Lysosomal cyst(e)ine storage potentiates tolerance to oxidative stress in cancer cells.

Cyst(e)ine is a key precursor for the synthesis of glutathione (GSH), which protects cancer cells from oxidative stress. Cyst(e)ine is stored in lysosomes, but its role in redox regulation is unclear. Here, we show that breast cancer cells upregulate major facilitator superfamily domain containing 12 (MFSD12) to increase lysosomal cyst(e)ine storage, which is released by cystinosin (CTNS) to maintain GSH levels and buffer oxidative stress. We find that mTORC1 regulates MFSD12 by directly phosphorylating residue T254, while mTORC1 inhibition enhances lysosome acidification that activates CTNS. This switch modulates lysosomal cyst(e)ine levels in response to oxidative stress, fine-tuning redox homeostasis to enhance cell fitness. MFSD12-T254A mutant inhibits MFSD12 function and suppresses tumor progression. Moreover, MFSD12 overexpression correlates with poor neoadjuvant chemotherapy response and prognosis in breast cancer patients. Our findings reveal the critical role of lysosomal cyst(e)ine storage in adaptive redox homeostasis and suggest that MFSD12 is a potential therapeutic target.

Loss of UBE2S causes meiosis I arrest with normal spindle assembly checkpoint dynamics in mouse oocytes.

The timely degradation of proteins that regulate the cell cycle is essential for oocyte maturation. Oocytes are equipped to degrade proteins via the ubiquitin-proteasome system. In meiosis, anaphase promoting complex/cyclosome (APC/C), an E3 ubiquitin-ligase, is responsible for the degradation of proteins. Ubiquitin-conjugating enzyme E2 S (UBE2S), an E2 ubiquitin-conjugating enzyme, delivers ubiquitin to APC/C. APC/C has been extensively studied, but the functions of UBE2S in oocyte maturation and mouse fertility are not clear. In this study, we used Ube2s knockout mice to explore the role of UBE2S in mouse oocytes. Ube2s-deleted oocytes were characterized by meiosis I arrest with normal spindle assembly and spindle assembly checkpoint dynamics. However, the absence of UBE2S affected the activity of APC/C. Cyclin B1 and securin are two substrates of APC/C, and their levels were consistently high, resulting in the failure of homologous chromosome separation. Unexpectedly, the oocytes arrested in meiosis I could be fertilized and the embryos could become implanted normally, but died before embryonic day 10.5. In conclusion, our findings reveal an indispensable regulatory role of UBE2S in mouse oocyte meiosis and female fertility.

Mad2 is dispensable for accurate chromosome segregation but becomes essential when oocytes are subjected to environmental stress.

Accurate chromosome segregation, monitored by the spindle assembly checkpoint (SAC), is crucial for the production of euploid cells. Previous in vitro studies by us and others showed that Mad2, a core member of the SAC, performs a checkpoint function in oocyte meiosis. Here, through an oocyte-specific knockout approach in mouse, we reconfirmed that Mad2-deficient oocytes exhibit an accelerated metaphase-to-anaphase transition caused by premature degradation of securin and cyclin B1 and subsequent activation of separase in meiosis I. However, it was surprising that the knockout mice were completely fertile and the resulting oocytes were euploid. In the absence of Mad2, other SAC proteins, including BubR1, Bub3 and Mad1, were normally recruited to the kinetochores, which likely explains the balanced chromosome separation. Further studies showed that the chromosome separation in Mad2-null oocytes was particularly sensitive to environmental changes and, when matured in vitro, showed chromosome misalignment, lagging chromosomes, and aneuploidy with premature separation of sister chromatids, which was exacerbated at a lower temperature. We reveal for the first time that Mad2 is dispensable for proper chromosome segregation but acts to mitigate environmental stress in meiotic oocytes.

PPP4C facilitates homologous recombination DNA repair by dephosphorylating PLK1 during early embryo development.

Mammalian early embryo cells have complex DNA repair mechanisms to maintain genomic integrity, and homologous recombination (HR) plays the main role in response to double-strand DNA breaks (DSBs) in these cells. Polo-like kinase 1 (PLK1) participates in the HR process and its overexpression has been shown to occur in a variety of human cancers. Nevertheless, the regulatory mechanism of PLK1 remains poorly understood, especially during the S and G2 phase. Here, we show that protein phosphatase 4 catalytic subunit (PPP4C) deletion causes severe female subfertility due to accumulation of DNA damage in oocytes and early embryos. PPP4C dephosphorylated PLK1 at the S137 site, negatively regulating its activity in the DSB response in early embryonic cells. Depletion of PPP4C induced sustained activity of PLK1 when cells exhibited DNA lesions that inhibited CHK2 and upregulated the activation of CDK1, resulting in inefficient loading of the essential HR factor RAD51. On the other hand, when inhibiting PLK1 in the S phase, DNA end resection was restricted. These results demonstrate that PPP4C orchestrates the switch between high-PLK1 and low-PLK1 periods, which couple the checkpoint to HR.

Open Active Sites in Ni-Based MOF with High Oxidation States for Electrooxidation of Benzyl Alcohol.

The kinetics of electrocatalytic reactions are closely related to the number and intrinsic activity of the active sites. Open active sites offer easy access to the substrate and allow for efficient desorption and diffusion of reaction products without significant hindrance. Metal-organic frameworks (MOFs) with open active sites show great potential in this context. To increase the density of active sites, trimesic acid was utilized as a ligand to anchor more Ni sites and in situ construct the nickel foam-loaded Ni-based trimesic MOF electrocatalyst (Ni-TMA-MOF/NF). When tested as an electrocatalyst for benzyl alcohol oxidation, Ni-TMA-MOF/NF exhibited lower overpotential and superior durability compared to Ni foam-loaded Ni-based terephthalic MOF electrocatalyst (Ni-PTA-MOF/NF) and Ni(OH)2 nanosheet array (Ni(OH)2/NF). Ni-TMA-MOF/NF required only a low potential of 1.65 V to achieve a high current density of 400 mA cm-2. Even after 40000 s of electrocatalytic oxidation at 1.5 V, Ni-TMA-MOF/NF maintained a current density of 175 mA cm-2 with ∼68% retention, showing its potential for benzyl alcohol oxidation. Through a combination of experimental and theoretical investigations, it was found that Ni-TMA-MOF/NF displayed superior electrocatalytic activity due to an optimized electron structure with high-valence Ni species and a high density of active sites, enabling long-term stable operation at high current densities. This study provides a new perspective on the design of electrocatalysts for benzyl alcohol oxidation.

The phospholipid flippase ATP9A enhances macropinocytosis to promote nutrient starvation tolerance in hepatocellular carcinoma.

Macropinocytosis is an effective strategy to mitigate nutrient starvation. It can fuel cancer cell growth in nutrient-limited conditions. However, whether and how macropinocytosis contributes to the rapid proliferation of hepatocellular carcinoma cells, which frequently experience an inadequate nutrient supply, remains unclear. Here, we demonstrated that nutrient starvation strongly induced macropinocytosis in some hepatocellular carcinoma cells. It allowed the cells to acquire extracellular nutrients and supported their energy supply to maintain rapid proliferation. Furthermore, we found that the phospholipid flippase ATP9A was critical for regulating macropinocytosis in hepatocellular carcinoma cells and that high ATP9A levels predicted a poor outcome for patients with hepatocellular carcinoma. ATP9A interacted with ATP6V1A and facilitated its transport to the plasma membrane, which promoted plasma membrane cholesterol accumulation and drove RAC1-dependent macropinocytosis. Macropinocytosis inhibitors significantly suppressed the energy supply and proliferation of hepatocellular carcinoma cells characterised by high ATP9A expression under nutrient-limited conditions. These results have revealed a novel mechanism that overcomes nutrient starvation in hepatocellular carcinoma cells and have identified the key regulator of macropinocytosis in hepatocellular carcinoma. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Mitochondrial E3 ubiquitin ligase MARCH5 is required for mouse oocyte meiotic maturation†.

As the most abundant organelles in oocytes, mitochondria play an important role in maintaining oocyte quality. Here, we report that March5, encoding a mitochondrial ubiquitin ligase that promotes mitochondrial elongation, plays a critical role in mouse oocyte meiotic maturation via regulating mitochondrial function. The subcellular localization of MARCH5 was similar to the mitochondrial distribution during mouse oocyte meiotic progression. Knockdown of March5 caused decreased ratios of the first polar body extrusion. March5-siRNA injection resulted in oocyte mitochondrial dysfunctions, manifested by increased reactive oxygen species, decreased ATP content as well as decreased mitochondrial membrane potential, leading to reduced ability of spindle formation and an increased ratio of kinetochore-microtubule detachment. Further study showed that the continuous activation of the spindle assembly checkpoint and the failure of Cyclin B1 degradation caused MI arrest and first polar body (PB1) extrusion failure in March5 knockdown oocytes. Taken together, our results demonstrated that March5 plays an essential role in mouse oocyte meiotic maturation, possibly via regulation of mitochondrial function and/or ubiquitination of microtubule dynamics- or cell cycle-regulating proteins.

Physiologically-based pharmacokinetic modeling-guided rational combination of tacrolimus and voriconazole in patients with different CYP3A5 and CYP2C19 alleles.

The drug-drug interactions (DDIs) between tacrolimus and voriconazole are highly variable among individuals. We aimed to develop a physiologically based pharmacokinetic (PBPK) model to predict the DDIs in people with different CYP3A5 and CYP2C19 alleles. First, pharmacokinetic data of humans receiving tacrolimus with or without voriconazole from the literature were used to construct and validate the PBPK model. Thereafter, we developed a model incorporating the metabolism of voriconazole mediated by CYP2C19 and the inhibitory effect of voriconazole on CYP3A4/5. Finally, the model was used to evaluate the dose adjustment of tacrolimus in people with different CYP3A5 and CYP2C19 alleles. When tacrolimus was administered alone (3 mg PO, single dose), the predicted AUC0-∞ of tacrolimus in CYP3A5 nonexpressers (19.22) was 3.5-fold higher than that in expressers (5.48). Following voriconazole (200 mg PO, bid) administration in human with different CYP2C19 genotypes, the AUC0-∞ of tacrolimus increased by 5.1- to 8.3-fold in CYP3A5 expressers and by 5.3- to 10.2-fold in CYP3A5 nonexpressers. The lower the gene expression level of CYP2C19 in the population, the higher the exposure to tacrolimus. When tacrolimus was combined with voriconazole (200 mg, bid; 400 mg, bid, on Day 1), the final model simulations suggested that the dose regimen of tacrolimus should be regulated to 0.15 mg/kg/day (qd) in CYP3A5 expressers with different CYP2C19 genotypes. For CYP3A5 nonexpressers, the dosing schedule of tacrolimus should be modified to 0.05 mg/kg/24 h for patients with 2C19 EM, 0.05 mg/kg/48 h for 2C19 IM and 0.05 mg/kg/72 h for 2C19 PM. In conclusion, a PBPK model with CYP3A5 and CYP2C19 polymorphisms was successfully established, providing more insights regarding the DDIs between tacrolimus and voriconazole to guide the clinical use of tacrolimus.

Glioblastoma and Solitary Brain Metastasis: Differentiation by Integrating Demographic-MRI and Deep-Learning Radiomics Signatures.

BACKGROUND: Studies have shown that deep-learning radiomics (DLR) could help differentiate glioblastoma (GBM) from solitary brain metastasis (SBM), but whether integrating demographic-MRI and DLR features can more accurately distinguish GBM from SBM remains uncertain. PURPOSE: To construct and validate a demographic-MRI deep-learning radiomics nomogram (DDLRN) integrating demographic-MRI and DLR signatures to differentiate GBM from SBM preoperatively. STUDY TYPE: Retrospective. POPULATION: Two hundred and thirty-five patients with GBM (N = 115) or SBM (N = 120), randomly divided into a training cohort (90 GBM and 98 SBM) and a validation cohort (25 GBM and 22 SBM). FIELD STRENGTH/SEQUENCE: Axial T2-weighted fast spin-echo sequence (T2WI), T2-weighted fluid-attenuated inversion recovery sequence (T2-FLAIR), and contrast-enhanced T1-weighted spin-echo sequence (CE-T1WI) using 1.5-T and 3.0-T scanners. ASSESSMENT: The demographic-MRI signature was constructed with seven imaging features ("pool sign," "irregular ring sign," "regular ring sign," "intratumoral vessel sign," the ratio of the area of peritumoral edema to the enhanced tumor, the ratio of the lesion area on T2-FLAIR to CE-T1WI, and the tumor location) and demographic factors (age and sex). Based on multiparametric MRI, radiomics and deep-learning (DL) models, DLR signature, and DDLRN were developed and validated. STATISTICAL TESTS: The Mann-Whitney U test, Pearson test, least absolute shrinkage and selection operator, and support vector machine algorithm were applied for feature selection and construction of radiomics and DL models. RESULTS: DDLRN showed the best performance in differentiating GBM from SBM with area under the curves (AUCs) of 0.999 and 0.947 in the training and validation cohorts, respectively. Additionally, the DLR signature (AUC = 0.938) outperformed the radiomics and DL models, and the demographic-MRI signature (AUC = 0.775) was comparable to the T2-FLAIR radiomics and DL models in the validation cohort (AUC = 0.762 and 0.749, respectively). DATA CONCLUSION: DDLRN integrating demographic-MRI and DLR signatures showed excellent performance in differentiating GBM from SBM. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 2.

Kinetochore scaffold 1 regulates SAC function during mouse oocyte meiotic maturation.

Precise regulation of chromosome separation through spindle assembly checkpoint (SAC) during oocyte meiosis is critical for mammalian reproduction. The kinetochore plays an important role in the regulation of SAC through sensing microtubule tension imbalance or missing microtubule connections. Here, we report that kinetochore scaffold 1 (KNL1, also known as CASC5), an outer kinetochore protein, plays a critical role in the SAC function of mouse oocytes. KNL1 localized at kinetochores from GVBD to the MII stage, and microinjection of KNL1-siRNA caused accelerated metaphase-anaphase transition and premature first meiosis completion, producing aneuploid eggs. The SAC was prematurely silenced in the presence of unstable kinetochore-microtubule attachments and misaligned chromosomes in KNL1-depleted oocytes. Additionally, KNL1 and MPS1 had a synergistic effect on the activation and maintenance of SAC. Taken together, our results suggest that KNL1, as a kinetochore platform protein, stabilizes SAC to ensure timely anaphase entry and accurate chromosome segregation during oocyte meiotic maturation.

MAPRE2 regulates the first meiotic progression in mouse oocytes.

Microtubule plus-end tracking proteins (+TIPs) associate with growing microtubule plus ends and control microtubule dynamics and interactions with different cellular structures during cell division, cell migration and morphogenesis. Microtubule-associated RP/EB family member 2 (MAPRE2/EB2) is a highly conserved core component of +TIPs networks, but whether this molecule is required for mammalian meiotic progression is unknown. In this study, we investigated the expression and function of MAPRE2 during oocyte maturation. Our results showed that MAPRE2 was consistently expressed from germinal vesicle (GV) to metaphase II (MII) stages and that MAPRE2 was distributed in the cytoplasm of oocytes at GV stage and along the spindle at metaphase I (MI) and MII stages. Small interfering RNA-mediated knockdown of Mapre2 severely impaired microtubule stability, kinetochore-microtubule attachment, and chromosome alignment and subsequently caused spindle assembly checkpoint (SAC) activation and cyclin B1 nondegradation, leading to failure of chromosome segregation and first polar body extrusion. This study demonstrates for the first time that MAPRE2 plays an important role during mouse oocyte meiosis.

Septin 4 controls CCNB1 stabilization via APC/CCDC20 during meiotic G2/M transition in mouse oocytes.

In mammals, oocytes are arrested at G2/prophase for a long time, which is called germinal vesicle (GV) arrest. After puberty, fully-grown oocytes are stimulated by a gonadotropin surge to resume meiosis as indicated by GV breakdown (GVBD). CCNB1 is accumulated to a threshold level to trigger the activation of maturation promoting factor (MPF), inducing the G2/M transition. It is generally recognized that the anaphase-promoting complex/cyclosome (APC/C) and its cofactor CDH1 (also known as FZR1) regulates the accumulation/degradation of CCNB1. Here, by using small interfering RNA (siRNA) and messenger RNA (mRNA) microinjection, immunofluorescence and confocal microscopy, immunoprecipitation, time-lapse live imaging, and immunoblotting analysis, we showed that Septin 4 regulates the G2/M transition by regulating the accumulation of CCNB1 via APC/CCDC20 . Depletion of Septin 4 caused GV arrest by reducing CCNB1 accumulation. Unexpectedly, the expression level of CDC20 was higher in Septin 4 siRNA-injected oocytes than in control oocytes, but there was no significant change in the expression level of CDH1. Importantly, the reduced GVBD after Septin 4 depletion could be rescued not only by over-expressing CCNB1 but also could be partially rescued by depleting CDC20. Taken together, our results demonstrate that Septin 4 may play a critical role in meiotic G2/M transition by indirect regulation of CCNB1 stabilization in mouse oocytes.

Toxic effects of AZD1208 on mouse oocytes and its possible mechanisms.

AZD1208, a pan-inhibitor that can effectively inhibit PIM kinase, is used for the treatment of advanced solid tumors and malignant lymphomas. Numerous studies have proved its curative effects while its potential cellular toxicity on reproduction was still little known. In this study, we investigated the toxic effects of AZD1208 on mouse oocytes. The results showed that AZD1208 treatment did not affect meiotic resumption, but postponed oocyte maturation as indicated by delayed first polar body extrusion. Further mechanistic study showed that AZD1208 treatment delayed spindle assembly. In addition, we found that oocytes treated with AZD1208 showed mitochondrial dysfunction. Abnormal mitochondrial clusters with decreased mitochondrial membrane potential were observed in oocytes during incubation in vitro. Moreover, increased oxidative stress was observed by testing the level of reactive oxygen species. In summary, our results suggest that AZD1208 treatment influences oocyte meiotic progression by causing mitochondrial dysfunctions and subsequent delayed spindle assembly.

Miro1 regulates mitochondrial homeostasis and meiotic resumption of mouse oocyte.

Miro1, a mitochondrial Rho GTPase1, is a kind of mitochondrial outer membrane protein involved in the regulation of mitochondrial anterograde transport and its subcellular distribution. Mitochondria influence reproductive processes of mammals in some aspects. Mitochondria are important for oocyte maturation, fertilization and embryonic development. The purpose of this study was to evaluate whether Miro1 regulates mouse oocyte maturation by altering mitochondrial homeostasis. We showed that Miro1 was expressed in mouse oocyte at different maturation stages. Miro1 mainly distributed in the cytoplasm and around the spindle during oocyte maturation. Small interference RNA-mediated Miro1 depletion caused significantly abnormal distribution of mitochondria and endoplasmic reticulum as well as mitochondrial dysfunction, resulting in severely impaired germinal vesicle breakdown (GVBD) of mouse oocytes. For those oocytes which went through GVBD in the Miro1-depleted group, part of them were inhibited in meiotic prophase I stage with abnormal chromosome arrangement and scattered spindle length. Our results suggest that Miro1 is essential for maintaining the maturation potential of mouse oocyte.

CENP-T regulates both the G2/M transition and anaphase entry by acting through CDH1 in meiotic oocytes.

Oocyte meiotic maturation failure is one of the major causes for female infertility. Meiotic resumption (the G2/M transition) and progression through metaphase I (MI) are two critical stages of oocyte meiotic maturation. Here, we report that centromere protein T (CENP-T), an internal kinetochore protein, plays a critical role in meiotic resumption of mouse oocytes. Depletion of CENP-T by siRNA injection increased the CDH1 (also known as FZR1) level, resulting in increased activity of the anaphase-promoting complex (APC)-CDH1 complex, and further leading to decreased levels of the cyclin protein CCNB1, attenuated maturation-promoting factor (MPF) activity, and finally severely compromised meiotic resumption. The impaired meiotic resumption caused by CENP-T depletion could be rescued by overexpression of exogenous CCNB1 or knockdown of endogenous CDH1. Overexpression of exogenous CENP-T resulted in decreased CDH1 levels, which accelerated the progression of G2/M transition, and accelerated meiotic cell cycle progression after germinal vesicle breakdown (GVBD). Unexpectedly, spindle organization after GVBD was not affected by the overexpression, but the distribution of chromosomes was affected. Our findings reveal a novel role for CENP-T in regulating meiotic progression by acting through CDH1.

The cyclin B2/CDK1 complex inhibits separase activity in mouse oocyte meiosis I.

Chromosome segregation is driven by separase, activity of which is inhibited by binding to securin and cyclin B1/CDK1. In meiosis, premature separase activity will induce aneuploidy or abolish chromosome segregation owing to the untimely destruction of cohesin. Recently, we have proved that cyclin B2 can compensate for cyclin B1 in CDK1 activation for the oocyte meiosis G2/M transition. In the present study, we identify an interaction between cyclin B2/CDK1 and separase in mouse oocytes. We find that cyclin B2 degradation is required for separase activation during the metaphase I-anaphase I transition because the presence of stable cyclin B2 leads to failure of homologous chromosome separation and to metaphase I arrest, especially in the simultaneous absence of securin and cyclin B1. Moreover, non-phosphorylatable separase rescues the separation of homologous chromosomes in stable cyclin B2-arrested cyclin B1-null oocytes. Our results indicate that cyclin B2/CDK1 is also responsible for separase inhibition via inhibitory phosphorylation to regulate chromosome separation in oocyte meiosis, which may not occur in other cell types.

BOP1 confers chemoresistance of triple-negative breast cancer by promoting CBP-mediated ß-catenin acetylation.

Chemoresistance is a major obstacle to the treatment of triple-negative breast cancer (TNBC), which has a poor prognosis. Increasing evidence has demonstrated the essential role of cancer stem cells (CSCs) in the process of TNBC chemoresistance. However, the underlying mechanism remains unclear. In the present study, we report that block of proliferation 1 (BOP1) serves as a key regulator of chemoresistance in TNBC. BOP1 expression was significantly upregulated in chemoresistant TNBC tissues, and high expression of BOP1 correlated with shorter overall survival and relapse-free survival in patients with TNBC. BOP1 overexpression promoted, while BOP1 downregulation inhibited the drug resistance and CSC-like phenotype of TNBC cells in vitro and in vivo. Moreover, BOP1 activated Wnt/ß-catenin signaling by increasing the recruitment of cyclic AMP response element-binding protein (CBP) to ß-catenin, enhancing CBP-mediated acetylation of ß-catenin, and increasing the transcription of downstream stemness-related genes CD133 and ALDH1A1. Notably, treating with the ß-catenin/CBP inhibitor PRI-724 induced an enhancement of chemotherapeutic response of paclitaxel in BOP1-overexpressing TNBC cells. These findings indicate that BOP1 is involved in chemoresistance development and might serve as a prognostic marker and therapeutic target in TNBC. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Macrophage NFATc3 prevents foam cell formation and atherosclerosis: evidence and mechanisms.

AIMS: Our previous study demonstrated that Ca2+ influx through the Orai1 store-operated Ca2+ channel in macrophages contributes to foam cell formation and atherosclerosis via the calcineurin-ASK1 pathway, not the classical calcineurin-nuclear factor of activated T-cell (NFAT) pathway. Moreover, up-regulation of NFATc3 in macrophages inhibits foam cell formation, suggesting that macrophage NFATc3 is a negative regulator of atherogenesis. Hence, this study investigated the precise role of macrophage NFATc3 in atherogenesis. METHODS AND RESULTS: Macrophage-specific NFATc3 knockout mice were generated to determine the effect of NFATc3 on atherosclerosis in a mouse model of adeno-associated virus-mutant PCSK9-induced atherosclerosis. NFATc3 expression was decreased in macrophages within human and mouse atherosclerotic lesions. Moreover, NFATc3 levels in peripheral blood mononuclear cells from atherosclerotic patients were negatively associated with plaque instability. Furthermore, macrophage-specific ablation of NFATc3 in mice led to the atherosclerotic plaque formation, whereas macrophage-specific NFATc3 transgenic mice exhibited the opposite phenotype. NFATc3 deficiency in macrophages promoted foam cell formation by potentiating SR-A- and CD36-meditated lipid uptake. NFATc3 directly targeted and transcriptionally up-regulated miR-204 levels. Mature miR-204-5p suppressed SR-A expression via canonical regulation. Unexpectedly, miR-204-3p localized in the nucleus and inhibited CD36 transcription. Restoration of miR-204 abolished the proatherogenic phenotype observed in the macrophage-specific NFATc3 knockout mice, and blockade of miR-204 function reversed the beneficial effects of NFATc3 in macrophages. CONCLUSION: Macrophage NFATc3 up-regulates miR-204 to reduce SR-A and CD36 levels, thereby preventing foam cell formation and atherosclerosis, indicating that the NFATc3/miR-204 axis may be a potential therapeutic target against atherosclerosis.

Role of Citrullinated Collagen in Autoimmune Arthritis.

Citrullination of proteins plays an important role in protein function and it has recently become clear that citrullinated proteins play a role in immune responses. In this study we examined how citrullinated collagen, an extracellular matrix protein, affects T-cell function during the development of autoimmune arthritis. Using an HLA-DR1 transgenic mouse model of rheumatoid arthritis, mice were treated intraperitoneally with either native type I collagen (CI), citrullinated CI (cit-CI), or phosphate buffered saline (PBS) prior to induction of autoimmune arthritis. While the mice given native CI had significantly less severe arthritis than controls administered PBS, mice receiving cit-CI had no decrease in the severity of autoimmune arthritis. Using Jurkat cells expressing the inhibitory receptor leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1), Western blot analysis indicated that while CI and cit-CI bound to LAIR-1 with similar affinity, only CI induced phosphorylation of the LAIR ITIM tyrosines; cit-CI was ineffective. These data suggest that cit-CI acts as an antagonist of LAIR-1 signaling, and that the severity of autoimmune arthritis can effectively be altered by targeting T cells with citrullinated collagen.

Influence of Electronic Modulation of Phenanthroline-Derived Ligands on Separation of Lanthanides and Actinides.

The solvent extraction, complexing ability, and basicity of tetradentate N-donor 2,9-bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-1,2,4-benzotriazin-3-yl)-1,10-phenanthroline (CyMe4-BT- Phen) and its derivatives functionalized by Br, hydroxyphenyl, nitryl were discussed and compared. It was demonstrated that four BTPhen ligands are able to selectively extract Am(lll) over Eu(lll). It was notable that the distribution ratio of 5-nitryl-CyMe4-BTPhen for Eu(lll) was suppressed under 0.02, which was much lower compared to DEu(lll) = 1 by CyMe4-BTPhen. The analysis of the effect of the substituent on the affinity to lanthanides was conducted by UV/vis and fluorescence spectroscopic titration. The stability constants of various ligands with Eu(lll) were obtained by fitting titration curve. Additionally, the basicity of various ligands was determined to be 3.1 ± 0.1, 2.3 ± 0.2, 0.9 ± 0.2, 0.5 ± 0.1 by NMR in the media of CD3OD with the addition of DClO4. The basicity of ligands follows the order of L1 > L2 > L3 > L4, indicating the tendency of protonation decreases with the electron-withdrawing ability increase.