Changes in bone turnover markers and bone mineral density after radiofrequency ablation for mild primary hyperparathyroidism: a prospective cohort study.

Background: The application of radiofrequency ablation (RFA) is becoming increasingly widespread in the treatment of primary hyperparathyroidism (PHPT). However, the effect of RFA treatment on the skeleton in mild PHPT remains unclear. Therefore, the aim of this study was to investigate the change in bone turnover markers and bone mineral density (BMD) before and 2 years after RFA in patients with mild PHPT. Methods: In this open-label, prospective study, 81 patients with mild PHPT including 36 treated with RFA and 45 observed without intervention (OBS), along with 81 age-matched healthy controls, were enrolled from November 2018 to September 2021 at Gansu Provincial Hospital. The main outcome measures were levels of serum calcium, serum intact parathyroid hormone (iPTH), and bone turnover markers, including bone-specific alkaline phosphatase (ALP), C-terminal cross-linking telopeptides of type I collagen (ß-CTx), and osteocalcin (OC). BMD (femoral neck and lumbar spine) was measured with dual-energy X-ray absorptiometry, and spine radiographs were obtained for vertebral fracture assessment. Paired and unpaired two-tailed t-tests and Spearman rank correlation coefficient were used for statistical analyses. Results: Normalized outcomes for both iPTH and calcium levels were achieved in 32 of 36 (88.9%) patients with mild PHPT treated with RFA. There was a significant treatment effect of RFA on bone turnover biomarkers compared with OBS before the treatment (P=0.04) and at the end of follow-up or (P=0.03). BMD of the lumbar spine increased by 1.8% (P=0.03) and remained stable in the femoral neck (P=0.17) after RFA. However, there was an obvious treatment effect of RFA on BMD compared with OBS (P 0.04). The only compartment with a T-score increase in the RFA group was the lumbar spine in (P<0.001). There was no difference in fracture frequency between groups during the follow-up period. Conclusions: RFA can improve serum bone turnover markers in patients with mild PHPT and can be expected to increase BMD in the L1-L4 vertebrae and preserve BMD in the femoral neck. Whether RFA can reduce fracture risk in the long-term is a clinical concern for patients with mild PHPT.

Overexpression of Let-7a mitigates diploidization in mouse androgenetic haploid embryonic stem cells.

Mouse androgenetic haploid embryonic stem cells (mAG-haESCs) can be utilized to uncover gene functions, especially those of genes with recessive effects, and to produce semicloned mice when injected into mature oocytes. However, mouse haploid cells undergo rapid diploidization during long-term culture in vitro and subsequently lose the advantages of haploidy, and the factors that drive diploidization are poorly understood. In this study, we compared the small RNAs (sRNAs) of mAG-haESCs, normal embryonic stem cells (ESCs), and mouse round spermatids by high-throughput sequencing and identified distinct sRNA profiles. Several let-7 family members and miR-290-295 cluster microRNAs (miRNAs) were found significantly differentially transcribed. Knockdown and overexpression experiments showed that let-7a and let-7g suppress diploidization while miR-290a facilitates diploidization. Our study revealed the unique sRNA profile of mAG-haESCs and demonstrated that let-7a overexpression can mitigate diploidization in mAG-haESCs. These findings will help us to better understand mAG-haESCs and utilize them as tools in the future.

SRSF2 is required for mRNA splicing during spermatogenesis.

BACKGROUND: RNA splicing plays significant roles in fundamental biological activities. However, our knowledge about the roles of alternative splicing and underlying mechanisms during spermatogenesis is limited. RESULTS: Here, we report that Serine/arginine-rich splicing factor 2 (SRSF2), also known as SC35, plays critical roles in alternative splicing and male reproduction. Male germ cell-specific deletion of Srsf2 by Stra8-Cre caused complete infertility and defective spermatogenesis. Further analyses revealed that deletion of Srsf2 disrupted differentiation and meiosis initiation of spermatogonia. Mechanistically, by combining RNA-seq data with LACE-seq data, we showed that SRSF2 regulatory networks play critical roles in several major events including reproductive development, spermatogenesis, meiotic cell cycle, synapse organization, DNA recombination, chromosome segregation, and male sex differentiation. Furthermore, SRSF2 affected expression and alternative splicing of Stra8, Stag3 and Atr encoding critical factors for spermatogenesis in a direct manner. CONCLUSIONS: Taken together, our results demonstrate that SRSF2 has important functions in spermatogenesis and male fertility by regulating alternative splicing.

SRSF1-mediated alternative splicing is required for spermatogenesis.

Alternative splicing (AS) plays significant roles in a multitude of fundamental biological activities. AS is prevalent in the testis, but the regulations of AS in spermatogenesis is only little explored. Here, we report that Serine/arginine-rich splicing factor 1 (SRSF1) plays critical roles in alternative splicing and male reproduction. Male germ cell-specific deletion of Srsf1 led to complete infertility by affecting spermatogenesis. Mechanistically, by combining RNA-seq data with LACE-seq data, we showed that SRSF1 affected the AS of Stra8 in a direct manner and Dazl, Dmc1, Mre11a, Syce2 and Rif1 in an indirect manner. Our findings demonstrate that SRSF1 has crucial functions in spermatogenesis and male fertility by regulating alternative splicing.

A heterozygous ZP2 mutation causes zona pellucida defects and female infertility in mouse and human.

The zona pellucida (ZP) is an extracellular glycoprotein matrix surrounding mammalian oocytes. Recently, numerous mutations in genes encoding ZP proteins have been shown to be possibly related to oocyte abnormality and female infertility; few reports have confirmed the functions of these mutations in living animal models. Here, we identified a novel heterozygous missense mutation (NM_001376231.1:c.1616C>T, p.Thr539Met) in ZP2 from a primary infertile female. We showed that the mutation reduced ZP2 expression and impeded ZP2 secretion in cell lines. Furthermore, we constructed the mouse model with the mutation (Zp2T541M) using CRISPR-Cas9. Zp2WT/T541M female mice had normal fertility though generated oocytes with the thin ZP, whereas Zp2T541M female mice were completely infertile due to degeneration of oocytes without ZP. Additionally, ZP deletion impaired folliculogenesis and caused female infertility in Zp2T541M mice. Our study not only expands the spectrum of ZP2 mutation sites but also, more importantly, increases the understanding of pathogenic mechanisms of ZP2 mutations.

NLRP14 Safeguards Calcium Homeostasis via Regulating the K27 Ubiquitination of Nclx in Oocyte-to-Embryo Transition.

Sperm-induced Ca2+ rise is critical for driving oocyte activation and subsequent embryonic development, but little is known about how lasting Ca2+ oscillations are regulated. Here it is shown that NLRP14, a maternal effect factor, is essential for keeping Ca2+ oscillations and early embryonic development. Few embryos lacking maternal NLRP14 can develop beyond the 2-cell stage. The impaired developmental potential of Nlrp14-deficient oocytes is mainly caused by disrupted cytoplasmic function and calcium homeostasis due to altered mitochondrial distribution, morphology, and activity since the calcium oscillations and development of Nlrp14-deficient oocytes can be rescued by substitution of whole cytoplasm by spindle transfer. Proteomics analysis reveal that cytoplasmic UHRF1 (ubiquitin-like, containing PHD and RING finger domains 1) is significantly decreased in Nlrp14-deficient oocytes, and Uhrf1-deficient oocytes also show disrupted calcium homeostasis and developmental arrest. Strikingly, it is found that the mitochondrial Na+ /Ca2+ exchanger (NCLX) encoded by Slc8b1 is significantly decreased in the Nlrp14mNull oocyte. Mechanistically, NLRP14 interacts with the NCLX intrinsically disordered regions (IDRs) domain and maintain its stability by regulating the K27-linked ubiquitination. Thus, the study reveals NLRP14 as a crucial player in calcium homeostasis that is important for early embryonic development.

Atmospheric dryness thresholds of grassland productivity decline in China.

Atmospheric dryness events are bound to have a broad and profound impact on the functions and structures of grassland ecosystems. Current research has confirmed that atmospheric dryness is a key moisture constraint that inhibits grassland productivity, yet the risk threshold for atmospheric dryness to initiate ecosystem productivity loss has not been explored. Based on this, we used four terrestrial ecosystem models to simulate gross primary productivity (GPP) data, analyzed the role of vapor pressure deficit (VPD) in regulating interannual variability in Chinese grasslands by focusing on the dependence structure of VPD and GPP, and then constructed a bivariate linkage function to calculate the conditional probability of ecosystem GPP loss under atmospheric dryness, and further analyzed the risk threshold of ecosystem GPP loss triggered by atmospheric dryness. The main results are as follows: we found that (1) the observed and modeled VPD of Chinese grasslands increases rapidly in both historical and future periods. VPD has a strongly negative regulation on ecosystem GPP, and atmospheric dryness is an important moisture constraint that causes deficit and even death to ecosystem GPP. (2) The probability of the enhanced atmospheric dryness that induced GPP decline in Chinese grasslands in the future period increases significantly. (3) When the VPD is higher than 40.07 and 27.65 percentile of the past and future time series, respectively, the risk threshold of slight ecosystem GPP loss can be easily initiated by atmospheric dryness. (4) When the VPD is higher than 82.57 and 65.09 percentile, respectively, the threshold of moderate ecosystem GPP loss can be exceeded by the benchmark probability. (5) The risk threshold of severe ecosystem GPP loss is not initiated by atmospheric dryness in the historical period, and the threshold of severe ecosystem GPP loss can be initiated when the future VPD is higher than 91.92 percentile. In total, a slight atmospheric dryness event is required to initiate a slight ecosystem GPP loss threshold, and a stronger atmospheric dryness event is required to initiate a severe ecosystem GPP loss. Our study enhances the understandings of past and future atmospheric dryness on grassland ecosystems, and strongly suggests that more attention be invested in improving next-generation models of vegetation dynamics processes with respect to the response of mechanisms of ecosystem to atmospheric dryness.

Release of STK24/25 suppression on MEKK3 signaling in endothelial cells confers cerebral cavernous malformation.

Loss-of-function mutations in cerebral cavernous malformation (CCM) genes and gain-of-function mutation in the MAP3K3 gene encoding MEKK3 cause CCM. Deficiency of CCM proteins leads to the activation of MEKK3-KLF2/4 signaling, but it is not clear how this occurs. Here, we demonstrate that deletion of the CCM3 interacting kinases STK24/25 in endothelial cells causes defects in vascular patterning during development as well as CCM lesion formation during postnatal life. While permanent deletion of STK24/25 in endothelial cells caused developmental defects of the vascular system, inducible postnatal deletion of STK24/25 impaired angiogenesis in the retina and brain. More importantly, deletion of STK24/25 in neonatal mice led to the development of severe CCM lesions. At the molecular level, a hybrid protein consisting of the STK kinase domain and the MEKK3 interacting domain of CCM2 rescued the vascular phenotype caused by the loss of ccm gene function in zebrafish. Our study suggests that CCM2/3 proteins act as adapters to allow recruitment of STK24/25 to limit the constitutive MEKK3 activity, thus contributing to vessel stability. Loss of STK24/25 causes MEKK3 activation, leading to CCM lesion formation.

Septin 9 controls CCNB1 stabilization via APC/CCDC20 during meiotic metaphase I/anaphase I transition in mouse oocytes.

The anaphase promoting complex/cyclosome (APC/C) and its cofactors CDH1 and CDC20 regulate the accumulation/degradation of CCNB1 during mouse oocyte meiotic maturation. Generally, the CCNB1 degradation mediated by APC/CCDC20 activity is essential for the transition from metaphase to anaphase. Here, by using siRNA and mRNA microinjection, as well as time-lapse live imaging, we showed that Septin 9, which mediates the binding of septins to microtubules, is critical for oocyte meiotic cell cycle progression. The oocytes were arrested at the MI stage and the connection between chromosome kinetochores and spindle microtubules was disrupted after Septin 9 depletion. As it is well known that spindle assembly checkpoint (SAC) is an important regulator of the MI-AI transition, we thus detected the SAC activity and the expression of CDC20 and CCNB1 which were the downstream proteins of SAC during this critical period. The signals of Mad1 and BubR1 still remained on the kinetochores of chromosomes in Septin 9 siRNA oocytes at 9.5 h of in vitro culture when most control oocytes entered anaphase I. The expression of CCNB1 did not decrease and the expression of CDC20 did not increase at 9.5 h in Septin 9 siRNA oocytes. Microinjection of mRNA encoding Septin 9 or CDC20 could partially rescue MI arrest caused by Septin 9 siRNA. These results suggest that Septin 9 is required for meiotic MI-AI transition by regulating the kinetochore-microtubule connection and SAC protein localization on kinetochores, whose effects are transmitted to APC/CCDC20 activity and CCNB1 degradation in mouse oocytes.

Satellite greenness and solar-induced chlorophyll fluorescence reveal reverse desertification in Gurbantunggut Desert.

The desertification reversal is a process of revegetation and natural restoration in fragile dryland areas due to human activities and climate change mediation. Understanding the impact of desertification reversion on terrestrial ecosystems, including vegetation greenness and photosynthetic capacity, is crucial for land policy-making and carbon-cycle model improvement. However, the phenomenon of desertification reversal is rarely mentioned in previous studies, which dramatically limits the understanding of vegetation dynamics in the arid area. Therefore, it is of great necessity to investigate the status of desertification reversal on the ecosystem in arid areas. In this study, we first reported the phenomenon of desertification reversion over the southern edge of the Gurbantunggut Desert through the Moderate-resolution Imaging Spectroradiometer classification map year by year. We discussed the consequences, ways, and causes of desertification reversion. Our results showed that the desertification reversal significantly increased vegetation greenness and photosynthetic capacity, which largely offset the negative impact of desertification on the ecosystem productivity; cropland expansion and grassland's natural restoration were the two main ways of desertification reversal; the improvement of soil-water condition was an essential environmental factor leading to the phenomenon of reverse desertification. This finding highlights the importance of desertification reversal in the carbon cycle of dryland ecosystems and prove that desertification reversal is an integral part of global and dryland vegetation greening.

Comparative study of temperature effects on white sandstone and rockburst-like materials.

Rockburst physical model test, as one of the important means to study deep tunnel engineering, reflects the main influencing factors of rockburst into the model test through similar theory, so as to reveal the formation mechanism, influencing factors and evolution law of different types of rockburst in deep tunnels. In order to study the mechanical properties of white sandstone in deeply buried tunnels at high ground temperatures, materials suitable for conducting rockburst physical and mechanical tests were developed on the basis of the Daqian Shi Ling tunnel project, and similar material ratios were preferentially selected on the basis of white sandstone. Judged by the rock burst propensity, similar materials with low strength and high brittle characteristics, can better simulate the characteristics of white sandstone, and all show a strong propensity to rock burst, is the ideal rock burst similar materials. Uniaxial compressive tests were conducted on similar materials and the original rock at different temperatures, and comparative analysis was performed. Through the study of stress, displacement and modulus of elasticity, it was concluded that the compressive strength of similar materials gradually increased with temperature in the range of 20-100°C, and the vertical displacement at peak strength decreased with increasing temperature. The damage forms of white sandstone and similar materials at different temperatures were comparatively analyzed, and it was obtained that the damage forms of white sandstone and similar materials were basically the same, with a few specimens showing tensile and shear damage, and most specimens showing the form of combined tensile and shear damage. The study of rock burst similar materials and the development of the failure characteristics of rock burst under the action of thermal coupling are of great significance to the mechanism of rock burst generation and prediction.

Transcriptomics Profiling of Acer pseudosieboldianum Molecular Mechanism against Freezing Stress.

Low temperature is an important environmental factor that affects the growth and development of trees and leads to the introduction of failure in the genetic improvement of trees. Acer pseudosieboldianum is a tree species that is well-known for its bright red autumn leaf color. These trees are widely used in landscaping in northeast China. However, due to their poor cold resistance, introduced A. pseudosieboldianum trees suffer severe freezing injury in many introduced environments. To elucidate the physiological indicators and molecular mechanisms associated with freezing damage, we analyzed the physiological indicators and transcriptome of A. pseudosieboldianum, using kits and RNA-Seq technology. The mechanism of A. pseudosieboldianum in response to freezing stress is an important scientific question. In this study, we used the shoots of four-year-old A. pseudosieboldianum twig seedlings, and the physiological index and the transcriptome of A. pseudosieboldianum under low temperature stress were investigated. The results showed that more than 20,000 genes were detected in A. pseudosieboldianum under low temperature (4 °C) and freezing temperatures (-10 °C, -20 °C, -30 °C, and -40 °C). There were 2505, 6021, 5125, and 3191 differential genes (DEGs) between -10 °C, -20°C, -30°C, -40 °C, and CK (4 °C), respectively. Among these differential genes, 48 genes are involved in the MAPK pathway and 533 genes are involved in the glucose metabolism pathway. In addition, the important transcription factors (MYB, AP2/ERF, and WRKY) involved in freezing stress were activated under different degrees of freezing stress. A total of 10 sets of physiological indicators of A. pseudosieboldianum were examined, including the activities of five enzymes and the accumulation of five hormones. All of the physiological indicators except SOD and GSH-Px reached their maximum values at -30 °C. The enzyme activity of SOD was highest at -10 °C, and that of GSH-Px was highest at -20 °C. Our study is the first to provide a more comprehensive understanding of the differential genes (DEGs) involved in A. pseudosieboldianum under freezing stress at different temperatures at the transcriptome level. These results may help to clarify the molecular mechanism of cold tolerance of A. pseudosieboldianum and provide new insights and candidate genes for the genetic improvement of the freezing tolerance of A. pseudosieboldianum.

SRSF10 is essential for progenitor spermatogonia expansion by regulating alternative splicing.

Alternative splicing expands the transcriptome and proteome complexity and plays essential roles in tissue development and human diseases. However, how alternative splicing regulates spermatogenesis remains largely unknown. Here, using a germ cell-specific knockout mouse model, we demonstrated that the splicing factor Srsf10 is essential for spermatogenesis and male fertility. In the absence of SRSF10, spermatogonial stem cells can be formed, but the expansion of Promyelocytic Leukemia Zinc Finger (PLZF)-positive undifferentiated progenitors was impaired, followed by the failure of spermatogonia differentiation (marked by KIT expression) and meiosis initiation. This was further evidenced by the decreased expression of progenitor cell markers in bulk RNA-seq, and much less progenitor and differentiating spermatogonia in single-cell RNA-seq data. Notably, SRSF10 directly binds thousands of genes in isolated THY+ spermatogonia, and Srsf10 depletion disturbed the alternative splicing of genes that are preferentially associated with germ cell development, cell cycle, and chromosome segregation, including Nasp, Bclaf1, Rif1, Dazl, Kit, Ret, and Sycp1. These data suggest that SRSF10 is critical for the expansion of undifferentiated progenitors by regulating alternative splicing, expanding our understanding of the mechanism underlying spermatogenesis.

Cerebral cavernous malformation development in chronic mouse models driven by dual recombinases induced gene deletion in brain endothelial cells.

Cerebral cavernous malformation (CCM) is a brain vascular disease which can cause stroke, cerebral hemorrhage and neurological deficits in affected individuals. Loss-of-function mutations in three genes (CCM1, CCM2 and CCM3) cause CCM disease. Multiple mouse models for CCM disease have been developed although each of them are associated with various limitations. Here, we employed the Dre-Cre dual recombinase system to specifically delete Ccm genes in brain endothelial cells. In this new series of CCM mouse models, robust CCM lesions now develop in the cerebrum. The survival curve and lesion burden analysis revealed that Ccm2 deletion causes modest CCM lesions with a median life expectance of ∼10 months and Ccm3 gene deletion leads to the most severe CCM lesions with median life expectance of ∼2 months. The extended lifespan of these mutant mice enables their utility in behavioral analyses of neurologic deficits in adult mice, and allow the development of methods to quantify lesion burden in mice over time and also permit longitudinal drug testing in live animals.

The Manchurian Walnut Genome: Insights into Juglone and Lipid Biosynthesis.

BACKGROUND: Manchurian walnut (Juglans mandshurica Maxim.) is a tree with multiple industrial uses and medicinal properties in the Juglandaceae family (walnuts and hickories). J. mandshurica produces juglone, which is a toxic allelopathic agent and has potential utilization value. Furthermore, the seed of J. mandshurica is rich in various unsaturated fatty acids and has high nutritive value. FINDINGS: Here, we present a high-quality chromosome-scale reference genome assembly and annotation for J. mandshurica (n = 16) with a contig N50 of 21.4 Mb by combining PacBio high-fidelity reads with high-throughput chromosome conformation capture data. The assembled genome has an estimated sequence size of 548.7 Mb and consists of 657 contigs, 623 scaffolds, and 40,453 protein-coding genes. In total, 60.99% of the assembled genome consists of repetitive sequences. Sixteen super-scaffolds corresponding to the 16 chromosomes were assembled, with a scaffold N50 length of 33.7 Mb and a BUSCO complete gene percentage of 98.3%. J. mandshurica displays a close sequence relationship with Juglans cathayensis, with a divergence time of 13.8 million years ago. Combining the high-quality genome, transcriptome, and metabolomics data, we constructed a gene-to-metabolite network and identified 566 core and conserved differentially expressed genes, which may be involved in juglone biosynthesis. Five CYP450 genes were found that may contribute to juglone accumulation. NAC, bZip, NF-YA, and NF-YC are positively correlated with the juglone content. Some candidate regulators (e.g., FUS3, ABI3, LEC2, and WRI1 transcription factors) involved in the regulation of lipid biosynthesis were also identified. CONCLUSIONS: Our genomic data provide new insights into the evolution of the walnut genome and create a new platform for accelerating molecular breeding and improving the comprehensive utilization of these economically important tree species.

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.

Chromosome-Level Genome Assembly for Acer pseudosieboldianum and Highlights to Mechanisms for Leaf Color and Shape Change.

Acer pseudosieboldianum (Pax) Komarov is an ornamental plant with prominent potential and is naturally distributed in Northeast China. Here, we obtained a chromosome-scale genome assembly of A. pseudosieboldianum combining HiFi and Hi-C data, and the final assembled genome size was 690.24 Mb and consisted of 287 contigs, with a contig N50 value of 5.7 Mb and a BUSCO complete gene percentage of 98.4%. Genome evolution analysis showed that an ancient duplication occurred in A. pseudosieboldianum. Phylogenetic analyses revealed that Aceraceae family could be incorporated into Sapindaceae, consistent with the present Angiosperm Phylogeny Group system. We further construct a gene-to-metabolite correlation network and identified key genes and metabolites that might be involved in anthocyanin biosynthesis pathways during leaf color change. Additionally, we identified crucial teosinte branched1, cycloidea, and proliferating cell factors (TCP) transcription factors that might be involved in leaf morphology regulation of A. pseudosieboldianum, Acer yangbiense and Acer truncatum. Overall, this reference genome is a valuable resource for evolutionary history studies of A. pseudosieboldianum and lays a fundamental foundation for its molecular breeding.

Liver Endothelial Heg Regulates Vascular/Biliary Network Patterning and Metabolic Zonation Via Wnt Signaling.

BACKGROUND & AIMS: The liver has complex interconnecting blood vessel and biliary networks; however, how the vascular and biliary network form and regulate each other and liver function are not well-understood. We aimed to examine the role of Heg in mammalian liver development and functional maintenance. METHODS: Global (Heg-/-) or liver endothelial cell (EC)-specific deletion of Heg (Lyve1-Cre;Hegfl/fl ) mice were used to study the in vivo function of Heg in the liver. Carbon-ink anterograde and retrograde injection were used to visualize the 3-dimensional patterning of liver portal and biliary networks, respectively. RNA sequencing, histology, and molecular and biochemical assays were used to assess liver gene expression, protein distribution, liver injury response, and function. RESULTS: Heg deficiency in liver ECs led to a sparse liver vascular and biliary network. This network paucity does not compromise liver function under baseline conditions but did alter liver zonation. Molecular analysis revealed that endothelial Heg deficiency decreased expression of Wnt ligands/agonists including Wnt2, Wnt9b, and Rspo3 in ECs, which limits Axin2 mediated canonical Wnt signaling and the expression of cytochrome P450 enzymes in hepatocytes. Under chemical-induced stressed conditions, Heg-deficiency in liver ECs protected mice from drug-induced liver injuries. CONCLUSION: Our study found that endothelial Heg is essential for the 3-D patterning of the liver vascular and indirectly regulates biliary networks and proper liver zonation via its regulation of Wnt ligand production in liver endothelial cells. The endothelial Heg-initiated changes of the liver metabolic zonation and metabolic enzyme expression in hepatocytes was functionally relevant to xenobiotic metabolism and drug induced liver toxicity.

Combined transcriptome and metabolome integrated analysis of Acer mandshuricum to reveal candidate genes involved in anthocyanin accumulation.

The red color formation of Acer mandshuricum leaves is caused by the accumulation of anthocyanins primarily, but the molecular mechanism researches which underlie anthocyanin biosynthesis in A. mandshuricum were still lacking. Therefore, we combined the transcriptome and metabolome and analyzed the regulatory mechanism and accumulation pattern of anthocyanins in three different leaf color states. In our results, 26 anthocyanins were identified. Notably, the metabolite cyanidin 3-O-glucoside was found that significantly correlated with the color formation, was the predominant metabolite in anthocyanin biosynthesis of A. mandshuricum. By the way, two key structural genes ANS (Cluster-20561.86285) and BZ1 (Cluster-20561.99238) in anthocyanidin biosynthesis pathway were significantly up-regulated in RL, suggesting that they might enhance accumulation of cyanidin 3-O-glucoside which is their downstream metabolite, and contributed the red formation of A. mandshuricum leaves. Additionally, most TFs (e.g., MYBs, bZIPs and bHLHs) were detected differentially expressed in three leaf color stages that could participate in anthocyanin accumulation. This study sheds light on the anthocyanin molecular regulation of anthocyanidin biosynthesis and accumulation underlying the different leaf color change periods in A. mandshuricum, and it could provide basic theory and new insight for the leaf color related genetic improvement of A. mandshuricum.