FASEB Journal最新文献

Pulmonary hypertension (PH) is a chronic and progressive disease with significant morbidity and mortality. It is characterized by remodeled pulmonary vessels associated with perivascular and intravascular accumulation of inflammatory cells. Although there is compelling evidence that bone marrow-derived cells, such as macrophages and T cells, cluster in the vicinity of pulmonary vascular lesions in humans and contribute to PH development in different animal models, the role of dendritic cells in PH is less clear. Dendritic cells' involvement in PH is likely since they are responsible for coordinating innate and adaptive immune responses. We hypothesized that dendritic cells drive hypoxic PH. We demonstrate that a classical dendritic cell (cDC) subset (cDC2) is increased and activated in wild-type mouse lungs after hypoxia exposure. We observe significant protection after the depletion of cDCs in ZBTB46 DTR chimera mice before hypoxia exposure and after established hypoxic PH. In addition, we find that cDC depletion is associated with a reduced number of two macrophage subsets in the lung (FolR2⁺ MHCII⁺ CCR2⁺ and FolR2⁺ MHCII⁺ CCR2⁻). We found that depleting cDC2s, but not cDC1s, was protective against hypoxic PH. Finally, proof-of-concept studies in human lungs show increased perivascular cDC2s in patients with Idiopathic Pulmonary Arterial Hypertension (IPAH). Our data points to an essential role of cDCs, particularly cDC2s, in the pathophysiology of experimental PH.

Albuminuria is characterized by a disruption of the glomerular filtration barrier, which is composed of the fenestrated endothelium, the glomerular basement membrane, and the slit diaphragm. Nephrin is a major component of the slit diaphragm. Apart from hemodynamic effects, Ang II enhances albuminuria by β-Arrestin2-mediated nephrin endocytosis. Blocking the AT1 receptor with candesartan and irbesartan reduces the Ang II-mediated nephrin-β-Arrestin2 interaction. The inhibition of MAPK ERK 1/2 blocks Ang II-enhanced nephrin-β-Arrestin2 binding. ERK 1/2 signaling, which follows AT1 receptor activation, is mediated by G-protein signaling, EGFR transactivation, and β-Arrestin2 recruitment. A mutant AT1 receptor defective in EGFR transactivation and β-Arrestin2 recruitment reduces the Ang II-mediated increase in nephrin β-Arrestin2 binding. The mutation of β-Arrestin2^K11,K12, critical for AT1 receptor binding, completely abrogates the interaction with nephrin, independent of Ang II stimulation. β-Arrestin2^K11R,K12R does not influence nephrin cell surface expression. The data presented here deepen our molecular understanding of a blood-pressure-independent molecular mechanism of AT-1 receptor blockers (ARBs) in reducing albuminuria.

The skeleton plays a fundamental role in the maintenance of organ function and daily activities. The insulin-like growth factor (IGF) family is a group of polypeptide substances with a pronounced role in osteoblast differentiation, bone development, and metabolism. Disturbance of the IGFs and the IGF signaling pathway is inextricably linked with assorted developmental defects, growth irregularities, and jeopardized skeletal structure. Recent findings have illustrated the significance of the action of the IGF signaling pathway via growth factors and receptors and its interactions with dissimilar signaling pathways (Wnt/β-catenin, BMP, TGF-β, and Hh/PTH signaling pathways) in promoting the growth, survival, and differentiation of osteoblasts. IGF signaling also exhibits profound influences on cartilage and bone development and skeletal homeostasis via versatile cell–cell interactions in an autocrine, paracrine, and endocrine manner systemically and locally. Our review summarizes the role and regulatory function as well as a potentially integrated gene network of the IGF signaling pathway with other signaling pathways in bone and cartilage development and skeletal homeostasis, which in turn provides an enlightening insight into visualizing bright molecular targets to be eligible for designing effective drugs to handle bone diseases and maladies, such as osteoporosis, osteoarthritis, and dwarfism.

Previous studies showed that the bladder extracellular matrix (B-ECM) could increase the differentiation efficiency of mesenchymal cells into smooth muscle cells (SMC). This study investigates the potential of human amniotic membrane-derived hydrogel (HAM-hydrogel) as an alternative to xenogeneic B-ECM for the myogenic differentiation of the rabbit adipose tissue-derived MSC (AD-MSC). Decellularized human amniotic membrane (HAM) and sheep urinary bladder (SUB) were utilized to create pre-gel solutions for hydrogel formation. Rabbit AD-MSCs were cultured on SUB-hydrogel or HAM-hydrogel-coated plates supplemented with differentiation media containing myogenic growth factors (PDGF-BB and TGF-β1). An uncoated plate served as the control. After 2 weeks, real-time qPCR, immunocytochemistry, flow cytometry, and western blot were employed to assess the expression of SMC-specific markers (MHC and α-SMA) at both protein and mRNA levels. Our decellularization protocol efficiently removed cell nuclei from the bladder and amniotic tissues, preserving key ECM components (collagen, mucopolysaccharides, and elastin) within the hydrogels. Compared to the control, the hydrogel-coated groups exhibited significantly upregulated expression of SMC markers (p ≤ .05). These findings suggest HAM-hydrogel as a promising xenogeneic-free alternative for bladder tissue engineering, potentially overcoming limitations associated with ethical concerns and contamination risks of xenogeneic materials.

The role of programmed cell death 4 (PDCD4) in multiple myeloma (MM) development remains unknown. Here, we investigated its role and action mechanism in MM. Bioinformatic analysis indicated that patients with MM and high PDCD4 expression had higher overall survival than those with low PDCD4 expression. PDCD4 expression promoted MM cell apoptosis and inhibited their viability in vitro and tumor growth in vivo. RNA-binding protein immunoprecipitation sequencing analysis showed that PDCD4 is bound to the 5′ UTR of the apoptosis-related genes PIK3CB, Cathepsin Z (CTSZ), and X-chromosome-linked apoptosis inhibitor (XIAP). PDCD4 knockdown reduced the cell apoptosis rate, which was rescued by adding PIK3CB, CTSZ, or XIAP inhibitors. Dual luciferase reporter assays confirmed the internal ribosome entry site (IRES) activity of the 5′ UTRs of PIK3CB and CTSZ. An RNA pull-down assay confirmed binding of the 5′ UTR of PIK3CB and CTSZ to PDCD4, identifying the specific binding fragments. PDCD4 is expected to promote MM cell apoptosis by binding to the IRES domain in the 5′ UTR of PIK3CB and CTSZ and inhibiting their translation. Our findings suggest that PDCD4 plays an important role in MM development by regulating the expression of PIK3CB, CTSZ, and XIAP, and highlight new potential molecular targets for MM treatment.

Mesenchymal stem cells (MSC)-derived exosomes (Exo) are a possible option for hyperoxia-induced lung injury (HLI). We wanted to see if melatonin (MT)-pretreated MSC-derived exosomes (MT-Exo) were more effective against HLI, and we also tried to figure out the underlying mechanism. HLI models were established by hyperoxia exposure. HE staining was adopted to analyze lung pathological changes. MTT and flow cytometry were used to determine cell viability and apoptosis, respectively. The mitochondrial membrane potential (MMP) was analyzed using the JC-1 probe. LDH, ROS, SOD, and GSH-Px levels were examined by the corresponding kits. The interactions between miR-18a-5p, PUM2, and DUB3 were analyzed by molecular interaction experiments. MT-Exo could effectively inhibit hyperoxia-induced oxidative stress, inflammatory injury, and apoptosis in lung epithelial cells, while these effects of MT-Exo were weakened by miR-18a-5p knockdown in MSCs. miR-18a-5p reduced PUM2 expression in MLE-12 cells by directly targeting PUM2. In addition, PUM2 inactivated the Nrf2/HO-1 signaling pathway by promoting DUB3 mRNA decay post-transcriptionally. As expected, PUM2 overexpression or DUB3 knockdown abolished the protective effect of MT-Exo on hyperoxia-induced lung epithelial cell injury. MT-Exo carrying miR-18a-5p reduced hyperoxia-mediated lung injury in mice through activating Nrf2/HO-1 pathway. MT reduced PUM2 expression and subsequently activated the DUB3/Nrf2/HO-1 signal axis by increasing miR-18a-5p expression in MSC-derived exosomes to alleviate HLI.

End-ischemic normothermic mechanical perfusion (NMP) could provide a curative treatment to reduce cholestatic liver injury from donation after circulatory death (DCD) in donors. However, the underlying mechanism remains elusive. Our previous study demonstrated that air-ventilated NMP could improve functional recovery of DCD in a preclinical NMP rat model. Here, metabolomics analysis revealed that air-ventilated NMP alleviated DCD- and cold preservation-induced cholestatic liver injury, as shown by the elevated release of alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, and γ-glutamyl transferase (GGT) in the perfusate (p < .05) and the reduction in the levels of bile acid metabolites, including ω-muricholic acid, glycohyodeoxycholic acid, glycocholic acid, and glycochenodeoxycholate (GCDC) in the perfused livers (p < .05). In addition, the expression of the key bile acid metabolism enzyme UDP-glucuronosyltransferase 1A1 (UGT1A1), which is predominantly expressed in hepatocytes, was substantially elevated in the DCD rat liver, followed by air-ventilated NMP (p < .05), and in vitro, this increase was induced by decreased GCDC and hypoxia-reoxygenation in the hepatic cells HepG2 and L02 (p < .05). Knockdown of UGT1A1 in hepatic cells by siRNA aggravated hepatic injury caused by GCDC and hypoxia-reoxygenation, as indicated by the ALT and AST levels in the supernatant. Mechanistically, UGT1A1 is transcriptionally regulated by peroxisome proliferator-activator receptor-γ (PPAR-γ) under hypoxia–physoxia. Taken together, our data revealed that air-ventilated NMP could alleviate DCD- and cold preservation-induced cholestatic liver injury through PPAR-γ/UGT1A1 axis. Based on the results from this study, air-ventilated NMP confers a promising approach for predicting and alleviating cholestatic liver injury through PPAR-γ/UGT1A1 axis.

Visceral leishmaniasis (VL) is characterized by an uncontrolled infection of internal organs such as the spleen, liver and bone marrow (BM) and can be lethal when left untreated. No effective vaccination is currently available for humans. The importance of B cells in infection and VL protective immunity has been controversial, with both detrimental and protective effects described. VL infection was found in this study to increase not only all analyzed B cell subsets in the spleen but also the B cell progenitors in the BM. The enhanced B lymphopoiesis aligns with the clinical manifestation of polyclonal hypergammaglobulinemia and the occurrence of autoantibodies. In line with earlier reports, flow cytometric and microscopic examination identified parasite attachment to B cells of the BM and spleen without internalization, and transformation of promastigotes into amastigote morphotypes. The interaction appears independent of IgM expression and is associated with an increased detection of activated lysosomes. Furthermore, the extracellularly attached amastigotes could be efficiently transferred to infect macrophages. The observed interaction underscores the potentially crucial role of B cells during VL infection. Additionally, using immunization against a fluorescent heterologous antigen, it was shown that the infection does not impair immune memory, which is reassuring for vaccination campaigns in VL endemic areas.

RETRACTION: J.-H. Seo, J.-C. Rah, S. H. Choi, J. K. Shin, K. Min, H.-S. Kim, C. H. Park, S. Kim, E.-M. Kim, S.-H. Lee, S. Lee, S. Won Suh, and Y.-H. Suh, “Α-Synuclein regulates neuronal survival via Bcl-2 family expression and PI3/Akt kinase pathway,” The FASEB Journal 16, no. 13 (2002): 1–20, https://doi.org/10.1096/fj.02-0041fje.

The above article, published online on September 5, 2002, in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the journal Editor-in-Chief, Loren E. Wold; the Federation of American Societies for Experimental Biology; and Wiley Periodicals LLC. The retraction has been agreed upon following an investigation into concerns raised by a third party which revealed inappropriate image duplications within the western blot lanes of Figure 5B and across the lanes of Figures 4A,C and 5A,B. Due to the number and the level of errors identified in the published figures, the editors have lost confidence in the presented data and consider the conclusions substantially compromised. The authors have been informed about the concerns, but did not provide an explanation and due to the time elapsed since publication the original raw data were not available.

Endothelial dysfunction, prevalent in cardiovascular diseases (CVDs) and linked to conditions like diabetes, hypertension, obesity, renal failure, or hypercholesterolemia, is characterized by diminished nitric oxide (NO) bioavailability—a key signaling molecule for vascular homeostasis. Current two-dimensional (2D) in vitro studies on NO synthesis by endothelial cells (ECs) lack the crucial laminar shear stress, a vital factor in modulating the NO-generating enzyme, endothelial nitric oxide synthase (eNOS), under physiological conditions. Here we developed a tracer-based metabolomics approach to measure NO-specific metabolites with mass spectrometry (MS) and show the impact of fluid flow on metabolic parameters associated with NO synthesis using 2D and 3D platforms. Specifically, we tracked the conversion of stable-isotope labeled NO substrate L-Arginine to L-Citrulline and L-Ornithine to determine eNOS activity. We demonstrated clear responses in human coronary artery endothelial cells (HCAECs) cultured with ¹³C₆, ¹⁵N₄-L-Arginine, and treated with eNOS stimulator, eNOS inhibitor, and arginase inhibitor. Analysis of downstream metabolites, ¹³C₆, ¹⁵N₃ L-Citrulline and ¹³C₅, ¹⁵N₂ L-Ornithine, revealed distinct outcomes. Additionally, we evaluated the NO metabolic status in static 2D culture and 3D microvessel models with bidirectional and unidirectional fluid flow. Our 3D model exhibited significant effects, particularly in microvessels exposed to the eNOS stimulator, as indicated by the ¹³C₆, ¹⁵N₃ L-Citrulline/¹³C₅, ¹⁵N₂ L-Ornithine ratio, compared to the 2D culture. The obtained results indicate that the 2D static culture mimics an endothelial dysfunction status, while the 3D model with a unidirectional fluid flow provides a more representative physiological environment that provides a better model to study endothelial dysfunction.