HSP70-1 is required for interleukin-5-induced angiogenic responses through eNOS pathway

IL-28A/IL-10Rβ axis promotes angiogenesis via eNOS/AKT signaling and AP-1/NF-κB/MMP-2 network by regulating HSP70-1 expression

INTRODUCTION

Angiogenesis plays a significant role in the development of tumor progression and inflammatory diseases. The role of IL-28A in angiogenesis and its precise regulatory mechanisms remain rarely elucidated.

OBJECTIVES

We report the novel regulatory role of IL-28A in physiological angiogenesis. The study aimed to elucidate the regulatory mechanisms involved in IL-28A-mediated angiogenesis and identify key genes associated with IL-28A-induced angiogenic responses.

METHODS

To know the effect of IL-28A on angiogenesis, HUVECs were applied to perform proliferation, migration, invasion, tube formation, immunoblot, and EMSA. Gene expression changes in HUVECs following IL-28A treatment were analyzed by NGS. The functional role of HSP70-1 and IL-10Rβ in IL-28A-induced angiogenic responses was evaluated using PCR and siRNA knockdown. Animal studies were conducted by aortic ring ex vivo assays, Matrigel plug in vivo assays, and immunochemistry using HSP70-1 knockout and transgenic mice models. The efficacy of IL-28A in angiogenesis was confirmed in a hind-limb ischemia model.

RESULTS

Autocrine/paracrine actions in HUVECs regulated IL-28A protein expression. Exogenous IL-28A increased the proliferation of HUVECs via eNOS/AKT and ERK1/2 signaling. IL-28A treatment promoted migration, invasion, and capillary tube formation of HUVECs through induction of the AP-1/NF-κB/MMP-2 network, which was associated with eNOS/AKT and ERK1/2 signaling. The efficacy of IL-28A-induced angiogenic potential was confirmed by aortic ring and Matrigel plug assay. HSP70-1 was identified as an IL-28A-mediated angiogenic effector gene using bioinformatics. Knockdown of HSP70-1 abolished angiogenic responses and eNOS/AKT signaling in IL-28A-treated HUVECs. IL-28A-induced microvessel sprouting formation was testified in HSP70-1-deficient and HSP70-1 transgenic mice. Flow recovery in hind-limb ischemia mice was accelerated by IL-28A injection. Finally, ablation of the IL-10Rβ gene impeded the angiogenic responses and eNOS/AKT signaling stimulated by IL-28A in HUVECs.

CONCLUSION

HSP70-1 drives the progression of angiogenesis by the IL-28A/IL-10Rβ axis via eNOS/AKT signaling and the AP-1/NF-κB/MMP-2 network.

A biomimetic tri-phasic scaffold with spatiotemporal patterns of gastrodin to regulate hierarchical tissue-based vascular regeneration

Clinical use of small-diameter vascular grafts remains a challenging issue in neovessel regeneration in view of thrombosis and intimal hyperplasia. Developing a vascular graft with structure and function similar to those of the native vessels necessitates a major direction of vascular tissue regeneration. Thus, this study sought to design and fabricate a range of tri-phasic scaffolds (0, 2, and 5 wt% gastrodin-polyurethane (PU)) with spatiotemporally defined structure and gastrodin-release for regulating the highly coordinated processes in growth of the intima and media. While the small pores of inner layer guided infiltration of human umbilical vein endothelial cells (HUVECs), the bigger pores of medial layer could offer smooth muscle cell (SMC)-friendly habitat, and external fibers conferred adequate mechanical properties. Correspondingly, spatial distribution and differential regulation of key proteins in HUVECs and SMCs were mediated by hierarchical release of gastrodin, of which rapid release in inner layer elicited enhanced HUVEC proliferation and migration against those of the SMC via activated endothelial nitric oxide synthase (eNOS) and heat shock protein 70 (HSP70) signal. Of note, superior anti-coagulation was reflected in 2 wt% gastrodin-PU ex vivo extracorporeal blood circulation experiment. After in vivo implantation for 12 weeks, there was no formation of obvious thrombosis and intimal hyperplasia in 2 wt% gastrodin-PU. The scaffold maintained high patency and improved vascular remodeling, including the formation of thin endothelialization in lumen and dense extracellular matrix deposition in medial layer. Taken together, the results demonstrate the positive function of hierarchical releasing system that responded to tri-phasic structure, which not only suppressed intimal thickening but also tightly controlled tissue regeneration.

Tissue Eosinophilia in B-cell Lymphoma: An Underrecognized Phenomenon

Tissue eosinophilia is seldom reported in B-cell lymphoma. It poses diagnostic challenges and frequently leads to the consideration of other diagnoses, particularly T-cell lymphomas. The scarce literature underscores the need for in-depth studies to enhance awareness and understanding of this phenomenon. We investigated 54 cases of B-cell lymphoma with notable tissue eosinophils, analyzing clinical information, hematoxylin and eosin staining, immunohistochemistry, and PCR-based clonality analysis. Nodal marginal zone lymphoma (NMZL) emerged as the most prevalent type (n=26), followed by B-cell lymphoma, not otherwise specified (n=13), diffuse large B-cell lymphoma (n=10), follicular lymphoma (n=2), chronic lymphocytic leukemia/small lymphocytic lymphoma (n=1), extranodal marginal zone lymphoma (n=1), and primary cutaneous marginal zone lymphoma (n=1). Shared features across different lymphoma types, best exemplified by NMZL, included plasmacytic differentiation (57.7%), increased vascularity (84.6%) with a tendency for perivascular distribution of neoplastic cells, and a tumor microenvironment abundant in T cells and histiocytes; some cases showed increased PD-1-positive cells. These features often raise consideration of angioimmunoblastic T-cell lymphoma. Along with clonality analysis, features supporting the diagnosis of B-cell lymphoma included cytological atypia in B cells rather than T cells, and the lack of follicular dendritic cell meshwork expansion. In addition, diffuse large B-cell lymphoma frequently exhibited interfollicular distribution and monocytoid appearance, indicating the possibility of transformed NMZL. Collectively, tissue eosinophilia can occur in diverse B-cell lymphomas but is most prevalent in tumors with a postgerminal stage of differentiation.

Systemic inflammatory regulators and preeclampsia: a two-sample bidirectional Mendelian randomization study

Background

Systemic inflammatory regulators have been associated with preeclampsia (PE) during pregnancy; however, there is inconsistent evidence from animal models and observational results.

Methods

Using summary data from genome-wide association studies (GWASs), we performed a bidirectional Mendelian randomization (MR) analysis of two samples of systemic inflammatory regulators (n = 8,186) and PE (n = 267,242) individuals of European ancestry. As our primary analysis, we used the random-effects inverse-variance weighted (IVW) approach. Sensitivity and pleiotropy analyses were conducted using the MR-Egger method, weighted median, MR Pleiotropy RESidual Sum and Outlier (MR-PRESSO), and Cochran's Q test.

Results

The results indicate that there is a correlation between a higher circulating level of tumor necrosis factor alpha (TNF-α) and interleukin-9 (IL-9) and an increased risk of PE (odds ratio [OR] = 1.32, 95% confidence interval [CI] = 1.09-1.60, p = 0.004 and OR = 1.28, 95% CI: 1.02-1.62, p = 0.033, respectively). Conversely, lower levels of stem cell growth factor beta (SCGF-β) (OR = 0.89, 95% CI: 0.80-0.99, p = 0.027) and interleukin-5 (IL-5) (OR = 0.80, 95% CI: 0.65-0.98, p = 0.030) are linked to an increased risk of PE. The macrophage migration inhibitory factor (MIF) is the downstream inflammatory regulator of PE, according to reverse magnetic resonance imaging studies.

Conclusion

Our study suggests that SCGF-β, IL-5, IL-9, and TNF-α causally affect the PE risk, while PE is causally associated with MIF. Further studies are needed to validate these biomarkers in managing PE.

The multifunction of HSP70 in cancer: Guardian or traitor to the survival of tumor cells and the next potential therapeutic target

Heat shock protein 70 (HSP70) is a highly conserved protein composed of nucleotide-binding domains (NBD) and C-terminal substrate binding domain (SBD) that can function as a "molecular chaperone". HSP70 was discovered to directly or indirectly play a regulatory role in both internal and external apoptosis pathways. Studies have shown that HSP70 can not only promote tumor progression, enhance tumor cell resistance and inhibit anticancer effects but also induce an anticancer response by activating immune cells. In addition, chemotherapy, radiotherapy and immunotherapy for cancer may be affected by HSP70, which has shown promising potential as an anticancer drug. In this review, we summarized the molecular structure and mechanism of HSP70 and discussed the dual effects of HSP70 on tumor cells and the possibility and potential methods of using HSP70 as a target to treat cancer.

IL-4 and IL-13, not eosinophils, drive type 2 airway inflammation, remodeling and lung function decline

RATIONALE

Type 2 (T2) asthma is characterized by airflow limitations and elevated levels of blood and sputum eosinophils, fractional exhaled nitric oxide, IgE, and periostin. While eosinophils are associated with exacerbations, the contribution of eosinophils to lung inflammation, remodeling and function remains largely hypothetical.

OBJECTIVES

To determine the effect of T2 cytokines IL-4, IL-13 and IL-5 on eosinophil biology and compare the impact of depleting just eosinophils versus inhibiting all aspects of T2 inflammation on airway inflammation.

METHODS

Human eosinophils or endothelial cells stimulated with IL-4, IL-13 or IL-5 were assessed for gene changes or chemokine release.Mice exposed to house dust mite extract received anti-IL-4Rα (dupilumab), anti-IL-5 or control antibodies and were assessed for changes in lung histological and inflammatory endpoints.

MEASUREMENTS AND MAIN RESULTS

IL-4 or IL-13 stimulation of human eosinophils and endothelial cells induced gene expression changes related to granulocyte migration; whereas, IL-5 induced changes reflecting granulocyte differentiation.In a mouse model, blocking IL-4Rα improved lung function by impacting multiple effectors of inflammation and remodeling, except peripheral eosinophil counts, thereby disconnecting blood eosinophils from airway inflammation, remodeling and function. Blocking IL-5 globally reduced eosinophil counts but did not impact inflammatory or functional measures of lung pathology. Whole lung transcriptome analysis revealed that IL-5 or IL-4Rα blockade impacted eosinophil associated genes, whereas IL-4Rα blockade also impacted genes associated with multiple cells, cytokines and chemokines, mucus production, cell:cell adhesion and vascular permeability.

CONCLUSIONS

Eosinophils are not the sole contributor to asthma pathophysiology or lung function decline and emphasizes the need to block additional mediators to modify lung inflammation and impact lung function.

Heat Shock Protein 70 in Penile Neurovascular Regeneration Requires Cystathionine Gamma-Lyase

Purpose

Diabetes mellitus, one of the major causes of erectile dysfunction, leads to a poor response to phosphodiesterase-5 inhibitors. Heat shock protein 70 (Hsp70), a ubiquitous molecular chaperone, is known to play a role in cell survival and neuroprotection. Here, we aimed to assess whether and how Hsp70 improves erectile function in diabetic mice.

Materials and Methods

Eight-week-old male C57BL/6 mice and Hsp70-Tg mice were used in this study. We injected Hsp70 protein into the penis of streptozotocin (STZ)-induced diabetic mice. Detailed mechanisms were evaluated in WT or Hsp70-Tg mice under normal and diabetic conditions. Primary MCECs, and MPG and DRG tissues were cultivated under normal-glucose and high-glucose conditions.

Results

Using Hsp70-Tg mice or Hsp70 protein administration, we demonstrate that elevated levels of Hsp70 restores erectile function in diabetic mice. We found that cystathionine gamma-lyase (Cse) is a novel target of Hsp70 in this process, showing that Hsp70-Cse acts through the SDF1/HO-1/PI3K/Akt/eNOS/NF-κB p65 pathway to exert its neurovascular regeneration-promoting effects. Coimmunoprecipitation and pull-down assays using mouse cavernous endothelial cells treated with Hsp70 demonstrated physical interactions between Hsp70 and Cse with a dissociation constant of 1.8 nmol/L.

Conclusions

Our findings provide novel and solid evidence that Hsp70 acts through a Cse-dependent mechanism to mediate neurovascular regeneration and restoration of erectile function under diabetic conditions.

Editome landscape of CCM-derived endothelial cells

By regulating several phases of gene expression, RNA editing modifications contribute to maintaining physiological RNA expression levels. RNA editing dysregulation can affect RNA molecule half-life, coding/noncoding RNA interaction, alternative splicing, and circular RNA biogenesis. Impaired RNA editing has been observed in several pathological conditions, including cancer and Alzheimer's disease. No data has been published yet on the editome profile of endothelial cells (ECs) isolated from human cerebral cavernous malformation (CCM) lesions. Here, we describe a landscape of editome modifications in sporadic CCM-derived ECs (CCM-ECs) by comparing editing events with those observed in human brain microvascular endothelial cells (HBMECs). With a whole transcriptome-based variant calling pipeline, we identified differential edited genes in CCM-ECs that were enriched in pathways related to angiogenesis, apoptosis and cell survival, inflammation and, in particular, to thrombin signalling mediated by protease-activated receptors and non-canonical Wnt signalling. These pathways, not yet associated to CCM development, could be a novel field for further investigations on CCM molecular mechanisms. Moreover, enrichment analysis of differentially edited miRNAs suggested additional small noncoding transcripts to consider for development of targeted therapies.

Evaluation of cytokine profile in the different phases of the autologous hematopoietic stem cell transplantation in patients with multiple myeloma

BACKGROUND

The autologous hematopoietic stem cell transplantation (ASCT) is of fundamental importance in the treatment of patients with multiple myeloma (MM). Nevertheless, due to its toxicity, it decreases the number of bone marrow cells available, altering the cell interactions and causing an imbalance between pro- and anti-inflammatory cytokines.

METHODS

Thus, we determined the serum levels of pro- and anti-inflammatory cytokines in samples of patients with MM obtained from the different phases of ASCT.

RESULTS

In summary, the cytokines levels varied considering the different phases of ASCT. The levels of IL-1ra tend to increase in the post-apheresis period suggesting an anti-inflammatory role induced by the apheresis process. A response characterized by the increase in the concentrations of IL-5 and IL-8 was observed in the post-conditioning bone marrow aplasia phase. The rise in IL-5 levels was not correlated with any clinical or laboratory event in this framework; IL-8 was associated with positive blood cultures and seems to have an effect against microbial agents. The increase in the levels of IL-10 and IL-12 suggests a possible regulatory effect of the inflammatory response in the period of bone marrow recovery and IL-12 seems to be inversely associated with the presence of minimal residual disease.

CONCLUSIONS

Apheresis process seems to induce an anti-inflammatory response, followed by a pro-inflammatory response and a stimulus for granulocytes differentiation.

HSP70s in Breast Cancer: Promoters of Tumorigenesis and Potential Targets/Tools for Therapy

The high frequency of breast cancer worldwide and the high mortality among women with this malignancy are a serious challenge for modern medicine. A deeper understanding of the mechanisms of carcinogenesis and emergence of metastatic, therapy-resistant breast cancers would help development of novel approaches to better treatment of this disease. The review is dedicated to the role of members of the heat shock protein 70 subfamily (HSP70s or HSPA), mainly inducible HSP70, glucose-regulated protein 78 (GRP78 or HSPA5) and GRP75 (HSPA9 or mortalin), in the development and pathogenesis of breast cancer. Various HSP70-mediated cellular mechanisms and pathways which contribute to the oncogenic transformation of mammary gland epithelium are reviewed, as well as their role in the development of human breast carcinomas with invasive, metastatic traits along with the resistance to host immunity and conventional therapeutics. Additionally, intracellular and cell surface HSP70s are considered as potential targets for therapy or sensitization of breast cancer. We also discuss a clinical implication of Hsp70s and approaches to targeting breast cancer with gene vectors or nanoparticles downregulating HSP70s, natural or synthetic (small molecule) inhibitors of HSP70s, HSP70-binding antibodies, HSP70-derived peptides, and HSP70-based vaccines.

Evaluation of 3,4,4,9-trichlorocarbanilide to zebrafish developmental toxicity based on transcriptomics analysis

Triclocarban (TCC), considered an endocrine-disrupting, persistent, and bioaccumulating organic matter, has attracted a great deal of attention for its pollution and health risks. However, studies on its toxicological mechanism, especially for embryo development are limited. This article explores the cardiac developmental toxicity induced in zebrafish embryos after exposure to different TCC concentrations. First, liquid chromatography-tandem mass spectrometry was used in detecting TCC in embryos in vivo after exposure to various TCC. Results showed that embryonic TCC content reached 9.23 ng after exposure to 300 μg/L TCC, the heart rates of the embryos markedly decreased, heart abnormalities significantly increased. In addition, obvious pericardial effusion was observed in the larvae. Through transcriptome sequencing, 200 differential gene expression (DGE) patterns were detected in the TCC (300 μg/L) experimental and control groups. The results of GO function analysis and KEGG pathway of DGE showed that aryl hydrocarbon receptor (AhR) activation and cyp-related genes (cyp1a, cyp1b1 and cyp1c) were significantly up-regulated. these affected the normal development of zebrafish embryonic heart, tissue edema, and hemorrhage. TCC exhibited strong cardiac teratogenic effects and developmental toxicity, which is partly related to AhR activation. Transcriptome-based results are helpful in precisely determining the risk of TCC exposure. The potential mechanism between TCC and AhR should be further investigated.

Interleukin-5-induced eosinophil population improves cardiac function after myocardial infarction

AIMS

Interleukin (IL)-5 mediates the development of eosinophils (EOS) that are essential for tissue post-injury repair. It remains unknown whether IL-5 plays a role in heart repair after myocardial infarction (MI). This study aims to test whether IL-5-induced EOS population promotes the healing and repair process post-MI and to reveal the underlying mechanisms.

METHOD AND RESULTS

MI was induced by permanent ligation of the left anterior descending coronary artery in wild-type C57BL/6 mice. Western blot and real-time polymerase chain reaction revealed elevated expression of IL-5 in the heart at 5 days post-MI. Immunohistostaining indicated that IL-5 was secreted mainly from macrophages and type 2 innate lymphoid cells in the setting of experimental MI. External supply of recombinant mouse IL-5 (20 min, 1 day, and 2 days after MI surgery) reduced the infarct size and increased ejection fraction and angiogenesis in the border zone. A significant expansion of EOS was detected in both the peripheral blood and infarcted myocardium after IL-5 administration. Pharmacological depletion of EOS by TRFK5 pretreatment muted the beneficial effects of IL-5 in MI mice. Mechanistic studies demonstrated that IL-5 increased the accumulation of CD206+ macrophages in infarcted myocardium at 7 days post-MI. In vitro co-culture experiments showed that EOS shifted bone marrow-derived macrophage polarization towards the CD206+ phenotypes. This activity of EOS was abolished by IL-4 neutralizing antibody, but not IL-10 or IL-13 neutralization. Western blot analyses demonstrated that EOS promoted the macrophage downstream signal transducer and activator of transcription 6 (STAT6) phosphorylation.

CONCLUSION

IL-5 facilitates the recovery of cardiac dysfunction post-MI by promoting EOS accumulation and subsequent CD206+ macrophage polarization via the IL-4/STAT6 axis.

TRANSLATIONAL PERSPECTIVE

Accumulating evidence suggests that modulation of innate and adaptive immune responses is a promising therapeutic strategy for myocardial infarction. In this study, we demonstrate that IL-5 exerts cardioprotective effects on infarcted myocardium by promoting eosinophil accumulation and subsequent CD206+ macrophage polarization via the IL-4/STAT6 axis. Hence, regulation of cardiac IL-5 level or eosinophil count may become a therapeutic approach for post-myocardial infarction cardiac repair in humans.

Function, Therapeutic Potential, and Inhibition of Hsp70 Chaperones

Hsp70s are among the most highly conserved proteins in all of biology. Through an iterative binding and release of exposed hydrophobic residues on client proteins, Hsp70s can prevent aggregation and promote folding to the native state of their client proteins. The human proteome contains eight canonical Hsp70s. Because Hsp70s are relatively promiscuous they play a role in folding a large proportion of the proteome. Hsp70s are implicated in disease through their ability to regulate protein homeostasis. In recent years, researchers have attempted to develop selective inhibitors of Hsp70 isoforms to better understand the role of individual isoforms in biology and as potential therapeutics. Selective inhibitors have come from rational design, forced localization, and serendipity, but the development of completely selective inhibitors remains elusive. In the present review, we discuss the Hsp70 structure and function, the known Hsp70 client proteins, the role of Hsp70s in disease, and current efforts to discover Hsp70 modulators.

A Novel Cyclic Pentadepsipeptide, N-Methylsansalvamide, Suppresses Angiogenic Responses and Exhibits Antitumor Efficacy against Bladder Cancer

Simple Summary

We found a novel cyclic pentadepsipeptide, N-methylsansalvamide (MSSV), and evaluated its anti-tumor action against bladder cancer using in vitro and in vivo model systems. Additionally, we report its anti-angiogenic responses both in vitro and in vivo. Moreover, acute toxicity test and tissue staining for liver function revealed that orally administered MSSV (2000 mg/kg for 14 days) exerted no harmful effects as it did not cause animal death, undesirable weigh alteration, adverse clinical symptoms, and abnormal biochemical marker levels (AST, ALT).

Abstract

Here, we explored the anti-tumor efficacy of a cyclic pentadepsipeptide, N-methylsansalvamide (MSSV), in bladder cancer. MSSV inhibited the proliferation of both bladder cancer 5637 and T24 cells, which was attributed to the G1-phase cell cycle arrest, apoptosis induction, and alteration of mitogen-activated protein kinases (MAPKs) and protein kinase b (AKT) signaling pathways. Additionally, the treatment of bladder cancer cells with MSSV suppressed migratory and invasive potential via the transcription factor-mediated expression of matrix metalloproteinase 9 (MMP-9). MSSV abrogated vascular endothelial growth factor (VEGF)-induced angiogenic responses in vitro and in vivo. Furthermore, our result showed the potent anti-tumor efficacy of MSSV in a xenograft mouse model implanted with bladder cancer 5637 cells. Finally, acute toxicity test data obtained from blood biochemical test and liver staining indicated that the oral administration of MSSV at 2000 mg/kg caused no adverse cytotoxic effects. Our preclinical data described the potent anti-angiogenic and anti-tumor efficacy of MSSV and showed no signs of acute toxicity, thereby suggesting the putative potential of oral MSSV as a novel anti-tumor agent in bladder cancer treatment.

Carnosine Impedes PDGF-Stimulated Proliferation and Migration of Vascular Smooth Muscle Cells In Vitro and Sprout Outgrowth Ex Vivo

Carnosine, a naturally producing dipeptide, exhibits various beneficial effects. However, the possible role of carnosine in vascular disorders associated with pathological conditions, including proliferation and migration of vascular smooth muscle cells (VSMCs), largely remains unrevealed. Here, we investigated the regulatory role and mechanism of carnosine in platelet-derived growth factor (PDGF)-induced VSMCs. Carnosine inhibited the proliferation of PDGF-induced VSMCs without any cytotoxic effects. Carnosine treatment also induced G1-phase cell cycle arrest by causing a p21WAF1-mediated reduction in the expression of both cyclin-dependent kinases (CDKs) and cyclins in PDGF-treated VSMCs. Carnosine treatment suppressed c-Jun N-terminal kinase (JNK) phosphorylation in PDGF-stimulated signaling. Additionally, carnosine significantly prevented the migration of VSMCs exposed to PDGF. Carnosine abolished matrix metalloproteinase (MMP)-9 activity via reduced transcriptional binding activity of NF-κB, Sp-1, and AP-1 motifs in PDGF-treated VSMCs. Moreover, using aortic assay ex vivo, it was observed that carnosine addition attenuated PDGF-stimulated sprout outgrowth of VSMCs. Taken together, these results demonstrated that carnosine impeded the proliferation and migration of PDGF-stimulated VSMCs by regulating cell cycle machinery, JNK signaling, and transcription factor-mediated MMP-9 activity as well as prevented ex vivo sprout outgrowth of blood vessels. Thus, carnosine may be a potential candidate for preventing vascular proliferative disease.

HSP70-eIF4G Interaction Promotes Protein Synthesis and Cell Proliferation in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide and features various tumor escape mechanisms from treatment-induced stress. HSP70 plays a critical role in cell protection under stress. eIF4G physiologically regulates the formation of the protein-ribosomal complex and maintains cellular protein synthesis. However, the precise cooperation of both in HCC remains poorly understood. In this study, we demonstrate that HSP70 expression is positively correlated with eIF4G in tumor specimens from 25 HCC patients, in contrast to the adjacent non-tumorous tissues, and that both influence the survival of HCC patients. Mechanistically, this study indicates that HSP70 and eIF4G interact with each other in vitro. We further show that the HSP70–eIF4G interaction contributes to promoting cellular protein synthesis, enhancing cell proliferation, and inhibiting cell apoptosis. Collectively, this study reveals the pivotal role of HSP70–eIF4G interaction as an escape mechanism in HCC. Therefore, modulation of the HSP70–eIF4G interaction might be a potential novel therapeutic target of HCC treatment.

Anti-interleukin-5-neutralizing antibody attenuates caradiac injury and cadiac dysfunction by aggravating the inflammatory response in doxorubicin-treated mice

Previous studies have demonstrated that interleukins (ILs) are closely associated with doxorubicin (DOX)-induced cardiac injury. IL-5 is an important member of the IL family, and this study was performed to investigate whether IL-5 affects DOX-induced cardiac injury and its underlying mechanisms. The cardiac IL-5 expression was first detected and the results showed that cardiac IL-5 levels were significantly lower in DOX-treated mice, and IL-5 was mainly derived from cardiac macrophage (Mø). In addition, some DOX-treated mice received an injection of anti-IL-5-neutralizing antibody (nAb), and we found that treatment with a mouse anti-IL-5 nAb significantly upregulated the levels of myocardial injury markers, aggravated cardiac dysfunction, increased M1 macrophage (Mø1) and decreased M2 macrophage (Mø2) differentiation, and promoted apoptotic marker expression. Furthermore, the effect of mouse IL-5 nAb on DOX-induced Mø differentiation and its role on mouse cardiomyocyte (MCM) cells apoptosis were detected in vitro, and the results exhibited that mouse IL-5 nAb promoted Mø1 differentiation but inhibited Mø2 differentiation in vitro and alleviated apoptosis in MCM cells. Our results found a mouse anti-IL-5 nAb-aggravated DOX-induced cardiac injury and dysfunction by alleviating the inflammatory response and myocardial cell apoptosis.

HSP70 Multi-Functionality in Cancer

The 70-kDa heat shock proteins (HSP70s) are abundantly present in cancer, providing malignant cells selective advantage by suppressing multiple apoptotic pathways, regulating necrosis, bypassing cellular senescence program, interfering with tumor immunity, promoting angiogenesis and supporting metastasis. This direct involvement of HSP70 in most of the cancer hallmarks explains the phenomenon of cancer "addiction" to HSP70, tightly linking tumor survival and growth to the HSP70 expression. HSP70 operates in different states through its catalytic cycle, suggesting that it can multi-function in malignant cells in any of these states. Clinically, tumor cells intensively release HSP70 in extracellular microenvironment, resulting in diverse outcomes for patient survival. Given its clinical significance, small molecule inhibitors were developed to target different sites of the HSP70 machinery. Furthermore, several HSP70-based immunotherapy approaches were assessed in clinical trials. This review will explore different roles of HSP70 on cancer progression and emphasize the importance of understanding the flexibility of HSP70 nature for future development of anti-cancer therapies.

Exosomes isolated from the plasma of remote ischemic conditioning rats improved cardiac function and angiogenesis after myocardial infarction through targeting Hsp70

Remote ischemic conditioning (RIC) is a promising therapeutic strategy to protect heart against ischemic-reperfusion injury. Exosomes have been proved to be an important regulator in many pathological processes. Whether the exosomes derived from RIC could improve cardiac remodeling and function after myocardial infarction (MI) has not been reported. MI animal model was established by ligating the left coronary artery. The bilateral hindlimbs of rats were subjected to RIC treatment using tourniquets. Exosomes were isolated from the plasma of RIC rats and identified by transmission electron microscope. The proliferation, migration, and apoptosis of endothelial cells were measured by CCK8, traswell, and flow cytometry. Western blotting, and qRT-PCR were applied to measure the expression of angiogenesis-related molecules, and immunohistochemistry staining was used to observe the expression of vWF. RIC and RIC exosomes remarkably facilitated cardiac function, cardiac cell remodeling, and angiogenesis. RIC exosomes markedly increased the cell ratio in the G1 phase, cell migration, cell proliferation, tube formation, and inhibited cell apoptosis through Hsp70. The expression of eNOS, iNOS, HIF-1α, Ang-1, and VEGF was markedly increased by RIC exosomes. RIC exosomes significantly improved cardiac function, cardiac remodeling, and angiogenesis after MI, and they accelerated angiogenesis through increasing the levels of angiogenesis-related molecules.

Bystander effects of ionizing radiation: conditioned media from X-ray irradiated MCF-7 cells increases the angiogenic ability of endothelial cells

BACKGROUND

Non-targeting effects of radiotherapy have become as clinical concern due to secondary tumorigenesis in the patients receiving radiotherapy. Radiotherapy also affects non-tumoral cells present in the tumor microenvironment and surrounding tissues. As such, the irradiated cells are thought to communicate the signals that promote secondary tumorigenesis by affecting the function and fate of non-irradiated cells in the vicinity including endothelial cells. This may include up-regulation of genes in irradiated cells, secretion of paracrine factors and induction of gene expression in surrounding non-irradiated cells, which favor cell survival and secondary tumorigenesis. In the current study, we aimed to investigate whether the conditioned media from X-ray irradiated MCF-7 cells contribute to induction of gene expression in human umbilical vein endothelial cells (HUVECs) in vitro and modulate their angiogenic capability and migration.

METHODS

Following the co-culturing of X-ray irradiated MCF-7 media with HUVECs, the migration and wound healing rate of HUVECs was monitored using Transwell plate and scratch wound healing assay, respectively. The levels of angiogenic protein i.e. vascular endothelial growth factor (VEGF-A) in the conditioned media of MCF-7 cells was measured using ELISA. Additionally, we quantified mRNA levels of VEGFR-2, HSP-70, Ang-2, and Ang-1 genes in HUVECs by real time-PCR. Tubulogenesis capacity of endothelial cells was measured by growth factor reduced Matrigel matrix, whereas expression of CD34 (a marker of angiogenic tip cells) was detected by flow cytometry.

RESULTS

Data showed that VEGF-A protein content of conditioned media of irradiated MCF-7 cells was increased (P < 0.05) with increase in dose. Data showed that irradiated conditioned media from MCF-7 cells, when incubated with HUVECs, significantly enhanced the cell migration and wound healing rate of HUVECs in a dose-dependent manner (P < 0.05). The mRNA levels of VEGFR-2, HSP-70, Ang-2, and Ang-1 were dose-dependently enhanced in HUVECs incubated with irradiated conditioned media (P < 0.05). Importantly, HUVECs treated with irradiated conditioned media showed a marked increase in the tube formation capability as well as in expression of CD34 marker (P < 0.05).

CONCLUSIONS

Our findings indicate that conditioned media from irradiated MCF-7 cells induce angiogenic responses in endothelial cells in vitro, which could be due to transfer of overexpressed VEGF-A and possibly other factors secreted from irradiated MCF-7 cells to endothelial cells, and induction of intrinsic genes (VEGFR-2, HSP-70, Ang-2, and Ang-1) in endothelial cells. Video abstract.

Improving the Function and Engraftment of Transplanted Pancreatic Islets Using Pulsed Focused Ultrasound Therapy

This study demonstrates that pulsed focused ultrasound (pFUS) therapy can non-invasively enhance the function and engraftment of pancreatic islets following transplantation. In vitro, we show that islets treated with pFUS at low (peak negative pressure (PNP): 106kPa, spatial peak temporal peak intensity (I_sptp): 0.71 W/cm²), medium (PNP: 150kPa, I_sptp: 1.43 W/cm²) or high (PNP: 212kPa, I_sptp: 2.86 W/cm²) acoustic intensities were stimulated resulting in an increase in their function (i.e. insulin secretion at low-intensity: 1.15 ± 0.17, medium-intensity: 2.02 ± 0.25, and high-intensity: 2.54 ± 0.38 fold increase when compared to control untreated islets; P < 0.05). Furthermore, we have shown that this improvement in islet function is a result of pFUS increasing the intracellular concentration of calcium (Ca²⁺) within islets which was also linked to pFUS increasing the resting membrane potential (V_m) of islets. Following syngeneic renal sub-capsule islet transplantation in C57/B6 mice, pFUS (PNP: 2.9 MPa, I_sptp: 895 W/cm²) improved the function of transplanted islets with diabetic animals rapidly re-establishing glycemic control. In addition, pFUS was able to enhance the engraftment by facilitating islet revascularization and reducing inflammation. Given a significant number of islets are lost immediately following transplantation, pFUS has the potential to be used in humans as a novel non-invasive therapy to facilitate islet function and engraftment, thereby improving the outcome of diabetic patients undergoing islet transplantation.

Carnosine exerts antitumor activity against bladder cancers in vitro and in vivo via suppression of angiogenesis

Carnosine, a naturally occurring dipeptide, was recently reported to exhibit anticancer activity; however, the molecular mechanisms and regulators underlying its activity against tumor-associated angiogenesis remain unidentified. In this study, we evaluated the in vitro and in vivo antitumor effects of carnosine in EJ bladder cancer cells and EJ-xenografted BALB/c nude mice, respectively. In addition, in vitro capillary tube formation of HUVECs, ex vivo aortic ring and in vivo Matrigel plug assays were employed to examine the antiangiogenic potential of carnosine. Carnosine significantly inhibited EJ cell proliferation. Flow cytometric and immunoblot analyses indicated that carnosine modulated regulators of the G1 cell cycle phase, including cyclin D1, CDK4 and p21WAF1. The mitogen-activated protein kinases, ERK and p38, but not JNK or AKT, responded to carnosine. Carnosine inhibited the migratory and invasive potential of EJ cells by inhibiting MMP-9 activity, which was associated with suppression of binding activity of NF-κB, SP-1 and AP-1. In xenograft tumors, carnosine exhibited antitumor activity equivalent to cisplatin, but no weight loss occurred in carnosine-treated mice. In HUVECs, carnosine inhibited VEGF-mediated proliferation, colony tube formation, migration and invasion. The antiangiogenic activity of carnosine was partially due to the suppression of VEGFR-2-mediated ERK/AKT/eNOS signaling and MMP-2. Furthermore, using aortic ring and Matrigel plug assays, we confirmed the antiangiogenic activity of carnosine. Given that targeting tumor-associated angiogenesis is a proven effective therapeutic strategy, our results may provide valuable information for the development of preventive or therapeutic agents for bladder cancer patients.

Thermal inkjet bioprinting triggers the activation of the VEGF pathway in human microvascular endothelial cells in vitro

One biofabrication process that has gained tremendous momentum in the field of tissue engineering and regenerative medicine is cell-printing or most commonly bioprinting. We have shown that thermal inkjet bioprinted human microvascular endothelial cells were recruited or otherwise involved in the formation of microvasculature to form graft-host anastomoses upon implantation. The present study aims to quantify and characterize the expression and activation of specific cytokines and kinases in vitro. Morphological characteristics demonstrate elongated protrusions of TIB-HMVECs at 5-6 times the size of manually pipetted cells. Moreover, annexin V-FITC and propidium iodide apoptosis assay via flow cytometry demonstrated a 75% apoptosis among printed cells as compared to among control cells. Cell viability at a 3 d incubation period was significantly higher for printed cells as compared to control. Milliplex magnetic bead panels confirmed significant overexpression of HSP70, IL-1α, VEGF-A, IL-8, and FGF-1 of printed cells compared to control. In addition, a Human phospho-kinase array displayed a significant over activation of the heat-shock proteins HSP27 and HSP60 of printed cells compared to the manually seeded cells. Collectively, it is suggested that the massive appearance of capillary blood vessels upon implantation that has been reported elsewhere may be due to the activation of the HSP-NF-κB pathway to produce VEGF. This cell activation may be used as a new strategy for vascularization of tissue engineered constructs which are in high demand in regenerative medicine applications.

Heat Shock Proteins (HSPs): A Novel Target for Cancer Metastasis Prevention

Background:

Heat shock proteins (HSPs) are predominant molecular chaperones which are actively involved in the protein folding; which is essential in protecting the structure and functioning of proteins during various stress conditions. Though HSPs have important physiological roles, they have been well known for their roles in various pathogenic conditions such as carcinogenesis; however, limited literature has consolidated its potential as an anti-metastatic drug target.

Objectives:

The present review outlines the role of different HSPs on cancer progression and metastasis; possible role of HSP inhibitors as anti-neoplastic agents is also discussed.

Methods:

The data were collected from PubMed/Medline and other reputed journal databases. The literature that was too old and had no significant role to the review was then omitted.

Results:

Despite their strong physiological functions, HSPs are considered as good markers for cancer prognosis and diagnosis. They have control over survival, proliferation and progression events of cancer including drug resistance, metastasis, and angiogenesis. Since, neoplastic cells are more dependent on HSPs for survival and proliferation, the selectivity and specificity of HSP-targeted cancer drugs remain high. This has made various HSPs potential clinical and experimental targets for cancer prevention. An array of HSP inhibitors has been in trials and many others are in experimental conditions as anticancer and anti-metastatic agents. Several natural products are also being investigated for their efficacy for anticancer and anti-metastatic agents by modulating HSPs.

Conclusion:

Apart from their role as an anticancer drug target, HSPs have shown to be promising targets for the prevention of cancer progression. Extensive studies are required for the use of these molecules as anti-metastatic agents. Further studies in this line may yield specific and effective antimetastatic agents.

ADAR1 promotes robust hypoxia signaling via distinct regulation of multiple HIF-1α-inhibiting factors

Adenosine deaminase acting on RNA (ADAR)-catalyzed adenosine-to-inosine RNA editing is potentially dysregulated in neoplastic progression. However, how this transcriptome recoding process is functionally correlated with tumorigenesis remains largely elusive. Our analyses of RNA editome datasets identify hypoxia-related genes as A-to-I editing targets. In particular, two negative regulators of HIF-1A-the natural antisense transcript HIF1A-AS2 and the ubiquitin ligase scaffold LIMD1-are directly but differentially modulated by ADAR1. We show that HIF1A-AS2 antagonizes the expression of HIF-1A in the immediate-early phase of hypoxic challenge, likely through a convergent transcription competition in cis ADAR1 in turn suppresses transcriptional progression of the antisense gene. In contrast, ADAR1 affects LIMD1 expression post-transcriptionally, by interfering with the cytoplasmic translocation of LIMD1 mRNA and thus protein translation. This multi-tier regulation coordinated by ADAR1 promotes robust and timely accumulation of HIF-1α upon oxygen depletion and reinforces target gene induction and downstream angiogenesis. Our results pinpoint ADAR1-HIF-1α axis as a hitherto unrecognized key regulator in hypoxia.