The contribution of dietary advanced glycation end-products and genetic risk in the development of inflammatory bowel disease: a prospective cohort study.

BACKGROUND: Dietary advanced glycation end products (AGEs) may promote oxidative stress and inflammation in the gastrointestinal tract. AIMS: The aim of this study is to investigate the association between dietary AGE intake and the risk of inflammatory bowel disease (IBD). METHODS: We included 121,978 participants without IBD at baseline from the UK Biobank. We estimated consumption of three common AGEs (Nε-(carboxymethyl)-lysine (CML), Nε-(1-carboxyethyl)-lysine (CEL), and Nδ-(5-hydro-5-methyl-4-imidazolon-2-yl)-ornithine (MG-H1)) by matching 24-h dietary questionnaires to a validated dietary AGE database. We used Cox proportional hazards regression models to calculate the hazard ratio (HR) and 95% CI of the association between dietary AGEs and IBD risk. RESULTS: During a median follow-up of 13.72 years, 671 participants developed IBD (192 with Crohn's disease (CD) and 478 with ulcerative colitis (UC)). Among the assessed dietary AGEs, only CEL was associated with an increased risk of IBD (HR = 1.09, 95% CI: 1.01-1.18, p = 0.020) and CD (HR = 1.18, 95% CI: 1.03-1.36, p = 0.014), particularly for participants who were overweight, physically inactive, and non-smokers. Among participants at a high genetic risk of CD, HRs (95% CI) of CD were 1.26 (1.00-1.57) for CML, 1.41 (1.12-1.77) for CEL, and 1.28 (1.01-1.62) for MG-H1 (p < 0.05 for each). However, none of the dietary AGEs was significantly associated with UC risk, irrespective of genetic predisposition. CONCLUSIONS: Dietary CEL was associated with an increased risk of IBD and CD, but not UC. Further interventional studies are required to support the potential benefit of AGE restriction, especially for individuals at a high genetic risk of CD.

Take vedolizumab home: transition from intravenous to subcutaneous treatment.

In 2020, the European Medicines Agency approved subcutaneous (SC) vedolizumab (VDZ) for the maintenance treatment of adult patients with moderate to severe inflammatory bowel disease (IBD). This article reviews the efficacy, safety, persistence, pharmacology, patient satisfaction, and economic implications of transitioning to SC VDZ treatment and explores whether SC formulations can be recommended by the same guidelines as intravenous (IV) formulations. Clinical trials and real-world evidence indicate that transitioning from IV to SC VDZ in patients with IBD maintains clinical, biochemical, and patient-reported clinical remission and is well-tolerated, with no new safety issues identified, except for injection site reactions. Moreover, SC VDZ has an exposure-response relationship and low immunogenicity, is economical, and provides a high level of patient satisfaction. Owing to these advantages, transitioning may be advisable. In the future, more studies are needed to clarify the exact role of SC VDZ in IBD treatment, including optimization and transitioning strategies and individualized treatments based on baseline characteristics.

Subcutaneous vedolizumab for inflammatory bowel disease Transitioning from intravenous to subcutaneous vedolizumab (SC VDZ) in patients with inflammatory bowel disease maintains clinical, biochemical, and patient-reported clinical remission and is well-tolerated, with no new safety issues identified, except for injection site reactions. Moreover, SC VDZ has an exposure-response relationship and low immunogenicity, is economical, and provides a high level of patient satisfaction. Owing to these advantages, transitioning may be advisable.

Butyrate Prevents the Pathogenic Anemia-Inflammation Circuit by Facilitating Macrophage Iron Export.

Most patients with inflammatory bowel disease (IBD) develop anemia, which is attributed to the dysregulation of iron metabolism. Reciprocally, impaired iron homeostasis also aggravates inflammation. How this iron-mediated, pathogenic anemia-inflammation crosstalk is regulated in the gut remains elusive. Herein, it is for the first time revealed that anemic IBD patients exhibit impaired production of short-chain fatty acids (SCFAs), particularly butyrate. Butyrate supplementation restores iron metabolism in multiple anemia models. Mechanistically, butyrate upregulates ferroportin (FPN) expression in macrophages by reducing the enrichment of histone deacetylase (HDAC) at the Slc40a1 promoter, thereby facilitating iron export. By preventing iron sequestration, butyrate not only mitigates colitis-induced anemia but also reduces TNF-α production in macrophages. Consistently, macrophage-conditional FPN knockout mice exhibit more severe anemia and inflammation. Finally, it is revealed that macrophage iron overload impairs the therapeutic effectiveness of anti-TNF-α antibodies in colitis, which can be reversed by butyrate supplementation. Hence, this study uncovers the pivotal role of butyrate in preventing the pathogenic circuit between anemia and inflammation.

Epithelial CRL4DCAF2 Is Critical for Maintaining Intestinal Homeostasis Against DSS-Induced Colitis by Regulating the Proliferation and Repair of Intestinal Epithelial Cells.

BACKGROUND AND AIMS: Inflammatory bowel disease (IBD) is currently gaining an increasing global interest. Intestinal epithelial barrier dysfunction is crucial toward developing IBD; however, the underlying mechanisms are not yet elucidated. This study is aimed at elucidating the function of CRL4DCAF2, an E3 ligase, toward mediating intestinal homeostasis. METHODS: Colon samples were collected from patients with IBD and healthy individuals to examine the expression of CRL4DCAF2. CRL4DCAF2 conditional knockdown in mouse intestinal epithelial cells (IECs) (DCAF2EKD) were constructed. DCAF2EKD and their littermate control (DCAF2EWT) were treated with dextran sodium sulfate (DSS) to induce acute colitis. Transcriptome analysis was performed on inflamed colon samples obtained from the mice. Cell cycle regulators were evaluated using real-time polymerase chain reaction (PCR), while tight junction and apoptosis proteins were examined via immunofluorescence and western blot. RESULTS: CRL4DCAF2 expression was significantly decreased in the inflamed IBD epithelium, and low expression of CRL4DCAF2 associated with high recurrence risk. Mice with DCAF2 specific knockout in IECs suffer from embryonic death. Multiple genes involved in cell proliferation, immune response, and gap junction were differentially expressed in inflamed colon from DCAF2EKD compared with DCAF2EWT. Furthermore, conditional downregulation of CRL4DCAF2 in the intestinal epithelium induced primarily epithelial damage, increased intestinal permeability, and diminished tight junction protein expression. In vivo and in vitro cell transfection experiments revealed that CRL4DCAF2 enhanced cell proliferation by promoting p21 ubiquitination and degradation, thereby inhibiting G2/M cell cycle. In addition, CRL4DCAF2 can also inhibit IEC apoptosis and promote cell autophagy. CONCLUSIONS: CRL4DCAF2 downregulation in IECs promotes intestinal barrier dysfunction and inhibits IEC proliferation, thus making it more susceptible to inflammation.

Ethylene signaling modulates air humidity responses in plants.

Air humidity significantly impacts plant physiology. However, the upstream elements that mediate humidity sensing and adaptive responses in plants remain largely unexplored. In this study, we define high humidity-induced cellular features of Arabidopsis plants and take a quantitative phosphoproteomics approach to obtain a high humidity-responsive landscape of membrane proteins, which we reason are likely the early checkpoints of humidity signaling. We found that a brief high humidity exposure (i.e., 0.5 h) is sufficient to trigger extensive changes in membrane protein abundance and phosphorylation. Enrichment analysis of differentially regulated proteins reveals high humidity-sensitive processes such as 'transmembrane transport', 'response to abscisic acid', and 'stomatal movement'. We further performed a targeted screen of mutants, in which high humidity-responsive pathways/proteins are disabled, to uncover genes mediating high humidity sensitivity. Interestingly, ethylene pathway mutants (i.e., ein2 and ein3eil1) display a range of altered responses, including hyponasty, reactive oxygen species level, and responsive gene expression, to high humidity. Furthermore, we observed a rapid induction of ethylene biosynthesis genes and ethylene evolution after high humidity treatment. Our study sheds light on the potential early signaling events in humidity perception, a fundamental but understudied question in plant biology, and reveals ethylene as a key modulator of high humidity responses in plants.

An aging-related gene signature to predict the prognosis of hepatocellular carcinoma.

Aging increases the susceptibility of various diseases, including hepatocellular carcinoma (HCC). This study aimed to establish an aging-related prognostic model for HCC and to investigate the role of aging-related genes in HCC progression. Transcriptome and clinical information of HCC cases were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Aging-related prognostic genes were identified through univariate Cox regression analysis, protein-protein interaction analysis, and least absolute shrinkage and selection operator (LASSO) analysis. An aging-related risk signature was then constructed, including LDHA, MMP12, ATAD3A, CD8A, TPI1, CST3, and TPM1. The risk score was inversely associated with the overall survival of patients with HCC and correlated well with known prognostic factors. The area under the curve of 1-, 3-, and 5-year survival in the training dataset was 0.83, 0.83, and 0.84, respectively. Univariate and multivariate cox regression analysis verified that the aging-related risk signature independently predicted the overall survival in HCC. To increase the clinical utility of the prognostic model, a nomogram was developed by incorporating the risk score with key clinical features. Finally, single-cell transcriptomes of HCC were analyzed to elucidate the expression pattern of the prognostic genes across different tissues, pathologic stages, and cell types. Collectively, the aging-related prognostic model shed light on HCC pathogenesis and held potential for optimizing the management of HCC.

High air humidity dampens salicylic acid pathway and NPR1 function to promote plant disease.

The occurrence of plant disease is determined by interactions among host, pathogen, and environment. Air humidity shapes various aspects of plant physiology and high humidity has long been known to promote numerous phyllosphere diseases. However, the molecular basis of how high humidity interferes with plant immunity to favor disease has remained elusive. Here we show that high humidity is associated with an "immuno-compromised" status in Arabidopsis plants. Furthermore, accumulation and signaling of salicylic acid (SA), an important defense hormone, are significantly inhibited under high humidity. NPR1, an SA receptor and central transcriptional co-activator of SA-responsive genes, is less ubiquitinated and displays a lower promoter binding affinity under high humidity. The cellular ubiquitination machinery, particularly the Cullin 3-based E3 ubiquitin ligase mediating NPR1 protein ubiquitination, is downregulated under high humidity. Importantly, under low humidity the Cullin 3a/b mutant plants phenocopy the low SA gene expression and disease susceptibility that is normally observed under high humidity. Our study uncovers a mechanism by which high humidity dampens a major plant defense pathway and provides new insights into the long-observed air humidity influence on diseases.

Effectiveness and safety of vedolizumab for ulcerative colitis: a single-center retrospective real-world study in China.

Introduction: The effectiveness and safety of vedolizumab (VDZ) against ulcerative colitis (UC) have been validated in several randomized controlled trials and real-world studies in Western countries. However, there are few studies on VDZ in Asia, and the follow-up period for these studies is generally short. Therefore, this study evaluates the long-term effectiveness and safety of VDZ in Chinese patients with UC. Methods: This retrospective study included patients with moderate to severe UC treated with VDZ between September 2019 and April 2022 at Sir Run Run Shaw Hospital, College of Medicine Zhejiang University. Clinical response and remission were assessed using the patient reported outcomes and the partial Mayo Score, and mucosal remission and healing were assessed using the Mayo Endoscopy Score. The primary endpoint was defined as clinical remission at week 14, and secondary endpoints included clinical response and steroid-free clinical remission at week 14, clinical response, clinical remission, and steroid-free clinical remission at week 52, and mucosal remission and healing at weeks 14 ± 8 and 52 ± 8. Results: Overall, 64 patients with moderate to severe UC were enrolled. The clinical response, clinical remission, and steroid-free clinical remission rates at week 14 were 73.4% (47/64), 65.6% (42/64), and 54.7% (35/64), respectively. Mucosal remission and healing rates at week 14 ± 8 were 64.7% (22/34) and 38.2% (13/34), respectively. A total of 48 patients were treated with VDZ for 52 weeks. Based on intention-to-treat analysis, the clinical response, clinical remission, and steroid-free clinical remission rates at week 52 were 68.8% (44/64), 64.1% (41/64), and 64.1% (41/64), respectively. Mucosal remission and healing rates at week 52 ± 8 were 70.6% (12/17) and 35.3% (6/17), respectively. During the follow-up period, the most common adverse event was skin rash (6/64). No cases of acute infusion reactions, delayed allergic reactions, new hepatitis B infections, active tuberculosis, or malignant tumors were reported. Conclusion: In this single-center retrospective real-world study, the effectiveness of long-term use of VDZ for Chinese patients with UC was similar to the outcomes previously reported in other geographical regions and populations; no new safety signals were found compared with other registered studies.

Pulmonary cryptococcosis after immunomodulator treatment in patients with Crohn's disease: Three case reports.

BACKGROUND: Corticosteroids and anti-tumor necrosis factor α mAbs are widely used to treat Crohn's disease (CD). However, one disadvantage of this treatment is impairment of normal immune function, leading to an increased risk of infection. Cryptococcus infection is an opportunistic infection that occurs mainly in immunocompromised patients and poses a significant diagnostic challenge in patients with CD. CASE SUMMARY: Here, we report three cases of pulmonary cryptococcosis in patients with CD after receiving immunomodulatory treatment. The patients presented with no or mild respiratory symptoms. Chest computed tomography scans revealed pulmonary nodules in the unilateral or bilateral lobes. Diagnoses were made using pathological examination and metagenomic sequencing. The patients were treated with fluconazole 400 mg once daily for 1 to 6 mo, and symptoms were resolved. Literature searches were conducted in PubMed, Web of Science, and Embase to retrieve previously reported cases and summarize patient characteristics. CONCLUSION: The incidence of cryptococcus infection has increased along with immunomodulator use. Clinical vigilance is required for early identification and standardized treatment.

Isosteviol attenuates DSS-induced colitis by maintaining intestinal barrier function through PDK1/AKT/NF-κB signaling pathway.

Inflammatory bowel diseases (IBD) are chronic debilitating inflammatory disorders of the gastrointestinal tract that is characterized by intestinal epithelial barrier dysfunction and excessive activation of the mucosal immune system. Isosteviol (IS) has been reported to possess anti-inflammatory properties. In this study, we aimed to investigate effects and mechanisms of IS against intestinal inflammation. C57BL/6 mice were randomly divided into Sham, IS, dextran sodium sulfate (DSS), and DSS + IS groups. In vivo colitis model was established using 3.0 % DSS. In vitro, tumor necrosis factor-α (TNF-α)-treated Caco-2 cells were used as an inflammatory model. Clinical characteristics, histological performance, proinflammatory cytokine expression, and intestinal barrier function were measured. In addition, activation of the pyruvate dehydrogenase kinase 1/protein kinase B/nuclear factor-κB (PDK1/AKT/NF-κB) signaling pathway was determined by western blotting and quantitative polymerase chain reaction. The results showed that IS mitigated DSS-induced colitis by reducing body weight loss, colonic shortening, and disease activity index score, and by inhibiting expressions of proinflammatory cytokines IL-1ß, IL-6, and TNF-α. IS restored impaired barrier function by regulating tight junctions and intestinal epithelial permeability. Furthermore, we found that IS ameliorated intestinal barrier injury by regulating PDK1/AKT/NF-κB signaling pathway. In conclusion, our results demonstrate that IS attenuates experimental colitis by preserving intestinal barrier function, probably mediated by PDK1/AKT/NF-κB signaling pathway. These findings highlight the potential of IS as a therapeutic agent for IBD.

Trends in medication use and treatment patterns in Chinese patients with inflammatory bowel disease.

BACKGROUND: Medications for inflammatory bowel disease (IBD) have changed dramatically over time. However, no study on long-term medication profiles has been conducted in the Chinese population. AIM: To evaluate temporal changes in medication use and treatment patterns for Chinese patients with IBD. METHODS: A multicenter retrospective cohort study was conducted among Chinese patients newly diagnosed with Crohn's disease (CD) and ulcerative colitis (UC) between January 1999 and December 2019. Baseline characteristics and drug prescriptions were collected. Trends in medication use and therapeutic patterns were analyzed. RESULTS: In total, 3610 patients were analyzed. During follow-up, 5-aminosalicylates (5-ASA) and corticosteroids (CS) prescriptions gradually decreased, accompanied by a notable increase in immunosuppressants (IMS) and infliximab (IFX) prescriptions in patients with CD. Prescription rates of 5-ASA and CS were stable, whereas IMS and IFX slightly increased since 2007 in patients with UC. Subgroup (n = 957) analyses showed a switch from conventional medications to IFX in patients with CD, while 5-ASA and CS were still steadily prescribed in patients with UC. Logistic regression analyses revealed that surgical history, disease behavior, and disease location were associated with initial therapeutic strategies in patients with CD. However, medications before diagnosis, disease location, and diagnostic year might affect initial strategies in patients with UC. CONCLUSION: Long-term treatment strategies analyses has provided unique insight into the switch from conventional drugs to IFX in Chinese patients with CD.

Temporal Changes in the Treatment Paradigm and Long-term Prognosis of Patients With Crohn's Disease: A Hospital-Based Cohort Study in China.

BACKGROUND: The temporal trends in medical treatment and long-term outcomes of patients with Crohn's disease (CD) have not been well elucidated in China over the past 2 decades. Accordingly, we aimed to evaluate the treatment paradigm and long-term clinical course of Chinese patients with CD in a hospital-based cohort. METHODS: All adult patients newly diagnosed with CD (n = 1338) between 1999 and 2019 in the Sir Run Run Shaw Hospital were included in this cohort. Medication utilization, disease outcomes, and risk factors were investigated. RESULTS: Overall, 48.7%, 35.6%, 67.8%, and 61.6% of patients used 5-aminosalicylates (5-ASA), corticosteroids, thiopurines, and infliximab (IFX), respectively. The cumulative risk of 5-ASA and corticosteroid initiation decreased during follow-up, whereas that of IFX initiation increased. Throughout a median follow-up duration of 26.4 (interquartile range, 12.0-49.2) months, a total of 486 and 300 patients underwent hospitalization and surgery, respectively. Of the 1097 patients with B1/B2 disease behavior at diagnosis, 10.3% experienced phenotype progression. The hospitalization rate decreased after 2015; however, surgery and phenotype progression rates did not significantly change. A Cox regression analysis indicated that IFX use since diagnosis was a contributing factor for lower rates of hospitalization and phenotype progression, whereas thiopurine use was associated with a lower surgery rate. CONCLUSIONS: Infliximab use was observed to increase as 5-ASA and corticosteroid use decreased. Additionally, hospitalization rates decreased following temporal changes in IFX management, yet the surgery and phenotype progression rates remained the same.

Reasons and Factors Contributing to Chinese Patients' Preference for Ustekinumab in Crohn's Disease: A Multicenter Cross-Sectional Study.

Background and Aims: Ustekinumab (UST) was approved in China for treating moderate-to-severe Crohn's disease (CD) in 2020. We aimed to identify the reasons and possible contributing factors for UST preference in Chinese patients with CD. Methods: We conducted a multicenter cross-sectional survey among patients with moderate to severe CD who underwent UST treatment in 27 hospitals. Patients completed a 46-item questionnaire that included information on demographics, clinical characteristics, reasons in favor of UST and shared decision-making perception. Logistic regression analysis was performed to examine the predictive factors of different UST preferences. Results: Overall, 127 patients (73 males; mean age, 25.9 ± 9.9 years) completed the questionnaire. Most patients (74.8%) had biologic failure. The most common reason for the latest treatment disconnection was unresponsiveness to the previous medications. The major UST information sources were physicians (96.1%). Nearly half of the patients (44.9%) reported shared decision making regarding UST treatment. No difference was found in the decision-making patterns in terms of sex and age. The most influential reason for UST preference was "effectiveness" (77%, 98/127), followed by "safety" (65%, 83/127), "frequency of administration" (39%, 49/127), and "mode of administration" (37%, 47/127). Multivariate logistic regression analysis revealed that a positive self-rated health status was a contributing factor for UST preference with a low frequency of administration. Conclusion: This is the first multicenter survey of Chinese patients with CD to identify the possible contributing factors for UST preference. Treatment choice should be discussed with patients because individual preferences are determined by diverse factors.

Effect of Cuttlebone on Healing of Indomethacin-Induced Acute Gastric Mucosal Lesions in Rats.

The continuing use of nonsteroidal anti-inflammatory drugs (NSAIDs) usually increases the side effects such as peptic ulcer and acute gastric lesions in the gastrointestinal tract. Cuttlebone (CB), isolated from Sepiella maindroni de Rochebrune, was reported to have antioxidant activities, but its role in the treatment of indomethacin-induced gastric lesions has not yet been confirmed. In this research, we investigate the protective effect of cuttlebone on indomethacin-related ulcers in rats and possible mechanisms. Here, gastric ulcers were induced by oral administration of indomethacin, and then the rats were treated with omeprazole (4 mg/kg) or different doses (750, 1500, and 3000 mg/kg of body weight) of cuttlebone. We evaluated lesion index, inflammation score, and a series of oxidant/antioxidant parameters. The data demonstrated that cuttlebone could protect against gastric ulcers induced by indomethacin in a dose-dependent manner (positive correlation). Also, these effects were associated with attenuating the expression of malonaldehyde (MDA) and increasing the levels of some protective ingredients like epidermal growth factor (EGF), prostaglandin E2 (PGE2), and superoxide dismutase (SOD). Thus, considering its ability to protect indomethacin-induced acute gastric mucosal lesions and the underlying mechanisms, CB might be a potential candidate for treating gastric damage caused by NSAIDs.

A plant genetic network for preventing dysbiosis in the phyllosphere.

The aboveground parts of terrestrial plants, collectively called the phyllosphere, have a key role in the global balance of atmospheric carbon dioxide and oxygen. The phyllosphere represents one of the most abundant habitats for microbiota colonization. Whether and how plants control phyllosphere microbiota to ensure plant health is not well understood. Here we show that the Arabidopsis quadruple mutant (min7 fls2 efr cerk1; hereafter, mfec)1, simultaneously defective in pattern-triggered immunity and the MIN7 vesicle-trafficking pathway, or a constitutively activated cell death1 (cad1) mutant, carrying a S205F mutation in a membrane-attack-complex/perforin (MACPF)-domain protein, harbour altered endophytic phyllosphere microbiota and display leaf-tissue damage associated with dysbiosis. The Shannon diversity index and the relative abundance of Firmicutes were markedly reduced, whereas Proteobacteria were enriched in the mfec and cad1S205F mutants, bearing cross-kingdom resemblance to some aspects of the dysbiosis that occurs in human inflammatory bowel disease. Bacterial community transplantation experiments demonstrated a causal role of a properly assembled leaf bacterial community in phyllosphere health. Pattern-triggered immune signalling, MIN7 and CAD1 are found in major land plant lineages and are probably key components of a genetic network through which terrestrial plants control the level and nurture the diversity of endophytic phyllosphere microbiota for survival and health in a microorganism-rich environment.

Madecassoside inhibits estrogen deficiency-induced osteoporosis by suppressing RANKL-induced osteoclastogenesis.

Osteoporosis is the most common osteolytic disease characterized by excessive osteoclast formation and resultant bone loss, which afflicts millions of patients around the world. Madecassoside (MA), isolated from Centella asiatica, was reported to have anti-inflammatory and antioxidant activities, but its role in osteoporosis treatment has not yet been confirmed. In our study, MA was found to have an inhibitory effect on the RANKL-induced formation and function of OCs in a dose-dependent manner without cytotoxicity. These effects were attributed to its ability to suppress the activity of two transcription factors (NFATc1 and c-Fos) indispensable for osteoclast formation, followed by inhibition of the expression of bone resorption-related genes and proteins (Acp5/TRAcP, CTSK, ATP6V0D2/V-ATPase-d2, and integrin ß3). Furthermore, we examined the underlying mechanisms and found that MA represses osteoclastogenesis by blocking Ca2+ oscillations and the NF-κB and MAPK pathways. In addition, the therapeutic effect of MA on preventing bone loss in vivo was further confirmed in an ovariectomized mouse model. Therefore, considering its ability to inhibit RANKL-mediated osteoclastogenesis and the underlying mechanisms, MA might be a potential candidate for treating osteolytic bone diseases.

Evodiamine inhibits RANKL-induced osteoclastogenesis and prevents ovariectomy-induced bone loss in mice.

Postmenopausal osteoporosis (PMO) is a progressive bone disease characterized by the over-production and activation of osteoclasts in elderly women. In our study, we investigated the anti-osteoclastogenic effect of evodiamine (EVO) in vivo and in vitro, as well as the underlying mechanism. By using an in vitro bone marrow macrophage (BMM)-derived osteoclast culture system, we found that EVO inhibited osteoclast formation, hydroxyapatite resorption and receptor activator of NF-κB ligand (RANKL)-induced osteoclast marker gene and protein expression. Mechanistically, we found that EVO inhibited the degradation and RANKL-induced transcriptional activity of IκBα. RANKL-induced Ca2+ oscillations were also abrogated by EVO. In vivo, an ovariectomized (OVX) mouse model was established to mimic PMO, and OVX mice received oral administration of either EVO (10 mg/kg) or saline every other day. We found that EVO can attenuate bone loss in OVX mice by inhibiting osteoclastogenesis. Taken together, our findings suggest that EVO suppresses RANKL-induced osteoclastogenesis through NF-κB and calcium signalling pathways and has potential value as a therapeutic agent for PMO.

The AWPM-19 Family Protein OsPM1 Mediates Abscisic Acid Influx and Drought Response in Rice.

Abscisic acid (ABA) regulates plant stress responses and development. However, how the ABA signal is transmitted in response to stresses remains largely unclear, especially in monocots. In this study, we found that rice (Oryza sativa) OsPM1 (PLASMA MEMBRANE PROTEIN1), encoded by a gene of AWPM-19 like family, mediates ABA influx through the plasma membrane. OsPM1 is predominantly expressed in vascular tissues, guard cells, and mature embryos. Phenotypic analysis of overexpression, RNA interference (RNAi), and knockout (KO) lines showed that OsPM1 is involved in drought responses and seed germination regulation. 3H-(±)ABA transport activity and fluorescence resonance energy transfer assays both demonstrated that OsPM1 facilitates ABA uptake into cells. The physiological isomer of ABA, (+)-ABA, is the preferred substrate of OsPM1. Higher ABA accumulation and faster stomatal closure in response to ABA treatment were observed in the overexpression lines compared with the wild-type control. Many ABA-responsive genes were upregulated more in the OsPM1-overexpression lines but less in the RNAi lines compared with wild-type plants. Further investigation revealed that OsPM1 expression is regulated by the AREB/ABF family transcription factor OsbZIP46. Our results thus revealed that OsPM1 is an ABA influx carrier that plays an important role in drought responses.

MID1 plays an important role in response to drought stress during reproductive development.

Drought during rice reproductive development results in yield loss. It is important to understand the functions of drought-responsive genes in reproductive tissues for improving rice yield under water-deficit conditions. We show here that MID1 (MYB Important for Drought Response1), encoding a putative R-R-type MYB-like transcription factor, can improve rice yield under drought. MID1 was primarily expressed in root and leaf vascular tissues, with low level in the tapetum, and was induced by drought and other abiotic stresses. Compared with wild type, MID1-overexpressing plants were more tolerant to drought at both vegetative and reproductive stages and produced more grains under water stress. MID1-overexpressing plants exhibited less severe anther defects such as deformed anther locules, abnormal tapetum, degenerated microspores and expanded middle layer, with improved pollen fertility and higher seed setting rate. MID1 was localized to the nucleus and could activate gene expression in yeast, and its homologs were identified in many other plants with high levels sequence similarity. In addition, candidate MID1-regulated genes were analyzed using RNA-seq and qRT-PCR, including genes crucial for stress responses and anther development, with altered expressions in the florets of MID1-overexpressing plants and RNAi lines. Furthermore, MID1 could bind to the promoters of two drought-related genes (Hsp17.0 and CYP707A5) and one anther developmental gene (KAR) according to ChIP-qPCR data. Our findings suggest that MID1 is a transcriptional regulator that promotes rice male development under drought by modulating the expressions of drought-related and anther developmental genes and provide valuable information for crop improvement.

The role of ANAC072 in the regulation of chlorophyll degradation during age- and dark-induced leaf senescence.

KEY MESSAGE: ANAC072 positively regulates both age- and dark-induced leaf senescence through activating the transcription of NYE1. Leaf senescence is integral to plant development, which is age-dependent and strictly regulated by internal and environmental signals. Although a number of senescence-related mutants and senescence-associated genes (SAGs) have been identified and characterized in the past decades, the general regulatory network of leaf senescence is still far from being elucidated. Here, we report the role of ANAC072, an SAG identified through bioinformatics analysis, in the regulation of chlorophyll degradation during natural and dark-induced leaf senescence. The expression of ANAC072 was increased with advancing leaf senescence in Arabidopsis. Leaf degreening was significantly delayed under normal or dark-induced conditions in anac072-1, a knockout mutant of ANAC072, with a higher chlorophyll level detected. In contrast, an overexpression mutant, anac072-2, with ANAC072 transcription markedly upregulated, showed an early leaf-yellowing phenotype. Consistently, senescent leaves of the loss-of-function mutant anac072-1 exhibited delays in the decrease of photosynthesis efficiency of photosystem II (F v/F m ratio) and the increase of plasma membrane ion leakage rate as compared with corresponding leaves of wild-type Col-0 plants, whereas the overexpression mutant anac072-2 showed opposite changes. Our data suggest that ANAC072 plays a positive role during natural and dark-induced leaf senescence. In addition, the transcript level of NYE1, a key regulatory gene in chlorophyll degradation, relied on the function of ANAC072. Combining these analyses with electrophoretic mobility shift assay and chromatin immunoprecipitation, we demonstrated that ANAC072 directly bound to the NYE1 promoter in vitro and in vivo, so ANAC072 may promote chlorophyll degradation by directly upregulating the expression of NYE1.