The RPT2a-MET1 axis regulates TERMINAL FLOWER1 to control inflorescence meristem indeterminacy in Arabidopsis.

Plant inflorescence architecture is determined by inflorescence meristem (IM) activity and controlled by genetic mechanisms associated with environmental factors. In Arabidopsis (Arabidopsis thaliana), TERMINAL FLOWER1 (TFL1) is expressed in the IM and is required to maintain indeterminate growth, whereas LEAFY (LFY) is expressed in the floral meristems (FMs) formed at the periphery of the IM and is required to activate determinate floral development. Here, we address how Arabidopsis indeterminate inflorescence growth is determined. We show that the 26S proteasome subunit REGULATORY PARTICLE AAA-ATPASE 2a (RPT2a) is required to maintain the indeterminate inflorescence architecture in Arabidopsis. rpt2a mutants display reduced TFL1 expression levels and ectopic LFY expression in the IM and develop a determinate zigzag-shaped inflorescence. We further found that RPT2a promotes DNA METHYLTRANSFERASE1 degradation, leading to DNA hypomethylation upstream of TFL1 and high TFL1 expression levels in the wild-type IM. Overall, our work reveals that proteolytic input into the epigenetic regulation of TFL1 expression directs inflorescence architecture in Arabidopsis, adding an additional layer to stem cell regulation.

SALT OVERLY SENSITIVE2 stabilizes phytochrome-interacting factors PIF4 and PIF5 to promote Arabidopsis shade avoidance.

Sun-loving plants trigger the shade avoidance syndrome (SAS) to compete against their neighbors for sunlight. Phytochromes are plant red (R) and far-red (FR) light photoreceptors that play a major role in perceiving the shading signals and triggering SAS. Shade induces a reduction in the level of active phytochrome B (phyB), thus increasing the abundance of PHYTOCHROME-INTERACTING FACTORS (PIFs), a group of growth-promoting transcription factors. However, whether other factors are involved in modulating PIF activity in the shade remains largely obscure. Here, we show that SALT OVERLY SENSITIVE2 (SOS2), a protein kinase essential for salt tolerance, positively regulates SAS in Arabidopsis thaliana. SOS2 directly phosphorylates PIF4 and PIF5 at a serine residue close to their conserved motif for binding to active phyB. This phosphorylation thus decreases their interaction with phyB and posttranslationally promotes PIF4 and PIF5 protein accumulation. Notably, the role of SOS2 in regulating PIF4 and PIF5 protein abundance and SAS is more prominent under salt stress. Moreover, phyA and phyB physically interact with SOS2 and promote SOS2 kinase activity in the light. Collectively, our study uncovers an unexpected role of salt-activated SOS2 in promoting SAS by modulating the phyB-PIF module, providing insight into the coordinated response of plants to salt stress and shade.

Reconstitution of phytochrome A-mediated light modulation of the ABA signaling pathways in yeast.

Abscisic acid (ABA), a classical plant hormone, plays an essential role in plant adaptation to environmental stresses. The ABA signaling mechanisms have been extensively investigated, and it was shown that the PYR1 (PYRABACTIN RESISTANCE1)/PYL (PYR1-LIKE)/RCAR (REGULATORY COMPONENT OF ABA RECEPTOR) ABA receptors, the PP2C coreceptors, and the SnRK2 protein kinases constitute the core ABA signaling module responsible for ABA perception and initiation of downstream responses. We recently showed that ABA signaling is modulated by light signals, but the underlying molecular mechanisms remain largely obscure. In this study, we established a system in yeast cells that was not only successful in reconstituting a complete ABA signaling pathway, from hormone perception to ABA-responsive gene expression, but also suitable for functionally characterizing the regulatory roles of additional factors of ABA signaling. Using this system, we analyzed the roles of several light signaling components, including the red and far-red light photoreceptors phytochrome A (phyA) and phyB, and the photomorphogenic central repressor COP1, in the regulation of ABA signaling. Our results showed that both phyA and phyB negatively regulated ABA signaling, whereas COP1 positively regulated ABA signaling in yeast cells. Further analyses showed that photoactivated phyA interacted with the ABA coreceptors ABI1 and ABI2 to decrease their interactions with the ABA receptor PYR1. Together, data from our reconstituted yeast ABA signaling system provide evidence that photoactivated photoreceptors attenuate ABA signaling by directly interacting with the key components of the core ABA signaling module, thus conferring enhanced ABA tolerance to light-grown plants.

Mutations in CLCN6 as a Novel Genetic Cause of Neuronal Ceroid Lipofuscinosis in a Murine Model.

OBJECTIVE: The aim of this study was to explore the pathogenesis of CLCN6-related disease and to assess whether its Cl-/H+-exchange activity is crucial for the biological role of ClC-6. METHODS: We performed whole-exome sequencing on a girl with development delay, intractable epilepsy, behavioral abnormities, retinal dysfunction, progressive brain atrophy, suggestive of neuronal ceroid lipofuscinoses (NCLs). We generated and analyzed the first knock-in mouse model of a patient variant (p.E200A) and compared it with a Clcn6-/- mouse model. Additional functional tests were performed with heterologous expression of mutant ClC-6. RESULTS: We identified a de novo heterozygous p.E200A variant in the proband. Expression of disease-causing ClC-6E200A or ClC-6Y553C mutants blocked autophagic flux and activated transcription factors EB (TFEB) and E3 (TFE3), leading to autophagic vesicle and cholesterol accumulation. Such alterations were absent with a transport-deficient ClC-6E267A mutant. Clcn6E200A/+ mice developed severe neurodegeneration with typical features of NCLs. Mutant ClC-6E200A, but not loss of ClC-6 in Clcn6-/- mice, increased lysosomal biogenesis by suppressing mTORC1-TFEB signaling, blocked autophagic flux through impairing lysosomal function, and increased apoptosis. Carbohydrate and lipid deposits accumulated in Clcn6E200A/+ brain, while only lipid storage was found in Clcn6-/- brain. Lysosome dysfunction, autophagy defects, and gliosis were early pathogenic events preceding neuron loss. INTERPRETATION: CLCN6 is a novel genetic cause of NCLs, highlighting the importance of considering CLCN6 mutations in the diagnostic workup for molecularly undefined forms of NCLs. Uncoupling of Cl- transport from H+ countertransport in the E200A mutant has a dominant effect on the autophagic/lysosomal pathway. ANN NEUROL 2024;96:608-624.

COP1 positively regulates ABA signaling during Arabidopsis seedling growth in darkness by mediating ABA-induced ABI5 accumulation.

CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1), a well-characterized E3 ubiquitin ligase, is a central repressor of seedling photomorphogenic development in darkness. However, whether COP1 is involved in modulating abscisic acid (ABA) signaling in darkness remains largely obscure. Here, we report that COP1 is a positive regulator of ABA signaling during Arabidopsis seedling growth in the dark. COP1 mediates ABA-induced accumulation of ABI5, a transcription factor playing a key role in ABA signaling, through transcriptional and post-translational regulatory mechanisms. We further show that COP1 physically interacts with ABA-hypersensitive DCAF1 (ABD1), a substrate receptor of the CUL4-DDB1 E3 ligase targeting ABI5 for degradation. Accordingly, COP1 directly ubiquitinates ABD1 in vitro, and negatively regulates ABD1 protein abundance in vivo in the dark but not in the light. Therefore, COP1 promotes ABI5 protein stability post-translationally in darkness by destabilizing ABD1 in response to ABA. Interestingly, we reveal that ABA induces the nuclear accumulation of COP1 in darkness, thus enhancing its activity in propagating the ABA signal. Together, our study uncovers that COP1 modulates ABA signaling during seedling growth in darkness by mediating ABA-induced ABI5 accumulation, demonstrating that plants adjust their ABA signaling mechanisms according to their light environment.

Mutual upregulation of HY5 and TZP in mediating phytochrome A signaling.

Phytochrome A (phyA) is the far-red (FR) light photoreceptor in plants that is essential for seedling de-etiolation under FR-rich environments, such as canopy shade. TANDEM ZINC-FINGER/PLUS3 (TZP) was recently identified as a key component of phyA signal transduction in Arabidopsis thaliana; however, how TZP is integrated into the phyA signaling networks remains largely obscure. Here, we demonstrate that ELONGATED HYPOCOTYL5 (HY5), a well-characterized transcription factor promoting photomorphogenesis, mediates FR light induction of TZP expression by directly binding to a G-box motif in the TZP promoter. Furthermore, TZP physically interacts with CONSTITUTIVE PHOTOMORPHOGENIC1 (COP1), an E3 ubiquitin ligase targeting HY5 for 26S proteasome-mediated degradation, and this interaction inhibits COP1 interaction with HY5. Consistent with those results, TZP post-translationally promotes HY5 protein stability in FR light, and in turn, TZP protein itself is destabilized by COP1 in both dark and FR light conditions. Moreover, tzp hy5 double mutants display an additive phenotype relative to their respective single mutants under high FR light intensities, indicating that TZP and HY5 also function in largely independent pathways. Together, our data demonstrate that HY5 and TZP mutually upregulate each other in transmitting the FR light signal, thus providing insights into the complicated but delicate control of phyA signaling networks.

Exosomes isolated from TNF-α-treated bone marrow mesenchymal stem cells ameliorate pelvic floor dysfunction in rats.

Exosomes derived from bone marrow-derived mesenchymal stem cells (BMSCs) can alleviate the symptoms of pelvic floor dysfunction (PFD) in rats. However, the potential therapeutical effects of exosomes derived from BMSCs treated with tumour necrosis factor (TNF)-α on the symptoms of PFD in rats are unknown. Exosomes extracted from BMSCs treated with or without TNF-α were applied to treat PFD rats. Our findings revealed a significant elevation in interleukin (IL)-6 and TNF-α, and matrix metalloproteinase-2 (MMP2) levels in the vaginal wall tissues of patients with pelvic organ prolapse (POP) compared with the control group. Daily administration of exosomes derived from BMSCs, treated either with or without TNF-α (referred to as Exo and TNF-Exo), resulted in increased void volume and bladder void pressure, along with reduced peak bladder pressure and leak point pressure in PFD rats. Notably, TNF-Exo treatment demonstrated superior efficacy in restoring void volume, bladder void pressure and the mentioned parameters compared with Exo treatment. Importantly, TNF-Exo exhibited greater potency than Exo in restoring the levels of multiple proteins (Elastin, Collagen I, Collagen III, IL-6, TNF-α and MMP2) in the anterior vaginal walls of PFD rats. The application of exosomes derived from TNF-α-treated BMSCs holds promise as a novel therapeutic approach for treating PFD.

Transcriptomic analysis of hub genes regulating albinism in light- and temperature-sensitive albino tea cultivars 'Zhonghuang 1' and 'Zhonghuang 2'.

Albino tea cultivars have high economic value because their young leaves contain enhanced free amino acids that improve the quality and properties of tea. Zhonghuang 1 (ZH1) and Zhonghuang 2 (ZH2) are two such cultivars widely planted in China; however, the environmental factors and molecular mechanisms regulating their yellow-leaf phenotype remain unclear. In this study, we demonstrated that both ZH1 and ZH2 are light- and temperature-sensitive. Under natural sunlight and low-temperature conditions, their young shoots were yellow with decreased chlorophyll and an abnormal chloroplast ultrastructure. Conversely, young shoots were green with increased chlorophyll and a normal chloroplast ultrastructure under shading and high-temperature conditions. RNA-seq analysis was performed for high light and low light conditions, and pairwise comparisons identified genes exhibiting different light responses between albino and green-leaf cultivars, including transcription factors, cytochrome P450 genes, and heat shock proteins. Weighted gene coexpression network analyses of RNA-seq data identified the modules related to chlorophyll differences between cultivars. Genes involved in chloroplast biogenesis and development, light signaling, and JA biosynthesis and signaling were typically downregulated in albino cultivars, accompanied by a decrease in JA-ILE content in ZH2 during the albino period. Furthermore, we identified the hub genes that may regulate the yellow-leaf phenotype of ZH1 and ZH2, including CsGDC1, CsALB4, CsGUN4, and a TPR gene (TEA010575.1), which were related to chloroplast biogenesis. This study provides new insights into the molecular mechanisms underlying leaf color formation in albino tea cultivars.

Association between cholelithiasis, cholecystectomy, and risk of breast and gynecological cancers: Evidence from meta-analysis and Mendelian randomization study.

BACKGROUND: Observational studies have shown that cholelithiasis and cholecystectomy are associated with the risk of breast cancer (BC) and gynecological cancers, but whether these relationships are causal has not been established and remains controversial. METHODS: Our study began with a meta-analysis that synthesized data from prior observational studies to examine the association between cholelithiasis, cholecystectomy, and the risk of BC and gynecological cancers. Subsequently, a two-sample Mendelian randomization (MR) analysis was conducted utilizing genetic variant data to investigate the potential causal relationship between cholelithiasis, cholecystectomy, and the aforementioned cancers. RESULTS: The results of the meta-analysis demonstrated a significant association between cholecystectomy and the risk of BC (risk ratio [RR] = 1.04, 95% confidence interval [CI]: 1.01-1.06, p = 0.002) and endometrial cancer (EC) (RR = 1.26, 95% CI: 1.02-1.56, p = 0.031). Conversely, no significant association was observed between cholelithiasis and the risk of BC, EC, and ovarian cancer. The MR analysis revealed no discernible causal connection between cholelithiasis and overall BC (p = 0.053), as well as BC subtypes (including estrogen receptor-positive/negative). Similarly, there was no causal effect of cholecystectomy on BC risk (p = 0.399) and its subtypes. Furthermore, no causal associations were identified between cholelithiasis, cholecystectomy, and the risk of gynecological cancers (ovarian, endometrial, and cervical cancer [CC]) (all p > 0.05). CONCLUSION: This study does not support a causal link between cholelithiasis and cholecystectomy and an increased risk of female cancers such as breast, endometrial, ovarian, and CC.

MHY1485 promotes adriamycin sensitivity in HepG2 cells by inhibiting autophagy.

MHY1485 is an mTOR activator that inhibits the autophagy process by inhibiting the fusion between autophagosomes and lysosomes. This study aimed to explore the role and mechanism of MHY1485 in hepatocellular carcinoma (HCC) and to provide an in-depth understanding of the mechanisms of autophagy regulation in relation to adriamycin (ADM) resistance, as well as the development of a molecularly targeted autophagy-modulating approach. Here, ADM was used to treat HepG2 cells and construct an ADM-resistant cell model. The HepG2/ADM cell line and HepG2 cells were treated with MHY1485 and ADM, respectively, and the proliferation and apoptosis of HCC cells were detected using CCK8, clone formation, flow cytometry, and 5-ethynyl-2'-deoxyuridine staining assays. Ki-67, mTOR phosphorylation, and LC3A expression were detected by IF staining; the expression or phosphorylation levels of autophagy-related proteins (i.e., GLUT1, PGI, PFK, END, and MTHFD2) and apoptosis-related proteins (caspase-3, caspase-8, and caspase-9) were detected by qPCR and western blotting. The number of autophagosomes was determined by monodansylcadaverine staining. Our results showed that MHY1485 can inhibit the proliferation and growth of liver cancer cells, and that MHY1485 combined with ADM can effectively inhibit the tolerance of HepG2/ADM cells to ADM and enhance the efficacy of ADM. The results of the detection of the autophagy-related protein LC3A also indicated that MHY1485 activates mTOR and can affect the phosphorylation level of ULK1, inhibit autophagy, and enhance the sensitivity of liver cancer cells to adriamycin. In summary, MHY1485 can enhance the sensitivity of adriamycin-resistant cells to adriamycin by activating mTOR and blocking the autophagy process in cells; therefore, mTOR may become a potential target for the treatment of liver cancer.

Investigating risk factors and treatment options for severe, partially steroid responsive, and steroid-refractory checkpoint inhibitor pneumonitis.

BACKGROUND: Immune checkpoint inhibitors (ICIs) have revolutionized cancer care with incredible reductions in mortality. One of the most devastating complications of treatment is ICI-related pneumonitis (ICI-p). Despite this, little is known regarding risk factors for severe pneumonitis and treatment effectiveness of various therapeutic options for steroid-refractory disease. To address this, we conducted a retrospective study on patients with cancer who developed ICI-p. METHODS: We examined consecutive patients who received ICIs and developed ICI-p. Risk factors of interest for severe disease and steroid-refractory ICI-p, including pre-treatment pulmonary function tests (PFTs) and chest imaging, were compared between patients with severe (grades 3-5) and mild (grades 1-2) pneumonitis. The clinical and treatment courses for patients with steroid-refractory ICI-p were recorded. RESULTS: A total of 132 patients developed ICI-p, with 60 patients having mild and 72 with severe disease. We found that lower forced vital capacity percent predicted (66.24 vs 85.05, P = .05), lower total lung capacity percent predicted (85.23 vs 99.71, P = .13), and specific radiographic patterns on pre-treatment chest imaging were predictors of severe disease. Initial corticosteroid dose of less than 1 milligram per kilogram prednisone equivalent (P = .14) was correlated with partially steroid-responsive or steroid-refractory ICI-p. Ten patients had steroid refractory ICI-p, and those who received IVIG alone as the immune suppressant beyond corticosteroids had improved survival (P = 05). CONCLUSIONS: We are the first to identify pre-treatment PFTs and chest imaging abnormalities as risk factors for severe ICI-p. We also found that lower corticosteroid doses were associated with partially steroid-responsive and steroid-refractory ICI-p. Larger, prospective studies are needed to validate our results.

Toehold Strand Displacement-Mediated Exponential HCR for Highly Sensitive and Specific Analysis of miRNA in Living Cells.

As an important disease biomarker, the development of sensitive detection strategies for miRNA, especially intracellular miRNA imaging strategies, is helpful for early diagnosis of diseases, pathological research, and drug development. Hybridization chain reaction (HCR) is widely used for miRNA imaging analysis because of its high specificity and lack of biological enzymes. However, the classic HCR reaction exhibits linear amplification with low efficiency, limiting its use for the rapid analysis of trace miRNA in living cells. To address this problem, we proposed a toehold-mediated exponential HCR (TEHCR) to achieve highly sensitive and efficient imaging of miRNA in living cells using ß-FeOOH nanoparticles as transfection vectors. The detection limit of TEHCR was as low as 92.7 fM, which was 8.8 × 103 times lower compared to traditional HCR, and it can effectively distinguish single-base mismatch with high specificity. The TEHCR can also effectively distinguish the different expression levels of miRNA in cancer cells and normal cells. Furthermore, TEHCR can be used to construct OR logic gates for dual miRNA analysis without the need for additional probes, demonstrating high flexibility. This method is expected to play an important role in clinical miRNA-related disease diagnosis and drug development as well as to promote the development of logic gates.

Upregulation of collagen type X alpha 1 promotes the progress of triple-negative breast cancer via Wnt/ß-catenin signaling.

Triple-negative breast cancer (TNBC) is a malignant tumor with high degree of malignancy and lack of effective target treatment. The research aims to explore the role and mechanism of X collagen alpha-1 chain protein (COL10A1 gene) in TNBC. UALCAN and Kaplan-Meier were used to detect the expression of COL10A1 and its role in the prognosis of breast cancer patients. The cells with stably expressing high levels of COL10A1 were obtained by recombinant lentivirus infection. The expression of COL10A1 in cells was temporarily downregulated by siRNA interference fragments. Real-time quantitative polymerase chain reaction and western blot analysis were utilized to detect the changes of COL10A1 mRNA and protein expression. The biological functions of the cells were evaluated by colony formation, cell counting kit-8, cell invasion and wound healing experiments. In addition, the effect of COL10A1 on angiogenesis was investigated by tube formation assay. Xenograft tumor model was used to confirm the effect of COL10A1 on tumorigenicity in vivo and multiplex fluorescent immunohistochemistry to detect multiple proteins simultaneously. The possible molecular mechanism of the function of COL10A1 was speculated through the detection of proteins in functionally related pathways. COL10A1 is highly expressed and is significantly associated with worse overall survival (OS) and recurrence-free survival (RFS) in TNBC. Overexpression of COL10A1 increased the clone formation rate and cell migration capacity of TNBC cells. In the COL10A1 overexpression group, the clone formation rates of MD-MB-231 and BT-549 cells (21.5 ± 0.62, 27.83 ± 3.72)% were significantly higher than those in the control group(15.23 ± 2.79, 19.4 ± 1.47)%, and the relative migration ratio (47.40 ± 3.09, 41.26 ± 4.33)% were higher than those in the control group (34.48 ± 2.03, 21.80 ± 1.03)%. When the expression of COL10A1 was downregulated, the ability of clone formation and wound-healing migration capacity in TNBC cells was weakened. Upregulated COL10A1 in TNBC cells generated more junctions and longer total segments between vascular endothelial cells, and promoted angiogenesis of the cells, and thus enhanced the tumorigenesis. In TNBC, it was found that COL10A1 might affect epithelial-mesenchymal transition (EMT) of the cells through Wnt/ß-catenin signaling pathway by the detection of the related pathway proteins. COL10A1 is highly expressed in TNBC, and its high expression leads to poor OS and RFS. COL10A1 may enhance TNBC cell proliferation, migration and tumor-related angiogenesis, and promote tumorigenesis in vivo via Wnt/ß-catenin signaling.

Association of triglyceride-glucose index and its combination with adiposity-related indices with the incidence of myocardial infarction: a cohort study from the UK Biobank.

BACKGROUND: The triglyceride-glucose (TyG) index performs better at reflecting insulin resistance when combined with waist circumference (WC), body mass index (BMI), and waist-to-height ratio (WHtR) than when used alone. This study aimed to prospectively examine the relationships between TyG, TyG-BMI, TyG-WC, and TyG-WHtR with the incidence of myocardial infarction (MI) and its subtypes. METHODS: This cohort study included 370,390 participants from the UK Biobank. The Cox proportional hazards model and restricted cubic spline regression model were used to assess the associations of TyG, TyG-BMI, TyG-WC, and TyG-WHtR with MI, ST-elevation MI (STEMI) and non-ST-elevation MI (NSTEMI). The receiver operating characteristic (ROC) curve and the area under the curve (AUC) were employed to examine the predictive value of four indicators. RESULTS: The hazard ratios (HRs) and 95% confidence intervals (CIs) of MI in the highest quartiles for TyG, TyG-BMI, TyG-WC, and TyG-WHtR were 1.36 (1.28-1.44), 1.47 (1.39-1.56), 1.53 (1.43-1.64), and 1.58 (1.48-1.68) in the fully-adjusted model. Comparable findings were observed when the outcomes were reclassified as STEMI or NSTEMI. However, the associations of TyG-BMI, TyG-WC, and TyG-WHtR with the risk of STEMI were weaker than MI and NSTEMI. A linear dose-response association between TyG and the risk of MI and NSTEMI were demonstrated. TyG-BMI, TyG-WC, and TyG-WHtR all showed nonlinear patterns in their associations with the risk of MI, STEMI, and NSTEMI. TyG-WC was most effective in diagnosing MI (AUC: 0.648, 95% CI: 0.644-0.653), STEMI (AUC: 0.631, 95% CI: 0.622-0.639), and NSTEMI (AUC: 0.647, 95% CI: 0.641-0.654). CONCLUSION: The TyG index was linearly associated with increased risk of MI and NSTEMI, whereas TyG-BMI, TyG-WC, and TyG-WHtR were nonlinearly associated with increased risk of MI and NSTEMI. There were distinct patterns in the relationships between these indicators with STEMI. TyG-WC provided the best diagnostic effectiveness for MI, STEMI, and NSTEMI.

A WRI1-dependent module is essential for the accumulation of auxin and lipid in somatic embryogenesis of Arabidopsis thaliana.

The potential for totipotency exists in all plant cells; however, the underlying mechanisms remain largely unknown. Earlier findings have revealed that the overexpression of LEAFY COTYLEDON 2 (LEC2) can directly trigger the formation of somatic embryos on the cotyledons of Arabidopsis. Furthermore, cotyledon cells that overexpress LEC2 accumulate significant lipid reserves typically found in seeds. The precise mechanisms and functions governing lipid accumulation in this process remain unexplored. In this study, we demonstrate that WRINKLED1 (WRI1), the key regulator of lipid biosynthesis, is essential for somatic embryo formation, suggesting that WRI1-mediated lipid biosynthesis plays a crucial role in the transition from vegetative to embryonic development. Our findings indicate a direct interaction between WRI1 and LEC2, which enhances the enrichment of LEC2 at downstream target genes and stimulates their induction. Besides, our data suggest that WRI1 forms a complex with LEC1, LEC2, and FUSCA3 (FUS3) to facilitate the accumulation of auxin and lipid for the somatic embryo induction, through strengthening the activation of YUCCA4 (YUC4) and OLEOSIN3 (OLE3) genes. Our results uncover a regulatory module controlled by WRI1, crucial for somatic embryogenesis. These findings provide valuable insights into our understanding of plant cell totipotency.

Single-cell transcriptome landscape elucidates the cellular and developmental responses to tomato chlorosis virus infection in tomato leaf.

Plant viral diseases compromise the growth and yield of the crop globally, and they tend to be more serious under extreme temperatures and drought climate changes. Currently, regulatory dynamics during plant development and in response to virus infection at the plant cell level remain largely unknown. In this study, single-cell RNA sequencing on 23 226 individual cells from healthy and tomato chlorosis virus-infected leaves was established. The specific expression and epigenetic landscape of each cell type during the viral infection stage were depicted. Notably, the mesophyll cells showed a rapid function transition in virus-infected leaves, which is consistent with the pathological changes such as thinner leaves and decreased chloroplast lamella in virus-infected samples. Interestingly, the F-box protein SKIP2 was identified to play a pivotal role in chlorophyll maintenance during virus infection in tomato plants. Knockout of the SlSKIP2 showed a greener leaf state before and after virus infection. Moreover, we further demonstrated that SlSKIP2 was located in the cytomembrane and nucleus and directly regulated by ERF4. In conclusion, with detailed insights into the plant responses to viral infections at the cellular level, our study provides a genetic framework and gene reference in plant-virus interaction and breeding in the future research.

Role of Exosomes in Cardiovascular Diseases.

Exosomes (EXOs) are a subgroup of extracellular vesicles (EVs) that contain numerous biologically active molecules. They exhibit an essential mode of cell communication, primarily between distinct cell populations, for the maintenance of tissue homeostasis and coordination of adaptive responses to various stresses. These intercellular communications are vital for the complex, multicellular cardiovascular system. In the last ten years, their potential role as effective tissue-to-tissue communicators has received increasing attention in cardiovascular physiology and pathology. There is growing evidence that repair of the heart and regeneration can be promoted by EXOs derived from cardiomyocytes or stem/progenitor cells. However, the underlying mechanisms remain unclear. EVs derived from different stem/progenitor cell populations have been used as cell-free therapies in different preclinical models involving cardiovascular diseases and have shown promising results. In this review, we have summarized the recent developments in EXOs research, the impact of EXOs derived from different cells on the cardiovascular system, their potential therapeutic roles as well as new diagnostic biomarkers, and the possible clinical translational outcomes.

Serum miRNA-1 may serve as a promising noninvasive biomarker for predicting treatment response in breast cancer patients receiving neoadjuvant chemotherapy.

BACKGROUND: MicroRNA-1 (miR-1) is a tumour suppressor that can inhibit cell proliferation and invasion in several cancer types. In addition, miR-1 was found to be associated with drug sensitivity. Circulating miRNAs have been proven to be potential biomarkers with predictive and prognostic value. However, studies of miR-1 expression in the serum of breast cancer (BC) patients are relatively scarce, especially in patients receiving neoadjuvant chemotherapy (NAC). METHODS: Serum samples from 80 patients were collected before chemotherapy, and RT-PCR was performed to detect the serum expression of miR-1. The correlation between miR-1 expression in serum and clinicopathological factors, including pathological complete response (pCR), was analyzed by the chi-squared test and logistic regression. KEGG and GSEA analysis were also performed to determine the biological processes and signalling pathways involved. RESULTS: The miR-1 high group included more patients who achieved a pCR than did the miR-1 low group (p < 0.001). Higher serum miR-1 levels showed a strong correlation with decreased ER (R = 0.368, p < 0.001) and PR (R = 0.238, p = 0.033) levels. The univariate model of miR-1 for predicting pCR achieved an AUC of 0.705 according to the ROC curve. According to the interaction analysis, miR-1 interacted with Ki67 to predict the NAC response. According to the Kaplan-Meier plot, a high serum miR-1 level was related to better disease-free survival (DFS) in the NAC cohort. KEGG analysis and GSEA results indicated that miR-1 may be related to the PPAR signalling pathway and glycolysis. CONCLUSIONS: In summary, our data suggested that miR-1 could be a potential biomarker for pCR and survival outcomes in patients with BC treated with NAC.

Effects of SARS-CoV-2 infection during ovarian stimulation on ART outcomes.

RESEARCH QUESTION: Does severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection during ovarian stimulation affect assisted reproductive technology outcomes? DESIGN: This retrospective cohort study conducted at the Reproductive Medicine Centre of The First Affiliated Hospital of Anhui Medical University aimed to assess the effects of acute SARS-CoV-2 infection during IVF on treatment outcomes and the reproductive system. The study included 151 treatment cycles involving couples with coronavirus disease 2019 (COVID-19) during ovarian stimulation, along with 224 cycles of non-infected couples as a control group. Clinical characteristics and laboratory parameters were analysed, including total gonadotrophin dosage, duration of ovarian stimulation, number of oocytes retrieved, fertilization method, fertilization rate, and number of blastocyst embryos available. Forty-six follicular fluid samples, 38 semen samples and 78 embryo culture medium samples from patients with COVID-19 were tested for SARS-CoV-2 RNA using reverse transcription polymerase chain reaction assay. RESULTS: The treatment and control groups showed similar cycle characteristics, including fertilization method, total gonadotrophin dosage and duration of ovarian stimulation. The mean number of oocytes retrieved per cycle and rate of mature oocytes in intracytoplasmic sperm injection cycles were comparable. No significant difference was observed in the total number of blastocyst embryos available between the groups. Furthermore, no SARS-CoV-2 RNA was detected in any of the samples of patients with COVID-19. CONCLUSIONS: In conclusion, acute SARS-CoV-2 infection during ovarian stimulation does not have a significant impact on IVF treatment outcomes. Additionally, no risk to the reproductive system was observed in patients infected with SARS-CoV-2. Therefore, individuals with asymptomatic or mild COVID-19 can safely continue IVF treatment. Future research is needed to investigate the long-term effects of COVID-19 on fertility and reproductive outcomes.

Citrobacter enshiensis sp. nov., isolated from seleniferous soil.

Two Gram-stain-negative, facultative anaerobic, rod-shaped bacterial strains, S171T and S2-9, were isolated from seleniferous soil in China. Comprehensive phylogenetic analyses based on 16S rRNA genes, multilocus sequences and whole genome sequences indicated that the two strains belonged to the genus Citrobacter. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values of strains S171T and S2-9 with the closest relative Citrobacter koseri NCTC 10786T were 83.6-83.7% and 27.7-27.8 %, respectively, which were below the species cutoff values. The ANI and dDDH values between the two strains were 97.9% and 84.8 %, respectively. The biochemical characteristics revealed that selenite tolerance, H2S and indole production, arginine dihydrolase, ornithine decarboxylase, as well as acid production from carbon sources such as d-sorbitol and arbutin are distinctive features of the two strains. Based on these results, strain S171T and strain S2-9 represent a novel species of the genus Citrobacter, for which the name Citrobacter enshiensis sp. nov. is proposed, with strain S171T (=GDMCC 1.3637T=JCM 35851T) as the type strain. The genome size of strain S171T was 4.92 Mb with a G+C content of 52.6 mol%. The genome size of strain S2-9 was 4.89 Mb with a G+C content of 52.6 mol%.