bims-kishpe 2024-11-10 papers

bims-kishpe

Biomed News

on HSP70 role in hypoxia and metabolism in ECs

Issue of 2024–11–10
ten papers selected by
Alia Ablieh, Universität Heidelberg

The HIF2α-dependent Upregulation of SETDB1 Facilitates Hypoxia-induced Functional and Phenotypical Changes of Pulmonary Microvascular Endothelial Cells.
Silencing METTL3 Increases HSP70 Expression and Alleviates Fibrosis in Keratocytes.
A bovine model of hypoxia-induced pulmonary hypertension reveals a gradient of immune and matrisome response with a complement signature found in circulation.
Dephosphorylated uncarboxylated Matrix-Gla-Protein as candidate biomarker for immune-mediated vascular remodeling and prognosis in pulmonary hypertension.
Direct activation of HSF1 by macromolecular crowding and misfolded proteins.
Atypical chemokine receptor 2 expression is directly regulated by hypoxia inducible factor-1 alpha in cancer cells under hypoxia.
Increased BMP-Responsive Transcription Factors in Distinct Endothelial and Mesenchymal Cells in PAH.
VE-cadherin shedding in vitro and in patients with aortic aneurysm and dissection.
Role of glycogen in cardiac metabolic stress.
PDGFRB promotes dedifferentiation and pulmonary metastasis through rearrangement of cytoskeleton under hypoxic microenvironment in osteosarcoma.

Am J Physiol Cell Physiol. 2024 Nov 04.

The HIF2α-dependent Upregulation of SETDB1 Facilitates Hypoxia-induced Functional and Phenotypical Changes of Pulmonary Microvascular Endothelial Cells.

Yin Zhou, Kai Yang, Zizhou Zhang, Feng Wei, Lishi Chen, Dongling Luo, Ziyang Yang, Kaixun Zhao, Nanshan Xie, Wenrui Li, Shuxin Liang, Mingmei Xiong, Haiyang Tang, Jian Wang, Caojin Zhang.

  Background: Emerging studies have reported the vital role of histone modification in the dysfunction of pulmonary vascular endothelial cells, which acts as the key reason to drive the hypoxia-induced pulmonary vascular remodeling and pulmonary hypertension (PH). This study aims to investigate the role of a histone 3 lysine 9 (H3K9) methyltransferase, SET domain bifurcated 1 (SETDB1), in hypoxia-induced functional and phenotypical changes of pulmonary vascular endothelial cells. Methods: Primarily cultured rat pulmonary microvascular endothelial cells (PMVECs) were used as cell model. Specific knockdown and overexpression strategies were used to systematically determine the molecular regulation and function of SETDB1 in PMVECs. Results: SETDB1 is highly expressed and significantly upregulated in the pulmonary vascular endothelium of lung tissue isolated from SU5416/hypoxia-induced PH (SuHx-PH) rats, and also in pulmonary arterial endothelial cells (PAECs) from idiopathic pulmonary arterial hypertension (IPAH) patients, comparing to their respective controls. In primarily cultured rat PMVECs, treatment of hypoxia or CoCl2 induces significant upregulation of HIF2α, SETDB1 and H3K9me3. Specific knockdown and overexpression strategies indicate the hypoxia- or CoCl2-induced upregulation of SETDB1 is mediated through a HIF2α-dependent mechanism. Knockdown of SETDB1 significantly inhibits the hypoxia- or CoCl2-induced apoptosis, senescence and endothelial to mesenchymal transition (EndoMT) in rat PMVECs. Moreover, treatment of the specific inhibitor of histone methyltransferase, Chaetocin, effectively attenuates the disease pathogenesis of SuHx-PH in rat. Conclusions: Our results suggest that the HIF2α-dependent upregulation of SETDB1 facilitates hypoxia-induced functional and phenotypical changes of PMVECs, potentially contributing to the hypoxia-induced pulmonary vascular remodeling and PH.

Keywords:  HIF2α; Hypoxia; Pulmonary hypertension; Pulmonary microvascular endothelial cell; SETDB1

DOI:  https://doi.org/10.1152/ajpcell.00732.2023
Invest Ophthalmol Vis Sci. 2024 Nov 04. 65(13): 9

Silencing METTL3 Increases HSP70 Expression and Alleviates Fibrosis in Keratocytes.

Yapeng Jing, Jun Li, Peng Hao, Shulei Xing, Xuan Li.

Purpose: To explore the potential role of N6-methyladenosine (m6A) and its regulatory factors in corneal fibrosis response using both in vivo and in vitro models.
Methods: This study utilized the C57BL/6 mouse corneal alkali burn as an in vivo model and stimulated keratocytes with transforming growth factor beta 1 (TGF-β1) in vitro. Small interfering RNA (siRNA) was employed to downregulate the expression of YTH domain family member 2 (YTHDF2), methyltransferase-like 3 (METTL3), and fat mass and obesity-associated protein (FTO) in keratocytes. The expression of relevant genes was quantified by real-time quantitative reverse-transcription PCR (qRT-PCR), western blotting, and immunohistochemistry.
Results: After an alkali burn, m6A modification in corneas increased, with the most notable increase observed on the fourth day after the injury. The levels of METTL3 and FTO initially decreased and then increased. After 21 days following an alkali burn, the corneal fibrosis was most significant. The levels of METTL3 and FTO were elevated. There were higher levels in m6A modification and the expression of METTL3 and FTO in keratocytes stimulated by TGF-β1. In corneas after alkali burns and in keratocytes stimulated by TGF-β1, the expression of heat shock protein 70 (HSP70) was negatively correlated with fibrotic response markers. Silencing METTL3 and YTHDF2 in keratocytes increased HSP70 expression and reduced the expression of fibrosis-related indicators in keratocytes stimulated by TGF-β1. However, silencing FTO did not significantly affect the expression of HSP70 and fibrosis.
Conclusions: These findings indicate that METTL3 is involved in the modulation of corneal fibrosis through the regulation of HSP70 expression in a manner that is dependent on YTHDF2.

DOI: https://doi.org/10.1167/iovs.65.13.9
Am J Physiol Cell Physiol. 2024 Nov 04.

A bovine model of hypoxia-induced pulmonary hypertension reveals a gradient of immune and matrisome response with a complement signature found in circulation.

Jason Williams, Franklyn N Iheagwam, Sean P Maroney, Lauren R Schmitt, R Dale Brown, Greta M Krafsur, Maria G Frid, Maxwell C McCabe, Aneta Gandjeva, Kurt J Williams, James P Luyendyk, Anthony J Saviola, Rubin M Tuder, Kurt Stenmark, Kirk C Hansen.

  Pulmonary hypertension (PH) is a progressive vascular disease characterized by vascular remodeling, stiffening, and luminal obstruction, driven by dysregulated cell proliferation, inflammation, and extracellular matrix (ECM) alterations. Despite the recognized contribution of ECM dysregulation to PH pathogenesis, the precise molecular alterations in the matrisome remain poorly understood. In this study, we employed a matrisome-focused proteomics approach to map the protein composition in a young bovine calf model of acute hypoxia-induced PH. Our findings reveal distinct alterations in the matrisome along the pulmonary vascular axis, with the most prominent changes observed in the main pulmonary artery. Key alterations included a strong immune response and wound repair signature, characterized by increased levels of complement components, coagulation cascade proteins, and provisional matrix markers. Additionally, we observed upregulation of ECM-modifying enzymes, growth factors, and core ECM proteins implicated in vascular stiffening, such as collagens, periostin, tenacsin-C, and fibrin(ogen). Notably, these alterations correlated with increased mean pulmonary arterial pressure and vascular remodeling. In the plasma, we identified increased levels of complement components, indicating a systemic inflammatory response accompanying the vascular remodeling. Our findings shed light on the dynamic matrisome remodeling in early-stage PH, implicating a wound-healing trajectory with distinct patterns from the MPA to the distal vasculature. This study provides novel insights into the molecular underpinnings of PH pathogenesis and highlights potential biomarkers and therapeutic targets within the matrisome landscape.

Keywords:  Extracellular Matrix; Pulmonary hypertension; fibrosis; hypoxia; injury

DOI:  https://doi.org/10.1152/ajpcell.00274.2024
Sci Rep. 2024 11 04. 14(1): 26633

Dephosphorylated uncarboxylated Matrix-Gla-Protein as candidate biomarker for immune-mediated vascular remodeling and prognosis in pulmonary hypertension.

R Tobal, J Potjewijd, F de Vries, D P C van Doorn, A Jaminon, R Bittner, C Akbulut, V van Empel, P Heeringa, J Damoiseaux, L Schurgers, P van Paassen.

  Pulmonary arterial hypertension (PAH) is a disease characterized by pulmonary vascular remodeling. Since dephosphorylated-uncarboxylated Matrix Gla-Protein (dp-ucMGP) is associated with cardiovascular mortality in systemic sclerosis, a disease associated with PAH, and immune-system involvement in PAH is increasingly recognized, we investigated the relationship between dp-ucMGP, vascular remodeling and soluble immune-checkpoint proteins in PAH. This prospective cohort study included patients with idiopathic (I)PAH, connective tissue disease (CTD)-PAH, chronic thrombo-embolic PH (CTEPH) and CTD patients without PAH. Patients with IPAH and CTD-PAH were stratified by clinical signs of immune-mediated inflammatory disease (IMID). We measured dp-ucMGP plasma levels, soluble immune-checkpoint proteins (sICPs), and vascular smooth muscle cell (iVSMC) calcification. We found elevated dp-ucMGP levels in all PAH subtypes and CTD patients compared to healthy controls. PAH patients showed increased iVSMC calcification, but no direct correlation was found with dp-ucMGP. IMID-PAH patients had higher dp-ucMGP levels than non-IMID PAH patients. dp-ucMGP correlated with several sICPs in both IPAH and CTD patients; multiple sICPs were elevated in IMID PAH patients. High dp-ucMGP levels in IPAH patients were associated with worse survival. Our findings suggest dp-ucMGP as a potential biomarker of immune-mediated vascular remodeling in PAH. Hence, dp-ucMGP, could help identify PAH patients who might benefit from immunosuppressive therapies.

Keywords:  Biomarkers; Dp-ucMGP; Immune checkpoint proteins; Inflammation; Pulmonary hypertension; Vascular remodeling

DOI:  https://doi.org/10.1038/s41598-024-77000-w
PLoS One. 2024 ;19(11): e0312524

Direct activation of HSF1 by macromolecular crowding and misfolded proteins.

Oliver Simoncik, Vlastimil Tichy, Michal Durech, Lenka Hernychova, Filip Trcka, Lukas Uhrik, Miroslav Bardelcik, Philip J Coates, Borivoj Vojtesek, Petr Muller.

Stress responses play a vital role in cellular survival against environmental challenges, often exploited by cancer cells to proliferate, counteract genomic instability, and resist therapeutic stress. Heat shock factor protein 1 (HSF1), a central transcription factor in stress response pathways, exhibits markedly elevated activity in cancer. Despite extensive research into the transcriptional role of HSF1, the mechanisms underlying its activation remain elusive. Upon exposure to conditions that induce protein damage, monomeric HSF1 undergoes rapid conformational changes and assembles into trimers, a key step for DNA binding and transactivation of target genes. This study investigates the role of HSF1 as a sensor of proteotoxic stress conditions. Our findings reveal that purified HSF1 maintains a stable monomeric conformation independent of molecular chaperones in vitro. Moreover, while it is known that heat stress triggers HSF1 trimerization, a notable increase in trimerization and DNA binding was observed in the presence of protein-based crowders. Conditions inducing protein misfolding and increased protein crowding in cells directly trigger HSF1 trimerization. In contrast, proteosynthesis inhibition, by reducing denatured proteins in the cell, prevents HSF1 activation. Surprisingly, HSF1 remains activated under proteotoxic stress conditions even when bound to Hsp70 and Hsp90. This finding suggests that the negative feedback regulation between HSF1 and chaperones is not directly driven by their interaction but is realized indirectly through chaperone-mediated restoration of cytoplasmic proteostasis. In summary, our study suggests that HSF1 serves as a molecular crowding sensor, trimerizing to initiate protective responses that enhance chaperone activities to restore homeostasis.

DOI: https://doi.org/10.1371/journal.pone.0312524
Sci Rep. 2024 11 04. 14(1): 26589

Atypical chemokine receptor 2 expression is directly regulated by hypoxia inducible factor-1 alpha in cancer cells under hypoxia.

Alice Benoit, Audrey Lequeux, Phillip Harter, Guy Berchem, Bassam Janji.

  Lack of significant and durable clinical benefit from anti-cancer immunotherapies is partly due to the failure of cytotoxic immune cells to infiltrate the tumor microenvironment. Immune infiltration is predominantly dependent on the chemokine network, which is regulated in part by chemokine and atypical chemokine receptors. We investigated the impact of hypoxia in the regulation of Atypical Chemokine Receptor 2 (ACKR2), which subsequently regulates major pro-inflammatory chemokines reported to drive cytotoxic immune cells into the tumor microenvironment. Our in silico analysis showed that both murine and human ACKR2 promoters contain hypoxia response element (HRE) motifs. Murine and human colorectal, melanoma, and breast cancer cells overexpressed ACKR2 under hypoxic conditions in a HIF-1α dependent manner; as such overexpression was abrogated in melanoma cells expressing non-functional deleted HIF-1α. We also showed that decreased expression of ACKR2 in HIF-1α-deleted cells under hypoxia was associated with increased CCL5 levels. Chromatin immunoprecipitation data confirmed that ACKR2 is directly regulated by HIF-1α at its promoter in B16-F10 melanoma cells. This study provides new key elements on how hypoxia can impair immune infiltration in the tumor microenvironment.

Keywords:  Atypical chemokine receptors; Cancer; Chemokines; Hypoxia; Immune infiltration

DOI:  https://doi.org/10.1038/s41598-024-77628-8
Am J Respir Crit Care Med. 2024 Nov 05.

Increased BMP-Responsive Transcription Factors in Distinct Endothelial and Mesenchymal Cells in PAH.

Adam Michael Andruska, Rodrigo Cantu Valadez, Kenzo Ichimura, Pauline Chu, Tianyi Zhang, Katharina Schimmel, Lingli Wang, Aiqin Cao, Micheala A Aldred, Edda Spiekerkoetter.



Keywords:  BMPR2, Pulmonary Arterial Hypertension, Spatial Transcriptomics

DOI:  https://doi.org/10.1164/rccm.202405-1039LE
Sci Rep. 2024 11 05. 14(1): 26743

VE-cadherin shedding in vitro and in patients with aortic aneurysm and dissection.

Paul Stammer, Inka Terhorst, Jiangang Guo, Abdulhakim Ibrahim, Alexander Oberhuber, Thorsten Eierhoff.

  VE-cadherin (VEC) is a major endothelial adhesion protein, which controls vascular homeostasis. During vascular diseases, VEC can be shed from the endothelial surface by proteases like ADAM10/17, which cleave the extracellular domain of VEC in response to inflammatory cytokines like TNF-α. The resulting, soluble fragments (sVEC) are discussed as a potential marker for endothelial barrier breakdown. However, its pathologic role or its potential as a specific biomarker for aortic diseases is yet unknown. Here we investigated the specificity and linkage of sVEC production with ADAM10/17 and TNF-α, both in vitro and in patients with aortic aneurysms and dissections, comparing the findings with those from patients with carotid stenosis and varicosis. Thereby, the baseline levels of sVEC, TNF-α, ADAM10 and Albumin was measured in clinical plasma samples and cell culture supernatants of human aortic endothelial cells (HAOEC) treated with TNF-α or ADAM10/17 inhibitors. The integrity of HAOEC monolayers was tested by permeability assays using Alexa488-conjugated dextran (10 kDa). Peripheral EDTA plasma samples taken preoperatively from patients ≥ 18 years of age that were diagnosed for aortic dissection (n = 29), aortic aneurysm (n = 76), carotid stenosis (n = 29) and varicose veins (n = 24) were included. In vitro shedding of VEC was induced by TNF-α and depends on ADAM10/17, which led to altered endothelial permeability. Absolute plasma sVEC levels in patients with aortic dissection (3016 ± 1008 ng/mL) and aneurysm (3288 ± 1376 ng/mL) were not statistically significantly different from patients with carotid stenosis (3013 ± 687.6 ng/mL) and varicose veins (3313 ± 1337 ng/mL). Plasma sVEC levels correlated positively with plasma TNF-α (r = 0.5586, p < 0.0001) and ADAM10 (r = 0.7003, p < 0.0001) levels with the highest degree of correlation between ADAM10 and sVEC for chronic aortic dissection (r = 0.7890, p = 0.0013), reflecting TNF-α and ADAM10 dependency of VEC shedding. In summary, VEC shedding and (plasma) sVEC levels are influenced by TNF-α and ADAM10/17 and could play a relevant role in the specific pathophysiological context of aortic diseases.

Keywords:  ADAM10; Aortic disease; Microbiota; TNF-α; VE-cadherin

DOI:  https://doi.org/10.1038/s41598-024-77940-3
Metabolism. 2024 Nov 03. pii: S0026-0495(24)00287-7. [Epub ahead of print] 156059

Role of glycogen in cardiac metabolic stress.

Ke-Fa Xiang, Jing-Jing Wan, Peng-Yuan Wang, Xia Liu.

  Metabolic stress in the myocardium arises from a diverse array of acute and chronic pathophysiological contexts. Glycogen mishandling is a key feature of metabolic stress, while maladaptation in energy-stress situations confers functional deficits. Cardiac glycogen serves as a pivotal reserve for myocardial energy, which is classically described as an energy source and contributes to glucose homeostasis during hypoxia or ischemia. Despite extensive research activity, how glycogen metabolism affects cardiovascular disease remains unclear. In this review, we focus on its regulation across myocardial energy metabolism in response to stress, and its role in metabolism, immunity, and autophagy. We further summarize the cardiovascular-related drugs regulating glycogen metabolism. In this way, we provide current knowledge for the understanding of glycogen metabolism in the myocardium.

Keywords:  Autophagy; Cardiac glycogen; Glycolysis; Immune regulation; Lipid metabolism; Metabolic stress; Mitochondrial function

DOI:  https://doi.org/10.1016/j.metabol.2024.156059
Cell Signal. 2024 Nov 04. pii: S0898-6568(24)00476-5. [Epub ahead of print] 111501

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

Enjie Xu, Zhen Huang, Kunpeng Zhu, Jianping Hu, Xiaolong Ma, Yongjie Wang, Jiazhuang Zhu, Chunlin Zhang.

   BACKGROUND: 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.
METHODS: 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.
RESULTS: 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.
CONCLUSION: 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.

Keywords:  Cytoskeleton rearrangement; Dedifferentiation; Hypoxia; Metastasis; Osteosarcoma; PDGFRB

DOI:  https://doi.org/10.1016/j.cellsig.2024.111501