Intravitreal Injection of ZYAN1 Restored Autophagy and Alleviated Oxidative Stress in Degenerating Retina via the HIF-1α/BNIP3 Pathway
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PROVIDER: S-EPMC10669006 | biostudies-literature | 2023 Oct
REPOSITORIES: biostudies-literature
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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:Background/objectivesThe avascular nature of the follicle creates a hypoxic microenvironment, establishing a niche where granulosa cells (GCs) rely on glycolysis to produce energy in the form of lactate (L-lactate). Autophagy, an evolutionarily conserved stress-response process, involves the formation of autophagosomes to encapsulate intracellular components, delivering them to lysosomes for degradation. This process plays a critical role in maintaining optimal follicular development. However, whether hypoxia regulates autophagy in GCs via lactate remains unclear.MethodsIn this study, we investigated lactate-induced autophagy under hypoxia by utilizing glycolysis inhibitors or silencing related genes.ResultsWe observed a significant increase in autophagy in ovarian GCs under hypoxic conditions, indicated by elevated LC3II levels and reduced P62 levels. Suppressing lactate production through glycolytic inhibitors (2-DG and oxamate) or silencing lactate dehydrogenase (LDHA/LDHB) effectively reduced hypoxia-induced autophagy. Further investigation revealed that the HIF1-α/BNIP3/Beclin-1 axis is essential for lactate-induced autophagy under hypoxic conditions. Inhibiting HIF-1α activity using siRNAs or PX-478 downregulated BNIP3 expression and subsequently suppressed autophagy. Similarly, BNIP3 silencing with siRNAs repressed lactate-induced autophagy in hypoxic conditions. Mechanistically, immunoprecipitation experiments showed that BNIP3 disrupted pre-existing Bcl-2/Beclin-1 complexes by competing with Bcl-2 to form Bcl-2/BNIP3 complexes. This interaction released Beclin-1, which subsequently triggered lactate-induced autophagy under hypoxic conditions.ConclusionsThese findings unveil a novel mechanism by which hypoxia regulates GC autophagy through lactate production, highlighting its potential role in sustaining follicular development under hypoxic conditions.
| S-EPMC11765430 | biostudies-literature
Project description:In the process of ischemic stroke (IS), cellular macroautophagy/autophagy and apoptosis play a vital role in neuroprotection against it. Therefore, regulating their balance is a potential therapeutic strategy. It has been proved that hydroxysafflor yellow A (HSYA) has anti-inflammatory and antioxidant effects, which can both protect neurons. By exploring bioinformatics combined with network pharmacology, we found that HIF1A and CASP3, key factors regulating autophagy and apoptosis, may be important targets of HSYA for neuroprotection in an oxygen glucose deprivation and reperfusion (OGD/R) model. In this study, we explored a possible new mechanism of HSYA neuroprotection in the OGD/R model. The results showed that OGD/R increased the expression of HIF1A and CASP3 in SH-SY5Y cells and induced autophagy and apoptosis, while HSYA intervention further promoted the expression of HIF1A and inhibited the level of CASP3, accompanied by an increase in autophagy and a decrease in apoptosis in SH-SY5Y cells. The inhibition of HIF1A diminished the activation of autophagy induced with HSYA, while the inhibition of autophagy increased cell apoptosis and blocked the neuroprotective effect of HSYA, suggesting that the neuroprotective effect of HSYA should be mediated by activating the HIF1A/BNIP3 signaling pathway to induce autophagy. These results demonstrate that HSYA may be a promising agent for treating IS.
| S-EPMC9736542 | biostudies-literature
Project description:During the luteinization after ovulation in mammalian ovary, the containing cells undergo an energy consuming function re-determination process to differentiate into luteal cells under avascular environment. Previous evidences have delineated the contribution of autophagy to the cell differentiation and the catabolic homeostasis in various types of mammalian cells, whereas few interest had been focused on the involvement of autophagy in the luteinization of granulosa cells during the formation of early corpus luteum. Herein, the present study investigated that expression and contribution of autophagy during granulosa cell luteinization and early luteal development through in vivo and in vitro experiments. The results clearly demonstrated that HIF-1α/BNIP3-mediated autophagy plays a vital role in the luteinization of granulosa cells during the early luteal formation in vivo and in vitro. In the neonatal corpus luteum, HIF-1α up-regulated BNIP3 expressions, which contributed to the autophagic initiation by disrupting beclin1 from Bcl-2/beclin1 complex and protected cells from apoptosis by curbing the skew of mitochondria balance under avascular niche. Notably, Inhibition of HIF-1α activity by echinomycin enhanced the levels of cytoplasmic cytochrome c and cell apoptosis in the nascent corpus luteum. These findings revealed that HIF-1α/BNIP3-mediated autophagy enabled the process of granulosa cell luteinization and protected the granulosa-lutein cells from further apoptosis under hypoxia niche. To our knowledge, the present study firstly clarified that HIF-1α/BNIP3-mediated autophagy contributes to the luteinization of granulosa cells during the formation of pregnant corpus luteum, which will help us further understanding the luteal biology and provide us new clues for the treatment of luteal insufficiency.
| S-EPMC7848109 | biostudies-literature
Project description:PurposeAdeno-associated virus serotype 2 (AAV2) has been shown to be effective in transducing inner retinal neurons after intravitreal injection in several species. However, results in nonprimates may not be predictive of transduction in the human inner retina, because of differences in eye size and the specialized morphology of the high-acuity human fovea. This was a study of inner retina transduction in the macaque, a primate with ocular characteristics most similar to that of humans.MethodsIn vivo imaging and histology were used to examine GFP expression in the macaque inner retina after intravitreal injection of AAV vectors containing five distinct promoters.ResultsAAV2 produced pronounced GFP expression in inner retinal cells of the fovea, no expression in the central retina beyond the fovea, and variable expression in the peripheral retina. AAV2 vector incorporating the neuronal promoter human connexin 36 (hCx36) transduced ganglion cells within a dense annulus around the fovea center, whereas AAV2 containing the ubiquitous promoter hybrid cytomegalovirus (CMV) enhancer/chicken-?-actin (CBA) transduced both Müller and ganglion cells in a dense circular disc centered on the fovea. With three shorter promoters--human synapsin (hSYN) and the shortened CBA and hCx36 promoters (smCBA and hCx36sh)--AAV2 produced visible transduction, as seen in fundus images, only when the retina was altered by ganglion cell loss or enzymatic vitreolysis.ConclusionsThe results in the macaque suggest that intravitreal injection of AAV2 would produce high levels of gene expression at the human fovea, important in retinal gene therapy, but not in the central retina beyond the fovea.
| S-EPMC3088562 | biostudies-literature
Project description:Hypoxia-induced retinal neovascularization is a leading cause of blindness worldwide. Oxygen-induced retinopathy (OIR) mouse, a well-established angiogenesis model, has been extensively used to evaluate the effect of anti-angiogenic agents through intravitreal injection. Here, we serendipitously found that the needles used for intravitreal injection caused an unexpected "anti-angiogenic" effect in the OIR mice. To evaluate the effects of various intravitreal puncture sizes on retinal neovascularization and explore the potential underlying mechanism, intravitreal punctures using 0.5 mm (25 G), 0.3 mm (30 G), or 0.21 mm (33 G) needles were performed in OIR mice. Compared with 0.3 mm and 0.21 mm puncture, the 0.5 mm puncture remarkably suppressed the formation of pathological angiogenesis, inhibited vascular leakage, and remodeled the retinal vasculature. Mechanistically, the 0.5 mm puncture induced a substantial reduction in intraocular pressure (IOP), leading to an improvement in oxygen partial pressure (pO2) and significant reduction in Hif1a expression, resulting in resolution of angiogenic and inflammatory responses. Furthermore, IOP-lowering drugs, Travatan or Azarga, also promoted the alleviation of hypoxia and exhibited a potent anti-angiogenesis efficacy. Our study revealed an acute and significant reduction in IOP caused by a large puncture, which could remarkably suppress HIF-1α-mediated retinal neovascularization, indicating that lowering IOP may be a promising therapeutic avenue for treating retinal neovascular diseases.
| S-EPMC10605289 | biostudies-literature
Project description:PurposeIntravitreal injection therapy (IVT) is the most performed procedure in ophthalmology. This study was conducted to determine current trends in IVT delivery.MethodsAn online, 31-question, multiple-choice survey was sent to 1677 retina specialists. The survey consisted of 3 sections: general questions, procedure technique, and postprocedure technique.ResultsA total of 264 (16%) retina specialists completed the survey. The use of povidone-iodine (100%) and small-gauge needles (97%) was common, whereas ocular anesthesia was split among lidocaine gel (31%), lidocaine drops (25%), subconjunctival lidocaine (28%), and lidocaine-soaked pledgets (15%). More than 85% indicated povidone-iodine contributes to post-IVT corneal toxicity, and 12% reported that a needlestick injury to physician or staff occurred during IVT.ConclusionsKey areas for IVT improvement include optimized ocular anesthesia, development of a guarded needle for ocular drug delivery, and formulation of a less toxic ocular antiseptic.
| S-EPMC9976099 | biostudies-literature
Project description:BNIP3 is a mitophagy receptor with context-dependent roles in cancer, but whether and how it modulates melanoma growth in vivo remains unknown. Here, we found that elevated BNIP3 levels correlated with poorer melanoma patient's survival and depletion of BNIP3 in B16-F10 melanoma cells compromised tumor growth in vivo. BNIP3 depletion halted mitophagy and enforced a PHD2-mediated downregulation of HIF-1α and its glycolytic program both in vitro and in vivo. Mechanistically, we found that BNIP3-deprived melanoma cells displayed increased intracellular iron levels caused by heightened NCOA4-mediated ferritinophagy, which fostered PHD2-mediated HIF-1α destabilization. These effects were not phenocopied by ATG5 or NIX silencing. Restoring HIF-1α levels in BNIP3-depleted melanoma cells rescued their metabolic phenotype and tumor growth in vivo, but did not affect NCOA4 turnover, underscoring that these BNIP3 effects are not secondary to HIF-1α. These results unravel an unexpected role of BNIP3 as upstream regulator of the pro-tumorigenic HIF-1α glycolytic program in melanoma cells.
| S-EPMC8126921 | biostudies-literature
Project description:Currently speaking, it is noted that radiofrequency ablation (RFA) has been the most widely used treatment for hepatocellular carcinoma (HCC) occurring in patients. However, accumulating evidence has demonstrated that the incidence of insufficient RFA (IRFA) may result in the identified rapid progression of residual HCC in the patient, which can greatly hinder the effectiveness and patient reported benefits of utilizing this technique. Although many efforts have been proposed, the underlying mechanisms triggering the rapid progression of residual HCC after IRFA have not yet been fully clarified through current research literature reviews. It was shown in this study that cell proliferation, migration and invasion of residual HepG2 and SMMC7721 cells were significantly increased after the IRFA was simulated in vitro. In other words, it is noted that IRFA could do this by enhancing the image of autophagy of the residual HCC cell via the HIF-1α/BNIP3 pathway. Consequently, the down-regulation of BNIP3 may result in the inhibition of the residual HCC cell progression and autophagy after IRFA. Our present study results suggest that IRFA could promote residual HCC cell progression in vitro by enhancing autophagy via the HIF-1α/BNIP3 pathway. For this reason, it is noted that the targeting of the BNIP3 may be useful in preventing the rapid growth and metastasis of residual HCC after IRFA. [BMB Reports 2019; 52(4): 277-282].
| S-EPMC6507849 | biostudies-literature
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