Factors associated with antiretroviral treatment adherence among people living with HIV in Guangdong Province, China: a cross sectional analysis.

BACKGROUND: Understanding factors associated with antiretroviral treatment (ART) adherence is crucial for ART success among people living with HIV (PLHIV) in the "test and treat" era. Multiple psychosocial factors tend to coexist and have a syndemic effect on ART adherence. We aimed to explore factors associated with ART adherence and the syndemic effect of multiple psychosocial factors on ART adherence among PLHIV newly starting ART in Guangdong Province, China. METHODS: Newly diagnosed PLHIV from six cities in Guangdong Province were recruited between May 2018 and June 2019, and then followed up from May 2019 to August 2020. Baseline and follow-up data were collected from a questionnaire and the national HIV surveillance system, the follow-up data of which were analyzed in this study. A Center for Adherence Support Evaluation (CASE) index > 10 points was defined as optimal ART adherence, which was measured via participants' self-reported adherence during follow-up survey. Multivariable logistic regression was used to identify factors associated with ART adherence. Exploratory factor analysis (EFA) and multi-order latent variable structural equation modeling (SEM) were performed to explore the syndemic effect of multiple psychosocial factors on ART adherence. RESULTS: A total of 734 (68.53%) follow-up participants were finally included in this study among the 1071 baseline participants, of whom 91.28% (670/734) had self-reported optimal ART adherence. Unemployment (aOR = 1.75, 95%CI: 1.01-3.02), no medication reminder (aOR = 2.28, 95%CI: 1.09-4.74), low medication self-efficacy (aOR = 2.28, 95%CI: 1.27-4.10), low social cohesion (aOR = 1.82, 95%CI: 1.03-3.19), no social participation (aOR = 5.65, 95%CI: 1.71-18.63), and ART side effects (aOR = 0.46, 95%CI: 0.26-0.81) were barriers to optimal ART adherence. The EFA and second-order latent variable SEM showed a linear relationship (standardized coefficient = 0.43, P < 0.001) between ART adherence and the latent psychosocial (syndemic) factor, which consisted of the three latent factors of medication beliefs and self-efficacy (standardized coefficient = 0.65, P < 0.001), supportive environment (standardized coefficient = 0.50, P < 0.001), and negative emotions (standardized coefficient=-0.38, P < 0.01). The latent factors of medication beliefs and self-efficacy, supportive environment, and negative emotions explained 42.3%, 25.3%, and 14.1% of the variance in the latent psychosocial factor, respectively. CONCLUSIONS: About nine out of ten PLHIV on ART in Guangdong Province self-reported optimal ART adherence. However, more efforts should be made to address barriers to optimal ART adherence.

Molecular evidence provides new insights into the evolutionary origin of an ancient traditional Chinese medicine, the domesticated "Baizhi".

Introduction: "Baizhi" is a famous herbal medicine in China, and it includes four landraces named as 'Hangbaizhi', 'Chuanbaizhi', 'Qibaizhi', and 'Yubaizhi'. Long-term artificial selection had caused serious degradation of these germplasms. Determining the wild progenitor of the landraces would be benefit for their breed improvements. Previous studies have suggested Angelica dahurica var. dahurica, A. dahurica var. formosana, or A. porphyrocaulis as potential candidates, but the conclusion remains uncertain, and their phylogenetic relationships are still in controversy. Methods: In this study, the genetic variation and phylogenetic analyses of these species and four landraces were conducted on the basis of both the nrITS and plastome datasets. Results: Genetic variation analysis showed that all 8 population of four landraces shared only one ITS haplotype, meanwhile extremely low variation occurred within 6 population at plastid genome level. Both datasets supported the four landraces might be originated from a single wild germplasm. Phylogenetic analyses with both datasets revealed largely consistent topology using Bayesian inference and Maximum likelihood methods. Samples of the four landraces and all wild A. dahurica var. dahurica formed a highly supported monophyletic clade, and then sister to the monophyly clade comprised by samples of A. porphyrocaulis, while four landraces were clustered into one clade, which further clustered with a mixed branches of A. porphyrocaulis and A. dahurica var. dahurica to form sister branches for plastid genomes. Furthermore, the monophyletic A. dahurica var. formosana was far distant from the A. dahurica var. dahurica-"Baizhi" clade in Angelica phylogeny. Such inferences was also supported by the evolutionary patterns of nrITS haplotype network and K2P genetic distances. The outcomes indicated A. dahurica var. dahurica is most likely the original plant of "Baizhi". Discussion: Considering of phylogenetic inference and evolutionary history, the species-level status of A. dahurica var. formosana should be accepted, and the taxonomic level and phylgenetic position of A. porphyrocaulis should be further confirmed. This study preliminarily determined the wild progenitor of "Baizhi" and clarified the phylogenetic relationships among A. dahurica var. dahurica, A. dahurica var. formosana and A. porphyrocaulis, which will provide scientific guidance for wild resources protections and improvement of "Baizhi".

Colon microbiota and metabolite potential impact on tail fat deposition of Altay sheep.

Tail fat deposition of Altay sheep not only increased the cost of feeding but also reduced the economic value of meat. Currently, because artificial tail removal and gene modification methods cannot solve this problem, it is maybe to consider reducing tail fat deposition from the path of intestinal microbiota and metabolite. We measured body weight and tail fat weight, collected the serum for hormone detection by enzyme-linked immunosorbent assay, and collected colon contents to 16S rRNA sequence and liquid chromotography with mass spectrometry detection to obtain colon microbiota and metabolite information, from 12 3-month-old and 6-month-old Altay sheep. Subsequently, we analyzed the correlation between colon microbiota and tail fat weight, hormones, and metabolites, respectively. We identified that the tail fat deposition of Altay sheep increased significantly with the increase of age and body weight, and the main microbiota that changed were Verrucomicrobia, Cyanobacteria, Akkermansia, Bacteroides, Phocaeicola, Escherichia-Shigella, and Clostridium_sensu_stricto_1. The results indicated that the diversities of metabolites in the colon contents of 3-months old and 6-months old were mainly reflected in phosphocholine (PC) and phosphatidylethanolamine (PE) in the lipid metabolism pathway. The correlations analyzed showed that Verrucomicrobia, Chlamydiae, Akkermansia, Ruminococcaceae_UCG-005, Bacteroides, and Phocaeicola were negatively correlated with tail fat deposition. Verrucomicrobia, Akkermansia, and Bacteroides were negatively correlated with growth hormone (GH). Verrucomicrobia was positively correlated with L-a-lysophosphatidylserine and PE(18:1(9Z)/0:0). Our results showed that tail fat deposition of Altay sheep was probably correlated with the abundance of Verrucomicrobia, Akkermansia, Bacteroides of colon microbiota, PC, PE of metabolites, and GH of serum. IMPORTANCE: Excessive tail fat deposition of Altay sheep caused great economic losses, and the current research results could not solve this problem well. Now, our research speculates that the tail fat deposition of Aletay sheep may be related to the abundance of Verrucomicrobia, Akkermansia, Bacteroides, metabolites phosphocholine, phosphatidylethanolamine, and growth hormone of serum. Further investigation of the interaction mechanism between these microbiota or metabolites and tail fat deposition is helpful in reducing tail fat deposition of Altay sheep and increasing the economic benefits of breeding farms.

Glochidionyangchunense (Phyllanthaceae), a new species with discoid flowers from Guangdong Province, China.

Phyllanthodendron can be readily morphologically distinguished from Glochidion, but recent molecular evidence showed that Phyllanthodendron is paraphyletic due to Glochidion being nested within it. In this study, a new species of the former Phyllanthodendron is described and illustrated as Glochidionyangchunense Z.Q. Song & Gang Yao from the limestone areas of South China. This is a peculiar new species and morphologically distinguished by its discoid flowers, T-shaped disc segments, and glabrous flowering branches. A key to Glochidionyangchunense and related species in China is provided here.

One-Step Construction of 1,3,4-Oxadiazoles with Anticancer Activity from Tertiary Amines via a Sequential Copper(I)-Catalyzed Oxidative Ugi/aza-Wittig Reaction.

An unparalleled copper(I)-catalyzed synthesis of 1,3,4-oxadiazoles from tertiary amines in one step has been described. The one-pot reactions involving (N-isocyanimine)triphenylphosphorane, tertiary amines, and carboxylic acids resulted in the formation of 1,3,4-oxadiazoles in moderate to good yields through a consecutive oxidative Ugi/aza-Wittig reaction, enabling the direct functionalization of sp3 C-H bonds adjacent to the nitrogen atom. This method offered several notable advantages, including ligands-free, exceptional productivity and a high functional group tolerance. The preliminary biological evaluation demonstrated that compound 4f inhibited hepatoma cells efficiently, suggesting potentially broad applications of the approach for synthesis and medicinal chemistry.

A new species and three records of Chloroperlidae (Plecoptera) from China.

A new species of the genus Suwallia Ricker, 1943, S. rostrata sp. nov., from Xizang of southwestern China is described, illustrated and compared with similar species. Alloperla kurentzovi Zhiltzova & Zapekina-Dulkeit, 1977, A. kurilensis Zhiltzova, 1978, A. teleckojensis mal, 1939 are reported for the first time from China. The diagnostic features of these species are illustrated with color images.

Boosting Thermoelectric Performance of PbBi2 Te4 via Reduced Carrier Scattering and Intensified Phonon Scattering.

Materials with low intrinsic lattice thermal conductivity are crucial in the pursuit of high-performance thermoelectric (TE) materials. Here, the TE properties of PbBi2 Te4-x Sex (0 ≤ x ≤ 0.6) samples are systematically investigated for the first time. Doping with Se in PbBi2 Te4 can simultaneously reduce carrier concentration and increase carrier mobility. The Seebeck coefficient is significantly increased by doping with Se, based on the density functional theory calculation, it is shown to be due to the increased bandgap and electronic density of states. In addition, the lattice strain is enhanced due to the difference in the size of Se and Te atoms, and the multidimensional defects formed by Se doping, such as vacancies, dislocations, and grain boundaries, enhance the phonon scattering and reduce the lattice thermal conductivity by about 37%. Finally, by using Se doping to reduce carrier concentration and thermal conductivity, a large ZTmax = 0.56 (at 574K) is achieved for PbBi2 Te3.5 Se0.5 , which is around 64% larger than those of the PbBi2 Te4 pristine sample. This work not only demonstrates that PbBi2 Te4 is a potential medium temperature thermoelectric material, but also provides a reference for enhancing thermoelectric properties through defect and energy band engineering.

Integrated analysis of microRNA and messenger RNA expression profiles reveals functional microRNA in infectious bovine rhinotracheitis virus-induced mitochondrial damage in Madin-Darby bovine kidney cells.

BACKGROUND: Studies have confirmed that Infectious bovine rhinotracheitis virus (IBRV) infection induces mitochondrial damage. MicroRNAs (miRNAs) are a class of noncoding RNA molecules, which are involved in various biological processes and pathological changes associated with mitochondrial damage. It is currently unclear whether miRNAs participate in IBRV-induced mitochondrial damage in Madin-Darby bovine kidney (MDBK) cells. RESULTS: In the present study, we used high-throughput sequencing technology, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis to screen for mitochondria-related miRNAs and messenger RNAs (mRNAs). In total, 279 differentially expressed miRNAs and 832 differentially expressed mRNAs were identified in 6 hours (IBRV1) versus 24 hours (IBRV2) after IBRV infection in MDBK cells. GO and KEGG enrichment analysis revealed that 42 differentially expressed mRNAs and 348 target genes of differentially expressed miRNAs were correlated with mitochondrial damage, and the miRNA-mitochondria-related target genes regulatory network was constructed to elucidate their potential regulatory relationships. Among the 10 differentially expressed miRNAs, 8 showed expression patterns consistent with the high-throughput sequencing results. Functional validation results showed that overexpression of miR-10a and miR-182 aggravated mitochondrial damage, while inhibition of miR-10a and miR-182 alleviated mitochondrial damage. CONCLUSIONS: This study not only revealed the expression changes of miRNAs and mRNAs in IBRV-infected MDBK cells, but also revealed possible biological regulatory relationship between them. MiR-10a and miR-182 may have the potential to be developed as biomarkers for the diagnosis and treatment of IBRV. Together, Together, these data and analyses provide additional insights into the roles of miRNA and mRNA in IBRV-induced mitochondria damage.

'Out of Africa' origin of the pantropical staghorn fern genus Platycerium (Polypodiaceae) supported by plastid phylogenomics and biogeographical analysis.

BACKGROUND AND AIMS: The staghorn fern genus Platycerium is one of the most commonly grown ornamental ferns, and it evolved to occupy a typical pantropical intercontinental disjunction. However, species-level relationships in the genus have not been well resolved, and the spatiotemporal evolutionary history of the genus also needs to be explored. METHODS: Plastomes of all the 18 Platycerium species were newly sequenced. Using plastome data, we reconstructed the phylogenetic relationships among Polypodiaceae members with a focus on Platycerium species, and further conducted molecular dating and biogeographical analyses of the genus. KEY RESULTS: The present analyses yielded a robustly supported phylogenetic hypothesis of Platycerium. Molecular dating results showed that Platycerium split from its sister genus Hovenkampia ~35.2 million years ago (Ma) near the Eocene-Oligocene boundary and began to diverge ~26.3 Ma during the late Oligocene, while multiple speciation events within Platycerium occurred during the middle to late Miocene. Biogeographical analysis suggested that Platycerium originated in tropical Africa and then dispersed eastward to southeast Asia-Australasia and westward to neotropical areas. CONCLUSIONS: Our analyses using a plastid phylogenomic approach improved our understanding of the species-level relationships within Platycerium. The global climate changes of both the Late Oligocene Warming and the cooling following the mid-Miocene Climate Optimum may have promoted the speciation of Platycerium, and transoceanic long-distance dispersal is the most plausible explanation for the pantropical distribution of the genus today. Our study investigating the biogeographical history of Platycerium provides a case study not only for the formation of the pantropical intercontinental disjunction of this fern genus but also the 'out of Africa' origin of plant lineages.

De novo chromosome-level genome assembly of Chinese motherwort (Leonurus japonicus).

Chinese motherwort (Leonurus japonicus), a member of Lamiaceae family, is a commonly used medicinal herb for treating obstetrical and gynecological diseases, producing over 280 officinal natural products. Due to limited genomic resources, little progress has been made in deciphering the biosynthetic pathway of valuable natural products in L. japonicus. Here, we de novo assembled the L. japonicus genome using high-coverage ONT long reads and Hi-C reads. The chromosome-level genome assembly contained ten chromosomes representing 99.29% of 489.34 Mb genomic sequence with a contig and scaffold N50 of 7.27 Mb and 50.86 Mb, respectively. Genome validations revealed BUSCO and LAI score of 99.2% and 21.99, respectively, suggesting high quality of genome assembly. Using transcriptomic data from various tissues, 22,531 protein-coding genes were annotated. Phylogenomic analysis of 13 angiosperm plants suggested L. japonicus had 58 expanded gene families functionally enriched in specialized metabolism such as diterpenoid biosynthesis. The genome assembly, annotation, and sequencing data provide resources for the elucidation of biosynthetic pathways behind natural products of pharmaceutical applications in L. japonicus.

Discovery and SAR Study of Boronic Acid-Based Selective PDE3B Inhibitors from a Novel DNA-Encoded Library.

Human genetic evidence shows that PDE3B is associated with metabolic and dyslipidemia phenotypes. A number of PDE3 family selective inhibitors have been approved by the FDA for various indications; however, given the undesirable proarrhythmic effects in the heart, selectivity for PDE3B inhibition over closely related family members (such as PDE3A; 48% identity) is a critical consideration for development of PDE3B therapeutics. Selectivity for PDE3B over PDE3A may be achieved in a variety of ways, including properties intrinsic to the compound or tissue-selective targeting. The high (>95%) active site homology between PDE3A and B represents a massive obstacle for obtaining selectivity at the active site; however, utilization of libraries with high molecular diversity in high throughput screens may uncover selective chemical matter. Herein, we employed a DNA-encoded library screen to identify PDE3B-selective inhibitors and identified potent and selective boronic acid compounds bound at the active site.

lncRNA-Gm5532 regulates osteoclast differentiation through the miR-125a-3p/TRAF6 axis.

Long noncoding RNAs (lncRNAs) are important regulators of bone metabolism. In this study, lncRNA microarray analysis was used to identify differentially expressed lncRNAs in differentiated osteoclasts. lncRNA-Gm5532 is highly expressed during osteoclast differentiation. lncRNA-Gm5532 knockdown impairs osteoclast formation and bone resorption. Mechanistic experiments show that lncRNA-Gm5532 functions as a competing endogenous RNA (ceRNA) and acts as a sponge for miR-125a-3p, which promotes TNF receptor-associated factor 6 (TRAF6) expression. miR-125a-3p mimics suppress osteoclast differentiation and TAK1/NF-κB/MAPK signaling. The miR-125a-3p inhibitor reverses the negative effects of siGm5532 on osteoclast differentiation. In summary, our study reveals that lncRNA-Gm5532 functions as an activator in osteoclast differentiation by targeting the miR-125a-3p/TRAF6 axis, making it a novel biomarker and potential therapeutic target for osteoporosis.

Role and Mechanism of NUP160-regulated Autophagy in Pathogenesis of Diabetic Nephropathy.

\Introduction. Diabetes mellitus (DM) is one of the most common chronic diseases worldwide, and diabetic nephropathy (DN) is the most significant complication of DM, which is highly prevalent and difficult to cure. This research project aims to investigate the role and mechanism of Nucleoporin 160kDa (NUP160)-regulated autophagy in the pathogenesis of DN. METHODS: NUP160 levels in diabetic and non-diabetic kidney tissues were measured by Western blot, and the connection between NUP160 and renal function of DN patients was analyzed. The podocytes were divided into four groups, namely the standard group (culture medium: standard glucose solution), high glucose (HG) group (HG solution), HG+si-NUP160 group (HG solution+si-NUP160 transfection) and HG+si-NC group (HG solution+si-NUP 160 transfection) for the determination of apoptosis by flow cytometry and measurements of LC3B, Prostacyclin-62 (P62), Janus kinase 2 (JAK2) and Signal transducer and activator of transcription3 (STAT3) by Western blot. RESULTS: In DN patients, NUP160 decreased in podocytes and was inversely proportional to Blood urea nitrogen (BUN), Serum creatinine (Scr) and ß2-Microglobulin (ß2-MG) (P < .05). Compared with a standard group, the apoptosis rate, P62 level, and the ratios of phosphorylation-JAK2 (p-JAK2)/JAK2, phosphorylation-STAT3 (p-STAT3)/STAT3, and LC3B-Ⅱ/LC3B-Ⅰ elevated in the other three groups (P < .05). Apoptosis rate and P62 level, p-JAK2/JAK2 and p-STAT3/STAT3 ratios increased, and LC3B-Ⅱ/LC3B-Ⅰ ratio decreased in the HG+si-NUP160 group (P < .05), while those in HG+si-NC group showed no evident changes, compared with HG group (P > .05). CONCLUSION: NUP160 is downregulated in DN and can affect cellular autophagy through the activation of JAK2/STAT3 signaling pathway.  DOI: 10.52547/ijkd.7884.

Enhancing efficacy and safety of glioma treatment: optimization and evaluation of a novel dual-cavity capsule structure through orthogonal testing.

Existing glioma treatments face challenges in simultaneously combining radiotherapy and chemotherapy while achieving long-term, stable continuous irradiation at low doses. To address this clinical challenge, two types of radiochemotherapy integrated dual-cavity capsules, single-capsule dual-cavity, and dual-capsule dual-cavity, were designed in this research. We employed finite element simulation and the Monte Carlo method to conduct stress-deformation simulation and dose analysis on the structure and manufacturing materials of the capsules. Based on these simulations, the structure of the dual-cavity capsule was optimized through orthogonal tests to obtain optimal results for tumor radiation therapy. Dose analysis experiments revealed that the dual-capsule dual-cavity structure exhibited improved irradiation effects on the lesion while minimizing damage to surrounding tissues and organs compared to the single-capsule dual-cavity structure. Stress-deformation simulation indicated that using polyetheretherketone as the capsule material enabled higher central dose rates and reduced deformation. Furthermore, the material's ease of processing and low-cost characteristics facilitated the development of personalized and precise treatment approaches. The proposed capsule structure realizes the integrated combination of internal radiotherapy and internal chemotherapy, establishing a new mode of long-term stable local high-dose and peripheral low-dose radiation therapy. This scheme offers a novel treatment plan and advanced technical reserve for the integrated treatment of intracranial glioma radiotherapy and chemotherapy.

Active Center Size-Dependent Fenton-Like Chemistry for Sustainable Water Decontamination.

Accurately controlling catalytic activity and mechanism as well as identifying structure-activity-selectivity correlations in Fenton-like chemistry is essential for designing high-performance catalysts for sustainable water decontamination. Herein, active center size-dependent catalysts with single cobalt atoms (CoSA), atomic clusters (CoAC), and nanoparticles (CoNP) were fabricated to realize the changeover of catalytic activity and mechanism in peroxymonosulfate (PMS)-based Fenton-like chemistry. Catalytic activity and durability vary with the change in metal active center sizes. Besides, reducing the metal size from nanoparticles to single atoms significantly modulates contributions of radical and nonradical mechanisms, thus achieving selective/nonselective degradation. Density functional theory calculations reveal evolutions in catalytic mechanisms of size-dependent catalytic systems over different Gibbs free energies for reactive oxygen species generation. Single-atom site contact with PMS is preferred to induce nonradical mechanisms, while PMS dissociates and generates radicals on clusters and nanoparticles. Differences originating from reaction mechanisms endow developed systems with size-dependent selectivity and mineralization for treating actual hospital wastewater in column reactors. This work brings an in-depth understanding of metal size effects in Fenton-like chemistry and guides the design of intelligent catalysts to fulfill the demand of specific scenes for water purification.

Hoyaspectatissima (Gentianales, Apocynaceae), a new species from Yunnan, China.

Hoyaspectatissima, a new species from Yunnan Province, China, is described and illustrated. Hoyaspectatissima is morphologically similar to H.lyi, but can be easily distinguished from the latter by its succulent leaves that are 2‒4.5 cm long (vs. coriaceous leaves that are up to 9 cm long), corolla that is pink to pale pink (vs. yellowish-white) and corona lobes that are sub-rhombic in top view (vs. ovoid in top view).

Epitaxial growth of Si thin films with hexagonal close-packed structures on metal substrates.

We have studied the epitaxial growth of Si thin films on the Cd(0001) surface using low-temperature scanning tunneling microscopy. When deposited at low temperatures (100 K), Si atoms form dendritic islands with triangular shapes, indicating the existence of anisotropic edge diffusion in the process of Si film growth. After annealing to elevated temperatures, the triangular dendritic Si islands become hexagonal compact islands. Moreover, the 2D Si islands located on two different substrate terraces exhibit different heights due to the influence of quantum-well states in Cd(0001) films. Based on high-resolution scanning tunneling microscopy images, it is observed that the first, second, and third Si layers show the pseudomorphic 1 × 1 structure. In particular, the first and second layer islands reveal the opposite triangles, indicating the hexagonal close-packed stacking of Si atoms. These results provide important information for the growth of pristine Si films on metal substrates and the understanding of Si-metal interaction.

Application of the suture needle retrograde threading method in scleral fixation of intraocular lenses.

BACKGROUND: Here we described a new threading technique for the universal fixation of any posterior chamber intraocular lens (IOL). METHODS: Twenty-seven eyes of 27 patients whose surgery done by Surgeon A with the needle-guided method or the suture needle retrograde threading (SNRT) method for intrascleral IOL fixation were enrolled in the first group. Thirty-four eyes of 34 patients whose surgery done by Surgeon A, Surgeon B or Surgeon C with the SNRT method for intrascleral IOL fixation were grouped into three sub-groups by surgeon. Information regarding age, sex, best-available visual acuity (BCVA), intraocular pressure (IOP), past ophthalmological history, threading time (from puncturing to externalizing suture) and complications during and after the surgery were gathered. RESULTS: The analysis showed that the threading time was less in the SNRT group than needle-guided group by Surgeon A. There was one eye with suture needle slipping from the guide needle when guiding out of the eye. The threading procedure was completed one time without suture ruptures or loop slippage in the SNRT group operated by Surgeon A. And using the SNRT method, Surgeon A, Surgeon B, and Surgeon C did not show any significant difference in threading time. No complications (e.g., vitreous hemorrhage, hyphemia, retinal detachment, suprachoroidal hemorrhage, or hypotony) were observed during surgery or postoperatively in all cases. No leakage occurred at the site of the puncture after the operation. CONCLUSIONS: The described technique appears to be a safe, simple, easy-to-learn, and universal surgical method, which is suitable for various types of IOLs.

NRF2 is essential for iron-overload stimulated osteoclast differentiation through regulation of redox and iron homeostasis.

Iron overload enhances osteoclastic bone resorption and induces osteoporosis. Excess iron is highly toxic. The modulation of redox and iron homeostasis is critical for osteoclast differentiation under iron-overload condition. Nuclear factor erythroid 2-related factor 2 (NRF2) is a transcription factor that regulates the cellular defense against oxidative stress and iron overload through the expression of genes involved in anti-oxidative processes and iron metabolism. Our studies demonstrated that NRF2 activation was suppressed during osteoclast differentiation. Under iron-overload condition, NRF2 and its mediated antioxidant and iron metabolism genes were activated by reactive oxygen species (ROS), which enhanced antioxidant capability. NRF2 mediated the upregulation of iron exporter ferroportin 1 (FPN1) and iron storage protein ferritin, contributing to decreased levels of intracellular iron. Nfe2l2 knockout induced oxidative stress and promoted osteoclast differentiation under normal condition, but induced ferroptosis under iron-overload condition. Nfe2l2 knockout alleviated iron overload induced bone loss by inhibiting osteoclast differentiation. Our results suggest that NRF2 activation is essential for osteoclast differentiation by enhancing antioxidant capability and reducing intracellular iron under iron-overload condition. Targeting NRF2 to induce ferroptosis could be a potential therapy for the treatment of iron-overload induced osteoporosis.