BNIP3 promotes HIF-1α-driven melanoma growth by curbing intracellular iron homeostasis.
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ABSTRACT:
SUBMITTER: Vara-Perez M
PROVIDER: S-EPMC8126921 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BackgroundThe morbidity of nephrolithiasis is 2-3 times higher in males than in females, suggesting that androgen plays a key role in nephrolithiasis. The death of renal tubular epithelial cells (TECs) is an important pathophysiological process contributing to the development of nephrolithiasis. Therefore, the aim of this study is to investigate whether androgen directly induces TECs apoptosis and necrosis and its underlying mechanisms in kidney stone formation.Materials and methodsWe compared serum testosterone level between male and female healthy volunteers and kidney stone patients. The in vivo nephrolithiasis model was established using glyoxylic acid, and calcium deposits were detected by van Kossa staining. In the in vitro study using mouse TECs (TCMK-1 cells) and human TECs (HK-2 cells), apoptosis, necrosis, and the expression of BH3-only protein Bcl-2-like 19 kDa-interacting protein 3 (BNIP3) were examined incubated with different doses of testosterone using flow cytometry. Levels of apoptosis-related proteins transfected with the BNIP3 siRNA were examined by western blotting. The mitochondrial potential (ΔΨm) was detected by JC-1 staining and flow cytometry. We monitored BNIP3 expression in the testosterone-induced TECs injury model after treatment with hypoxia inducible factor 1α (HIF-1α) and/or hypoxia inducible factor 2α (HIF-2α) inhibitors to determine the upstream protein regulating BNIP3 expression. Additionally, ChIP and luciferase assays were performed to confirm the interaction between HIF-1α and BNIP3.ResultsBoth male and female patients have significantly higher testosterones compared with healthy volunteers. More calcium deposits in the medulla were detected in male mice compared to female and castrated male mice. Testosterone induced TECs apoptosis and necrosis and increased BNIP3 expression in a dose-dependent manner. Testosterone also increased Bax expression, decreased Bcl-2 expression and induced a loss of ΔΨm. This effect was reversed by BNIP3 knockdown. HIF-1α inhibition significantly decreased BNIP3 expression and protected TECs from testosterone-induced apoptosis and necrosis. HIF-2α inhibition, however, did not influence BNIP3 expression or TECs apoptosis or necrosis. Finally, HIF-1α interacted with the BNIP3 promoter region.ConclusionBased on these results, testosterone induced renal TECs death by activating the HIF-1α/BNIP3 pathway.
| S-EPMC6394048 | biostudies-literature
Project description:In the present study, we hypothesized that hypoxia-inducible factor 1α (HIF-1α)-mediated mitophagy plays a protective role in ischemia/reperfusion (I/R)-induced acute kidney injury (AKI). Mitophagy was evaluated by measuring the changes of mitophagy flux, mitochondria DNA copy number, and the changes of mitophagy-related proteins including translocase of outer mitochondrial membrane 20 (TOMM20), cytochrome c oxidase IV (COX IV), microtubule-associated protein 1 light chain 3B (LC3B), and mitochondria adaptor nucleoporin p62 in HK2 cells, a human tubular cell line. Results show that HIF-1α knockout significantly attenuated hypoxia/reoxygenation (H/R)-induced mitophagy, aggravated H/R-induced apoptosis, and increased the production of reactive oxygen species (ROS). Similarly, H/R induced significantly increase in Bcl-2 19-kDa interacting protein 3 (BNIP3), a downstream regulator of HIF-1α. Notably, BNIP3 overexpression reversed the inhibitory effect of HIF-1α knockout on H/R-induced mitophagy, and prevented the enhancing effect of HIF-1α knockout on H/R-induced apoptosis and ROS production. For in vivo study, we established HIF-1αflox/flox; cadherin-16-cre mice in which tubular HIF-1α was specifically knockout. It was found that tubular HIF-1α knockout significantly inhibited I/R-induced mitophagy, and aggravated I/R-induced tubular apoptosis and kidney damage. In contrast, adenovirus-mediated BNIP3 overexpression significantly reversed the decreased mitophagy, and prevented enhanced kidney damage in tubular HIF-1α knockout mice with I/R injury. In summary, our study demonstrated that HIF-1α-BNIP3-mediated mitophagy in tubular cells plays a protective role through inhibition of apoptosis and ROS production in acute kidney damage.
| S-EPMC7452120 | biostudies-literature
Project description:Melanoma, the most aggressive skin cancer, is mainly treated with BRAF inhibitors or immunotheareapy. However, most patients who initially responded to BRAF inhibitors or immunotheareapy become resistant following relapse. Ferroptosis is a form of regulated cell death characterized by its dependence on iron ions and the accumulation of lipid reactive oxygen species (ROS). Recent studies have demonstrated that ferroptosis is a good method for tumor treatment, and iron homeostasis is closely associated with ferroptosis. Iron regulatory protein (IRP)1 and 2 play important roles in maintaining iron homeostasis, but their functions in ferroptosis have not been investigated. The present study reported that the expression of IRP1 and IRP2 was increased by the ferroptosis inducers erastin and RSL3 in melanoma cells. Depletion of IRP1 significantly suppressed erastin- and RSL3-induced ferroptosis. IRP2 had a weak effect but could enhance the promoting function of IRP1 on ferroptosis. Further, erastin and RSL3 promoted the transition of aconitase 1 to IRP1, which regulated downstream iron metabolism proteins, including transferrin receptor (TFRC), ferroportin (FPN) and ferritin heavy chain 1 (FTH1). Moreover, overexpression of TFRC and knockdown of FPN and FTH1 significantly promoted erastin- and RSL3-induced ferroptosis in IRP1 knockdown melanoma cells. Collectively, the present findings indicate that IRP1 plays an essential role in erastin- and RSL3-induced ferroptosis by regulating iron homeostasis.
| S-EPMC8299017 | biostudies-literature
Project description:Irinotecan is a topoisomerase I inhibitor which has been widely used to combat several solid tumors, whereas irinotecan therapy can induce liver injury. Liver injury generally leads to tissue hypoxia, and hypoxia-inducible factor-1α (HIF-1α), a pivotal transcription factor, mediates adaptive pathophysiological responses to lower oxygen condition. Previous studies have reported a relationship between HIF-1α and autophagy, and autophagy impairment is a common characteristic in a variety of diseases. Here, irinotecan (50 mg/kg) was employed on mice, and HepG2 and L-02 cells were cultured with irinotecan (10, 20 and 40 μM). In vivo study, we found that irinotecan treatment increased final liver index, serum aminotransferase level and hepatic lipid accumulation. Impaired autophagic flux and activation of HIF-1α/BNIP3 pathway were also demonstrated in the liver of irinotecan-treated mice. Moreover, irinotecan treatment significantly deteriorated hepatic oxidative stress, evidenced by increased MDA and ROS contents, as well as decreased GSH-Px, SOD and CAT contents. Interestingly, protein levels of NLRP3, cleaved-caspase 1 and IL-1β were enhanced in the liver of mice injected with irinotecan. In vitro study, irinotecan-treated HepG2 and L-02 cells also showed impaired autophagic flux, while HIF-1α inhibition efficaciously removed the accumulated autophagosomes induced by irinotecan. Additionally, irinotecan treatment aggravated lipid accumulation in HepG2 and L-02 cells, and HIF-1α inhibition reversed the effect of irinotecan. Furthermore, HIF-1α inhibition weakened irinotecan-induced NLRP3 inflammasome activation in HepG2 cells. Taken together, our results suggest that irinotecan induces liver injury by orchestrating autophagy via HIF-1α/BNIP3 pathway, and HIF-1α inhibition could alleviate irinotecan-induced lipid accumulation in HepG2 and L-02 cells, which will provide a new clue and direction for the prevention of side effects of clinical chemotherapy drugs.
| S-EPMC10121580 | biostudies-literature
Project description:Cell-based therapy is a promising strategy in regenerative medicine, but the poor survival rate of the implanted cells remains a major challenge and limits clinical translation. We preconditioned periosteal cells to the hypoxic and ischemic environment of the bone defect site by deleting prolyl hydroxylase domain-containing protein 2 (PHD2), resulting in hypoxia-inducible factor 1 alpha (HIF-1α) stabilization. This strategy increased postimplantation cell survival and improved bone regeneration. The enhanced cell viability was angiogenesis independent but relied on combined changes in glutamine and glycogen metabolism. HIF-1α stabilization stimulated glutaminase-mediated glutathione synthesis, maintaining redox homeostasis at baseline and during oxidative or nutrient stress. Simultaneously, HIF-1α signaling increased glycogen storage, preventing an energy deficit during nutrient or oxygen deprivation. Pharmacological inhibition of PHD2 recapitulated the adaptations in glutamine and glycogen metabolism and, consequently, the beneficial effects on cell survival. Thus, targeting cellular metabolism is an appealing strategy for bone regeneration and cell-based therapy in general.
| S-EPMC7611069 | biostudies-literature
Project description:Tumour cells under hypoxia tend to modulate the number and contents of extracellular vesicles (EVs) to regulate the tumour microenvironment (TME) and thus promote tumour progression. However, the mechanism of how hypoxia influences the secretion of EVs remains to be elucidated. Here, we confirm the increased production of EVs in head and neck squamous cell carcinoma (HNSCC) cells under hypoxia, where endosome-derived EVs are the main subtype affected by insufficient O2 . The accumulation of hypoxia-inducible factor-1α (HIF-1α) under hypoxia directly downregulates the expression of ATP6V1A, which is pivotal to maintain the homeostasis of lysosomes. Subsequently, impaired lysosomal degradation contributes to the reduced fusion of multivesicular bodies (MVBs) with lysosomes and enables the secretion of intraluminal vesicles (ILVs) as EVs. These findings establish a HIF-1α-regulated lysosomal dysfunction-EV release axis and provide an exquisite framework to better understand EV biogenesis.
| S-EPMC9903130 | biostudies-literature
Project description:Background Age-related macular degeneration (AMD) leads to gradual central vision loss and eventual irreversible blindness. Melatonin, an endogenous hormone, exhibits anti-inflammatory and antitumor effects; however, the role it plays in AMD remains unclear. Herein, we investigated the anti-AMD molecular mechanism of melatonin after sodium iodate (NaIO3) treatment of ARPE-19 cells in vitro and in animal models with the goal of improving the therapeutic effect. Results The in vitro results showed that melatonin protected against NaIO3-induced cell viability decline, mitochondrial dysfunction and apoptosis in ARPE-19 cells, and melatonin also alleviated NaIO3-induced reactive oxygen species (ROS) production, mitochondrial dysfunction and mitophagy activation. Melatonin reduced NaIO3-induced mitophagy activation through HIF-1α-targeted BNIP3/LC3B transcription, whereas ROS inhibition realized with N-acetylcysteine (NAC, a ROS inhibitor) combined with melatonin reduced the effect of NaIO3 on mitophagy. An animal model of AMD was established to confirm the in vitro data. Mouse tail vein injection of NaIO3 and melatonin was associated with enhanced repair of retinal layers within 7 days, as observed by optical coherence tomography (OCT) and hematoxylin and eosin (H&E) staining. A reduction in BNIP3 and HIF-1α levels, as determined by immunohistochemistry (IHC) assay, was also observed. Conclusions These results indicate that melatonin attenuated NaIO3-induced mitophagy of ARPE-19 cells via reduction in ROS-mediated HIF-1α targeted BNIP3/LC3B signaling in vitro and in vivo. Melatonin may be a potential therapeutic drug in the treatment of AMD. Supplementary Information The online version contains supplementary material available at 10.1186/s13578-022-00879-3.
| S-EPMC9389659 | biostudies-literature
Project description:The transcription factor HIF-1α is essential for cells to rapidly adapt to low oxygen levels (hypoxia). HIF-1α is frequently deregulated in cancer and correlates with poor patient prognosis. Here, we demonstrate that the deubiquitinase Cezanne regulates HIF-1α homeostasis. Loss of Cezanne decreases HIF-1α target gene expression due to a reduction in HIF-1α protein levels. Surprisingly, although the Cezanne-regulated degradation of HIF-1α depends on the tumour suppressor pVHL, hydroxylase and proteasome activity are dispensable. Our data suggest that Cezanne is essential for HIF-1α protein stability and that loss of Cezanne stimulates HIF-1α degradation via proteasome-independent routes, possibly through chaperone-mediated autophagy.
| S-EPMC4264929 | biostudies-literature
Project description:The E3 ubiquitin ligase cullin 3 (Cul3) is critical for invariant NKT (iNKT) cell development, as iNKT cells lacking Cul3 accumulate in the immature developmental stages. However, the mechanisms by which Cul3 mediates iNKT cell development remain unknown. In this study, we investigated the role of Cul3 in both immature and mature thymic iNKT cells using a mouse model with a T cell-specific deletion of Cul3. We found that mature iNKT cells lacking Cul3 proliferated and died more than wild-type cells did. These cells also displayed increased glucose metabolism and autophagy. Interestingly, we found that tight regulation of iron homeostasis is critical for iNKT cell development. Without Cul3, mature iNKT cells harbored higher levels of cytosolic iron, a phenotype associated with increased cell death. Taken together, our data suggest that Cul3 promotes iNKT cell development partially through intracellular iron homeostasis.
| S-EPMC10122431 | biostudies-literature
Project description:Nucleus pulposus (NP) cells reside in an avascular and hypoxic microenvironment of the intervertebral disc and are predominantly glycolytic due to robust HIF-1 activity. It is generally thought that NP cells contain few functional mitochondria compared with cells that rely on oxidative metabolism. Consequently, the contribution of mitochondria to NP cell metabolism and the role of hypoxia and HIF-1 in mitochondrial homeostasis is poorly understood. Using mitoQC reporter mice, we show for the first time to our knowledge that NP cell mitochondria undergo age-dependent mitophagy in vivo. Mechanistically, in vitro studies suggest that, under hypoxic conditions, mitochondria in primary NP cells undergo HIF-1α-dependent fragmentation, controlled by modulating the levels of key proteins DRP1 and OPA1 that are involved in mitochondrial fission and fusion, respectively. Seahorse assays and steady state metabolic profiling coupled with [1-2-13 C]-glucose flux analysis revealed that in hypoxia, HIF-1α regulated metabolic flux through coordinating glycolysis and the mitochondrial TCA cycle interactions, thereby controlling the overall biosynthetic capacity of NP cells. We further show that hypoxia and HIF-1α trigger mitophagy in NP cells through the mitochondrial translocation of BNIP3, an inducer of receptor-mediated mitophagy. Surprisingly, however, loss of HIF-1α in vitro and analysis of NP-specific HIF-1α null mice do not show a decrease in mitophagic flux in NP cells but a compensatory increase in NIX and PINK1-Parkin pathways with higher mitochondrial number. Taken together, our studies provide novel mechanistic insights into the complex interplay between hypoxia and HIF-1α signaling on the mitochondrial metabolism and quality control in NP cells. © 2020 American Society for Bone and Mineral Research.
| S-EPMC7778522 | biostudies-literature