Yes-associated protein inhibition ameliorates carbon tetrachloride-induced acute liver injury in mice by reducing VDR.

Carbon tetrachloride (CCl4) has a wide range of toxic effects, especially causing acute liver injury (ALI), in which rapid compensation for hepatocyte loss ensures liver survival, but proliferation of surviving hepatocytes (known as endoreplication) may imply impaired residual function. Yes-associated protein (YAP) drives hepatocytes to undergo endoreplication and ploidy, the underlying mechanisms of which remain a mystery. In the present study, we uncover during CCl4-mediated ALI accompanied by increased hepatocytes proliferation and YAP activation. Notably, bioinformatics analyses elucidate that hepatic-specific deletion of YAP substantially ameliorated CCl4-induced hepatic proliferation, effectively decreased the vitamin D receptor (VDR) expression. Additionally, a mouse model of acute liver injury substantiated that inhibition of YAP could suppress hepatocytes proliferation via VDR. Furthermore, we also disclosed that the VDR agonist nullifies CCl4-induced ALI alleviated by the YAP inhibitor in vivo. Importantly, hepatocytes were isolated from mice, and it was spotlighted that the anti-proliferative impact of the YAP inhibitor was abolished by the activation of VDR within these hepatocytes. Similarly, primary hepatic stellate cells (HSCs) were isolated and it was manifested that YAP inhibitor suppressed HSC activation via VDR during acute liver injury. Our findings further elucidate the YAP's role in ALI and may provide new avenues for protection against CCl4-drived acute liver injury.

Effect of vitamin D3 supplementation in winter on physical performance of university students: a one-month randomized controlled trial.

BACKGROUND: There is epidemiological evidence which suggests an association between 25-hydroxyvitamin D [25(OH)D] levels and bone and muscle function; however, it is unclear whether vitamin D supplementation has an added benefit beyond bone health. Here, we investigated the effects of vitamin D3 supplementation (1 month) on physical performance in Chinese university students in winter. METHODS: One hundred and seventeen eligible subjects with 25(OH)D (19.2 ± 7.8 ng/mL) were randomly assigned to either vitamin D3 supplement (N = 56; 1000 IU/day) or the control (N = 61) group for 1 month. Pre- and post-measurements included: 1) serum levels of 25(OH)D; 2) musculoskeletal and pulmonary function [vertical jump height (VJH) and right handgrip strength (RHS), forced vital capacity (FVC), and forced expiratory volume at 1s (FEV1)]; 3) bone turnover markers [parathyroid hormone (PTH), n-terminal osteocalcin (N-MID), and calcium]; 4) hemoglobin-related parameters [hemoglobin (Hb), hematocrit (HCT), red blood cells (RBC), and red cell distribution width (RDW)]; 5) lipid parameters [total triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C)]; 6) Fatigue-related indicators [serum creatine kinase (CK), lactate dehydrogenase (LDH), and total testosterone (T)]. In addition, aerobic capacity was assessed by measuring maximal oxygen uptake (VO2max) at baseline. RESULTS: During wintertime, supplementation with 1000 IU/d of vitamin D3 significantly increased serum 25(OH)D levels (from 18.85 ± 7.04 to 26.98 ± 5.88 ng/mL, p < 0.05), accompanied by a decrease of PTH (p < 0.05). However, vitamin D3 supplementation did not significantly impact the physical performance, serum lipid parameters, and bone turnover markers of students. Furthermore, 25(OH)D was found to be positively correlated with VJH and negatively correlated with PTH and TC at the beginning and end of the study (p < 0.05). In addition, the multiple linear regression analysis showed that 25(OH)D combined with athletic, gender, height, weight, Hb, and FVC could account for 84.0% of the VO2max value. CONCLUSIONS: The study demonstrated that one-month of 1000 IU/d of vitamin D3 supplementation during the winter had beneficial effects on 25(OH)D status and PTH. However, vitamin D3 intervention was not sufficient to improve physical performance. Furthermore, 25(OH)D levels combined with athletic, Hb and FVC could be a predictor of VO2max.

Jasmonate-regulated seed germination and crosstalk with other phytohormones.

Seed plants have evolved mechanisms that maintain the dormancy of mature seeds until the time is appropriate for germination. Seed germination is a critical step in the plant life cycle, and it is an important trait in relation to agricultural production. The process is precisely regulated by various internal and external factors, and in particular by diverse endogenous hormones. Jasmonates (JAs) are one of the main plant hormones that mediate stress responses, and recent studies have provided evidence of their inhibitory effects on seed germination. In this review, we summarize our current understanding of the molecular mechanisms underlying the regulatory roles of JAs during the seed germination stage. We describe the crosstalk between JA and other phytohormones that influence seed germination, such as abscisic acid and gibberellic acid.

Effect of 1α,25(OH)2D3-Treated M1 and M2 Macrophages on Cell Proliferation and Migration Ability in Ovarian Cancer.

The biological active form of vitamin D3, 1α,25-dehydroxyvitamin D3 [1α,25(OH)2D3], exerts pleiotropic effects including bone mineralization, anti-tumor, as well as immunomodulator. This study aimed to explore the potential impact of 1α,25(OH)2D3 on tumor-associated macrophages (TAMs) infiltration in ovarian cancer. Firstly, human monocytic THP-1 cells were differentiated into macrophages (M0) in the presence of phorbol 12-myristate 13-acetate (PMA). In Vivo, 1α,25(OH)2D3 not only reversed the polarization of M2 macrophages, but also decreased the proliferation and migration abilities of ovarian cancer cells induced by M2 macrophages supernatant. Furthermore, 1α,25(OH)2D3 dramatically decreased the secretion of TGF-ß1 and MMP-9 in M2 macrophages. However, no significant effect was observed in 1α,25(OH)2D3 treated M1 macrophages. In Vivo, vitamin D3 had an inhibitive effect of 1α,25(OH)2D3-treated M2 macrophages on tumorigenesis. In addition, we conducted the association of TAMs with the poor prognosis of patients with ovarian cancer by meta-analysis, which suggested the higher proportion of M2 macrophages was related to the poorer prognosis in ovarian cancer. Collectively, these results identified distinct roles of 1α,25(OH)2D3 treated M1 and M2 macrophages on cell proliferation and migration abilities in ovarian cancer.

Phytomelatonin inhibits seed germination by regulating germination-related hormone signaling in Arabidopsis.

Seed germination is a vital initial stage in the life cycle of a plant, which determines subsequent vegetative growth and reproduction. Melatonin acts as a plant's master regulator and is also involved in the process of seed germination. In a recent study, we show that the high concentration melatonin inhibited seed germination in Arabidopsis. Transcriptome and phenotype analysis implied that melatonin-mediated seed germination interacted with phytohormones abscisic acid (ABA), gibberellin (GA), and auxin. In this short communication, we discuss the mechanism of phytomelatonin that inhibits seed germination through ABA, GA, and IAA in Arabidopsis.

A stable tetrazagallole and its radical anion dimer.

The reaction of the carbazole ligand supported Ga(I) compound LGa(THF) (3) and 1-azido-4-(tert-butyl)benzene (ArN3) afforded the first stable tetrazagallole LGaN4Ar2 (4) bearing a three-coordinate Ga atom. Reduction of 4 with elemental potassium resulted in the radical dimer {[K(18-c-6)]+[4]˙-}2, featuring a strong antiferromagnetic interaction between the spin centers.

Melatonin inhibits seed germination by crosstalk with abscisic acid, gibberellin, and auxin in Arabidopsis.

Seed germination, an important developmental stage in the life cycle of seed plants, is regulated by complex signals. Melatonin is a signaling molecule associated with seed germination under stressful conditions, although the underlying regulatory mechanisms are largely unknown. In this study, we showed that a low concentration (10 µM or 100 µM) of melatonin had no effect on seed germination, but when the concentration of melatonin increased to 500 µM or 1000 µM, seed germination was significantly inhibited in Arabidopsis. RNA sequencing analysis showed that melatonin regulated seed germination correlated to phytohormones abscisic acid (ABA), gibberellin (GA), and auxin. Further investigation revealed that ABA and melatonin synergistically inhibited seed germination, while GA and auxin antagonized the inhibitory effect of seed germination by melatonin. Disruption of the melatonin biosynthesis enzyme gene serotonin N-acetyltransferase (SNAT) or N-acetylserotonin methyltransferase (ASMT) promoted seed germination, while overexpression of ASMT inhibited seed germination. Taken together, our study sheds new light on the function and mechanism of melatonin in modulating seed germination in Arabidopsis.

Molecular Mechanism Underlying the Synergetic Effect of Jasmonate on Abscisic Acid Signaling during Seed Germination in Arabidopsis.

Abscisic acid (ABA) is known to suppress seed germination and post-germinative growth of Arabidopsis (Arabidopsis thaliana), and jasmonate (JA) enhances ABA function. However, the molecular mechanism underlying the crosstalk between the ABA and JA signaling pathways remains largely elusive. Here, we show that exogenous coronatine, a JA analog structurally similar to the active conjugate jasmonate-isoleucine, significantly enhances the delayed seed germination response to ABA. Disruption of the JA receptor CORONATINE INSENSITIVE1 or accumulation of the JA signaling repressor JASMONATE ZIM-DOMAIN (JAZ) reduced ABA signaling, while jaz mutants enhanced ABA responses. Mechanistic investigations revealed that several JAZ repressors of JA signaling physically interact with ABSCISIC ACID INSENSITIVE3 (ABI3), a critical transcription factor that positively modulates ABA signaling, and that JAZ proteins repress the transcription of ABI3 and ABI5. Further genetic analyses showed that JA activates ABA signaling and requires functional ABI3 and ABI5. Overexpression of ABI3 and ABI5 simultaneously suppressed the ABA-insensitive phenotypes of the coi1-2 mutant and JAZ-accumulating (JAZ-ΔJas) plants. Together, our results reveal a previously uncharacterized signaling module in which JAZ repressors of the JA pathway regulate the ABA-responsive ABI3 and ABI5 transcription factors to integrate JA and ABA signals during seed germination and post-germinative growth.

The Transcription Factor INDUCER OF CBF EXPRESSION1 Interacts with ABSCISIC ACID INSENSITIVE5 and DELLA Proteins to Fine-Tune Abscisic Acid Signaling during Seed Germination in Arabidopsis.

ABSCISIC ACID INSENSITIVE5 (ABI5) is a crucial regulator of abscisic acid (ABA) signaling pathways involved in repressing seed germination and postgerminative growth in Arabidopsis (Arabidopsis thaliana). ABI5 is precisely modulated at the posttranslational level; however, the transcriptional regulatory mechanisms underlying ABI5 and its interacting transcription factors remain largely unknown. Here, we found that INDUCER OF CBF EXPRESSION1 (ICE1) physically associates with ABI5. ICE1 negatively regulates ABA responses during seed germination and directly suppresses ABA-responsive LATE EMBRYOGENESIS ABUNDANT6 (EM6) and EM1 expression. Genetic analysis demonstrated that the ABA-hypersensitive phenotype of the ice1 mutant requires ABI5. ICE1 interferes with the transcriptional activity of ABI5 to mediate downstream regulons. Importantly, ICE1 also interacts with DELLA proteins, which stimulate ABI5 during ABA signaling. Disruption of ICE1 partially restored the ABA-hyposensitive phenotype of the della mutant, gai-t6 rga-t2 rgl1-1 rgl2-1, indicating that ICE1 functions antagonistically with DELLA in ABA signaling. Consistently, DELLA proteins repress ICE1's transcriptional function and the antagonistic effect of ICE1 on ABI5. Collectively, our study demonstrates that ICE1 antagonizes ABI5 and DELLA activity to maintain the appropriate level of ABA signaling during seed germination, providing a mechanistic understanding of how ABA signaling is fine-tuned by a transcriptional complex involving ABI5 and its interacting partners.

Arabidopsis VQ18 and VQ26 proteins interact with ABI5 transcription factor to negatively modulate ABA response during seed germination.

Seed germination and early seedling establishment, critical developmental stages in the life cycle of seed plants, are modulated by diverse endogenous hormones and the surrounding environment. Arabidopsis ABSCISIC ACID-INSENSITIVE5 (ABI5) is a central transcription factor of abscisic acid (ABA) signaling that represses those processes. ABI5 is precisely modulated at post-translational level; however, whether it interacts with other crucial transcriptional regulators remains to be investigated. In this study, VQ18 and VQ26, two members of the recently-identified VQ family, were found to interact with ABI5 in vitro and in vivo. Phenotypic analysis showed that VQ18 and VQ26 are responsive to ABA and negatively mediate ABA signaling redundantly during seed germination. Simultaneously decreasing VQ18 and VQ26 expression levels enhanced ABA signaling to suppress seed germination, whereas overexpressing these two VQ genes resulted in the germinated seeds being less ABA-sensitive. Consistently, the expression levels of several ABI5 targets were modulated by VQ18 and VQ26. The increased ABA signaling of plants in which VQ18 and VQ26 were simultaneously suppressed required ABI5. Additionally, VQ18 and VQ26 acted as negative interactors of the ABI5 transcription factor. Our study reveals a previously unidentified regulatory role of VQ proteins, which act antagonistically with ABI5 to maintain the appropriate ABA signaling level to fine-tune seed germination and early seedling establishment.

Arabidopsis VQ10 interacts with WRKY8 to modulate basal defense against Botrytis cinerea.

Recent studies in Arabidopsis have revealed that some VQ motif-containing proteins physically interact with WRKY transcription factors; however, their specific biological functions are still poorly understood. In this study, we confirmed the interaction between VQ10 and WRKY8, and show that VQ10 and WRKY8 formed a complex in the plant cell nucleus. Yeast two-hybrid analysis showed that the middle region of WRKY8 and the VQ motif of VQ10 are critical for their interaction, and that this interaction promotes the DNA-binding activity of WRKY8. Further investigation revealed that the VQ10 protein was exclusively localized in the nucleus, and VQ10 was predominantly expressed in siliques. VQ10 expression was strongly responsive to the necrotrophic fungal pathogen, Botrytis cinerea and defense-related hormones. Phenotypic analysis showed that disruption of VQ10 increased mutant plants susceptibility to the fungal pathogen B. cinerea, whereas constitutive-expression of VQ10 enhanced resistance to B. cinerea. Consistent with these findings, expression of the defense-related PLANT DEFENSIN1.2 (PDF1.2) gene was decreased in vq10 mutant plants, after B. cinerea infection, but increased in VQ10-overexpressing transgenic plants. Taken together, our findings provide evidence that VQ10 physically interacts with WRKY8 and positively regulates plant basal resistance against the necrotrophic fungal pathogen B. cinerea.

Effects of PEMFs on Osx, Ocn, TRAP, and CTSK gene expression in postmenopausal osteoporosis model mice.

Objective: Ovariectomized mice were used to simulate the symptoms of postmenopausal women with osteoporosis, and observe the effects of PEMF treatment on expression of Osx, Ocn, TRAP, and CTSK in ovariectomized mice. Methods: Thirty-week-old wild-type C57BL/6 mice were randomly divided into three groups (n=10, each group): sham operation group, ovariectomy (OVX) group, and PEMF group. Mice in the sham group underwent sham ovariectomy, while mice in the remaining two groups were ovariectomized. On postoperative day two, mice in the PEMF treatment group received PEMF treatment at a frequency of 8 Hz and an intensity of 3.8 mT for one hour daily for four weeks. At the same time, mice in the remaining two groups were placed in the PEMF treatment area under power-down state daily, similar to that in the PEMF group. After four weeks, all relevant indicators were tested. Results: (1) Compared with mice in the sham group, the number of trabecular bones significantly decreased, the thickness of the trabecular bone became thinner, the number of osteoclasts significantly increased, the gene expression of Osx and Ocn significantly decreased, and the gene expression of TRAP and CTSK significantly increased in the OVX group (P<0.01). (2) Compared with the blank controls without operation, the number of osteoblasts increased in the PEMF group. (3) Compared with the OVX group, the number of osteoclasts significantly decreased, the expression of Osx and Ocn significantly increased, and the gene expression of TRAP and CTSK significantly decreased in the PEMF group (P<0.01). Conclusion: PEMF treatment can significantly promote bone formation, which may be realized through inhibition of osteoclast formation, achieving bone morphological protection. PEMFs can significantly upregulate Osx and Ocn osteogenesis-related genes, which affect bone formation, and downregulate TRAP and CTSK osteoclast-related genes, which affect bone resorption. PEMFs may be used to treat postmenopausal osteoporosis by regulating Osx, Ocn, TRAP, and CTSK gene expression.

Jasmonate regulates leaf senescence and tolerance to cold stress: crosstalk with other phytohormones.

Plants are challenged with numerous abiotic stresses, such as drought, cold, heat, and salt stress. These environmental stresses are major causes of crop failure and reduced yields worldwide. Phytohormones play essential roles in regulating various plant physiological processes and alleviating stressful perturbations. Jasmonate (JA), a group of oxylipin compounds ubiquitous in the plant kingdom, acts as a crucial signal to modulate multiple plant processes. Recent studies have shown evidence supporting the involvement of JA in leaf senescence and tolerance to cold stress. Concentrations of JA are much higher in senescent leaves compared with those in non-senescent ones. Treatment with exogenous JA induces leaf senescence and expression of senescence-associated genes. In response to cold stress, exogenous application of JA enhances Arabidopsis freezing tolerance with or without cold acclimation. Consistently, biosynthesis of endogenous JA is activated in response to cold exposure. JA positively regulates the CBF (C-REPEAT BINDING FACTOR) transcriptional pathway to up-regulate downstream cold-responsive genes and ultimately improve cold tolerance. JA interacts with other hormone signaling pathways (such as auxin, ethylene, and gibberellin) to regulate leaf senescence and tolerance to cold stress. In this review, we summarize recent studies that have provided insights into JA-mediated leaf senescence and cold-stress tolerance.

The DELLA-CONSTANS Transcription Factor Cascade Integrates Gibberellic Acid and Photoperiod Signaling to Regulate Flowering.

Gibberellin (GA) and photoperiod pathways have recently been demonstrated to collaboratively modulate flowering under long days (LDs). However, the molecular mechanisms underlying this collaboration remain largely unclear. In this study, we found that GA-induced expression of FLOWERING LOCUS T (FT) under LDs was dependent on CONSTANS (CO), a critical transcription factor positively involved in photoperiod signaling. Mechanistic investigation revealed that DELLA proteins, a group of crucial repressors in GA signaling, physically interacted with CO. The DELLA-CO interactions repressed the transcriptional function of CO protein. Genetic analysis demonstrated that CO acts downstream of DELLA proteins to regulate flowering. Disruption of CO rescued the earlier flowering phenotype of the gai-t6 rga-t2 rgl1-1 rgl2-1 mutant (dellap), while a gain-of-function mutation in GA INSENSITIVE (GAI, a member of the DELLA gene) repressed the earlier flowering phenotype of CO-overexpressing plants. In addition, the accumulation of DELLA proteins and mRNAs was rhythmic, and REPRESSOR OF GA1-3 protein was noticeably decreased in the long-day afternoon, a time when CO protein is abundant. Collectively, these results demonstrate that the DELLA-CO cascade inhibits CO/FT-mediated flowering under LDs, which thus provide evidence to directly integrate GA and photoperiod signaling to synergistically modulate flowering under LDs.

Arabidopsis VQ motif-containing proteins VQ12 and VQ29 negatively modulate basal defense against Botrytis cinerea.

Arabidopsis VQ motif-containing proteins have recently been demonstrated to interact with several WRKY transcription factors; however, their specific biological functions and the molecular mechanisms underlying their involvement in defense responses remain largely unclear. Here, we showed that two VQ genes, VQ12 and VQ29, were highly responsive to the necrotrophic fungal pathogen Botrytis cinerea. To characterize their roles in plant defense, we generated amiR-vq12 transgenic plants by using an artificial miRNA approach to suppress the expression of VQ12, and isolated a loss-of-function mutant of VQ29. Phenotypic analysis showed that decreasing the expression of VQ12 and VQ29 simultaneously rendered the amiR-vq12 vq29 double mutant plants resistant against B. cinerea. Consistently, the B. cinerea-induced expression of defense-related PLANT DEFENSIN1.2 (PDF1.2) was increased in amiR-vq12 vq29. In contrast, constitutively-expressing VQ12 or VQ29 confered transgenic plants susceptible to B. cinerea. Further investigation revealed that VQ12 and VQ29 physically interacted with themselves and each other to form homodimers and heterodimer. Moreover, expression analysis of VQ12 and VQ29 in defense-signaling mutants suggested that they were partially involved in jasmonate (JA)-signaling pathway. Taken together, our study indicates that VQ12 and VQ29 negatively regulate plant basal resistance against B. cinerea.