HMGB1-mediated apoptosis and autophagy in ischemic heart diseases

HMGB1 in the interplay between autophagy and apoptosis in cancer

Lysosome-mediated autophagy and caspase-dependent apoptosis are dynamic processes that maintain cellular homeostasis, ensuring cell health and functionality. The intricate interplay and reciprocal regulation between autophagy and apoptosis are implicated in various human diseases, including cancer. High-mobility group box 1 (HMGB1), a nonhistone chromosomal protein, plays a pivotal role in coordinating autophagy and apoptosis levels during tumor initiation, progression, and therapy. The regulation of autophagy machinery and the apoptosis pathway by HMGB1 is influenced by various factors, including the protein's subcellular localization, oxidative state, and interactions with binding partners. In this narrative review, we provide a comprehensive overview of the structure and function of HMGB1, with a specific focus on the interplay between autophagic degradation and apoptotic death in tumorigenesis and cancer therapy. Gaining a comprehensive understanding of the significance of HMGB1 as a biomarker and its potential as a therapeutic target in tumor diseases is crucial for advancing our knowledge of cell survival and cell death.

Evaluating the protective role of trimetazidine versus nano-trimetazidine in amelioration of bilateral renal ischemia/reperfusion induced neuro-degeneration: Implications of ERK1/2, JNK and Galectin-3 /NF-κB/TNF-α/HMGB-1 signaling

BACKGROUND

Renal ischemia/reperfusion (I/R) is a primary culprit of acute kidney injury. Neurodegeneration can result from I/R, but the mechanisms are still challenging. We studied the implications of bilateral renal I/R on brain and potential involvement of the oxidative stress (OS) driven extracellular signal-regulated kinase1/2, c-Jun N-terminal kinase (ERK1/2, JNK) and Galectin-3 (Gal-3)/nuclear factor Kappa B (NF-қB)/tumor necrosis factor-alpha (TNF-α), high mobility group box-1 (HMGB-1), and caspase-3 paths upregulation. We tested the impact of Nano-trimetazidine (Nano-TMZ) on these pathways being a target of its neuroprotective effects.

METHODS

Study groups; Sham, I/R, TMZ+I/R, and Nano-TMZ+I/R. Kidney functions, cognition, hippocampal OS markers, Gal-3, NF-қB, p65 and HMGB-1 gene expression, TNF-α level, t-JNK/p-JNK and t-ERK/p-ERK proteins, caspase-3, glial fibrillary acidic protein (GFAP) and ionized calcium binding protein-1 (Iba-1) were assessed.

RESULTS

Nano-TMZ averted renal I/R-induced hippocampal impairment by virtue of its anti: oxidative, inflammatory, and apoptotic properties.

CONCLUSION

Nano-TMZ is more than anti-ischemic.

TLR2 mediates renal apoptosis in neonatal mice subjected experimentally to obstructive nephropathy

Urinary tract obstruction during renal development leads to inflammation, tubular apoptosis, and interstitial fibrosis. Toll like receptors (TLRs) expressed on leukocytes, myofibroblasts and renal cells play a central role in acute inflammation. TLR2 is activated by endogenous danger signals in the kidney; its contribution to renal injury in early life is still a controversial topic. We analyzed TLR2 for a potential role in the neonatal mouse model of congenital obstructive nephropathy. Inborn obstructive nephropathies are a leading cause of end-stage kidney disease in children. Thus, newborn Tlr2-/- and wild type (WT) C57BL/6 mice were subjected to complete unilateral ureteral obstruction (UUO) or sham-operation on the 2nd day of life. The neonatal kidneys were harvested and analyzed at days 7 and 14 of life. Relative expression levels of TLR2, caspase-8, Bcl-2, Bax, GSDMD, GSDME, HMGB1, TNF, galectin-3, α-SMA, MMP-2, and TGF-β proteins were quantified semi-quantitatively by immunoblot analyses. Tubular apoptosis, proliferation, macrophage- and T-cell infiltration, tubular atrophy, and interstitial fibrosis were analyzed immunohistochemically. Neonatal Tlr2-/- mice kidneys exhibited less tubular and interstitial apoptosis as compared to those of WT C57BL/6 mice after UUO. UUO induced neonatally did trigger pyroptosis in kidneys, however to similar degrees in Tlr2-/- and WT mice. Also, tubular atrophy, interstitial fibrosis, tubular proliferation, as well as macrophage and T-cell infiltration were unremarkable. We conclude that while TLR2 mediates apoptosis in the kidneys of neonatal mice subjected to UUO, leukocyte recruitment, interstitial fibrosis, and consequent neonatal obstructive nephropathy might lack a TLR2 involvement.

Correlation of serum HMGB1 and HMGB2 levels with clinical symptoms in allergic rhinitis children

This research aimed to explore the serum high-mobility group box 1 (HMGB1) and high-mobility group box 2 (HMGB2) levels in allergic rhinitis (AR) children and its correlation with clinical results. This present prospective observational study enrolled 179 AR children and 100 healthy children who came to our hospital during October 2020 to August 2022. The serum HMGB1, HMGB2, interleukin (IL)-6, IL-1β, interferon-γ, and C-reactive protein (CRP) levels were measured by enzyme-linked immunosorbent assay. Demographic and clinical statistics including age, body mass index (BMI), sex, diastolic blood pressure, SBP, family history of allergy, Visual Analogue Score (VAS) and Rhinoconjunctivitis Quality of Life Questionnaire were collected. All data used SPSS 18.0 to statistical analyses. The proportion of family history of allergy was obviously higher in the AR group than that in the healthy group. The serum levels of HMGB1, HMGB2 and cytokines were remarkably enhanced in the AR patients. Spearman analysis supported that positive correlation existed among the HMGB1, HMGB2, CRP, IL-6 and IL-1β levels. Serum IL-6, CRP, HMGB2, IL-1β, VAS score and Rhinoconjunctivitis Quality of Life Questionnaire score levels were significantly higher and serum interferon-γ levels were significantly lower in the HMGB1 high expression group. Similar results were found in in the HMGB2 high group compared to the HMGB2 low group. In addition, HMGB1 and HMGB2 could be potential diagnostic biomarkers of AR patients. Finally, we found that HMGB1, HMGB2, IL-6, IL-1β, and family history of allergy were the risk factors for AR. This study showed that the serum HMGB1 and HMGB2 levels was remarkably enhanced in AR patients and closely associated with cytokines. This study may provide new targets and a comprehensive approach for the treatment of AR patients.

The Redox Protein High-Mobility Group Box 1 in Cell Death and Cancer

Significance: As a redox-sensitive protein, high-mobility group box 1 (HMGB1) is implicated in regulating stress responses to oxidative damage and cell death, which are closely related to the pathology of inflammatory diseases, including cancer. Recent Advances: HMGB1 is a nonhistone nuclear protein that acts as a deoxyribonucleic acid chaperone to control chromosomal structure and function. HMGB1 can also be released into the extracellular space and function as a damage-associated molecular pattern protein during cell death, including during apoptosis, necrosis, necroptosis, pyroptosis, ferroptosis, alkaliptosis, and cuproptosis. Once released, HMGB1 binds to membrane receptors to shape immune and metabolic responses. In addition to subcellular localization, the function and activity of HMGB1 also depend on its redox state and protein posttranslational modifications. Abnormal HMGB1 plays a dual role in tumorigenesis and anticancer therapy (e.g., chemotherapy, radiation therapy, and immunotherapy) depending on the tumor types and stages. Critical Issues: A comprehensive understanding of the role of HMGB1 in cellular redox homeostasis is important for deciphering normal cellular functions and pathological manifestations. In this review, we discuss compartmental-defined roles of HMGB1 in regulating cell death and cancer. Understanding these advances may help us develop potential HMGB1-targeting drugs or approaches to treat oxidative stress-related diseases or pathological conditions. Future Directions: Further studies are required to dissect the mechanism by which HMGB1 maintains redox homeostasis under different stress conditions. A multidisciplinary effort is also required to evaluate the potential applications of precisely targeting the HMGB1 pathway in human health and disease. Antioxid. Redox Signal. 39, 569-590.

Analysis of the influence of pyroptosis-related genes on molecular characteristics in patients with acute myocardial infarction

Pyroptosis is a newly identified mode of programmed cell death, but the potential role in patients with acute myocardial infarction (AMI) remains unclear. In this study, bioinformatics methods were used to identify differentially expressed genes from peripheral blood transcriptome data between normal subjects and patients with AMI which were downloaded by the Gene Expression Omnibus database. Comparing Random Forest (RF) and Support Vector Machine (SVM) training algorithms were used to identify pyroptosis-related genes, predicting patients with AMI by nomogram based on informative genes. Moreover, clustering was used to amplify the feature of pyroptosis, in order to facilitate analysis distinct biological differences. Diversity analysis indicated that a majority of pyroptosis-related genes are expressed at higher levels in patients with AMI. The receiver operating characteristic curves show that the RF model is more responsive than the SVM machine learning model to the pyroptosis characteristics of these patients in vivo. We obtained a column line graph diagnostic model which was developed based on 19 genes established by the RF model. After the consensus clustering algorithm of single sample Gene Set Enrichment Analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) Enrichment Analysis, the results for them found that pyroptosis-related genes mediate the activation of multiple immune cells and many inflammatory pathways in the body. We used RF and SVM algorithms to determine 19 pyroptosis-related genes and evaluate their immunological effects in patients with AMI. We also constructed a series of by nomogram related to pyroptosis-related genes to predict the risk of developing AMI.

Serum HMGB1 levels and its clinical significance in elderly patients with intertrochanteric fractures after intramedullary fixation surgery

BACKGROUND

Intramedullary fixation is a valuable alternative for the treatment of intertrochanteric fractures. However, further development of new biomarkers to predict the prognosis of the patient is still needed for timely and effective treatment and intervention. The present study aimed to explore the serum high-mobility group box 1 (HMGB1) levels in the prognosis of intertrochanteric fracture patients and its correlation with clinical results.

METHODS

The present prospective cohort study recruited 115 intertrochanteric fracture patients who were admitted from January 2015 to December 2019. All patients were evaluated preoperatively and treated (proximal femoral nail antirotation or intramedullary proximal femoral nail) by the same team. The serum HMGB1, interleukin-6, interleukin-1β, tumor necrosis factor α, and C-reactive protein levels were measured by enzyme-linked immunosorbent assay. Demographic and clinical data of all patients were collected. Harris score was used to assess the prognosis of intertrochanteric fracture patients after 6 months of treatment. Statistical analysis was conducted using SPSS software with P < .05 as statistically different.

RESULTS

The time of the operation and the amount of bleeding in intramedullary proximal femoral nail were remarkably elevated compared with the proximal femoral nail antirotation group (P < .05). The age, proportion of complications and visual analogue score VAS after 72 hours of surgery in the Harris score < 80 group were remarkably increased compared with Harris score ≥ 80 group (P < .05). In addition, we found that the serum HMGB1 levels in Harris score < 80 group were markedly elevated than the patients in Harris score ≥ 80 group at all time points (P < .05). The results showed that the serum HMGB1 levels at postoperative 48 hours had the highest predictive value for predicting poor prognosis in intertrochanteric fracture patients. It was found that HMGB1, age and VAS after 72 hours of surgery were the risk factors for poor prognosis of intertrochanteric fracture patients.

CONCLUSION

This study showed that the serum HMGB1 levels was significantly decreased in intertrochanteric fracture patients with bad prognoses. This study may provide a new approach to screening intertrochanteric fracture patients with worse prognoses in advance.

Myosin 1b Participated in the Modulation of Hypoxia/Reoxygenation-Caused H9c2 Cell Apoptosis and Autophagy

Myocardial ischemia/reperfusion (I/R) injury seriously threats the health and life of patients with ischemia heart disease. Herein, we probed the potential influence of myosin 1b (myo1b) on hypoxia/reoxygenation- (H/R-) stimulated cardiomyocyte H9c2 cell apoptosis and autophagy. After H/R stimulation, the myo1b mRNA level in H9c2 cells was tested via qRT-PCR. Myo1b overexpression plasmid (OE-myo1b) and small interfering RNA (siRNA) targeting myo1b (si-myo1b) were transfected into H9c2 cells to alter myo1b expression in H9c2 cells. Following H/R stimulation and/or OE-myo1b (or si-myo1b) transfection, H9c2 cell apoptosis, proliferation, and autophagy were detected, respectively. We found that H/R stimulation reduced the mRNA level of myo1b in H9c2 cells and resulted in H9c2 cell apoptosis, proliferation inhibition, and autophagy. Overexpression of myo1b reversed the H/R-resulted H9c2 cell apoptosis, proliferation inhibition, and autophagy. Silence of myo1b had opposite effects, which promoted H9c2 cell apoptosis, reduced cell proliferation, and accelerated cell autophagy. Taken together, Myo1b took part in the modulation of H/R-stimulated cardiomyocyte apoptosis and autophagy, which might be serve as a potential endogenous target for prevention and therapy of I/R injury.

Knockdown of lncRNA XIST Ameliorates IL-1β-Induced Apoptosis of HUVECs and Change of Tissue Factor Level via miR-103a-3p/HMGB1 Axis in Deep Venous Thrombosis by Regulating the ROS/NF-κB Signaling Pathway

Background

The effect of lncRNA X inactive-specific transcript (XIST) inducing cardiovascular diseases on deep vein thrombosis (DVT) and its mechanism has not been reported. In this study, we uncovered the mystery that lncRNA XIST causes DVT with HUVEC dysfunction.

Method

The expression levels of lncRNA XIST and miR-103a-3p were detected by qRT-PCR, and HMGB1 expression was determined by qRT-PCR and western blot. The correlations among the expression levels of lncRNA XIST, miR-103a-3p, and HMGB1 were determined by Spearman's rank-order correlation test. XIST siRNA (si-XIST) was transfected into HUVECs to knock down the intrinsic expression of lncRNA XIST. The influences of si-XIST on interleukin-1 beta- (IL-1β-) treated HUVEC viability and apoptosis and the level of tissue factor (TF) were detected by MTT, flow cytometry, and ELISA kit, respectively. The relationships between lncRNA XIST, miR-103a-3p, and HMGB1 were predicted by the Encyclopedia of RNA Interactomes (ENCORI) database and verified by dual luciferase reporter assay. The effects of lncRNA XIST and miR-103a-3p on HMGB1 expression were detected by qRT-PCR, western blot, and immunofluorescence analysis. The levels of ROS/NF-κB pathway-related proteins were detected to study the regulatory mechanism of lncRNA XIST/miR-103a-3p/HMGB1 on IL-1β-treated HUVECs apoptosis and change of TF level.

Results

The upregulated expression levels of lncRNA XIST and HMGB1 and downregulated level of miR-103a-3p were found in the plasma of DVT patients and IL-1β-treated HUVECs. Si-XIST promoted cell viability and inhibited HUVEC apoptosis and ameliorated the change of TF level triggered by IL-1β. lncRNA XIST sponged miR-103a-3p and miR-103a-3p targeted HMGB1. Si-XIST inhibited the ROS/NF-κB pathway to suppress HUVEC apoptosis and ameliorate the change of TF level induced by IL-1β via the miR-103a-3p/HMGB1 axis.

Conclusion

lncRNA XIST sponged miR-103a-3p improving HMGB1 expression to exacerbate DVT by activating the ROS/NF-κB signaling pathway. Our findings indicated that lncRNA XIST can be used as a potential therapeutic target in DVT.

The underlying pathological mechanism of ferroptosis in the development of cardiovascular disease

Cardiovascular diseases (CVDs) have been attracting the attention of academic society for decades. Numerous researchers contributed to figuring out the core mechanisms underlying CVDs. Among those, pathological decompensated cellular loss posed by cell death in different kinds, namely necrosis, apoptosis and necroptosis, was widely regarded to accelerate the pathological development of most heart diseases and deteriorate cardiac function. Recently, apart from programmed cell death revealed previously, ferroptosis, a brand-new cellular death identified by its ferrous-iron-dependent manner, has been demonstrated to govern the occurrence and development of different cardiovascular disorders in many types of research as well. Therefore, clarifying the regulatory function of ferroptosis is conducive to finding out strategies for cardio-protection in different conditions and improving the prognosis of CVDs. Here, molecular mechanisms concerned are summarized systematically and categorized to depict the regulatory network of ferroptosis and point out potential therapeutic targets for diverse cardiovascular disorders.

Monitoring yeast regulated cell death: trespassing the point of no return to loss of plasma membrane integrity

Acetic acid and hydrogen peroxide are the most common stimuli to induce apoptosis in yeast. The initial phase of this cell death process is characterized by the maintenance of plasma membrane integrity in cells that had already lost their viability. As loss of plasma membrane integrity is typically assessed by staining with propidium iodide (PI) after exposure of cells to a stimulus and cell viability is determined 48 h after plating, the percentage of cells with compromised plasma membrane integrity and c.f.u. counts often do not correlate. Herein, we developed a simple method to explore at what point after an apoptotic stimulus and plating cells do non-viable cells die as result of plasma membrane disruption, i.e., when cells surpass the point-of-no-return and undergo a secondary necrosis. The method consisted in washing cells and re-suspending them in stimulus-free medium after acetic acid and hydrogen peroxide treatments, to mimic transfer to plating, and then assessing plasma membrane integrity through PI staining. We show that, after the stimuli are removed, cells that had lost proliferative capacity but still maintained plasma membrane integrity continue the cell death process and later lose plasma membrane integrity when progressing to secondary necrosis. After exposure to hydrogen peroxide, cells undergo secondary necrosis preceded by Nhp6Ap-GFP cytosolic localization, in contrast to acetic acid exposure, where Nhp6Ap-GFP cytosolic localization mainly occurs simultaneously with an earlier emergence of secondary necrosis. In conclusion, the developed method allows monitoring the irreversible loss of plasma membrane integrity of dying apoptotic cells after the point-of-no-return is trespassed, and better characterize the process of secondary necrosis after apoptosis.

Cell type-specific response of colon cancer tumor cell lines to oncolytic HSV-1 virotherapy in hypoxia

Background

Novel strategies are required since the hypoxic tumor microenvironment is one of the important impediments for conventional cancer therapy. High mobility group box 1 (HMGB1) protein can block aerobic respiration in cancer cells. We hypothesized that HMGB1could also kill the colorectal cancer cells during hypoxia.

Methods

In this study, we developed oncolytic herpes simplex virus type 1 expressing HMGB1 protein (HSV-HMGB1) and investigated the cytotoxic effect of HSV-HMGB1 and its parental virus (HSV-ble) on three colorectal cancer cells (HCT116, SW480, and HT29) under normoxic (20% oxygen) and hypoxic (1% oxygen) conditions. We further identified potential autophagy- related genes in HT29 cells by retrieving mRNA expression microarray datasets from the Gene Expression Omnibus database. These genes were then detected in HT29 cells infected with HSV-HMGB1 and HSV-ble during normoxia and hypoxia by Real-Time quantitative PCR (qRT-PCR).

Results

The cytotoxic effect of HSV-HMGB1 was significantly higher than that of HSV-ble during normoxia; however, during hypoxia, HSV-HMGB1 enhanced the viability of HT29 cells at MOI 0.1. Analyzing the cell death pathway revealed that HSV-HMGB1 induced autophagy in HT29 cells under hypoxic conditions.

Conclusion

In conclusion, it appears that oncolytic virotherapy is cell context-dependent. Therefore, understanding the cancer cells’ characteristics, microenvironment, and cell signaling are essential to improve the therapeutic strategies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02564-4.

High-mobility group box 1 protein promotes dengue virus replication by interacting with untranslated regions of viral genome

Dengue virus (DENV) is most prevalent arthropod-borne human pathogen belongs to Flaviviridae family causes thousands of deaths annually. HMGB1 is highly conserved, ubiquitously expressed, non-histone nuclear protein which plays important role in diseases like metabolic disorders, cancer, and viral infections. However, the importance of HMGB1 in DENV infection is understudied. In this study, we observed that DENV-2 induces cytoplasmic translocation and secretion of HMGB1. Interestingly, inhibition of HMGB1 secretion by ethyl pyruvate (EP) enhanced viral propagation while silencing of HMGB1 resulted in abrogated viral replication in DENV-2 infected A549 cells. RNA-Electrophoretic mobility shift assay and immunoprecipitation showed that HMGB1 interacts with 5'-3' UTRs of DENV-2 genome. This interaction further stimulates production of proinflammatory cytokines like TNF-α, IL-6 and IL-1β which have been implicated in pathogenesis of severe DENV disease. Together, our finding suggests that DENV-2 modulates HMGB1 translocation and HMGB1-DENV-2 UTRs RNA interaction further induces proinflammatory cytokines production in A549 cells. This study discloses HMGB1 as an important host factor contributing to disease pathogenesis and hence can be targeted as an alternative approach for antiviral development against DENV virus infection.

Function and Mechanism of Trimetazidine in Myocardial Infarction-Induced Myocardial Energy Metabolism Disorder Through the SIRT1-AMPK Pathway

Myocardial energy metabolism (MEM) is an important factor of myocardial injury. Trimetazidine (TMZ) provides protection against myocardial ischemia/reperfusion injury. The current study set out to evaluate the effect and mechanism of TMZ on MEM disorder induced by myocardial infarction (MI). Firstly, a MI mouse model was established by coronary artery ligation, which was then treated with different concentrations of TMZ (5, 10, and 20 mg kg^-1 day^-1). The results suggested that TMZ reduced the heart/weight ratio in a concentration-dependent manner. TMZ also reduced the levels of Bax and cleaved caspase-3 and promoted Bcl-2 expression. In addition, TMZ augmented adenosine triphosphate (ATP) production and superoxide dismutase (SOD) activity induced by MI and decreased the levels of lipid peroxide (LPO), free fatty acids (FFA), and nitric oxide (NO) in a concentration-dependent manner (all P < 0.05). Furthermore, an H₂O₂-induced cell injury model was established and treated with different concentrations of TMZ (1, 5, and 10 μM). The results showed that SIRT1 overexpression promoted ATP production and reactive oxygen species (ROS) activity and reduced the levels of LPO, FFA, and NO in H9C2 cardiomyocytes treated with H₂O₂ and TMZ. Silencing SIRT1 suppressed ATP production and ROS activity and increased the levels of LPO, FFA, and NO (all P < 0.05). TMZ activated the SIRT1-AMPK pathway by increasing SIRT1 expression and AMPK phosphorylation. In conclusion, TMZ inhibited MI-induced myocardial apoptosis and MEM disorder by activating the SIRT1-AMPK pathway.

Metabolic Syndrome and Autophagy: Focus on HMGB1 Protein

Metabolic syndrome (MetS) affects the population worldwide and results from several factors such as genetic background, environment and lifestyle. In recent years, an interplay among autophagy, metabolism, and metabolic disorders has become apparent. Defects in the autophagy machinery are associated with the dysfunction of many tissues/organs regulating metabolism. Metabolic hormones and nutrients regulate, in turn, the autophagy mechanism. Autophagy is a housekeeping stress-induced degradation process that ensures cellular homeostasis. High mobility group box 1 (HMGB1) is a highly conserved nuclear protein with a nuclear and extracellular role that functions as an extracellular signaling molecule under specific conditions. Several studies have shown that HMGB1 is a critical regulator of autophagy. This mini-review focuses on the involvement of HMGB1 protein in the interplay between autophagy and MetS, emphasizing its potential role as a promising biomarker candidate for the early stage of MetS or disease's therapeutic target.

Ischemia-reperfusion Injury in the Transplanted Lung: A Literature Review

Lung ischemia-reperfusion injury (LIRI) and primary graft dysfunction are leading causes of morbidity and mortality among lung transplant recipients. Although extensive research endeavors have been undertaken, few preventative and therapeutic treatments have emerged for clinical use. Novel strategies are still needed to improve outcomes after lung transplantation. In this review, we discuss the underlying mechanisms of transplanted LIRI, potential modifiable targets, current practices, and areas of ongoing investigation to reduce LIRI and primary graft dysfunction in lung transplant recipients.

Protective Effect of miR-204 on Doxorubicin-Induced Cardiomyocyte Injury via HMGB1

The toxicity of doxorubicin (DOX) limits its clinical application. Nevertheless, at present, there is no effective drug to prevent DOX-induced cardiac injury. miR-204 is a newly discovered miRNA with many protective effects on cardiovascular diseases. However, little research has been done on the effects of miR-204 on DOX-induced cardiac injury. Our study is aimed at investigating the effect of miR-204 on DOX-induced myocardial injury. An adenoassociated virus system was used to achieve cardiac-specific overexpression of miR-204. Two weeks later, the mice were intraperitoneally injected with DOX (15 mg/kg) to induce cardiac injury. H9c2 myocardial cells were used to validate the role of miR-204 in vitro. Our study showed that miR-204 expression was decreased in DOX-treated hearts. miR-204 overexpression improved cardiac function and alleviated cardiac inflammation, apoptosis, and autophagy induced by DOX. In addition, our results showed that miR-204 prevented DOX-induced injury in cardiomyocytes by directly decreasing HMGB1 expression. Moreover, the overexpression of HMGB1 could offset the protective effects of miR-204 against DOX-induced cardiac injury. In summary, our study showed that miR-204 protected against DOX-induced cardiac injury via the inhibition of HMGB1, and increasing miR-204 expression may be a new treatment option for patients with DOX-induced cardiac injury.

Role of the CXCR4-SDF1-HMGB1 pathway in the directional migration of cells and regeneration of affected organs

In recent years, several studies have reported positive outcomes of cell-based therapies despite insufficient engraftment of transplanted cells. These findings have created a huge interest in the regenerative potential of paracrine factors released from transplanted stem or progenitor cells. Interestingly, this notion has also led scientists to question the role of proteins in the secretome produced by cells, tissues or organisms under certain conditions or at a particular time of regenerative therapy. Further studies have revealed that the secretomes derived from different cell types contain paracrine factors that could help to prevent apoptosis and induce proliferation of cells residing within the tissues of affected organs. This could also facilitate the migration of immune, progenitor and stem cells within the body to the site of inflammation. Of these different paracrine factors present within the secretome, researchers have given proper consideration to stromal cell-derived factor-1 (SDF1) that plays a vital role in tissue-specific migration of the cells needed for regeneration. Recently researchers recognized that SDF1 could facilitate site-specific migration of cells by regulating SDF1-CXCR4 and/or HMGB1-SDF1-CXCR4 pathways which is vital for tissue regeneration. Hence in this study, we have attempted to describe the role of different types of cells within the body in facilitating regeneration while emphasizing the HMGB1-SDF1-CXCR4 pathway that orchestrates the migration of cells to the site where regeneration is needed.