The NSUN5-FTH1/FTL pathway mediates ferroptosis in bone marrow-derived mesenchymal stem cells

Mice with NOP2/sun RNA methyltransferase 5 deficiency die before reaching puberty due to fatal kidney damage

BACKGROUND

NOP2/Sun RNA methyltransferase 5 (NSUN5) is an RNA methyltransferase that has a broad distribution and plays critical roles in various biological processes. However, our knowledge of the biological functions of NSUN5 in mammals is very limited. Therefore, in this study, we investigate the role of NSUN5 in mice.

METHODS

In the present research, we built a mouse model (Nsun5-/-) using the CRISPR/Cas9 system to investigated the specific role of NSUN5.

RESULTS

We observed that Nsun5-/- mice had a reduced body weight compared to wild-type mice. Additionally, their survival rate gradually decreased to 20% after postnatal day (PD) 21. Further examination revealed the Nsun5-/- mice had multiple organ damage, with the most severe damage occurring in the kidneys. Moreover, we observed glycogen deposition and fibrosis, along with a notable shorting of the primary foot processes of glomeruli in Nsun5-/- kidneys. Furthermore, we found that the kidneys of Nsun5-/- mice showed increased expression of the apoptotic signal Caspase-3 and accumulated stronger DNA damage at PD 21.

CONCLUSIONS

In our study, we found that mice lacking NSUN5 died before puberty due to kidney fatal damage caused by DNA damage and cell apoptosis. These results suggest that NSUN5 plays a vital role in preventing the accumulation of DNA damage and cell apoptosis in the kidney.

Ru single-atom nanozymes targeting ROS-ferroptosis pathways for enhanced endometrial regeneration in intrauterine adhesion therapy

Intrauterine adhesion (IUA) presents a significant challenge in gynecology, characterized by excessive fibrosis and compromised reproductive function, leading to severe infertility. Although biocompatible hydrogels integrated with stem cells offer a promising approach for IUA therapy, clinical applications remain limited. Recent studies have highlighted the role of ferroptosis and reactive oxygen species (ROS) in IUA pathogenesis, yet strategies targeting ferroptosis through antioxidant stress are underexplored. This study investigates the therapeutic effects and mechanisms of a Ru-Single-Atom Nanozyme (Ru-SAN) incorporated into chitosan hydrogel for treating IUA. Ru-SAN, which mimics the enzyme activities of catalase, superoxide dismutase, and glutathione peroxidase, effectively clears excess ROS and shows promise in treating oxidative stress-induced diseases. The results demonstrate the superior antioxidative capabilities of Ru-SAN, significantly suppressing the ROS-ferroptosis cycle at the injury site. This creates a favorable microenvironment for post-injury repair by inhibiting inflammation, enhancing mesenchymal-to-epithelial transformation, promoting angiogenesis, and polarizing M2 macrophages. Importantly, it mitigates adverse repair outcomes from inflammation and excessive collagen fiber deposition, ultimately restoring uterine glandular structures and thickness, thereby achieving the ultimate goal of restoring fertility and live birth rates. In conclusion, our study delineates a pioneering therapeutic approach leveraging the antioxidant properties of Ru-SAN to target ferroptosis, thereby offering an efficacious treatment for IUA.

PTPRC Inhibits Ferroptosis of Osteosarcoma Cells via Blocking TFEB/FTH1 Signaling

Protein tyrosine phosphatase receptor type C (PTPRC) is reported to function as an oncogenic role in various cancer. However, the studies on the roles of PTPRC in osteosarcoma (OS) are limited. This study aimed to explore the potentials of PTPRC in OS. mRNA levels were detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Protein expression was detected by western blot. Lysosome biogenesis was determined using immunofluorescence. The binding sites of transcription factor EB (TFEB) on the promoter of ferritin heavy chain 1 (FTH1) were predicted by the online dataset JASPAR and confirmed by luciferase and chromatin immunoprecipitation (ChIP) assays. Cell death was determined using propidium iodide (PI) and TdT-mediated dUTP nick-end labeling (TUNEL) staining. The results showed that PTPRC was significantly overexpressed in OS tissues and cells. PTPRC knockdown promoted the phosphorylation and nuclear translocation of TFEB. Moreover, PTPRC knockdown markedly promoted lysosome biogenesis and the accumulation of ferrous ion (Fe2+), whereas decreased the release of glutathione (GSH). Besides, PTPRC knockdown significantly promoted autophagy and downregulated mRNA expression of FTH1 and ferritin light chain (FTL). Additionally, TFEB transcriptionally inactivated FTH1. PTPRC knockdown significantly promoted the ferroptosis of OS cells, which was markedly alleviated by TFEB shRNA. Taken together, PTPRC knockdown-mediated TFEB phosphorylation and translocation dramatically promoted lysosome biogenesis, ferritinophagy, as well as the ferroptosis of OS cells via regulating FTH1/FTL signaling. Therefore, PTPRC/TFEB/FTH1 signaling may be a potential target for OS.

Pharmacokinetic characteristics of mesenchymal stem cells in translational challenges

Over the past two decades, mesenchymal stem/stromal cell (MSC) therapy has made substantial strides, transitioning from experimental clinical applications to commercial products. MSC therapies hold considerable promise for treating refractory and critical conditions such as acute graft-versus-host disease, amyotrophic lateral sclerosis, and acute respiratory distress syndrome. Despite recent successes in clinical and commercial applications, MSC therapy still faces challenges when used as a commercial product. Current detection methods have limitations, leaving the dynamic biodistribution, persistence in injured tissues, and ultimate fate of MSCs in patients unclear. Clarifying the relationship between the pharmacokinetic characteristics of MSCs and their therapeutic effects is crucial for patient stratification and the formulation of precise therapeutic regimens. Moreover, the development of advanced imaging and tracking technologies is essential to address these clinical challenges. This review provides a comprehensive analysis of the kinetic properties, key regulatory molecules, different fates, and detection methods relevant to MSCs and discusses concerns in evaluating MSC druggability from the perspective of integrating pharmacokinetics and efficacy. A better understanding of these challenges could improve MSC clinical efficacy and speed up the introduction of MSC therapy products to the market.

Ferritin light chain as a potential biomarker for the prognosis of liver hepatocellular carcinoma

High expression of the ferritin light chain (FTL) in cancer promotes its onset and progression and is associated with tumour evolution. However, the significance of FTL in pan-cancer progression and prognosis in humans remains unclear. Therefore, we selected various bioinformatics databases to perform a pan-cancer analysis on a public dataset. Our results showed that FTL was differentially expressed in pan-cancer tissues compared to normal tissues. High FTL expression significantly correlated with the clinicopathological characteristics of patients with liver hepatocellular carcinoma (LIHC). The subsequent validation experiments confirmed these observations. Notably, our study found for the first time that FTLs are closely associated with LIHC and that FTLs have important clinical diagnostic and prognostic value for patients with LIHC. We confirmed that FTL expression was closely associated with altered DNA cycles and immune infiltration in LIHC. In conclusion, high levels of FTL expression are associated with poor prognosis in LIHC patients and are expected to be a potential prognostic and immune marker for LIHC.

DNA Methylation-Mediated GPX4 Transcriptional Repression and Osteoblast Ferroptosis Promote Titanium Particle-Induced Osteolysis

Metal wear particles generated by the movement of joint prostheses inevitably lead to aseptic osteolytic damage and ultimately prosthesis loosening, which are aggravated by various types of regulated cell death of bone. Nevertheless, the exact cellular nature and regulatory network underlying osteoferroptosis are poorly understood. Here, we report that titanium particles (TP) induced severe peri-implant osteolysis and ferroptotic changes with concomitant transcriptional repression of a key anti-ferroptosis factor, GPX4, in a mouse model of calvarial osteolysis. GPX4 repression was accompanied by an increase in DNA methyltransferases (DNMTs) 1/3a/3b and hypermethylation of the Gpx4 promoter, which were partly mediated by the transcriptional regulator/co-repressor KLF5 and NCoR. Conversely, treatment with SGI-1027, a DNMT-specific inhibitor, resulted in marked reversal of Gpx4 promoter hypermethylation and GPX4 repression, as well as improvement in ferroptotic osteolysis to a similar extent as with a ferroptosis inhibitor, liproxstatin-1. This suggests that epigenetic GPX4 repression and ferroptosis caused by the increase of DNMT1/3a/3b have a causal influence on TP-induced osteolysis. In cultured primary osteoblasts and osteoclasts, GPX4 repression and ferroptotic changes were observed primarily in osteoblasts that were alleviated by SGI-1027 in a GPX4 inactivation-sensitive manner. Furthermore, we developed a mouse strain with Gpx4 haplodeficiency in osteoblasts (Gpx4 Ob+/-) that exhibited worsened ferroptotic osteolysis in control and TP-treated calvaria and largely abolished the anti-ferroptosis and osteoprotective effects of SGI-1027. Taken together, our results demonstrate that DNMT1/3a/3b elevation, resulting GPX4 repression, and osteoblastic ferroptosis form a critical epigenetic pathway that significantly contributes to TP-induced osteolysis, and that targeting DNMT aberration and the associated osteoferroptosis could be a potential strategy to prevent or slow down prosthesis-related osteolytic complications.

Alantolactone facilitates ferroptosis in non-small cell lung cancer through promoting FTH1 ubiquitination and degradation

Alantolactone (ALT), a natural sesquiterpene lactone from Inula helenium L., demonstrates potent antitumor activity in various human cancers, notably non-small cell lung cancer (NSCLC). Despite its recognized efficacy, the precise mechanisms of action remain elusive. Our study aimed to elucidate ALT's impact on NSCLC. Our findings suggested that ALT triggered apoptosis both in vitro and in vivo, underscoring its anticancer potential. Interestingly, the ferroptosis inhibitor (Fer-1), rather than necrostatin-1 (Nec-1) or Z-VAD-FMK, rescued ALT-induced cell death, implicating ferroptosis as pivotal. Subsequent analyses revealed ferroptosis as the primary mechanism underlying ALT-induced NSCLC cell death, supported by markers including ROS accumulation, MDA elevation, GSH depletion, Fe2+ generation, and GPX4 reduction. Through DARTS/MS proteomics, we identified FTH1 as the target of ALT-induced ferroptosis. Immunoblotting confirmed ALT's inhibition of FTH1 protein expression and accelerated its degradation in NSCLC cells. Immunoprecipitation assays demonstrated increased FTH1 ubiquitination induced by ALT. Additionally, ALT induced ferroptosis and facilitated Fe2+ accumulation via FTH1 ubiquitination. Importantly, ALT displayed potent antitumor effects in a subcutaneous xenograft model in BALB/c-nu/nu nude mice by enhancing ferroptosis. In summary, ALT induced ferroptosis by promoting intracellular Fe2+ accumulation through accelerated FTH1 degradation, highlighting its potential as an antitumor agent targeting ferroptosis.

The Role of Methylation in Ferroptosis

Methylation modification is a crucial epigenetic alteration encompassing RNA methylation, DNA methylation, and histone methylation. Ferroptosis represents a newly discovered form of programmed cell death (PCD) in 2012, which is characterized by iron-dependent lipid peroxidation. The comprehensive investigation of ferroptosis is therefore imperative for a more profound comprehension of the pathological and pathophysiological mechanisms implicated in a wide array of diseases. Researches show that methylation modifications can exert either promotive or inhibitory effects on cell ferroptosis. Consequently, this review offers a comprehensive overview of the pivotal role played by methylation in ferroptosis, elucidating its associated factors and underlying mechanisms.

SpRY-mediated screens facilitate functional dissection of non-coding sequences at single-base resolution

CRISPR mutagenesis screens conducted with SpCas9 and other nucleases have identified certain cis-regulatory elements and genetic variants but at a limited resolution due to the absence of protospacer adjacent motif (PAM) sequences. Here, leveraging the broad targeting scope of the near-PAMless SpRY variant, we have demonstrated that saturated SpRY mutagenesis and base editing screens can faithfully identify functional regulatory elements and essential genetic variants for target gene expression at single-base resolution. We further extended this methodology to investigate a genome-wide association study (GWAS) locus at 10q22.1 associated with a red blood cell trait, where we identified potential enhancers regulating HK1 gene expression, despite not all of these enhancers exhibiting typical chromatin signatures. More importantly, our saturated base editing screens pinpoint multiple causal variants within this locus that would otherwise be missed by Bayesian statistical fine-mapping. Our approach is generally applicable to functional interrogation of all non-coding genomic elements while complementing other high-coverage CRISPR screens.

Comparative time-dependent proteomics reveal the tolerance of cancer cells to magnetic iron oxide nanoparticles

Cancer is one of the most challenging diseases in the world. Recently, iron oxide nanoparticles (IONPs) are emerging materials with rapid development and high application value, and have shown great potential on tumor therapy due to their unique magnetic and biocompatible properties. However, some data hint us that IONPs were toxic to normal cells and vital organs. Thus, more data on biosafety evaluation is urgently needed. In this study, we compared the effects of silicon-coated IONPs (Si-IONPs) on two cell types: the tumor cells (Hela) and the normal cells (HEK293T, as 293 T for short), compared differences of protein composition, allocation and physical characteristics between these two cells. The major findings of our study pointed out that 293 T cells death occurred more significant than that of Hela cells after Si-IONPs treatment, and the rate and content of endocytosis of Si-IONPs in 293 T cells was more prominent than in Hela cells. Our results also showed Si-IONPs significant promoted the production of reactive oxygen species and disturbed pathways related to oxidative stress, iron homeostasis, apoptosis and ferroptosis in both two types of cells, however, Hela cells recovered from these disturbances more easily than 293 T. In conclusion, compared with Hela cells, IONPs are more likely to induce 293 T cells death and Hela cells have their own unique mechanisms to defense invaders, reminding scientists that future in vivo and in vitro studies of nanoparticles need to be cautious, and more safety data are needed for further clinical treatment.

CRYAB suppresses ferroptosis and promotes osteogenic differentiation of human bone marrow stem cells via binding and stabilizing FTH1

BACKGROUND

Bone formation and homeostasis are greatly dependent on the osteogenic differentiation of human bone marrow stem cells (BMSCs). Therefore, revealing the mechanisms underlying osteogenic differentiation of BMSCs will provide new candidate therapeutic targets for osteoporosis.

METHODS

The osteogenic differentiation of BMSCs was measured by analyzing ALP activity and expression levels of osteogenic markers. Cellular Fe and ROS levels and cell viability were applied to evaluate the ferroptosis of BMSCs. qRT-PCR, Western blotting, and co-immunoprecipitation assays were harnessed to study the molecular mechanism.

RESULTS

The mRNA level of CRYAB was decreased in the plasma of osteoporosis patients. Overexpression of CRYAB increased the expression of osteogenic markers including OCN, OPN, RUNX2, and COLI, and also augmented the ALP activity in BMSCs, on the contrary, knockdown of CRYAB had opposite effects. IP-MS technology identified CRYAB-interacted proteins and further found that CRYAB interacted with ferritin heavy chain 1 (FTH1) and maintained the stability of FTH1 via the proteasome mechanism. Mechanically, we unraveled that CRYAB regulated FTH1 protein stability in a lactylation-dependent manner. Knockdown of FTH1 suppressed the osteogenic differentiation of BMSCs, and increased the cellular Fe and ROS levels, and eventually promoted ferroptosis. Rescue experiments revealed that CRYAB suppressed ferroptosis and promoted osteogenic differentiation of BMSCs via regulating FTH1. The mRNA level of FTH1 was decreased in the plasma of osteoporosis patients.

CONCLUSIONS

Downregulation of CRYAB boosted FTH1 degradation and increased cellular Fe and ROS levels, and finally improved the ferroptosis and lessened the osteogenic differentiation of BMSCs.

Iron promotes ovarian cancer malignancy and advances platinum resistance by enhancing DNA repair via FTH1/FTL/POLQ/RAD51 axis

Iron is crucial for cell DNA synthesis and repair, but an excess of free iron can lead to oxidative stress and subsequent cell death. Although several studies suggest that cancer cells display characteristics of 'Iron addiction', an ongoing debate surrounds the question of whether iron can influence the malignant properties of ovarian cancer. In the current study, we initially found iron levels increase during spheroid formation. Furthermore, iron supplementation can promote cancer cell survival, cancer spheroid growth, and migration; vice versa, iron chelators inhibit this process. Notably, iron reduces the sensitivity of ovarian cancer cells to platinum as well. Mechanistically, iron downregulates DNA homologous recombination (HR) inhibitor polymerase theta (POLQ) and relieves its antagonism against the HR repair enzyme RAD51, thereby promoting DNA damage repair to resist chemotherapy-induced damage. Additionally, iron tightly regulated by ferritin (FTH1/FTL) which is indispensable for iron-triggered DNA repair. Finally, we discovered that iron chelators combined with platinum exhibit a synergistic inhibitory effect on ovarian cancer in vitro and in vivo. Our findings affirm the pro-cancer role of iron in ovarian cancer and reveal that iron advances platinum resistance by promoting DNA damage repair through FTH1/FTL/POLQ/RAD51 pathway. Our findings highlight the significance of iron depletion therapy, revealing a promising avenue for advancing ovarian cancer treatment.

Type 2 diabetic mellitus related osteoporosis: focusing on ferroptosis

With the aging global population, type 2 diabetes mellitus (T2DM) and osteoporosis(OP) are becoming increasingly prevalent. Diabetic osteoporosis (DOP) is a metabolic bone disorder characterized by abnormal bone tissue structure and reduced bone strength in patients with diabetes. Studies have revealed a close association among diabetes, increased fracture risk, and disturbances in iron metabolism. This review explores the concept of ferroptosis, a non-apoptotic cell death process dependent on intracellular iron, focusing on its role in DOP. Iron-dependent lipid peroxidation, particularly impacting pancreatic β-cells, osteoblasts (OBs) and osteoclasts (OCs), contributes to DOP. The intricate interplay between iron dysregulation, which comprises deficiency and overload, and DOP has been discussed, emphasizing how excessive iron accumulation triggers ferroptosis in DOP. This concise overview highlights the need to understand the complex relationship between T2DM and OP, particularly ferroptosis. This review aimed to elucidate the pathogenesis of ferroptosis in DOP and provide a prospective for future research targeting interventions in the field of ferroptosis.

Study on the differential hepatotoxicity of raw polygonum multiflorum and polygonum multiflorum praeparata and its mechanism

BACKGROUND

Polygonum multiflorum (PM), a widely used traditional Chinese medicine herb, is divided into two forms, namely raw polygonum multiflorum (RPM) and polygonum multiflorum praeparata (PMP), according to the processing procedure. Emerging data has revealed the differential hepatotoxicity of RPM and PMP, however, its potential mechanism is still unclear.

METHODS

In our study, we investigated the differential hepatotoxicity of RPM and PMP exerted in C57BL/6 mice. First, sera were collected for biochemical analysis and HE staining was applied to examine the morphological alternation of the liver. Then we treated L02 cells with 5 mg / mL of RPM or PMP. The CCK8 and EdU assays were utilized to observe the viability and proliferation of L02 cells. RNA sequencing was performed to explore the expression profile of L02 cells. Western blotting was performed to detect the expression level of ferroptosis-related protein. Flow cytometry was used to evaluate ROS accumulation.

RESULTS

In our study, a significant elevation in serum ALT, AST and TBIL levels was investigated in the RMP group, while no significant differences were observed in the PMP group, compared to that of the CON group. HE staining showed punctate necrosis, inflammatory cell infiltration and structural destruction can be observed in the RPM group, which can be significantly attenuated after processing. In addition, we also found RPM could decrease the viability and proliferation capacity of L02 cells, which can be reversed by ferroptosis inhibitor. RNA sequencing data revealed the adverse effect of PM exerted on the liver is closely associated with ferroptosis. Western blotting assay uncovered the protein level of GPX4, HO-1 and FTL was sharply decreased, while the ROS content was dramatically elevated in L02 cells treated with RPM, which can be partially restored after processing.

CONCLUSIONS

The hepatotoxicity induced by RPM was significantly lower than the PMP, and its potential mechanism is associated with ferroptosis.

Baicalein improves renal interstitial fibrosis by inhibiting the ferroptosis in vivo and in vitro

Evidence indicates that Baicalein can ameliorate renal interstitial fibrosis by inducing myofibroblast apoptosis and inhibit the RLS3-induced ferroptosis in melanocytes. However, the relationship between renal interstitial fibrosis and anti-ferroptosis affected by Baicalein remains unclear. In our study, the anti-fibrosis and anti-ferroptosis effects of Baicalein were assessed in a rat model induced by the UUO method in vivo, and the effects of Baicalein on Erastin-induced ferroptosis of renal MPC-5 cells were examined by Western blot of fibrosis-related and ferroptosis-related proteins in vitro. In the UUO-induced rat model, Baicalein decreased kidney weight loss, improved renal function assessed the biomarks of urinary albumin excretion, serum creatine, and BUN levels, and reduced renal tubular injury. Furthermore, Baicalein inhibited renal ferroptosis by reducing ROS and MDA levels and increasing SOD and GSH levels in the UUO rat model. In addition, Baicalein potently reduced the expression of fibrosis-related proteins such as TGF-β1, a-SMA, and Smad-2 to prevent renal interstitial fibrosis, and increased the expression of ferroptosis-related proteins such as SLC7A11, GPX4, and FTH to inhibit ferroptosis both in vitro and in vivo. Taken together, Baicalein exerts anti-fibrosis activity by reducing the ferroptosis response on the UUO-induced rat model and renal MPC5 cells. Therefore, Baicalein, as a novel therapeutic method on kidney diseases with strong activity in suppressing ferroptosis, could be a potential alternative treatment for renal interstitial fibrosis.

NSUN5/TET2-directed chromatin-associated RNA modification of 5-methylcytosine to 5-hydroxymethylcytosine governs glioma immune evasion

Malignant glioma exhibits immune evasion characterized by highly expressing the immune checkpoint CD47. RNA 5-methylcytosine(m5C) modification plays a pivotal role in tumor pathogenesis. However, the mechanism underlying m5C-modified RNA metabolism remains unclear, as does the contribution of m5C-modified RNA to the glioma immune microenvironment. In this study, we demonstrate that the canonical 28SrRNA methyltransferase NSUN5 down-regulates β-catenin by promoting the degradation of its mRNA, leading to enhanced phagocytosis of tumor-associated macrophages (TAMs). Specifically, the NSUN5-induced suppression of β-catenin relies on its methyltransferase activity mediated by cysteine 359 (C359) and is not influenced by its localization in the nucleolus. Intriguingly, NSUN5 directly interacts with and deposits m5C on CTNNB1 caRNA (chromatin-associated RNA). NSUN5-induced recruitment of TET2 to chromatin is independent of its methyltransferase activity. The m5C modification on caRNA is subsequently oxidized into 5-hydroxymethylcytosine (5hmC) by TET2, which is dependent on its binding affinity for Fe2+ and α-KG. Furthermore, NSUN5 enhances the chromatin recruitment of RBFOX2 which acts as a 5hmC-specific reader to recognize and facilitate the degradation of 5hmC caRNA. Notably, hmeRIP-seq analysis reveals numerous mRNA substrates of NSUN5 that potentially undergo this mode of metabolism. In addition, NSUN5 is epigenetically suppressed by DNA methylation and is negatively correlated with IDH1-R132H mutation in glioma patients. Importantly, pharmacological blockage of DNA methylation or IDH1-R132H mutant and CD47/SIRPα signaling synergistically enhances TAM-based phagocytosis and glioma elimination in vivo. Our findings unveil a general mechanism by which NSUN5/TET2/RBFOX2 signaling regulates RNA metabolism and highlight NSUN5 targeting as a potential strategy for glioma immune therapy.

APE1 inhibition enhances ferroptotic cell death and contributes to hepatocellular carcinoma therapy

Ferroptosis, a regulated form of cell death triggered by iron-dependent lipid peroxidation, has emerged as a promising therapeutic strategy for cancer treatment, particularly in hepatocellular carcinoma (HCC). However, the mechanisms underlying the regulation of ferroptosis in HCC remain to be unclear. In this study, we have identified a novel regulatory pathway of ferroptosis involving the inhibition of Apurinic/apyrimidinic endonuclease 1 (APE1), a key enzyme with dual functions in DNA repair and redox regulation. Our findings demonstrate that inhibition of APE1 leads to the accumulation of lipid peroxidation and enhances ferroptosis in HCC. At the molecular level, the inhibition of APE1 enhances ferroptosis which relies on the redox activity of APE1 through the regulation of the NRF2/SLC7A11/GPX4 axis. We have identified that both genetic and chemical inhibition of APE1 increases AKT oxidation, resulting in an impairment of AKT phosphorylation and activation, which leads to the dephosphorylation and activation of GSK3β, facilitating the subsequent ubiquitin-proteasome-dependent degradation of NRF2. Consequently, the downregulation of NRF2 suppresses SLC7A11 and GPX4 expression, triggering ferroptosis in HCC cells and providing a potential therapeutic approach for ferroptosis-based therapy in HCC. Overall, our study uncovers a novel role and mechanism of APE1 in the regulation of ferroptosis and highlights the potential of targeting APE1 as a promising therapeutic strategy for HCC and other cancers.

FERREG: ferroptosis-based regulation of disease occurrence, progression and therapeutic response

Ferroptosis is a non-apoptotic, iron-dependent regulatory form of cell death characterized by the accumulation of intracellular reactive oxygen species. In recent years, a large and growing body of literature has investigated ferroptosis. Since ferroptosis is associated with various physiological activities and regulated by a variety of cellular metabolism and mitochondrial activity, ferroptosis has been closely related to the occurrence and development of many diseases, including cancer, aging, neurodegenerative diseases, ischemia-reperfusion injury and other pathological cell death. The regulation of ferroptosis mainly focuses on three pathways: system Xc-/GPX4 axis, lipid peroxidation and iron metabolism. The genes involved in these processes were divided into driver, suppressor and marker. Importantly, small molecules or drugs that mediate the expression of these genes are often good treatments in the clinic. Herein, a newly developed database, named 'FERREG', is documented to (i) providing the data of ferroptosis-related regulation of diseases occurrence, progression and drug response; (ii) explicitly describing the molecular mechanisms underlying each regulation; and (iii) fully referencing the collected data by cross-linking them to available databases. Collectively, FERREG contains 51 targets, 718 regulators, 445 ferroptosis-related drugs and 158 ferroptosis-related disease responses. FERREG can be accessed at https://idrblab.org/ferreg/.

Regulation of ferroptosis by PI3K/Akt signaling pathway: a promising therapeutic axis in cancer

The global challenge posed by cancer, marked by rising incidence and mortality rates, underscores the urgency for innovative therapeutic approaches. The PI3K/Akt signaling pathway, frequently amplified in various cancers, is central in regulating essential cellular processes. Its dysregulation, often stemming from genetic mutations, significantly contributes to cancer initiation, progression, and resistance to therapy. Concurrently, ferroptosis, a recently discovered form of regulated cell death characterized by iron-dependent processes and lipid reactive oxygen species buildup, holds implications for diseases, including cancer. Exploring the interplay between the dysregulated PI3K/Akt pathway and ferroptosis unveils potential insights into the molecular mechanisms driving or inhibiting ferroptotic processes in cancer cells. Evidence suggests that inhibiting the PI3K/Akt pathway may sensitize cancer cells to ferroptosis induction, offering a promising strategy to overcome drug resistance. This review aims to provide a comprehensive exploration of this interplay, shedding light on the potential for disrupting the PI3K/Akt pathway to enhance ferroptosis as an alternative route for inducing cell death and improving cancer treatment outcomes.

Selenomethionine alleviates decabromodiphenyl ether-induced oxidative stress and ferroptosis via the NRF2/GPX4 pathway in the chicken brain

Decabromodiphenyl ether (BDE209) is a toxic environmental pollutant that can cause neurotoxicity, behavioral abnormalities, and cognitive impairment in animals. However, the specific mechanisms of BDE209-induced neurological injury and effective preventative and therapeutic interventions are lacking. Even though selenomethionine (Se-Met) has a significant detoxification effect and protects the nervous system, it remains unclear whether Se-Met can counteract the toxic effects of BDE209. For the in vivo test, we randomly divided 60 1-week-old hy-line white variety chicks into the Con, BDE209, Se-Met, and BDE209 +Se-Met groups. In vitro experiments were performed, exposing chick embryo brain neurons to BDE209, Se-Met, N-Acetylcysteine (NAC, a ROS inhibitor), and RSL3 (a GPX4 inhibitor). We demonstrated that BDE209 induced oxidative stress and ferroptosis in the chicken brain, which mainly manifested as mitochondrial atrophy, cristae breakage, increased Fe2+ and MDA content, decreased antioxidant enzyme activity, and the inhibition of the NRF2/GPX4 signaling pathway in the brain neurons. However, Se-Met supplementation reversed these changes by activating the NRF2/GPX4 pathway, reducing mitochondrial damage, enhancing antioxidant enzyme activity, and alleviating ferroptosis. This study provides insight into the mechanism of BDE209-related neurotoxicity and suggests Se-Met as an effective preventative and control measure against BDE209 poisoning.

Particulate Matter Induces Oxidative Stress and Ferroptosis in Human Lung Epithelial Cells

Numerous toxicological studies have highlighted the association between urban particulate matter (PM) and increased respiratory infections and lung diseases. The adverse impact on the lungs is directly linked to the complex composition of particulate matter, initiating reactive oxygen species (ROS) production and consequent lipid peroxidation. Excessive ROS, particularly within mitochondria, can destroy subcellular organelles through various pathways. In this study, we confirmed the induction of ferroptosis, an iron-dependent cell death, upon exposure to an urban PM using RT-qPCR and signaling pathway analysis. We used KRISS CRM 109-02-004, the certified reference material for the analysis of particulate matter, produced by the Korea Research Institute of Standards and Science (KRISS). To validate that ferroptosis causes lung endothelial toxicity, we assessed intracellular mitochondrial potential, ROS overproduction, lipid peroxidation, and specific ferroptosis biomarkers. Following exposure to the urban PM, a significant increase in ROS generation and a decrease in mitochondrial potential were observed. Furthermore, it induced hallmarks of ferroptosis, including the accumulation of lipid peroxidation, the loss of antioxidant defenses, and cellular iron accumulation. In addition, the occurrence of oxidative stress as a key feature of ferroptosis was confirmed by increased expression levels of specific oxidative stress markers such as NQO1, CYP1B1, FTH1, SOD2, and NRF. Finally, a significant increase in key ferroptosis markers was observed, including xCT/SLC7A11, NQO1, TRIM16, HMOX-1, FTL, FTH1, CYP1B1, CHAC1, and GPX4. This provides evidence that elevated ROS levels induce oxidative stress, which ultimately triggers ferroptosis. In conclusion, our results show that the urban PM, KRISS CRM, induces cellular and mitochondrial ROS production, leading to oxidative stress and subsequent ferroptosis. These results suggest that it may induce ferroptosis through ROS generation and may offer potential strategies for the treatment of lung diseases.

The mutation of NSUN5 R295C promotes preeclampsia by impairing decidualization through downregulating IL-11Rα

Preeclampsia (PE) is a pregnancy-specific hypertensive disorder that severely impairs maternal and fetal health. However, its pathogenesis remains elusive. NOP2/Sun5 (NSUN5) is an RNA methyltransferase. This study discovered a significant correlation between rs77133388 of NSUN5 and PE in a cohort of 868 severe PE patients and 982 healthy controls. To further explore this association, the researchers generated single-base mutant mice (NSUN5 R295C) at rs77133388. The pregnant NSUN5 R295C mice exhibited PE symptoms. Additionally, compared to the controls, the decidual area of the placenta was significantly reduced in NSUN5 R295C mice, and their decidualization was impaired with a significantly decrease in polyploid cell numbers after artificially induced decidualization. The study also found a decrease in phosphorylated JAK2, STAT3, and IL-11Rα, Cyclin D3 expression in NSUN5 R295C mice. Overall, these findings suggest that NSUN5 mutation potentially alters decidualization through the IL-11Rα/JAK2/STAT3/Cyclin D3 pathway, ultimately impairing placental development and contributing to PE occurrence.

Insights into the Roles of Epigenetic Modifications in Ferroptosis

Ferroptosis is a non-apoptotic mode of cell death driven by membrane lipid peroxidation and is characterized by elevated intracellular levels of Fe2+, ROS, and lipid peroxidation. Studies have shown that ferroptosis is related to the development of multiple diseases, such as cancer, neurodegenerative diseases, and acute myeloid leukemia. Ferroptosis plays a dual role in the occurrence and development of these diseases. Ferroptosis mainly involves iron metabolism, ROS, and lipid metabolism. Various mechanisms, including epigenetic regulation, have been reported to be deeply involved in ferroptosis. Abnormal epigenetic modifications have been reported to promote tumor onset or other diseases and resistance to chemotherapy drugs. In recent years, diversified studies have shown that epigenetic modification is involved in ferroptosis. In this review, we reviewed the current resistance system of ferroptosis and the research progress of epigenetic modification, such as DNA methylation, RNA methylation, non-coding RNAs, and histone modification in cancer and other diseases by regulating ferroptosis.

Notoginsenoside R1 promotes osteogenic differentiation of human bone marrow mesenchymal stem cells via ERα/GSK-3β/β-catenin signalling pathway

Human bone marrow mesenchymal stem cells (hBMSCs) are attractive therapeutic agents for bone tissue regeneration owing to their osteogenic differentiation potential. Notoginsenoside R1 (NGR1) is a novel phytoestrogen with diverse pharmacological activities. Here, we probed whether NGR1 has an effect on the osteogenic differentiation of hBMSCs. EdU, CCK-8 and Transwell assays were used to measure proliferation and migration of hBMSCs after treatment with different doses of NGR1. hBMSCs were treated with osteogenic differentiation induction medium for osteogenesis. Alizarin red S (ARS) and alkaline phosphatase (ALP) staining were used to measure mineralized nodule formation and ALP activity in hBMSCs, respectively. ICI 182780, an antagonist of oestrogen receptor alpha (ERα) was used to inhibit ERα expression. The results showed that NGR1 enhanced hBMSC proliferation and migration. NGR1 increased ALP activity and mineralized nodule formation as well as promoting ALP, RUNX2 and OCN expression in hBMSCs. NGR1 enhanced ERα expression and promoted GSK-3β/β-catenin signal transduction in hBMSCs. ICI 182780 reversed NGR1-mediated activation of the GSK-3β/β-catenin signalling and promoted an effect on hBMSC behaviour. Thus NGR1 promotes proliferation, migration and osteogenic differentiation of hBMSCs via the ERα/GSK-3β/β-catenin signalling pathway.

Ferroptosis: a promising candidate for exosome-mediated regulation in different diseases

Ferroptosis is a newly discovered form of cell death that is featured in a wide range of diseases. Exosome therapy is a promising therapeutic option that has attracted much attention due to its low immunogenicity, low toxicity, and ability to penetrate biological barriers. In addition, emerging evidence indicates that exosomes possess the ability to modulate the progression of diverse diseases by regulating ferroptosis in damaged cells. Hence, the mechanism by which cell-derived and noncellular-derived exosomes target ferroptosis in different diseases through the system Xc-/GSH/GPX4 axis, NAD(P)H/FSP1/CoQ10 axis, iron metabolism pathway and lipid metabolism pathway associated with ferroptosis, as well as its applications in liver disease, neurological diseases, lung injury, heart injury, cancer and other diseases, are summarized here. Additionally, the role of exosome-regulated ferroptosis as an emerging repair mechanism for damaged tissues and cells is also discussed, and this is expected to be a promising treatment direction for various diseases in the future. Video Abstract.

The Potential Role of Non-coding RNAs in Regulating Ferroptosis in Cancer: Mechanisms and Application Prospects

Cancer is the second leading cause of death globally. Despite some successes, conventional cancer treatments are insufficient to address the growing problem of drug resistance in tumors and to achieve efficient treatment outcomes. Therefore, there is an urgent need to explore new therapeutic options. Ferroptosis, a type of iron- and reactive oxygen species-dependent regulated cell death, has been closely associated with cancer development and progression. Non-coding RNAs (ncRNAs) are a class of RNAs that do not code for proteins, and studies have demonstrated their involvement in the regulation of ferroptosis in cancer. This review aims to explore the molecular regulatory mechanisms of ncRNAs involved in ferroptosis in cancer and to emphasize the feasibility of ferroptosis and ncRNAs as novel therapeutic strategies for cancer. We conducted a systematic and extensive literature review using PubMed, Google Scholar, Web of Science, and various other sources to identify relevant studies on ferroptosis, ncRNAs, and cancer. A deeper understanding of ferroptosis and ncRNAs could facilitate the development of new cancer treatment strategies.

Niujiao Dihuang Jiedu decoction promotes SLC7A11 m5C methylation modification against ferroptosis in acute-on-chronic liver failure

BACKGROUND

Acute-on-chronic liver failure (ACLF) constitutes a prevalent manifestation of liver failure within clinical settings. This condition manifests swiftly and is characterized by an exceedingly elevated fatality rate.

OBJECTIVE

While numerous investigations have delved into the role of RNA methylation in ferroptosis, the impact of such methylation on ACLF-associated ferroptosis remains notably underexplored. This study aimed to elucidate the molecular mechanism underlying the efficacy of Niujiao Dihuang Jiedu decoction (NDD) in mitigating ferroptosis in ACLF, with a specific focus on RNA 5-methylcytosine (m5C) methylation.

MATERIALS AND METHODS

An ACLF rat model was established alongside an erastin-induced ferroptosis model in LO2 cells. Both in vitro and in vivo experiments were conducted to substantiate NDD's influence on ferroptosis. The modifying influence of methylase NOL1/NOP2/sun domain (NSUN5) upon SLC7A11, a key ferroptosis-associated gene, was probed through dot blot, immunofluorescence co-localization, and RNA binding protein immunoprecipitation (RIP) experiments.

RESULTS

Serological and hepatic histopathological findings indicated NDD's discernible therapeutic impact on ACLF. Furthermore, ferroptosis phenotype experiments revealed NDD's proficiency in effectively impeding the occurrence and development of ferroptosis. Dot blot assays demonstrated a reduction in the overall RNA m5C levels during cellular ferroptosis. Furthermore, through immunofluorescence co-localization and RIP techniques, we found that the propensity of methylase NSUN5 to associate with SLC7A11 mRNA, thereby enhancing its protein translation and conferring resistance against ferroptosis.

CONCLUSION

RNA methylation is involved in the process of ACLF-associated ferroptosis, and NDD can inhibit ACLF-associated ferroptosis by fostering SLC7A11 m5C methylation.

Dissecting molecular mechanisms underlying ferroptosis in human umbilical cord mesenchymal stem cells: Role of cystathionine γ-lyase/hydrogen sulfide pathway

BACKGROUND

Ferroptosis can induce low retention and engraftment after mesenchymal stem cell (MSC) delivery, which is considered a major challenge to the effectiveness of MSC-based pulmonary arterial hypertension (PAH) therapy. Interestingly, the cystathionine γ-lyase (CSE)/hydrogen sulfide (H2S) pathway may contribute to mediating ferroptosis. However, the influence of the CSE/H2S pathway on ferroptosis in human umbilical cord MSCs (HUCMSCs) remains unclear.

AIM

To clarify whether the effect of HUCMSCs on vascular remodelling in PAH mice is affected by CSE/H2S pathway-mediated ferroptosis, and to investigate the functions of the CSE/H2S pathway in ferroptosis in HUCMSCs and the underlying mechanisms.

METHODS

Erastin and ferrostatin-1 (Fer-1) were used to induce and inhibit ferroptosis, respectively. HUCMSCs were transfected with a vector to overexpress or inhibit expression of CSE. A PAH mouse model was established using 4-wk-old male BALB/c nude mice under hypoxic conditions, and pulmonary pressure and vascular remodelling were measured. The survival of HUCMSCs after delivery was observed by in vivo bioluminescence imaging. Cell viability, iron accumulation, reactive oxygen species production, cystine uptake, and lipid peroxidation in HUCMSCs were tested. Ferroptosis-related proteins and S-sulfhydrated Kelch-like ECH-associating protein 1 (Keap1) were detected by western blot analysis.

RESULTS

In vivo, CSE overexpression improved cell survival after erastin-treated HUCMSC delivery in mice with hypoxia-induced PAH. In vitro, CSE overexpression improved H2S production and ferroptosis-related indexes, such as cell viability, iron level, reactive oxygen species production, cystine uptake, lipid peroxidation, mitochondrial membrane density, and ferroptosis-related protein expression, in erastin-treated HUCMSCs. In contrast, in vivo, CSE inhibition decreased cell survival after Fer-1-treated HUCMSC delivery and aggravated vascular remodelling in PAH mice. In vitro, CSE inhibition decreased H2S levels and restored ferroptosis in Fer-1-treated HUCMSCs. Interestingly, upregulation of the CSE/H2S pathway induced Keap1 S-sulfhydration, which contributed to the inhibition of ferroptosis.

CONCLUSION

Regulation of the CSE/H2S pathway in HUCMSCs contributes to the inhibition of ferroptosis and improves the suppressive effect on vascular remodelling in mice with hypoxia-induced PAH. Moreover, the protective effect of the CSE/H2S pathway against ferroptosis in HUCMSCs is mediated via S-sulfhydrated Keap1/nuclear factor erythroid 2-related factor 2 signalling. The present study may provide a novel therapeutic avenue for improving the protective capacity of transplanted MSCs in PAH.

Tert-butyl hydroperoxide induces ferroptosis of bone mesenchymal stem cells by repressing the prominin2/BACH1/ROS axis

Ferroptosis has been proven critical for survival following bone marrow mesenchymal stem cells (BMSCs) explantation. Suppression of ferroptosis in BMSCs will be a valid tactic to elevate the therapeutic potential of engrafted BMSCs. Prominin2 is a pentaspanin protein involved in mediating iron efflux and thus modulates resistance to ferroptosis, but its role in tert-butyl hydroperoxide (TBHP)-induced BMSCs ferroptosis remains elusive. We examined the biological effect of prominin2 in vitro and in vivo by using cell proliferation assay, iron assay, reactive oxygen species (ROS) examination, malondialdehyde assay, glutathione (GSH) examination, Western blot, quantitative reverse transcription-PCR, immunofluorescence staining assay, gene expression inhibition and activation, co-immunoprecipitation (CO-IP) assay, radiographic analysis, and histopathological analysis. Our study demonstrated that prominin2 activity was impaired in TBHP-induced BMSCs ferroptosis. We found that PROM2 (encoding the protein prominin2) activation delayed the onset of ferroptosis and PROM2 knockdown deteriorated the course of ferroptosis. CO-IP, Western blot, and immunofluorescence demonstrated that prominin2 exerts antiferroptosis effects by inhibiting BTB and CNC homology 1 (BACH1) that promotes ROS generation, and thus exerts potent antioxidant effects in oxidative stress (OS)-induced BMSCs ferroptosis, including elevating BMSCs' survival rate and enhancing GSH contents. BMSCs with PROM2 overexpression also partially delayed the progression of intervertebral disk degeneration in vivo, as illustrated by less loss of disk height and lower histological scores. Our findings revealed a mechanism that the prominin2/BACH1/ROS axis participates in BMSCs ferroptosis and the strengthening of this axis is promising to maintain BMSCs' survival after explantation.NEW & NOTEWORTHY We found that prominin2 might be a potential biomarker and is expected to be utilized to augment engrafted bone marrow mesenchymal stem cells (BMSCs) survival rate. The prominin2/BTB and CNC homology 1 (BACH1)/reactive oxygen species (ROS) axis, which participates in the regulation of BMSCs ferroptosis induced by tert-butyl hydroperoxide (TBHP), is uncovered in our study. The therapeutic targeting of the prominin2/BACH1/ROS axis components is promising to elevate the survival of transplanted BMSCs in clinical practice.

Role of single-cell ferroptosis regulation in intercellular communication and skin cutaneous melanoma progression and immunotherapy

BACKGROUND

The involvement of ferroptosis in the pathogenesis and progression of various cancers has been well established. However, limited studies have investigated the role of ferroptosis-mediated tumor microenvironment (TME) in skin cutaneous melanoma (SKCM).

METHODS

By leveraging single-cell RNA sequencing data, the nonnegative matrix factorization (NMF) approach was employed to comprehensively characterize and identify distinct gene signatures within ferroptosis-associated TME cell clusters. Prognostic and treatment response analyses were conducted using both bulk datasets and external cancer cohort to evaluate the clinical implications of TME clusters.

RESULTS

This NMF-based analysis successfully delineated fibroblasts, macrophages, T cells, and B cells into multiple clusters, enabling the identification of unique gene expression patterns and the annotation of distinct TME clusters. Furthermore, pseudotime trajectories, enrichment analysis, cellular communication analysis, and gene regulatory network analysis collectively demonstrated significant intercellular communication between key TME cell clusters, thereby influencing tumor cell development through diverse mechanisms. Importantly, our bulk RNA-seq analysis revealed the prognostic significance of ferroptosis-mediated TME cell clusters in SKCM patients. Moreover, our analysis of immune checkpoint blockade highlighted the crucial role of TME cell clusters in tumor immunotherapy, facilitating the discovery of potential immunotherapeutic targets.

CONCLUSIONS

In conclusion, this pioneering study employing NMF-based analysis unravels the intricate cellular communication mediated by ferroptosis within the TME and its profound implications for the pathogenesis and progression of SKCM. We provide compelling evidence for the prognostic value of ferroptosis-regulated TME cell clusters in SKCM, as well as their potential as targets for immunotherapy.

Single-Cell Integration of BMD GWAS Results Prioritize Candidate Genes Influencing Age-Related Bone Loss

The regulation of bone mineral density (BMD) is highly influenced by genetics and age. Although genome-wide association studies (GWAS) for BMD have uncovered many genes through their proximity to associated variants (variant nearest-neighbor [VNN] genes), the cell-specific mechanisms of each VNN gene remain unclear. This is primarily due to the inability to prioritize these genes by cell type and age-related expression. Using age-related transcriptomics, we found that the expression of many VNN genes was upregulated in the bone and marrow from aged mice. Candidate genes from GWAS were investigated using single-cell RNA-sequencing (scRNA-seq) datasets to enrich for cell-specific expression signatures. VNN candidate genes are highly enriched in osteo-lineage cells, osteocytes, hypertrophic chondrocytes, and Lepr+ mesenchymal stem cells. These data were used to generate a "blueprint" for Cre-loxp mouse line selection for functional validation of candidate genes and further investigation of their role in BMD maintenance throughout aging. In VNN-gene-enriched cells, Sparc, encoding the extracellular matrix (ECM) protein osteonectin, was robustly expressed. This, along with expression of numerous other ECM genes, indicates that many VNN genes likely have roles in ECM deposition by osteoblasts. Overall, we provide data supporting streamlined translation of GWAS candidate genes to potential novel therapeutic targets for the treatment of osteoporosis. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

NSUN5-FTH1 Axis Inhibits Ferroptosis to Promote the Growth of Gastric Cancer Cells

Recent studies revealed that NOP2/Sun RNA methyltransferase 5 (NSUN5) - ferritin heavy chain (FTH1) pathway is associated with ferroptosis in stem cells, whereas its roles in gastric cancer are still unclear. Our study aims to investigate the roles of the NSUN5-FTH1 axis in gastric cancer (GC) and its molecular mechanisms. Stable cell lines were constructed on SGC7901 cells by using shRNAs and pcDNA3.1 expression vectors, respectively. CCK-8 kits were used to determine cell viability. Biochemicals assays were used to detect lipid reactive oxygen species (ROS) and intracellular Fe2+ levels. RNA immunoprecipitation assay, qPCR, and Western blotting were used to determine the changes in biomarkers. GC xenograft mouse model was established to confirm the observation in vivo. An elevation of NSUN5 was observed in GC tumor tissues. NSUN5 inhibited ferroptosis including decreasing cell viability and increasing levels of lipid ROS and Fe2+ in GC cells. Besides, a positive correlation was also observed between NSUN5 and FTH1. Interestingly, NSUN5 regulated the levels of FTH1, instead of FTH1 regulating NSUN5 in GC cells. NSUN5-FTH1 axis regulated erastin-induced ferroptosis in SGC7901 cells. Consistently, silencing NSUN5 or FTH1 inhibited the growth of the SGC7901 tumor in vivo. NSUN5-FTH1 axis promoted the growth of GC cells in part by the regulation of ferroptosis.

RNA modifications in cancer

Currently, more than 170 modifications have been identified on RNA. Among these RNA modifications, various methylations account for two-thirds of total cases and exist on almost all RNAs. Roles of RNA modifications in cancer are garnering increasing interest. The research on m6A RNA methylation in cancer is in full swing at present. However, there are still many other popular RNA modifications involved in the regulation of gene expression post-transcriptionally besides m6A RNA methylation. In this review, we focus on several important RNA modifications including m1A, m5C, m7G, 2'-O-Me, Ψ and A-to-I editing in cancer, which will provide a new perspective on tumourigenesis by peeking into the complex regulatory network of epigenetic RNA modifications, transcript processing, and protein translation.

Identification of iron metabolism-related genes as prognostic indicators for papillary thyroid carcinoma: a retrospective study

Background

The thyroid cancer subtype that occurs more frequently is papillary thyroid carcinoma (PTC). Despite a good surgical outcome, treatment with traditional antitumor therapy does not offer ideal results for patients with radioiodine resistance, recurrence, and metastasis. The evidence for the connection between iron metabolism imbalance and cancer development and oncogenesis is growing. Nevertheless, the iron metabolism impact on PTC prognosis is still indefinite.

Methods

Herein, we acquired the medical data and gene expression of individuals with PTC from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) database. Typically, three predictive iron metabolism-related genes (IMRGs) were examined and employed to build a risk score (RS) model via the least absolute shrinkage and selection operator (LASSO) regression, univariate Cox, and differential gene expression analyses. Then we analyzed somatic mutation and immune cell infiltration among RS groups. We also validated the prognostic value of two IMRGs (SFXN3 and TFR2) by verifying their biological function through in vitro experiments.

Results

Based on RS, all patients with PTC were stratified into low- and high-risk groups, where Kaplan-Meier analysis indicated that disease-free survival (DFS) in the high-risk group was much lower than in the low-risk group (P < 0.0001). According to ROC analysis, the RS model successfully predicted the 1-, 3-, and 5-year DFS of individuals with PTC. Additionally, in the TCGA cohort, a nomogram model with RS was developed and exhibited a strong capability to anticipate PTC patients' DFS. In the high-risk group, the enriched pathological processes and signaling mechanisms were detected utilizing the gene set enrichment analysis (GSEA). Moreover, the high-risk group had a significantly higher level of BRAF mutation frequency, tumor mutation burden, and immune cell infiltration than the low-risk group. In vitro experiments found that silencing SFXN3 or TFR2 significantly reduced cell viability.

Conclusion

Collectively, our predictive model depended on IMRGs in PTC, which could be potentially utilized to predict the PTC patients' prognosis, schedule follow-up plans, and provide potential targets against PTC.

The Effects of Programmed Cell Death of Mesenchymal Stem Cells on the Development of Liver Fibrosis

Mesenchymal stem cells have shown noticeable potential for unlimited self-renewal. They can differentiate into specific somatic cells, integrate into target tissues via cell-cell contact, paracrine effects, exosomes, and other processes and then regulate the target cells and tissues. Studies have demonstrated that transplantation of MSCs could decrease the expression and concentration of collagen in the liver, thereby reducing liver fibrosis. A growing body of evidence indicates that apoptotic MSCs could inhibit harmful immune responses and reduce inflammatory responses more effectively than viable MSCs. Accumulating evidence suggests that mitochondrial transfer from MSCs is a novel strategy for the regeneration of various damaged cells via the rescue of their respiratory activities. This study is aimed at reviewing the functions of MSCs and the related roles of the programmed cell death of MSCs, including autophagy, apoptosis, pyroptosis, and ferroptosis, as well as the regulatory pathogenic mechanisms of MSCs in liver fibrosis. Research has demonstrated that the miR-200B-3p gene is differentially expressed gene between LF and normal liver samples, and that the miR-200B-3p gene expression is positively correlated with the degree of liver fibrosis, suggesting that MSCs could inhibit liver fibrosis through pyroptosis. It was confirmed that circulating monocytes could deliver MSC-derived immunomodulatory molecules to different sites by phagocytosis of apoptotic MSCs, thereby achieving systemic immunosuppression. Accordingly, it was suggested that characterization of the programmed cell death-mediated immunomodulatory signaling pathways in MSCs should be a focus of research.

Characterization of peripheral white blood cells transcriptome to unravel the regulatory signatures of bovine subclinical mastitis resistance

Subclinical bovine mastitis is a pathogenic infection of the breast characterized by a marked decrease in milk production and quality. As it has no obvious clinical symptoms, diagnosis and treatment are challenging. Therefore, searching for biomarkers in cows’ peripheral white blood cells is valuable for preventing and treating subclinical mastitis. Thus, in this study, the transcriptome of peripheral blood from healthy and subclinical mastitis cows was characterized to find the regulatory signatures of bovine subclinical mastitis using RNA-seq. A total of 287 differentially expressed genes (DEGs) and 70 differentially expressed lncRNAs (DELs) were detected, and 37 DELs were documented near known Quantitative Trait Loci (QTL) associated with the mastitis of cows. Bioinformatic analysis indicated that lncRNAs MSTRG25101.2, MSTRG.56327.1, and MSTRG.18968.1, which are adjacent to the SCS QTL and SCC QTL, may be candidate lncRNAs that influence the pathogenesis of mastitis in cows by up-regulating the expression of genes TLR4, NOD2, CXCL8, and OAS2. Moreover, the alternative splicing (AS) pattern of transcriptional sequence differences between healthy cows and subclinical mastitis cows suggested a molecular mechanism of mastitis resistance and susceptibility. A total of 2,212 differential alternative splicing (DAS) events, corresponding to 1,621 unique DAS genes, were identified in both groups and significantly enriched in immune and inflammatory pathways. Of these, 29 DAS genes were subject to regulation by 32 alternative splicing SNPs, showing diverse and specific splicing patterns and events. It is hypothesized that the PIK3C2B and PPRPF8 splice variants associated with AS SNPs (rs42705933 and rs133847062) may be risk factors for susceptibility to bovine subclinical mastitis. Altogether, these key blood markers associated with resistance to subclinical mastitis and SNPs associated with alternative splicing of genes provide the basis for genetic breeding for resistance to subclinical mastitis in cows.

More than a duologue: In-depth insights into epitranscriptomics and ferroptosis

Beyond transcription, RNA molecules are enzymatically modified to influence the biological functions of living organisms. The term “epitranscriptomics” describes the changes in RNA strands aside from altering the innate sequences. Modifications on adenosine (A) are the most widely characterized epitranscriptomic modification, including N⁶-methyladenosine (m⁶A), N¹-methyladenosine (m¹A), polyadenylation, and adenosine-to-inosine (A-to-I) RNA editing, and modifications on other nucleotides seem to be fewer, such as N⁷-methylguanosine (m⁷G), 5-methylcytosine (m⁵C), and pseudouridine (Ψ). These changes on the RNA strand surface, exclusively by their RNA-modifying proteins (RMPs), are reported in various biological phenomena, including programmed cell death (PCD). One necro-biological phenomenon that has been observed for long but has started to gain heed in recent years is “ferroptosis.” The phospholipid peroxidation by polyunsaturated-fatty-acid-containing-phospholipid hydroperoxyl (PLOOH) radicals destroys membrane integrity due to a series of mechanisms. The Fenton reaction, constituting the final Haber–Weiss reaction that is less recognized, collaboratively leading to the conversion of polyunsaturated fatty acid (PUFA) to PLOOH, is the etymological origin of ferroptosis. However, it is with increasing evidence that ferroptotic signaling is also intervened by epitranscriptomic modifications, although the truth is still ambiguous. We attempted to delineate some up-to-date discoveries on both epitranscriptomics and ferroptosis, bringing up the fundamentals to address any potential connection between the two. Next, we discussed whether a duologal relationship, or more, exists between the two, taking the ROS level and iron status into consideration. Lastly, we surveyed future perspectives that would favor the understanding of these topics.

Tocopherol attenuates the oxidative stress of BMSCs by inhibiting ferroptosis through the PI3k/AKT/mTOR pathway

Oxidative stress can induce bone tissue damage and the occurrence of multiple diseases. As a type of traditional medicine, tocopherol has been reported to have a strong antioxidant effect and contributes to osteogenic differentiation. The purpose of this study was to investigate the protective effect of tocopherol on the oxidative stress of rat bone marrow-derived mesenchymal stem cells (BMSCs) and the underlying mechanisms. By establishing an oxidative stress model in vitro, the cell counting kit-8 (CCK-8), reactive oxygen species (ROS) analysis, Western blot (WB), real-time PCR (RT-PCR), alkaline phosphatase (ALP) staining, and Alizarin Red staining (ARS) evaluated the effects of tocopherol on the cell viability, intracellular ROS levels, and osteogenic differentiation in BMSCs. In addition, ferroptosis-related markers were examined via Western blot, RT-PCR, and Mito-FerroGreen. Eventually, the PI3K/AKT/mTOR signaling pathway was explored. We found that tocopherol significantly maintained the cell viability, reduced intracellular ROS levels, upregulated the levels of anti-oxidative genes, promoted the levels of osteogenic-related proteins, and the mRNA of BMSCs stimulated by H₂O₂. More importantly, tocopherol inhibited ferroptosis and upregulated the phosphorylation levels of PI3K, AKT, and mTOR of BMSCs upon H₂O₂ stimulation. In summary, tocopherol protected BMSCs from oxidative stress damage via the inhibition of ferroptosis through the PI3K/AKT/mTOR pathway.

The Regulatory Role of Ferroptosis in Bone Homeostasis

Ferroptosis is an iron-dependent form of programmed cell death and an important type of biological catabolism. Through the action of divalent iron or ester oxygenase, ferroptosis can induce lipid peroxidation and cell death, regulating a variety of physiological processes. The role of ferroptosis in the modulation of bone homeostasis is a significant topic of interest. Herein, we review and discuss recent studies exploring the mechanisms and functions of ferroptosis in different bone-related cells, including mesenchymal stem cells, osteoblasts, osteoclasts, and osteocytes. The association between ferroptosis and disorders of bone homeostasis is also explored in this review. Overall, we aim to provide a detailed overview of ferroptosis, summarizing recent understanding on its role in regulation of bone physiology and bone disease pathogenesis.