalence of shoulder pain in the adult population is 11% to 27%, lifetime prevalence as high as 67%. There are also significant differences in the prevalence of shoulder pain across age and gender. Typically, shoulder pain stems from trauma, degeneration, inflammation, vascular disease, and referred pain from other parts of the head, neck, and hands. Studies have shown that in addition to personal risk factors such as age, arthritis, obesity, diabetes, and thyroid disease, external factors such as living and working environments can lead to varying degrees of pain, limited mobility, and dysfunction in the shoulder, It imposes a huge economic burden on social development and healthcare services.

Pentoxifylline in COVID-19 and considerations for its research in long COVID.

Pentoxifylline (PTX) affects most blood components and the blood vessels, potentially modulating various conditions. Due to its impact on markers linked to COVID-19 severity, research has explored PTX for acute COVID-19. Following the widespread administration of COVID-19 vaccinations, there has been a notable and consistently growing increase in research focusing on long COVID. Consequently, our examination of relevant acute COVID-19 data shall additionally be contextualized into long COVID research. Various Databases were searched until July 2024 for all primary clinical studies on Pentoxifylline (PTX) in COVID-19. Studies were on acute infection with SARS-CoV-2 where PTX was an adjuvant to standard therapy for ethical and practical reasons under the circumstance. PTX generally reduced hospitalization duration and improved some inflammatory markers, but its impact on mortality was inconsistent. Adverse events were minimal. Meta-analysis revealed a significant reduction in hospitalization duration. This systematic review and meta-analysis suggest that adding pentoxifylline (PTX) to standard COVID-19 therapy may significantly reduce hospitalization duration and improve some inflammatory markers. However, its impact on mortality rates is inconclusive. Adverse events are minimal. PTX can be favorable as an add-on in managing acute COVID-19 and could reduce the risk of long COVID, as well as assist in managing many of its most common symptoms.

Periosteum-bone inspired hierarchical scaffold with endogenous piezoelectricity for neuro-vascularized bone regeneration

The development of scaffolds for repairing critical-sized bone defects heavily relies on establishing a neuro-vascularized network for proper penetration of nerves and blood vessels. Despite significant advancements in using artificial bone-like scaffolds infused with various agents, challenges remain. Natural bone tissue consists of a porous bone matrix surrounded by a neuro-vascularized periosteum, with unique piezoelectric properties essential for bone growth. Drawing inspiration from this assembly, we developed a periosteum-bone-mimicking bilayer scaffold with piezoelectric properties for regeneration of critical-sized bone defects. The periosteum-like layer of this scaffold features a double network hydrogel composed of chelated alginate, gelatin methacrylate, and sintered whitlockite nanoparticles, emulating the viscoelastic and piezoelectric properties of the natural periosteum. The bone-like layer is composed of a porous structure of chitosan and bioactive hydroxyapatite created through a biomineralization process. Unlike conventional bone-like scaffolds, this bioinspired bilayer scaffold significantly enhances osteogenesis, angiogenesis, and neurogenesis combined with low-intensity pulsed ultrasound-assisted piezoelectric stimulation. Such a scheme enhances neuro-vascularized bone regeneration in vivo. The results suggest that the bilayer scaffold could serve as an effective self-powered electrical stimulator to expedite bone regeneration under dynamic physical stimulation.

Microglia and Macrophages in Human Pineal Gland

Background. The causal role of the inflammatory process in the central nervous system (CNS) in the pathogenesis of most nervous and mental diseases, as well as in aging, has been established in the last two decades. The most important immune cells in the CNS are microglial cells and macrophages. To date, microglia and macrophages have been studied in various areas of the central nervous system, but have not been studied in the human pineal gland. The purpose of the study was to investigate the morphological features, types and localization of human pineal gland microglial cells using immunohistochemistry. Material and methods. The work was carried out on samples of the human brain pineal gland aged from 16 to 61 years (n=7). An immunohistochemical reaction was performed on sections of the pineal gland using antibodies to Iba-1 and TMEM119, the selective markers of microgliocytes. The frequency of occurrence of immunostained cells was analyzed using statistical methods. Results. It has been established that the majority of phagocytic cells of the structurally normal human pineal gland are not macrophages, but microgliocytes, which are represented by both resting and activated forms. Microglia in the human pineal gland are typically localized in connective tissue trabeculae, both at and away from blood vessels. Microgliocytes are also found in the parenchyma of the pineal gland among the hormone-synthesizing pinealocytes. There was a statistically significant decrease in the number of Iba-1- and especially TMEM119-immunoreactive cells with aging. Conclusion. The present study is the first to examine microglial cells and macrophages in the human pineal gland. The prevalence of microglial cells over macrophages has been established. The morphological features and localization of the identified types of microglial cells indicate their participation primarily in immune defense, and also, probably, in the regulation of pinealocyte functions. In addition, data have been obtained indicating the participation of microglial cells in increasing inflammation in the human pineal gland during aging.

Changes in tissues and organs through PMCTA carrier substances.

To date, lipophilic contrast agents mixed with oil, usually paraffin oil, are the most commonly used contrast agents in post-mortem computed tomography angiography (PMCTA). Iodine-based hydrophilic contrast media in combination with a water-soluble carrier, e.g. polyethylene glycol (PEG), are also common. However, their influence on different tissues and organs is poorly understood. In order to analyse the changes in the cadavers caused by the different carrier substances, we evaluated the effects of PEG 200 and oil on the different tissues and organs. Therefore, during a forensic autopsy, liquid femoral vein blood and samples of different organs and vessels were taken and preserved at room temperature in the two liquids mentioned. The condition of the samples was documented during the autopsy and 24, 48 and 72h after preservation. Microscopic examination took place after 72h. After 24h, the samples placed in PEG 200 already showed a clear solidification of almost all structures. Crumbly blood agglomerates had formed in the previously liquid blood. In contrast, the samples stored in oil showed signs of classic cadaveric decomposition after 24h, which increased with time. The microscopic and immunohistochemical evaluation of the samples stored in PEG showed a good diagnostic quality. The analysis of tissues stored in oil was much more difficult due to putrefaction. PEG and oil show significantly different effects on human tissues, mainly conservation and dehydration are affected. It is crucial to be aware of these differences in order to choose the most appropriate PMCTA method for each forensic case.

A microvascularized in vitro liver model for disease modeling and drug discovery

Drug discovery for complex liver diseases faces alarming attrition rates. The lack of non-clinical models that recapitulate key aspects of liver (patho)-physiology is likely contributing to the inefficiency of developing effective treatments. Of particular notice is the common omission of an organized microvascular component despite its importance in maintaining liver function and its involvement in the development of several pathologies. Increasing the complexity ofin vitromodels is usually associated with a lack of scalability and robustness which hinders their implementation in drug development pipelines. Here, we describe a comprehensive liver microphysiological system comprising stellates, liver-derived endothelial cells and hepatocytes conceived within a scalable and automated platform. We show that endothelial cells self-organize in a microvascular network when co-cultured with stellates in a hydrogel. In a tri-culture, hepatocytes polarize accordingly, with a basolateral side facing blood vessels and an apical side facing bile-canaliculi-like structures. Stellates interact and surround the hollow microvessels. Steatosis was induced by exogenous administration of fatty acids which could be prevented by co-administration of firsocostat. Administration of TGF-βresulted in an activated stellate cells phenotype which could be prevented by the co-administration of SB-431542. The model was implemented on a microtiter plate format comprising 64 chips which enabled the development of a fully automated, multiplexed fibrosis assay with a robust Z' factor suitable for high-throughput applications.

Disease Overlap, Healthcare Resource Utilization, and Costs in Patients with Eosinophilic Granulomatosis with Polyangiitis: A REVEAL Sub-study.

Eosinophilic granulomatosis with polyangiitis (EGPA) is an eosinophil-associated disease (EAD) characterized by inflammation in small- to medium-sized blood vessels. Inthe REal-world inVestigation of Eosinophilic-Associated disease overLap (REVEAL) study, overlap among 11 EADswas assessed. In the present sub-study, we evaluated EGPA overlapwith other EADs, all-cause EAD- and EGPA-related healthcare resource utilization (HCRU) and costs, and their relationship with blood eosinophil count and treatments received. REVEAL, a retrospective study, used Optum's de-identified Clinformatics® Data Mart Database. In this sub-study, eligibility criteria included an age of ≥ 12years, ≥ 1 EAD, continuous health-plan eligibility, and compliance with the EGPA/GPA case definition per International Classification of Diseases Ninth/Tenth Revision diagnosticcodes between 1 January 2015 and 30 June 2018. Patients were grouped based on whether they had received immunomodulators/cyclophosphamide/mepolizumab (ICM) or not (non-ICM). Of 701 patients with EGPA, 29.5% were in the ICM group. Overall, 72.2% had ≥ 1 overlapping EAD. The number of overlaps was similar for the ICM and non-ICM groups. In patients with blood eosinophil counts ≥ 300 cells/µL, 22.8% had ≥ 1 overlapping EAD. The mean annual all-cause cost was $98,644, 54.1% of which was from outpatients and 33.6% from inpatients. The mean annual EAD- and EGPA-related costs were $23,820 and $9,306, respectively. Patients in the non-ICM groupversus the ICM group had higher all-cause ($101,560 vs $91,684) but lower EAD-related ($22,733 vs $26,412) and EGPA-related ($6,171 vs $16,786) costs. All-cause HCRU and costs increased with increasing overlap. EGPA was associated with substantial HCRU and costs, driven by outpatient and inpatient settings. More overlapping EADs were associated with higher HCRU and costs, highlighting the need for treatment to reduce healthcare expenditure in these patients. Infographic available for this article.

Oseltamivir phosphate (Tamiflu) alters neurobehavior of zebrafish larvae by inducing mitochondrial dysfunction

Antiviral drugs are widely used, yet their potential risks during early development, particularly within the central nervous system, remain contentious. Oseltamivir phosphate (OSE), a commonly prescribed antiviral, is increasingly detected in various environments. However, its toxicity to organisms and the underlying mechanisms are not well understood. In this study, we employed the zebrafish model to evaluate the developmental neurotoxic effects of OSE at environmentally and therapeutically relevant doses, through high-throughput behavioral analysis, in vivo two-photon imaging, transcriptomic sequencing, pharmacological intervention, and biochemical and molecular assays. Our results indicated that OSE exposure increased heart rate and induced pericardial edema in zebrafish larvae. Additionally, OSE-exposed larvae exhibited hyperactive behavior, impaired social interactions, and reduced habitual learning capacity. Although OSE at our selected levels did not significantly affect neuron count in the brain, it activated neuroinflammatory responses, altered blood vessel morphology, modulated neurotransmitter levels and the expression of neurodevelopment-related genes. Transcriptomic analysis revealed upregulation of mitochondria-related genes associated with oxidative phosphorylation. Further assessments of mitochondrial function demonstrated altered activities of respiratory chain complexes, reduced mitochondrial membrane potential (MMP), and decreased ATP content. Notably, co-treatment with mitochondrial protectants acetyl-l-carnitine-hydrochloride (ALC) or nicotinamide riboside (NR) effectively mitigated OSE-induced neurobehavioral disorders. These findings suggest that overuse of OSE can pose neurodevelopmental risks for both humans and animals, potentially attributable to mitochondrial dysfunction.

IL-33/ST2 signaling in monocyte-derived macrophages maintains blood-brain barrier integrity and restricts infarctions early after ischemic stroke

BackgroundBrain microglia and infiltrating monocyte-derived macrophages are vital in preserving blood vessel integrity after stroke. Understanding mechanisms that induce immune cells to adopt vascular-protective phenotypes may hasten the development of stroke treatments. IL-33 is a potent chemokine released from damaged cells, such as CNS glia after stroke. The activation of IL-33/ST2 signaling has been shown to promote neuronal viability and white matter integrity after ischemic stroke. The impact of IL-33/ST2 on blood-brain barrier (BBB) integrity, however, remains unknown. The current study fills this gap and reveals a critical role of IL-33/ST2 signaling in macrophage-mediated BBB protection after stroke.MethodsTransient middle cerebral artery occlusion (tMCAO) was performed to induce ischemic stroke in wildtype (WT) versus ST2 knockout (KO) male mice. IL-33 was applied intranasally to tMCAO mice with or without dietary PLX5622 to deplete microglia/macrophages. ST2 KO versus WT bone marrow or macrophage cell transplantations were used to test the involvement of ST2+ macrophages in BBB integrity. Macrophages were cocultured in transwells with brain endothelial cells (ECs) after oxygen-glucose deprivation (OGD) to test potential direct effects of IL33-treated macrophages on the BBB in vitro.ResultsThe ST2 receptor was expressed in brain ECs, microglia, and infiltrating macrophages. Global KO of ST2 led to more IgG extravasation and loss of ZO-1 in cerebral microvessels 3 days post-tMCAO. Intranasal IL-33 administration reduced BBB leakage and infarct severity in microglia/macrophage competent mice, but not in microglia/macrophage depleted mice. Worse BBB injury was observed after tMCAO in chimeric WT mice reconstituted with ST2 KO bone marrow, and in WT mice whose monocytes were replaced by ST2 KO monocytes. Macrophages treated with IL-33 reduced in vitro barrier leakage and maintained tight junction integrity after OGD. In contrast, IL-33 exerted minimal direct effects on the endothelial barrier in the absence of macrophages. IL-33-treated macrophages demonstrated transcriptional upregulation of an array of protective factors, suggesting a shift towards favorable phenotypes.ConclusionOur results demonstrate that early-stage IL-33/ST2 signaling in infiltrating macrophages reduces the extent of acute BBB disruption after stroke. Intranasal IL-33 administration may represent a new strategy to reduce BBB leakage and infarct severity.

A mathematical model describing the tip-stalk regulation in angiogenesis

Angiogenesis is the process of new blood vessel growth from existing vessels, involving extensive cell signaling. Under normal conditions, new vessels are robust and organized, with a balance among angiogenesis factors. In abnormal conditions, such as tumor development, vessels are stunted and tangled due to an imbalance of these factors. Pathological angiogenesis stimulates rapid vessel growth to feed the oxygen and nutriente starved tumor. Inhibiting angiogenesis can cause side effects like hypertension, thrombosis, and fatigue. To better understand this process, significant effort has gone into studying signaling pathways, contributing to drug development for diseases like cancer. This study presents a mathematical model describing angiogenesis on a microscopic scale, comparing its results with experimental data on vascular network topology. The model, implemented in MatLab®, uses ordinary differential equations to represent cell behavior. Results show that altering VEGF (Vascular Endothelial Growth Factor) disrupts system balance, impacting angiogenesis and possibly explaining differences in network topology seen experimentally.