Cellular and Molecular Life Sciences最新文献

The progression of spermatogenesis is under dynamic transcriptional regulation. As a subunit of the transcription-export complex 2 (TREX-2), PCI domain-containing protein 2 (PCID2), participates in RNA processing. However, the physiological functions of PCID2 in spermatogenesis remain poorly understood. Here, we generate germline conditional knockout (Pcid2-SKO) mice using Stra8-Cre, and it is found that Pcid2-SKO mice are infertile, exhibit extensive germ cell apoptosis, impaired spermatogonial differentiation, and failure of meiosis initiation. Single-cell transcriptome analysis reveals developmental arrest at the transition from type A to type B spermatogonia in Pcid2-SKO mice. Gene Set Enrichment Analysis (GSEA) demonstrates a significant decrease in the enrichment of mRNA splicing pathway in Pcid2-SKO germ cells. IP-MS results indicate candidate proteins interacting with PCID2 are significantly enriched in RNA splicing pathway. Co-IP results indicate that PCID2 interacts with SNRPG, hnRNPH1 and SF3B1 to modulate alternative splicing in germ cells. Combining RNA sequencing and PCR identifies four key genes (Prpf3, Nek3, Dvl2, and Slc30a9) as splicing targets of PCID2. Collectively, PCID2 is essential for normal spermatogenesis and male fertility by regulating the alternative splicing (AS) of genes critical for cell cycle progression, spliceosome assembly, and mitochondrial homeostasis. This study provides novel insights into the molecular mechanisms underlying spermatogenesis and highlights the importance of AS in germ cell development.

Neurons have adapted the transport and positioning of mitochondria to fit their extended shape and high energy needs. To sustain mitochondrial function, neurons developed systems that allow local biogenesis and adaption to locally regulate mitochondrial form and function. Likewise, fine-tuned degradative systems are required to protect the neurons from mitochondrial dysfunction. Throughout both domains of mitostasis, the local synthesis of the mitochondrial damage-induced kinase PINK1 emerges as a central player. Along with other nuclear encoded mitochondrial proteins, its mRNA associates with mitochondria to sustain mitochondrial function locally. It also regulates mitochondrial degradation, via regulation of proteases, the generation of mitochondria-derived vesicles and mitophagy. In this review, we provide a general overview of the mechanisms governing mitochondrial health in neurons, with a special focus on the role of PINK1 in this endeavor.

Human cytomegalovirus (HCMV) is the leading viral cause of congenital defects. The triggers of viral neuropathogenesis during congenital infection (cCMV) are still unclear, and treatment options are limited. We used both a two-dimensional model of dynamic neurogenesis and cerebral organoids (COs), recapitulating the developing brain in the first trimester of gestation, to investigate the neuropathogenesis induced by HCMV. We also evaluated antiviral and neuroprotective effects of different compounds, both approved, direct-acting drugs and investigational, host-directed antivirals. In differentiating neurons, treatment with direct-acting antivirals blocked HCMV active replication and provided some protection from virus-induced defects. COs exposed to two different strains of HCMV showed viral spread throughout the organoids, dysregulation of key players of neurogenesis, alteration of the tissue cytoarchitecture, and triggering of innate antiviral and pro-inflammatory responses. Inter-strain differences in virus release and growth attenuation were detected in infected COs. Regardless of the strain, treatment with direct-acting antivirals, particularly letermovir, completely abolished HCMV replication, protected COs from virus-induced disorganization of tissue architecture, and dampened innate immune and pro-inflammatory response activation. Importantly, we also demonstrated the efficacy of the antiviral treatment in HCMV-infected COs in blocking an already established infection. This study contributes to shed light on HCMV-induced neuropathogenesis that occurs during congenital infection. Importantly, we demonstrated the neuroprotective effects of letermovir in models of human developing brain, holding promise for its evaluation as a candidate therapeutic agent to ameliorate cCMV-associated neurodevelopmental defects.

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide and accounts for 2% of cancer-related deaths. Although the oncogenic role of HOXC6 in solid tumors is known, its functional relevance in HNSCC remains elusive. Using The Cancer Genome Atlas (TCGA, with 520 HNSCC samples) data and in vitro models, we investigated the functional role of HOXC6 in HNSCC. TCGA analysis revealed that HOXC6 overexpression in HNSCC tissues correlated with malignant progression and poor survival outcomes. In vitro studies confirmed HOXC6 overexpression in HNSCC cell lines, and knockdown of HOXC6 significantly reduced both cell proliferation and migration, highlighting the oncogenic role of HOXC6. Additionally, pathway analysis of RNA-seq data linked HOXC6 expression with immune evasion and dysregulation of cell cycle genes, particularly the E2F and G2M checkpoints. Furthermore, H3K27ac ChIP-seq data showed that histone acetylation at the HOXC6 promoter drives HOXC6 overexpression. This study identified HOXC6 as a key oncogenic driver in HNSCC and as a candidate biomarker for HNSCC. Targeting HOXC6 could pave the way for improved biomarker-driven approaches in HNSCC treatment to reduce recurrence and improve patient survival rates.

Sarcomas comprise over 100 mesenchymal malignancies characterised by extreme genomic heterogeneity, ranging from fusion-driven paediatric tumours to highly unstable adult leiomyosarcomas. This genetic complexity shapes tumour behaviour, influences growth and metastasis, and determines how patients respond to therapy. Accurate animal models must reflect not only the molecular characteristics of these tumours, but also their microenvironment and dynamic interaction with the host immune system. The diversity of this group of cancers presents different challenges for animal model selection, particularly as sarcoma-specific resources are very limited. Therefore, we have reviewed in detail several types of models, including: syngeneic (e.g., MCA205 and KRIMS series), chemically induced (e.g., MCA, DMBA), cell-derived xenografts (CDX; e.g., KCS8 and KCS9 osteosarcoma lines), patient-derived xenograft (PDX; e.g., pleomorphic leiomyosarcoma and GIST models), including humanised PDX (huPDX; e.g. HuNOG-EXL), and zebrafish (e.g. tp53M214K PNST and EWS-FLI1 transgenics) - to illustrate their sarcoma-specific use cases and discuss their advantages and limitations. Genetically engineered models and their development are not a subject of this review, as they represent a very broad subject independently and are discussed elsewhere.

Background: Triple-negative breast cancer (TNBC) is a highly invasive and refractory subtype of breast cancer. Despite the promise of immune checkpoint blockade (ICB) therapy, response rates remain limited. The immune resistance driven by the tumor microenvironment has not yet been understood entirely, which hinders the personalized precision treatment of TNBC.

Methods: We integrated single-cell RNA data from 12 cohorts with TNBC and performed a multi-omics analysis combining spatial transcriptomics (ST), bulk RNA sequencing, and multiplex immunofluorescence (mIF) staining to identify immune-resistant subpopulations. Cell-to-cell communication was explored based on NicheNet and CellChat, and the function of CAF was verified by gene knockdown and overexpression in human mammary fibroblasts, followed by co-culture experiments with TNBC cell lines. ST and mIF data were used to analyze and verify cellular co-localization, while deconvolution was used to examine the relationship between two-cell characteristics and immunotherapy or antibody-drug conjugates (ADC) agent benefit.

Results: We identified CA9+cancer-associated fibroblasts (CA9+CAF) as a key subset enriched in non-responders to ICB that promotes immune resistance by establishing a hypoxic and immunosuppressive microenvironment via abnormal angiogenesis and glycolysis. ST and mIF analyses revealed a strong co-localization and interaction between CA9+CAF and SPP1+tumor-associated macrophages (SPP1+TAM), forming a stroma-myeloid axis that promotes immune escape through VEGFA/NRP2 axis in co-localization core region compared to the boundary. In vitro experiments demonstrated that the over-expression of CA9 in fibroblasts enhanced the proliferation, invasion, and migration of TNBC cells, while CA9 knockdown inhibited the tumorigenic effects. The high CA9+CAF/SPP1+TAM profile indicated a poor prognosis, reduced effector T cell infiltration, and attenuated response to immunotherapy, may benefit from TROP2, MUC1, and NECTIN4-based ADC agents. The result was validated in TNBC samples treated with neoadjuvant immunotherapy from our center.

Conclusion: This study unveils the critical immunosuppressive axis orchestrated by CA9+CAF and SPP1+TAM in TNBC, offering novel insights into the stromal regulatory mechanisms driving immune resistance. The cell-to-cell interaction signature holds promise as predictor of immunotherapy response and potential therapeutic target.

Background and objectives: The liver continuously adjusts its metabolic activity to synchronize the nutrient supply with the body's demands. This synchronization involves the complex coordination of acute metabolic needs, nutrient availability, and activity levels, which is orchestrated according to cyclic internal rhythms governed by the circadian clock. This study aimed to decipher the role of circadian rhythms in liver metabolic functions, including mitochondrial activities that are critical for energy production and metabolic adaptation.

Methods: We investigated rhythmic changes in liver metabolism via comprehensive multiomics and kinetic mathematical modeling. The liver proteome of male mice was analyzed and modeled, and complementary serum lipidomic and metabolomic analyses were performed. Mitochondrial proteins were examined to evaluate the role of mitochondria in the oscillating regulation of energy production.

Results: Most metabolic functions, particularly those related to carbohydrate and fatty acid metabolism, exhibit rhythmic patterns on a 12-hour rather than a 24-hour cycle. The importance of this rhythmicity is function-dependent and can account for 25% to 50% of the overall variability. Mitochondrial activities also exhibit temporal fluctuations that are closely linked to nutrient availability. The strong correlation between metabolic functions and serum metabolites highlights the precise alignment between physiological demand and metabolic performance.

Conclusions: Hepatic metabolic functions follow a 12-hour cycle rather than a 24-hour cycle, significantly contributing to the liver's ability to meet nutrient demands throughout the day. Mitochondrial dynamics, which are influenced by nutrient availability, play a central role in adapting energy production to the body's metabolic needs.

Hepatitis E virus (HEV), a leading cause of acute and chronic viral hepatitis, poses a persistent global health challenge. A deeper mechanistic understanding of virus-host interactions is critical for identifying therapeutic targets to mitigate HEV-associated disease. In this study, we employ a systems biology framework to comprehensively map metabolic and bioenergetic alterations induced by HEV genotypes 1 and 3 in HepG2/C3a-MAVS-KD cells, a robust model of HEV infection, enabling reliable assessment of virus- and host-driven cellular changes. Our analyses reveal extensive remodelling of host metabolism, including reprogramming of the tricarboxylic acid (TCA) cycle, mitochondrial oxidative phosphorylation (OXPHOS), fatty acid metabolism, and β-oxidation-pathways that collectively sustain the energetic and biosynthetic demands of viral infection. HEV infection also reshapes the cellular lipidome, increasing levels of long-chain neutral lipids and lipid droplet abundance, alongside elevated levels of pro-inflammatory oxylipins. Functional metabolic assays demonstrate a reliance on lipid-fuelled OXPHOS rather than glycolysis for efficient HEV infection. These findings uncover critical host metabolic dependencies exploited by HEV and offer a conceptual framework for targeting metabolic hubs as a therapeutic strategy against HEV infection. Author Summary: Viruses are obligate intracellular pathogens that reprogramme host cellular machinery to their advantage. Yet, the extent to which Hepatitis E virus (HEV) infection orchestrates metabolic reprogramming, and the implications of these changes for viral fitness, remain poorly defined. By integrating large-scale proteomics with lipid metabolic profiling, we delineate molecular strategies through which HEV subverts host lipid metabolism and mitochondrial function. Our findings provide mechanistic insight into how HEV infection modulates host metabolic pathways to its advantage, highlighting potential targets for therapeutic intervention.

Parkinson's disease (PD) is characterized by progressive neurodegeneration closely linked to neuroinflammation and oxidative stress-induced damage and is characterized by the loss of dopaminergic (DAergic) neurons and the inflammatory response associated with glial cells. RRx-001 (RRx, 2-bromo-1-(3,3-dinitroazetidin-1-yl)ethanone) is a small-molecule immunoregulator. Recent studies have shown that it strongly inhibits NLRP3 (NOD-like receptor family pyrin domain containing 3) inflammasome activation, which is crucial for influencing neuroinflammation. However, the mechanism underlying the effect of RRx on PD remains unclear. In this study, we explored the potential effects of RRX on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mice, detected the transcriptome and metabolome of the substantia nigra, and performed 16 S microbial diversity sequencing and metabolomics of the intestinal tract. Our study revealed that RRx obviously relieves MPTP-induced DAergic neuronal loss and motor disorders. Mechanistically, RRx reversed the upregulated expression of lipocalin-2 (LCN2) and NLRP3 inflammasome activation in a PD model. Crucially, its protective effects on DAergic neurons involved improving LCN2-NLRP3 inflammasome activation-mediated astrocyte pyroptosis. RRx also reduced the levels of metabolites and signalling pathways associated with oxidative stress and PD in the substantia nigra. Furthermore, the 16 S rDNA analysis and metabolomic analysis of faecal pellets revealed that the intestinal tract of the RRx-treated PD mice presented a greater abundance of Deferribacterota at the phylum level than that of the PD model mice, and the gut microbiota metabolites and pathways were altered. Overall, the results of this study indicate that RRx has multiple effects on PD.

Naïve human pluripotent stem cells (hPSCs) represent an in vitro analog of the pre-implantation epiblast - the founder tissue of the embryo proper. A widely held assumption, based on prior studies in the mouse system, was that naïve hPSCs are restricted in their differentiation potential toward more mature stages of epiblast development, as a prelude to gastrulation. However, over the past 5 years, a growing body of literature has demonstrated that naïve hPSCs have an expanded lineage potential toward a broad range of embryonic and extraembryonic fates and can even be used as a starting point for generating 8-cell-like cells. The most emphatic demonstration of the broad lineage potential of naïve hPSCs is their remarkable capacity to self-organize into blastocyst-like structures ("blastoids") that model all three lineages of the pre-implantation embryo and can be cultured to post-implantation stages. Here, we discuss the broad spectrum of cell fates accessible from naïve hPSCs and the signaling pathways that guide the exit from the ground state of human pluripotency.