The requirement of the mitochondrial protein NDUFS8 for angiogenesis.

Mitochondria are important for the activation of endothelial cells and the process of angiogenesis. NDUFS8 (NADH:ubiquinone oxidoreductase core subunit S8) is a protein that plays a critical role in the function of mitochondrial Complex I. We aimed to investigate the potential involvement of NDUFS8 in angiogenesis. In human umbilical vein endothelial cells (HUVECs) and other endothelial cell types, we employed viral shRNA to silence NDUFS8 or employed the CRISPR/Cas9 method to knockout (KO) it, resulting in impaired mitochondrial functions in the endothelial cells, causing reduction in mitochondrial oxygen consumption and Complex I activity, decreased ATP production, mitochondrial depolarization, increased oxidative stress and reactive oxygen species (ROS) production, and enhanced lipid oxidation. Significantly, NDUFS8 silencing or KO hindered cell proliferation, migration, and capillary tube formation in cultured endothelial cells. In addition, there was a moderate increase in apoptosis within NDUFS8-depleted endothelial cells. Conversely, ectopic overexpression of NDUFS8 demonstrated a pro-angiogenic impact, enhancing cell proliferation, migration, and capillary tube formation in HUVECs and other endothelial cells. NDUFS8 is pivotal for Akt-mTOR cascade activation in endothelial cells. Depleting NDUFS8 inhibited Akt-mTOR activation, reversible with exogenous ATP in HUVECs. Conversely, NDUFS8 overexpression boosted Akt-mTOR activation. Furthermore, the inhibitory effects of NDUFS8 knockdown on cell proliferation, migration, and capillary tube formation were rescued by Akt re-activation via a constitutively-active Akt1. In vivo experiments using an endothelial-specific NDUFS8 shRNA adeno-associated virus (AAV), administered via intravitreous injection, revealed that endothelial knockdown of NDUFS8 inhibited retinal angiogenesis. ATP reduction, oxidative stress, and enhanced lipid oxidation were detected in mouse retinal tissues with endothelial knockdown of NDUFS8. Lastly, we observed an increase in NDUFS8 expression in retinal proliferative membrane tissues obtained from human patients with proliferative diabetic retinopathy. Our findings underscore the essential role of the mitochondrial protein NDUFS8 in regulating endothelial cell activation and angiogenesis.

Autophagy of OTUD5 destabilizes GPX4 to confer ferroptosis-dependent kidney injury.

Ferroptosis is an iron-dependent programmed cell death associated with severe kidney diseases, linked to decreased glutathione peroxidase 4 (GPX4). However, the spatial distribution of renal GPX4-mediated ferroptosis and the molecular events causing GPX4 reduction during ischemia-reperfusion (I/R) remain largely unknown. Using spatial transcriptomics, we identify that GPX4 is situated at the interface of the inner cortex and outer medulla, a hyperactive ferroptosis site post-I/R injury. We further discover OTU deubiquitinase 5 (OTUD5) as a GPX4-binding protein that confers ferroptosis resistance by stabilizing GPX4. During I/R, ferroptosis is induced by mTORC1-mediated autophagy, causing OTUD5 degradation and subsequent GPX4 decay. Functionally, OTUD5 deletion intensifies renal tubular cell ferroptosis and exacerbates acute kidney injury, while AAV-mediated OTUD5 delivery mitigates ferroptosis and promotes renal function recovery from I/R injury. Overall, this study highlights a new autophagy-dependent ferroptosis module: hypoxia/ischemia-induced OTUD5 autophagy triggers GPX4 degradation, offering a potential therapeutic avenue for I/R-related kidney diseases.

USP18 enhances the resistance of BRAF-mutated melanoma cells to vemurafenib by stabilizing cGAS expression to induce cell autophagy.

This study aims to discern the possible molecular mechanism of the effect of ubiquitin-specific peptidase 18 (USP18) on the resistance to BRAF inhibitor vemurafenib in BRAF V600E mutant melanoma by regulating cyclic GMP-AMP synthase (cGAS). The cancer tissues of BRAF V600E mutant melanoma patients before and after vemurafenib treatment were collected, in which the protein expression of USP18 and cGAS was determined. A BRAF V600E mutant human melanoma cell line (A2058R) resistant to vemurafenib was constructed with its viability, apoptosis, and autophagy detected following overexpression and depletion assays of USP18 and cGAS. Xenografted tumors were transplanted into nude mice for in vivo validation. Bioinformatics analysis showed that the expression of cGAS was positively correlated with USP18 in melanoma, and USP18 was highly expressed in melanoma. The expression of cGAS and USP18 was up-regulated in cancer tissues of vemurafenib-resistant patients with BRAF V600E mutant melanoma. Knockdown of cGAS inhibited the resistance to vemurafenib in A2058R cells and the protective autophagy induced by vemurafenib in vitro. USP18 could deubiquitinate cGAS to promote its protein stability. In vivo experimentations confirmed that USP18 promoted vemurafenib-induced protective autophagy by stabilizing cGAS protein, which promoted resistance to vemurafenib in BRAF V600E mutant melanoma cells. Collectively, USP18 stabilizes cGAS protein expression through deubiquitination and induces autophagy of melanoma cells, thereby promoting the resistance to vemurafenib in BRAF V600E mutant melanoma.

Glutathione metabolism rewiring protects renal tubule cells against cisplatin-induced apoptosis and ferroptosis.

Renal proximal tubular cells are highly vulnerable to different types of assaults during filtration and reabsorption, leading to acute renal dysfunction and eventual chronic kidney diseases (CKD). The chemotherapeutic drug cisplatin elicits cytotoxicity causing renal tubular cell death, but its executing mechanisms of action are versatile and elusive. Here, we show that cisplatin induces renal tubular cell apoptosis and ferroptosis by disrupting glutathione (GSH) metabolism. Upon cisplatin treatment, GSH metabolism is impaired leading to GSH depletion as well as the execution of mitochondria-mediated apoptosis and lipid oxidation-related ferroptosis through activating IL6/JAK/STAT3 signaling. Inhibition of JAK/STAT3 signaling reversed cell apoptosis and ferroptosis in response to cisplatin induction. Using a cisplatin-induced acute kidney injury (CAKI) mouse model, we found that inhibition of JAK/STAT3 significantly mitigates cisplatin nephrotoxicity with a reduced level of serum BUN and creatinine as well as proximal tubular distortion. In addition, the GSH booster baicalein also reclaims cisplatin-induced renal tubular cell apoptosis and ferroptosis as well as the in vivo nephrotoxicity. In conclusion, cisplatin disrupts glutathione metabolism, leading to renal tubular cell apoptosis and ferroptosis. Rewiring glutathione metabolism represents a promising strategy for combating cisplatin nephrotoxicity.

Long Non-Coding RNA CRNDE Functions as a Tumor Promoter by Modulating the ERK/MAPK Signaling Pathway in Neuroblastoma Cells.

OBJECTIVE: The long non-coding RNA (lncRNA) colorectal neoplasia differentially expressed (CRNDE) is considered a carcinogenic promoter in various human malignancies. However, the role and underlying mechanism of action of CRNDE during carcinogenesis in neuroblastoma remain unknown. METHODS: CRNDE transcript levels were detected in neuroblastoma tissues and adjacent normal tissues. The effects of CRNDE overexpression and knockdown on the viability of SH-SY5Y and SK-N-AS cells were determined using the Cell Counting Kit-8 (CCK-8) assay. Flow cytometry was performed to measure the role of CRNDE in apoptosis and the cell cycle in neuroblastoma cells. Moreover, the transwell assay was used to evaluate the role of CRNDE in the migration and invasion of tumor cells. The levels of ERK/MAPK pathway-related proteins were evaluated using western blotting. The in vivo role of CRNDE in tumor growth and apoptosis was evaluated in a xenograft mouse model of human neuroblastoma. RESULTS: The relative expression of CRNDE was significantly higher in neuroblastoma tissues than in the adjacent normal tissues. Moreover, knockdown of CRNDE inhibited tumor cell proliferation and induced apoptosis and cell cycle arrest, whereas elevation of CRNDE promoted cell growth and inhibited apoptosis in neuroblastoma cells. In addition, depletion of CRNDE suppressed migration and invasion, whereas overexpression of CRNDE enhanced the migratory and invasive potential of SH-SY5Y and SK-N-AS cells. At the mechanistic level, western blotting showed that CRNDE exerted its oncogenic role by affecting the ERK/MAPK signaling pathway. Furthermore, animal experiments confirmed that CRNDE promotes tumor growth and inhibits apoptosis in neuroblastoma in vivo. CONCLUSION: The present study revealed that CRNDE plays a critical role in the proliferation, apoptosis, migration, and invasion of neuroblastoma by altering the ERK/MAPK signaling pathway, representing a novel molecular target for the treatment of neuroblastoma.

Explore the multitarget mechanism of tetrahydrocurcumin preventing on UV-induced photoaging mouse skin.

UV induced photoaging is the main external factor of skin aging. In this study, we tested the protective effects of tetrahydrocurcumin on UV-induced skin photoaging of KM mice and researched the multi-target mechanism through RNA sequencing technology. Mouse experiments show that tetrahydrocurcumin strongly changed in skin appearance, epidermal thickness, and wrinkle-related parameters in UV-irradiated mice. RNA-seq result show that we found 29 differentially expressed mRNA transcripts in UV mice relative to Ctrl rats (18 up-regulated and 11 down-regulated) and 7 significantly dysregulated mRNAs were obtained in the THC group compared to the UV group (1 up-regulated and 6 down-regulated), respectively. Spink7, Edn3, Stab2 may be the key target genes of tetrahydrocurcumin in preventing aging. Bioinformatics analysis shows that the response to muscle contraction and melanin biosynthetic GO term and Inflammation related pathway such as PPAR, MAPK would involve in effects of tetrahydrocurcumin. The results of this study indicated that tetrahydrocurcumin can improve the appearance through anti-inflammatory, improving extracellular matrix and inhibiting melanin production. It could be suggested as a protective measure in the prevention of UV-induced photoaging.

ß-Elemene Triggers ROS-dependent Apoptosis in Glioblastoma Cells Through Suppressing STAT3 Signaling Pathway.

Glioblastoma is one of the most aggressive primary brain tumors with few treatment strategies. ß-Elemene is a sesquiterpene known to have broad spectrum antitumor activity against various cancers. However, the signaling pathways involved in ß-elemene induced apoptosis of glioblastoma cells remains poorly understood. In this study, we reported that ß-elemene exhibited antiproliferative activity on U87 and SHG-44 cells, and induced cell death through induction of apoptosis. Incubation of these cells with ß-elemene led to the activation of caspase-3 and generation of reactive oxygen species (ROS). Western blot assay showed that ß-elemene suppressed phosphorylation of STAT3, and subsequently down-regulated the activation of p-JAK2 and p-Src. Moreover, pre-incubation of cells with ROS inhibitor N-acetyl-L-cysteine (NAC) significantly reversed ß-elemene-mediated apoptosis effect and down-regulation of JAK2/Src-STAT3 signaling pathway. Overall, our findings implied that generation of ROS and suppression of STAT3 signaling pathway is critical for the apoptotic activity of ß-elemene in glioblastoma cells.

A novel selective mitochondrial-targeted curcumin analog with remarkable cytotoxicity in glioma cells.

Naturally occurring polyphenol curcumin (4) or demethoxycurcumin (5) and their synthetic derivatives display promising anticancer activities. However, their further development is limited by low bioavailability and poor selectivity. Thus, a mitochondria-targeted compound 14 (DMC-TPP) was prepared in the present study by conjugating a triphenylphosphine moiety to the phenolic hydroxyl group of demethoxycurcumin to enhance its bioavailability and treatment efficacy. The in vitro biological experiments of DMC-TPP showed that it not only displayed higher cytotoxicity as compared with its parent compound 5, but also exhibited superior mitochondria accumulation ability. Glioma cells were more sensitive to DMC-TPP, which inhibited the proliferation of U251 cells with an IC50 of 0.42 µM. The mechanism studies showed that DMC-TPP triggers mitochondria-dependent apoptosis, caused by caspase activation, production of reactive oxygen species (ROS) and decrease of mitochondrial membrane potential (MMP). In addition, DMC-TPP efficiently inhibited cellular thioredoxin reductase, which contributed to its cytotoxicity. Significantly, DMC-TPP delayed tumor progression in a mouse xenograft model of human glioma cancer. Taken together, the potent in vitro and in vivo antitumor activity of DMC-TPP warrant further comprehensive evaluation as a novel anti-glioma agent.

MiR-513c suppresses neuroblastoma cell migration, invasion, and proliferation through direct targeting glutaminase (GLS).

Neuroblastoma is a malignancy [corrected] of childhood and accounts for 7-10% of childhood cancers, leading to approximately 15% of pediatric cancer deaths. MicroRNAs (miRNAs) are a family of short (about 18-25 nucleotides), noncoding and single stranded endogenous RNAs, which complementarily bind to the 3' untranslated regions of their target genes. Recently, glutamine metabolism has been recognized as an important nutrition source for tumor cells, and hence targeting glutamine metabolism could benefit to development of anti-cancer agents. In this study, we investigate the roles of miR-513c in human neuroblastoma. We report miR-513c is significantly downregulated in human neuroblastoma tissues compared with their adjacent normal tissues. Moreover, miR-513c is significantly downregulated in neuroblastoma cell lines compared with normal neuroblast cells. Overexpression of miR-513c suppresses neuroblastoma cells' migration, invasion, and proliferation. We demonstrate the glutaminase (GLS) is a direct target of miR-513c in human neuroblastoma cells. In addition, we found restoration of GLS expression recovered the neuroblastoma cells' migration, invasion, and proliferation. In summary, this study illustrates a miR-513c mediated neuroblastoma cells suppression, providing a new aspect on the miRNA-based therapeutic approach for the treatments of neuroblastoma.