Biology subjects

li, l.

Publications and source records attributed to li, l..

9 recordsLinked to original sources

bioRxiv2026

β-Catenin Drives Apical-Basal Polarization to facilitate TE lineage commitment In Vitro and In Vivo

Embryo polarization is critical for the first cell fate segregation. While mechanisms underlying its initiation have been described, the intrinsic signaling pathways that regulate this process remain poorly understood. Here, we show that mouse embryonic stem cells, when aggregated under defined conditions, recapitulate the first lineage segregation to generate trophectoderm (TE)-like cell populations and undergo self-organized morphogenesis into blastocyst-like structures. In the blastoid-forming medium, we identify CHIR99021 is essential for the generation of blastoids from both ESCs and totipotent-like cells. CHIR99021 promotes cell polarization and TE differentiation by activating the WNT/{beta}-catenin pathway and upregulating associated genes. Consistent with this, genetic ablation of {beta}-catenin abolished the cell polarization and disrupted blastoid formation from ESCs, a defect that was restored by {beta}-catenin overexpression. Moreover, {beta}-catenin depletion compromised cell polarization in natural embryos. Collectively, this study establishes the Wnt/{beta}-catenin as a critical regulator initiating polarization in vitro and in mouse early embryo development.

developmental biology↗

bioRxiv2026

Lesion-Level-Dependent Neuroendocrine Surge Precedes Neuroinflammation and Endoplasmic Reticulum Stress in the Hypothalamus After Spinal Cord Injury: Dual-Cohort Transcriptomic Evidence for a Temporally Ordered AVP Cascade

BackgroundSpinal cord injury (SCI) triggers remote pathological changes in supraspinal regions, including neuroendocrine dysfunction that manifests clinically as hyponatremia and central diabetes insipidus. Clinical observations of lesion-level dependency and sequential transformation between these disorders suggest a temporally ordered hypothalamic cascade in which a compensatory arginine vasopressin (AVP)-driven neuroendocrine surge may precede a later neuroinflammation and endoplasmic reticulum (ER) stress-mediated neuronal exhaustion. Direct transcriptomic evidence for the temporal ordering of these events, however, has been lacking. MethodsWe performed a dual-cohort transcriptomic analysis. A discovery cohort (NCBI Sequence Read Archive PRJNA953752) comprised hypothalamic tissue from adult male Sprague-Dawley rats subjected to high-thoracic (T3) SCI, low-thoracic (T10) SCI, or sham surgery, sampled at post-injury day 7 and analyzed with edgeR/DESeq2 (|log2FC| > 1, Padj < 0.05). An independent chronic-phase validation cohort (Gene Expression Omnibus GSE297887) of hippocampal tissue from SCI and sham mice was interrogated as a sensitive supraspinal proxy for remote neuroinflammatory and ER-stress signatures. Pre-defined gene panels covered neuroendocrine, neuroinflammation, and ER-stress/unfolded-protein-response categories. ResultsIn the discovery cohort, high-thoracic SCI produced a lesion-level-dependent neuroendocrine surge in the hypothalamus: Avp (fold change 7.23; Padj = 0.002), Oxt (fold change 14.25; Padj = 2.3 x 10-7), and Ucn3 (fold change 9.22; Padj = 0.002) were among the most significantly upregulated genes genome-wide, whereas low-thoracic SCI failed to reach significance for any of these targets. Classical neuroinflammation markers and canonical ER-stress effectors remained transcriptionally silent (all Padj > 0.69). The PERK-pathway sentinel genes Trib3 and Ppp1r15a/GADD34 exhibited coordinated sub-threshold trends indicative of early activation, and Avp expression was tightly correlated with Mmp9 (r = 0.833; P = 0.0004). In the chronic-phase validation cohort, microglial P2ry12 and ferroptosis signatures were significantly upregulated (P2ry12 fold change 1.33; P = 0.008) suggesting a primed microglial state, while ER-stress effectors remained silent. ConclusionsThese data support a temporally ordered hypothalamic cascade after SCI in which an early compensatory neuroendocrine surge precedes -- and may precipitate, through biosynthetic overload and blood-brain-barrier disruption -- a subsequent neuroinflammation and ER-stress crisis. The defined molecular window between neuroendocrine activation and inflammatory/ER-stress engagement identifies a candidate therapeutic window for early neuroprotective intervention in acute SCI.

neuroscience↗

bioRxiv2025

Lactobacillus acidophilus Attenuates Polyethylene Glycol-Induced Susceptibility to Citrobacter rodentium Infection via Microbiota Modulation

ObjectivePolyethylene glycol (PEG), a globally prevalent laxative, is extensively utilized for bowel preparation prior to colonoscopy or abdominal surgery owing to its exceptional safety profile. Nevertheless, emerging evidence suggests that PEG administration may induce significant alterations in colonic microbiota composition, with dysbiotic effects persisting for over two weeks. The potential implications of such microbiota perturbations on the colonization and invasion of opportunistic pathogens remain underexplored. Methods and AnalysisTo investigate this, we employed a murine model infected with Citrobacter rodentium (C.R.), a surrogate for Enteropathogenic Escherichia coli (EPEC) and Enterohemorrhagic Escherichia coli (EHEC), following PEG-induced bowel preparation. ResultsThe severity of infectious enteritis was assessed, and the prophylactic efficacy of Lactobacillus acidophilus (LAC) supplementation was evaluated. Our findings indicate that PEG administration significantly elevated C.R. load, enhanced virulence gene expression, and exacerbated intestinal inflammation post-infection, with the infection window extending approximately 14 days. Through fecal metagenomic analysis and co-housing experiments, we demonstrated that PEG-associated enteritis is critically mediated by gut microbiota dysbiosis. Furthermore, supplementation with LAC was shown to mitigate susceptibility to C.R. infection. ConclusionsThese results suggest that PEG increases intestinal susceptibility to infection in a microbiota-dependent manner, highlighting the therapeutic potential of LAC in restoring microbial homeostasis.

microbiology↗

bioRxiv2024

BGMDB: A curated database linking gut microbiota dysbiosis to brain disorders

The gut microbiota plays a pivotal role in human health by modulating physiological homeostasis and influencing the pathogenesis of various diseases. Recent studies have underscored the close relationship between neurotransmitters, which act as communication mediators between the gut and brain, and the development and treatment of multiple brain disorders. Despite these advances, the intricate interactions between gut microbiota and brain diseases remain largely unexplored in the extensive biomedical literature. There is a notable absence of a structured database focusing on gut microbiota-brain disease associations. Introducing BGMDB (Brain Disease Gut Microbiota Database), a meticulously curated database designed to provide experimentally supported connections between gut microbiota and brain diseases. The current version of BGMDB extensively covers 1,419 associations involving 609 gut microbiota and 43 brain diseases, including 184 specific association triplets linking brain diseases, neurotransmitters, and gut microbiota among six neurotransmitters. Noteworthy is that BGMDB integrates gene data related to gut microbiota from the gutMGene database. Brain region and disease microbial networks are introduced to investigate potential common genetic relationships between brain diseases and brain region changes. Each entry in BGMDB offers detailed insights into specific associations, including the particular brain disease implicated, the involved gut microbiota, neurotransmitter, and a concise description of the relationship supported by relevant literature references. To facilitate easier access to relevant information for specific brain diseases, BGMDB provides enhanced graphical query options to address various biologically pertinent inquiries. Additionally, a user-friendly interface allows users to browse, retrieve, and download entries conveniently. BGMDB serves as a valuable resource for investigating microbes associated with human brain disorders. Access BGMDB through http://43.139.38.118:8080/demo02/.

bioinformatics↗

bioRxiv2020

Urine metabolomics of rats with chronic atrophic gastritis

Background/Aim: To use liquid chromatography-mass spectrometry (LC-MS) to identify endogenous differential metabolites in the urine of rats with chronic atrophic gastritis (CAG). Materials and Methods: Methylnitronitrosoguanidine (MNNG) was used to produce a CAG model in Wistar rats, and HE staining was used to determine the pathological model. LC-MS was used to detect the differential metabolic profiles in rat urine. Diversified analysis was performed by the statistical method. Results: Compared with the control group, the model group had 68 differential metabolites, 25 that were upregulated and 43 that were downregulated. The main metabolic pathways were D-glutamine and D-glutamic acid metabolism, histidine metabolism and purine metabolism. Conclusion: By searching for differential metabolites and metabolic pathways in the urine of CAG rats, this study provides effective experimental data for the pathogenesis and clinical diagnosis of CAG.View Full Text

molecular biology↗

bioRxiv2020

Selective Germline Genome Edited Pig Meninges Grafts for the Abdominal Wall Closure in Damage Control Surgery

Reconstruction of abdominal wall defects is still a big challenge in surgery, especially where there is insufficient fascia muscular or excessive tension of the defects in emergency and life-threatening scenarios. Indeed, the concept of damage control surgery has been advanced in the management of both traumatic and nontraumatic surgical settings. The strategy requires abridged surgery and quick back to intensive care units (ICU) for aggressive resuscitation. In the damage control laparotomy, patients are left with open abdomen or provisional closure of the abdomen with a planned return to the operating room for definitive surgery. So far, various techniques have been utilized to achieve early temporary abdominal closure, but there is no clear consensus on the ideal method or material for abdominal wall reconstruction. We recently successfully created the selective germline genome-edited pig (SGGEP) and here we aimed to explore the feasibility of in vivo reconstruction of the abdominal wall in a rabbit model with SGGEP meninges grafts (SGGEP-MGs). Our result showed that the SGGEP-MGs could restore the integrity of the defect very well. After 7 weeks of engraftment, there was no sign of herniation observed, the grafts were re-vascularized, and the defects were well repaired. Histologically, the boundary between the graft and the host was very well integrated and there was no strong inflammatory response. Therefore, this kind of closure could help restore the fluid and electrolyte balance and to dampen systemic inflammatory response in damge control surgery while ADM graft failed to establish re-vascularization as the same as the SGGEP-MG. It is concluded that the meninges of SGGEP could serve as a high-quality alternative for restoring the integrity of the abdominal wall, especially for damage control surgery.

synthetic biology↗

bioRxiv2019

GNMFLMI: Graph Regularized Nonnegative Matrix Factorization for Predicting LncRNA-MiRNA Interactions

Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been involved in various biological processes. Emerging evidence suggests that the interactions between lncRNAs and miRNAs play an important role in regulating of genes and the development of many diseases. Due to the limited scale of known lncRNA-miRNA interactions, and expensive time and labor costs for identifying them by biological experiments, more accurate and efficient lncRNA-miRNA interactions computational prediction approach urgently need to be developed. In this work, we proposed a novel computational method, GNMFLMI, to predict lncRNA-miRNA interactions using graph regularized nonnegative matrix factorization. More specifically, the similarities both lncRNA and miRNA are calculated based on known interaction information and their sequence information. Then, the affinity graphs for lncRNAs and miRNAs are constructed using the p-nearest neighbors, respectively. Finally, a graph regularized nonnegative matrix factorization model is developed to accurately identify potential interactions between lncRNAs and miRNAs. To evaluate the performance of GNMFLMI, five-fold cross validation experiments are carried out. GNMFLMI achieves the AUC value of 0.9769 which outperforms the compared methods NMF and CNMF. In the case studies for lncRNA nonhsat159254.1 and miRNA hsa-mir-544a, 20 and 16 of the top-20 associations predicted by GNMFLMI are confirmed, respectively. Rigorous experimental results demonstrate that GNMFLMI can effectively predict novel lncRNA-miRNA interactions, which can provide guidance for relevant biomedical research.

bioinformatics↗

bioRxiv2019

Structural basis for EPC1-mediated recruitment of MBTD1 into the NuA4/TIP60 acetyltransferase complex

MBTD1, a H4K20me reader, has recently been identified as a component of the NuA4/TIP60 acetyltransferase complex, regulating gene expression and DNA repair. NuA4/TIP60 inhibits 53BP1 binding to chromatin through recognition of the H4K20me mark by MBTD1 and acetylation of H2AK15, blocking the ubiquitination mark required for 53BP1 localization at DNA breaks. The NuA4/TIP60 non-catalytic subunit EPC1 enlists MBTD1 into the complex, but the detailed molecular mechanism remains incompletely explored. Here, we present the crystal structure of the MBTD1-EPC1 complex, revealing a hydrophobic C-terminal fragment of EPC1 engaging the MBT repeats of MBTD1 in a site distinct from the H4K20me binding site. Different cellular assays validate the physiological significance of the key residues involved in the MBTD1-EPC1 interaction. Our study provides a structural framework for understanding the mechanism by which MBTD1 recruits the NuA4/TIP60 acetyltransferase complex to influence transcription and DNA repair pathway choice.

biochemistry↗

bioRxiv2018

Genomic data provides new insights on the demographic history and the extent of recent material transfers in Norway spruce

Primeval forests are today exceedingly rare in Europe and transfer of forest reproductive material for afforestation and improvement have been very common, especially over the last two centuries. This can be a serious impediment when inferring past population movements in response to past climate changes such as the last glacial maximum (LGM), some 18,000 years ago. In the present study, we genotyped 1,672 individuals from three Picea species (P. abies, P. obovata, and P. omorika) at 400K SNPs using exome capture to infer the past demographic history of Norway spruce and estimate the amount of recent introduction used to establish the Norway spruce breeding program in Southern Sweden. Most of these trees belong to P. abies and originate from the base population of the Swedish breeding program. Others originate from populations across the natural ranges of the three species. Of the 1,499 individuals stemming from the breeding program, a large proportion corresponds to recent introductions. The split of P. omorika occurred 23 million years ago (mya), while the divergence between P. obovata and P. abies began 17.6 mya. Demographic inferences retrieved the same main clusters within P. abies than previous studies, i.e. a vast northern domain ranging from Norway to central Russia, where the species is progressively replaced by Siberian spruce (P. obovata) and two smaller domains, an Alpine domain, and a Carpathian one, but also revealed further subdivision and gene flow among clusters. The three main domains divergence was ancient (15 mya) and all three went through a bottleneck corresponding to the LGM. Approximately 17% of P. abies Nordic domain migrated from P. obovata ~103K years ago, when both species had much larger effective population sizes. Our analysis of genome-wide polymorphism data thus revealed the complex demographic history of Picea genus in Western Europe and highlighted the importance of material transfer in Swedish breeding program.

evolutionary biology↗