Search Results (394)

Background/Objectives: VitroScreenORA^® (by VitroScreen srl) Dermo Papilla spheroids, based on two micro-physiological systems (non-vascularized DP and vascularized VASC-DP), were used to study the molecular mechanisms behind hair cycle regression. Methods: Dermal papilla cells (HFDPC) were cultured to develop both models. Hair cycle regression was induced by exposing DP spheroids to TGF-β1 for 72 h and/or FGF-18 for an additional 24 h. Catagen phase entrance was evaluated by modulating specific genes (FGF7, CCND1, and WNT5B). The VASC-DP model was obtained by sequentially co-culturing HFDPC and primary dermal microvascular endothelial cells (HMDEC), mimicking the surrounding capillary loop. The vascular system’s impact was assessed at 5 and 10 days using IF on CD31 (micro-vessels) and Fibronectin (FN). Nanostring nCounter^® technology was applied to investigate the transcriptional signature based on the WNT pathway. Extended culture time up to 11 days simulated natural hair cycle regression, monitored by versican and FN expression (IF). Minoxidil, Doxorubicin, and Retinol-based products were used to modify physiological aging over time. Results: Data shows that the vascular system improves tissue physiology by modulating the associated genes. Extended culture time confirms progressive DP structure degeneration that is partially recoverable with Retinol-based treatments. Conclusions: Both models provide a reliable platform to investigate the hair cycle, paving the way for new testing systems for personalized therapies. Full article

The brain actively obtains nutrients through various transporters on brain microvessel endothelial cells (BMECs). Major facilitator superfamily domain–containing protein 2a (MFSD2A) serves as a key transporter of docosahexaenoic acid (DHA) at the blood–brain barrier (BBB) and is exclusively expressed in BMECs. Although brain pericytes (PCs) regulate MFSD2A expression in BMECs, the underlying mechanism remains unclear. To determine whether PDGF-BB/PDGFRβ signaling between endothelial cells (ECs) and PCs affects MFSD2A protein expression and plasma membrane localization in ECs, we examined the impact of AG1296 (a PDGF receptor inhibitor) and Pdgfrb-knockdown PCs on a non-contact coculture BBB model comprising the primary cultures of rat brain ECs and PCs. The effects of PCs on MFSD2A expression, localization, and brain endothelial DHA uptake was assessed using Western blot, immunofluorescence staining, and [¹⁴C]DHA uptake by ECs, respectively. In ECs cocultured with PCs, MFSD2A expression and plasma membrane localization were significantly higher than in EC monolayers. Moreover, conditioned medium derived from PCs failed to enhance MFSD2A expression. The increased expression and membrane localization of MFSD2A were inhibited by AG1296 and Pdgfrb-knockdown PCs. Furthermore, PCs significantly increased [¹⁴C]DHA uptake by ECs. These findings suggest that PCs enhance MFSD2A expression and plasma membrane localization in ECs through PDGF-BB/PDGFRβ signaling. Full article

Pericytes, specialized mural cells surrounding microvessels, play a crucial role in maintaining vascular homeostasis and function across various organs, including the eye. These versatile cells regulate blood flow, support the integrity of the blood–retinal barrier, and contribute to angiogenesis. Recent advancements in molecular and cellular biology have revealed the heterogeneity of pericytes and their critical involvement in ocular physiology and pathology. This review provides a comprehensive analysis of pericyte functions in ocular health and their implications in diseases such as diabetic retinopathy, age-related macular degeneration, glaucoma, and retinal vein occlusion. Pericyte dysfunction is implicated in vascular instability, neurovascular coupling failure, inflammation, and pathological neovascularization, contributing to vision-threatening disorders. The review further explores recent findings on pericyte-targeted therapies, including pharmacological agents, gene therapy, and cell-based approaches, aiming to restore pericyte function and preserve ocular health. Full article

Peripheral artery disease (PAD) is a chronic progressive accumulation of atherosclerotic lesions with varying degrees of arterial obstruction determining ischemic symptoms of the involved extremities. PAD is associated with decreased bioavailable nitric oxide due to endothelial cell dysfunction and the development and progression of vascular arterial stiffening (VAS). Atherosclerosis also plays an essential role in the development and progression of vascular arterial stiffening (VAS), which is associated with endothelial cell activation and dysfunction that results in a proinflammatory endothelium with a decreased ability to produce bioavailable nitric oxide (NO). NO is one of three gasotransmitters, along with carbon monoxide and hydrogen sulfide, that promotes vasodilation. NO plays a crucial role in the regulation of PAD, and a deficiency in its bioavailability is strongly linked to the development of atherosclerosis, VAS, and PAD. A decreased arterial patency may also occur due to a reduction in the elasticity or diameter of the vessel wall due to the progressive nature of VAS and atherosclerosis in PAD. Progressive atherosclerosis and VAS promote narrowing over time, which leads to impairment of vasorelaxation and extremity blood flow. This narrative review examines how atherosclerosis, aging and hypertension, metabolic syndrome and type 2 diabetes, tobacco smoking, and endothelial cell activation and dysfunction with decreased NO and VAS with its increased damaging pulsatile pulse pressure result in microvessel remodeling. Further, the role of ischemia and ischemia–reperfusion injury is discussed and how it contributes to ischemic skeletal muscle remodeling, ischemic neuropathy, and pain perception in PAD. Full article

Purinergic P2X receptors (P2X) are ATP-gated ion channels that are broadly expressed in the brain, particularly in the hypothalamus. As ionic channels with high permeability to calcium, P2X play an important and active role in neural functions. The hypothalamus contains a number of small nuclei with many molecularly defined types of peptidergic neurons that affect a wide range of physiological functions, including water balance, blood pressure, metabolism, food intake, circadian rhythm, childbirth and breastfeeding, growth, stress, body temperature, and multiple behaviors. P2X are expressed in hypothalamic neurons, astrocytes, tanycytes, and microvessels. This review focuses on cell-type specific expression of P2X in the most important hypothalamic nuclei, such as the supraoptic nucleus (SON), paraventricular nucleus (PVN), suprachiasmatic nucleus (SCN), anteroventral periventricular nucleus (AVPV), anterior hypothalamic nucleus (AHN), arcuate nucleus (ARC), ventromedial hypothalamic nucleus (VMH), dorsomedial hypothalamic nucleus (DMH), tuberomammillary nucleus (TMN), and lateral hypothalamic area (LHA).> The review also notes the possible role of P2X and extracellular ATP in specific hypothalamic functions. The literature summarized here shows that purinergic signaling is involved in the control of the hypothalamic-pituitary endocrine system, the hypothalamic–neurohypophysial system, the circadian systems and nonendocrine hypothalamic functions. Full article

Marfan syndrome is caused by a mutation in the FBN1 gene encoding fibrillin-1. This extracellular matrix glycoprotein, which assembles into microfibrils, is best known for its scaffolding role in the production of elastic fibers responsible for connective tissue elasticity and tensile strength. Research into Marfan syndrome mainly focuses on the pathophysiology involved in the degeneration of elastin-rich elastic fibers, which are essential components of the aortic wall. However, fibrillin-1 also exists in elastin-poor (elaunin) or elastin-free (oxytalan) microfibril bundles that were first described in the periodontal ligament (PDL). This dynamic, densely cellular, and highly vascularized tissue anchors teeth in their bone sockets and acts as a protective shock absorber during chewing. Current knowledge suggests that fibrillin microfibrils mechanically support blood vessels in the PDL and ensure their proper functioning. However, many more insights on the roles of fibrillin, especially independently of elastin, can be extracted from this tissue. Here, we review the phenotypic and functional characteristics of the PDL in connection with fibrillin-1, focusing on those related to microvessels. This review aims to shed light on this often-overlooked fibrillin-rich resource as a model for future studies investigating fibrillin functions in health and Marfan disease. Full article

Tumor angiogenesis and metastasis are critical processes in the progression of colon carcinoma. Curcumol, a bioactive sesquiterpenoid derived from curcuma, exhibits anti-angiogenic properties, though its underlying mechanisms remain unclear. In this study, an HT-29 xenograft mouse model demonstrated that curcumol combined with oxaliplatin significantly suppressed tumor growth (Ki67↓) and microvessel density (CD31↓). In vitro assays revealed that curcumol dose dependently inhibited proliferation (MTT), migration (Transwell), and tube formation (CAM assay) in Caco-2/HT-29 and HUVEC cells. Mechanistically, curcumol downregulated OTUB1 expression, promoting TGFB1 degradation via the ubiquitin–proteasome pathway. OTUB1 overexpression activated the TGFB1/VEGF axis, enhancing cell invasiveness and angiogenesis—effects reversed by high-dose curcumol. These findings identify the OTUB1-TGFB1/VEGF axis as a key target of curcumol in inhibiting colon cancer angiogenesis, elucidating its anti-tumor mechanism and offering a novel therapeutic strategy for targeted treatment. Full article

Multipotent vascular stem cells (MVSCs) are found in the vascular wall and surrounding tissues and possess the ability to differentiate into mesenchymal lineages. Previous studies have shown that MVSCs can be activated in response to vascular injury and differentiate into vascular smooth muscle cells (SMCs), contributing to vascular remodeling and microvessel formation. However, it remains unclear as to whether and how microenvironmental changes in the extracellular matrix, such as substrate stiffness, modulates MVSC differentiation under pathological conditions. This study demonstrated that MVSCs cultured on stiff substrates exhibited increased cell spreading, stronger cell adhesion, and a higher expression of SMC markers, including myosin heavy chain (MHC), myocardin (MYCD), calponin 1 (CNN1), and smooth muscle α-actin (SMA). In contrast, MVSCs on soft substrates showed an elevated expression of the chondrogenic markers aggrecan 1 (AGC1) and collagen-II (COL2A1). The presence of TGF-β1 further increased the expression of SMC markers on stiff substrates and chondrogenic markers on the soft substrates. Collectively, these results establish substrate stiffness as a key regulator of MVSC lineage commitment through cytoskeletal reorganization, with TGF-β1 acting as a biochemical amplifier. Our findings highlight the substrate-stiffness-dependent differentiation of MVSCs and provide mechanistic insights into the role of MVSCs in vascular remodeling during atherosclerosis development and blood vessel regeneration. Full article

Early-onset heart failure is a major treat to healthy aging individuals with HIV-1 infection. Women with HIV-1 infection (WLWH) are especially vulnerable and develop heart failure with preserved ejection fraction (HFpEF), of which left ventricular diastolic dysfunction, vascular deficits, myocardial infarction, and fibrosis are major components. HIV-infected rodent models that exhibit these pathophysiological features remain under-reported, and this has left a void in our understanding of their molecular causes and therapeutic strategies to blunt its development. Here, we show that female NOD.Cg-Prkdc^scidIl2rgt^m1Wjl/SzJ humanized mice (Hu-mice) infected with HIV-1_ADA and treated for 13 weeks with dolutegravir (DTG)/tenofovir disoproxil fumarate (TDF)/emtricitabine (FTC) develop progressive diastolic dysfunction with preserved ejection fraction (E:A ratio, E:e′, IVRT, left atrial volume and global longitudinal strain increased by 32.1 ± 5.1%, 28.2 ± 5.6%, 100.2 ± 12.6%, 26.6 ± 4.2% and 32.5 ± 4.3%, respectively). In vivo photoacoustic imaging revealed a 30.4 ± 6.8% reduction in saturated oxygenated hemoglobin in the anterior wall of the heart. The ex vivo analysis of hearts showed a reduction in density of perfused microvessels/ischemia (30.6 ± 6.2%) with fibrosis (20.2 ± 1.2%). The HIF-1α level was increased 2.6 ± 0.5-fold, while inflammation-induced serum semicarbazide amine oxidase and glycolysis byproduct methylglyoxal increased 2-fold and 2.1-fold, respectively. Treating H9C2 cardiac myocytes with DTG, FTC and TDF dose-dependently increased expression of HIF-1α. These data show that HIV-infected Hu-mice treated with DTG/TDF/FTC for thirteen weeks develop cardiac diastolic dysfunction, with vascular deficits, ischemia, and fibrosis like those reported in women living with HIV-1 infection (WLWH). They also show that DTG, TDF, and FTC treatment can increase total HIF-1α in H9C2 cells. Full article

People living with HIV (PLWH) develop cardiovascular diseases (CVDs) about a decade earlier and at rates 2–3 times higher than the general population. At present, pharmacological strategies to delay the onset of CVDs in PLWH are unavailable, in part because of an incomplete understanding of its molecular causes. We and others recently uncovered elevated levels of the toxic glycolysis and inflammation-induced byproduct methylglyoxal (MG) in plasma from PLWH and from HIV-infected humanized mice (Hu-mice). We also found a reduction in expression of the primary MG-degrading enzyme glyoxalase I (Glo-I) in autopsied cardiac tissues from HIV-1-infected individuals and HIV-1-infected Hu-mice. Increasing the expression of Glo-I in HIV-1-infected Hu-mice not only attenuated heart failure but also reduced endothelial cell damage, increased the density of perfused microvessels, prevented microvascular leakage and micro-ischemia, and blunted the expression of the inflammation-induced protein vascular protein-1 (VAP-1), key mediators of CVDs. In this narrative review, we posit that elevated MG is a contributing cause for the early onset of CVDs in PLWH. Pharmacological strategies to prevent MG accumulation and delay the development of early-onset CVDs in PLWH are also discussed. Full article

This study employs numerical techniques to investigate the motion characteristics of red blood cells (RBCs) and drug carriers (DCs) within microvessels. A coupled model of the lattice Boltzmann method (LBM) and immersed boundary method (IBM) is proposed to investigate the migration of particles in blood flow. The lattice Bhatnagar–Gross–Krook (LBGK) model is utilized to simulate the flow dynamics of blood. While the IBM is employed to simulate the motion of particles, using a membrane model based on the finite element method. The present model was validated and demonstrated good agreements with previous theoretical and numerical results. Our study mainly examines the impact of the Reynolds number, DC size, and stiffness. Results suggest that these factors would influence particles’ equilibrium regions, motion stability and interactions between RBCs and DCs. Within a certain range, under a higher Reynolds number, the motion of DCs remains stable and DCs can swiftly attain their equilibrium states. DCs with smaller sizes and softer stiffness demonstrate a relatively stable motion state and their interactions with RBCs are weakened. The findings would offer novel perspectives on drug transport mechanisms and the impact of drug release, providing valuable guidance for the design of DCs. Full article

By utilizing polydimethylsiloxane (PDMS), collagen hydrogel, and a cell line for human cerebral microvascular endothelial cells, we produced a 3D microchannel blood–brain barrier (BBB) model under physiological flow. This 3D BBB has a circular-shaped cross-section and a diameter of ~100 μm, which can properly mimic the cerebral microvessel responsible for material exchange between the circulating blood and brain tissue. The permeability of the 3D microchannel BBB to a small molecule (sodium fluorescein with a molecular weight of 376) and that to a large molecule (Dex-70k) are the same as those of rat cerebral microvessels. This 3D BBB model can replicate the effects of a plasma protein, orosomucoid, a cytokine, vascular endothelial growth factor (VEGF), and an enzyme, heparinase III, on either rat cerebral or mesenteric microvessesels in terms of permeability and the modulation of glycocalyx (heparan sulfate). It can also replicate the adhesion of a breast cancer cell, MDA-MB-231, in rat mesenteric microvessels under no treatment or treatments with VEGF, orosomucoid, and heparinase III. Because of difficulties in accessing human cerebral microvessels, this inexpensive and easy to assemble 3D human BBB model can be applied to investigate BBB-modulating mechanisms in health and in disease and to develop therapeutic interventions targeting tumor metastasis to the brain. Full article

Continuous perfusion is necessary to sustain microphysiological systems and other microfluidic cell cultures. However, most of the established microfluidic perfusion systems, such as syringe pumps, peristaltic pumps, and rocker plates, have several operational challenges and may be cost-prohibitive, especially for laboratories with no microsystems engineering expertise. Here, we address the need for a cost-efficient, easy-to-implement, and reliable microfluidic perfusion system. Our solution is a modular pumpless perfusion assembly (PPA), which is constructed from commercially available, interchangeable, and aseptically packaged syringes and syringe filters. The total cost for the components of each assembled PPA is USD 1–2. The PPA retains the simplicity of gravity-based pumpless flow systems but incorporates high resistance filters that enable slow and sustained flow for extended periods of time (hours to days). The perfusion characteristics of the PPA were determined by theoretical calculations of the total hydraulic resistance of the assembly and experimental characterization of specific filter resistances. We demonstrated that the PPA enabled reliable long-term culture of engineered endothelialized 3-D microvessels for several weeks. Taken together, our novel PPA solution is simply constructed from extremely low-cost and commercially available laboratory supplies and facilitates robust cell culture and compatibility with current microfluidic setups. Full article

Despite improved neonatal intensive care, the risk of premature-born infants developing bronchopulmonary dysplasia (BPD) and encephalopathy of prematurity (EoP) remains high. With hyperoxia being a major underlying factor, both preterm-birth-related complications are suggested to be closely interrelated. However, experimental models are lacking for the assessment of the potentially close interplay between both organs. To establish a model, suitable for the assessment of both affected organs, Wistar rats were exposed to 80% oxygen from postnatal day 2 (P2) for seven days. Brain and lung tissues were analysed via histomorphometry, immunohistochemistry, real-time PCR, and western blot at term P11. In the brain, hyperoxia induced significant hypomyelination accompanied by a reduction in oligodendrocytes and CD68 expression on microglia cells. These changes correlate with arrested alveolarisation and an increased number of macrophages in the lung. Interestingly, in contrast to the reduced formation of pulmonary microvessels, an increased vascular density was detected in the brain. Seven days of hyperoxia induces typical characteristics of BPD and EoP in neonatal rats, thereby linking impaired alveolarisation with disturbed myelination in the brain and providing an experimental model for understanding pathophysiological mechanisms and identifying organ-spanning novel therapeutic interventions targeting both diseases. Full article

Epigenetic changes have been reported to promote the development and progression of prostate cancer (PCa). Compared to normal prostate tissue, tumor samples from patients treated with androgen-deprivation therapy (ADT) show the hypermethylation of genes primarily implicated in PCa progression. A series of 90 radical prostatectomies was retrospectively analyzed. A total of 46 patients had undergone surgery alone (non-treated) and 44 had received ADT prior to surgery (treated). Promoter methylation analysis of the candidate genes possibly involved in PCa response to ADT (AR, ESR1, ESR2, APC, BCL2, CD44, CDH1, RASSF1, ZEB1) was conducted by pyrosequencing. The mRNA expression of differentially methylated genes was investigated by quantitative real-time PCR. Intratumoral microvessel density and ERG expression were also assessed using immunohistochemistry. A statistically significant difference in CD44 promoter methylation levels was found, with higher levels in the non-treated cases, which accordingly showed lower CD44 gene expression than the treated cases. Moreover, lower ESR1 methylation levels were associated with higher ERG expression, and the CD44 methylation levels were increased in ERG-overexpressing tumors, particularly in the treated cases. Our data suggest an interplay between ERG expression and the epigenetic modifications in key genes of prostate tumorigenesis, and that CD44 promoter methylation could serve as a promising molecular biomarker of PCa progression under androgen-deprived conditions. Full article