Advances in biological regulation最新文献

The presence of inositol lipids in the nucleus has been shown in the late 1980s and since then a considerable amount of interest has been raised about the role of these molecules in an autonomous nuclear signalling system different from that at both the plasma membrane and the cytoplasm. Here we review the main issues of nuclear structure and of nuclear inositol lipids and their related enzymes in cellular signaling, taking into account also the possible role in some human pathologies.

The immune system is central to the prevention and control of cancer, yet tumors evolve multiple strategies to subvert immune surveillance. Checkpoint inhibitors targeting CTLA-4, PD-1, and PD-L1 have revolutionized oncology by demonstrating that therapeutic restoration of T cell activity can yield durable remissions. However, their efficacy remains limited by the profoundly immunosuppressive tumor microenvironment (TME), where regulatory immune cells, suppressive cytokines, and metabolic stressors converge to dampen effector function. As interest in integrative and complementary approaches grows, plant-derived compounds - long used in traditional medicine - have been identified as bioactive agents capable of modulating immune function. This review focuses on three key phytochemicals: piperlongumine, berberine, and epigallocatechin gallate (EGCG). Piperlongumine, a pro-oxidative alkaloid from Piper longum, suppresses T cell activation and promotes regulatory T cell differentiation, suggesting potential for chronic inflammation but raising caution in oncology. Berberine, an isoquinoline alkaloid from Berberis vulgaris, reduces PD-L1 expression via CSN5 inhibition, thereby mimicking checkpoint blockade and enhancing cytotoxic T cell activity in preclinical models. EGCG, the major polyphenol in green tea, downregulates PD-L1 expression and augments anti-tumor immunity in murine melanoma. We critically assess the promise and pitfalls of these compounds in cancer immunotherapy, emphasizing mechanistic insights, pharmacokinetics, translational hurdles, and potential risks of interfering with established therapies. A precision immunology framework - integrating immune monitoring, patient stratification, and controlled clinical trials - will be essential to determine whether phytochemicals can be safely and effectively incorporated into oncology. Far from being benign, plant-derived agents exert potent immune effects that could either complement or compromise modern immunotherapy, underscoring the need for rigorous evaluation.

Nuclear receptors are lipid-regulated transcription factors that respond to the changing metabolic and signaling requirements of animal cells and tissues. Steroidogenic Factor 1 (SF-1, NR5A1) is a nuclear receptor and master regulator of steroidogenic gene expression. SF-1 is required for development and adult function of steroidogenic tissues, hyperactivation of SF-1 associates with adrenocortical carcinoma, while hypomorphic loss-of-function polymorphisms associate with disorders of sexual development. Many of these physiological functions of SF-1 are broadly understood, however the identity of the endogenous regulatory lipid ligands for SF-1 have yet to be well established, preventing progress on therapeutic development for human diseases, such as adrenocortical carcinoma. Several signaling lipids have been put forth as potential regulatory ligands of SF-1, including sphingosine, lyso-sphingomyelin, sphingomyelin, ceramide and several phosphoinositide species including PI(4,5)P2 and PI(3,4,5)P3. Here, we review the evidence linking the ability of these potential phospholipid ligands to regulate SF-1 mediated gene expression in metazoan cells, and discuss how lipid ligands regulate SF-1 from a structural perspective.

Diacylglycerol kinases (DGKs) are key enzymes that integrate lipid metabolism with multiple signaling pathways. DGKs regulate the conversion of diacylglycerol (DAG) into phosphatidic acid (PA), two essential bioactive lipids that promote the activation of distinctive proteins controlling cell growth, proliferation and differentiation. The variety of DGK isoforms enables them to perform specialized functions in different tissues, and dysregulation of DGK activity and expression contributes to diverse pathological conditions. DGKs exert potent inhibitory functions in T cells and are aberrantly expressed in a wide range of cancer types, which make DGKs attractive therapeutic targets for cancer immunotherapy. In recent years, the development of novel and highly isoform-specific inhibitors has opened exciting opportunities to further explore the fundamental functions of lipid metabolism in the maintenance of immune cell homeostasis and in the progression of several diseases. Besides T cells, DGKs play important roles in regulating inflammatory processes across distinct immune populations. The therapeutic potential of these drugs has been translated in several ongoing clinical trials. Therefore, it is crucial to delineate DGK-controlled signaling hubs to better understand their impact on immune signatures. In this work, we aimed to recapitulate the effects of modulating DAG/PA balance on immune cells that are relevant in the tumor microenvironment. By dissecting how DGK-mediated lipid signaling shapes immune cell behavior in the tumor microenvironment, we seek to provide mechanistic insights that may guide the rational use of drugs targeting DGKs to improve antitumor immunity.

Esophageal squamous cell carcinoma (eSCC) is an aggressive malignancy with poor prognosis and limited therapeutic options. The phosphoinositide 3-kinase (PI3K)/AKT pathway is frequently activated in eSCC, but clinical use of PI3K or AKT inhibitors is restricted by toxicity and compensatory signaling. SHIP2, an inositol 5-phosphatase encoded by INPPL1, modulates this pathway by converting PI(3,4,5)P₃ to PI(3,4)P₂, thereby regulating AKT activation. We previously identified INPPL1 amplification as recurrent in eSCC and demonstrated that SHIP2 inhibition suppresses tumor growth and synergizes with PLK1 inhibition. Here, we extend these findings and show that SHIP2-PLK1 synergy is not confined to eSCC but is also observed in multiple colorectal cancer cell lines, revealing a conserved vulnerability across tumor types. Mechanistic analyses demonstrate that this synergy depends on PI3K/AKT signaling, with SHIP2 inhibition producing stronger effects than direct PI3K blockade, suggesting additional regulatory functions beyond canonical PI3K control. Furthermore, SHIP2 inhibition enhances the cytotoxic activity of standard chemotherapies, including 5-fluorouracil and paclitaxel, in eSCC cells. Importantly, these effects occur at sub-cytotoxic drug concentrations, indicating potential therapeutic benefit with reduced toxicity. Collectively, our results identify SHIP2 as a central regulator of the PI3K/AKT axis in eSCC and colorectal cancer and highlight its value as a combinatorial target. SHIP2 inhibition represents a promising strategy to potentiate existing chemotherapies and targeted agents, opening new avenues for the treatment of refractory gastrointestinal cancers.

Class IA phosophoinositide kinases (PI3Ks) are master regulators of growth, metabolism, and immunity. The class IA PI3Ks are a heterodimer composed of a p110 catalytic subunit and one of five possible regulatory subunits (p85α, p85β, p55γ, p55α, p50α). The regulatory subunit plays critical roles in stability, inhibition, and activation of the p110 catalytic subunit. The p110α catalytic subunit frequently contains activating mutations in human cancer, with many of these mutations altering the interaction between catalytic and regulatory subunits. It has been found that different regulatory subunits play unique roles in human disease, but it is unknown how these different subunits regulate p110α. Here, using a synergy of biochemical assays and hydrogen deuterium exchange mass spectrometry (HDX-MS) we examined how the five different regulatory subunits inhibit, activate, and interact with the p110α catalytic subunit. We find that there are no significant differences in lipid kinase activity or in membrane recruitment between the different heterodimer complexes. HDX-MS in the presence and absence of an activating phosphopeptide also showed only minor conformational differences between different regulatory subunit complexes. Overall, our work reveals that the different regulatory subunits interact with and inhibit p110α in a similar fashion at a molecular level.

The unfolded protein response (UPR) is a central regulator of proteostasis, coordinating cellular adaptation to endoplasmic reticulum (ER) stress. It is comprised of three signaling branches: ATF6 (activating transcription factor 6), IRE1 (inositol-requiring enzyme 1), and PERK (protein kinase RNA-like ER kinase), which mediate transcriptional and translational reprogramming of the proteostasis network. These pathways display both functional redundancy and branch-specific activities. Dysregulated UPR signaling contributes to diverse pathologies: in cancer, UPR activation supports uncontrolled proliferation and treatment resistance, whereas in aging, proteostasis decline and diminished UPR responsiveness are hallmarks. Traditional approaches, including transcriptomics and western blotting, have been widely used to monitor UPR activity, but they offer limited insight into its regulation at the protein level. In contrast, liquid chromatography-tandem mass spectrometry (LC-MS/MS) based proteomics allows comprehensive, branch-specific profiling of UPR signaling. Recent advances, including data-independent acquisition (DIA) MS and automated sample preparation, have further improved sensitivity, reproducibility, and detection of low-abundance UPR target proteins. Proteomics thus provides a systematic and scalable framework to interrogate UPR regulation across cell types and disease models. When integrated with complementary datasets, protein-level measurements can uncover context-dependent molecular signatures of UPR activity, offering insights into disease mechanisms and guiding the rational design of targeted pharmacological interventions. Future work integrating high-resolution LC-MS/MS proteomics with tissue and single-cell analyses will further clarify the role of the UPR in health and disease.

Tepsin is an accessory protein in Adaptor Protein 4 (AP-4) coated vesicles responsible for trafficking cargo from the trans-Golgi network (TGN). AP-4 vesicles recognize and sort multiple cargoes including ATG9A, a lipid scramblase essential for autophagosome maturation. In cultured cells, tepsin loss alters ATG9A distribution and autophagosome morphology, and tepsin has been shown to contain a canonical LC3-interacting region (LIR) motif required for proper ATG9A distribution. Computational modeling in AlphaFold Multimer combined with biochemical and biophysical experiments identified three additional LC3B binding motifs within tepsin disordered regions. Structural models paired with bio-layer interferometry (BLI) uncovered and confirmed specific residues involved in each interaction and indicated all four motifs independently engage the LC3B LIR docking site (LDS). Thermodynamic and kinetic properties associated with each motif found in full-length tepsin were quantified. BLI and biochemical data reveal all four motifs in tepsin must be mutated to abrogate binding to LC3B in vitro, while stoichiometry data estimate one tepsin likely binds two LC3B at one time on a surface or membrane. Together, data suggest tepsin could respond dynamically to LC3B concentrations on membranes by leveraging multivalency to modulate binding strength.

Phosphatidic acid (PA) has emerged as a central regulator of membrane dynamics, vesicle trafficking, exocytosis, and intracellular signaling. Building on recent advances, including subspecies-specific functions of PA in neuroendocrine exocytosis, the primacy of PLD1-derived PA in vivo, and the development of natural-mimetic PA analogues, this review integrates biochemical, biophysical, and systems-level insights across eukaryotes. We contextualize the role of PA in vesicular trafficking, delineate how acyl-chain composition encodes molecular specificity, summarize enzymatic sources and sinks sculpting spatiotemporal control of PA pools within cells, and examine emerging tools used for measuring and disturbing PA in living cells to unravel its function. Given the pleiotropic roles of PA among numerous experimental contexts such as the nervous, endocrine, immune, and metabolic systems, mapping mechanistic connections to disease through mTOR and RAF/MEK/ERK signaling, autophagy, and organelle contact-site biology. Finally, we outline future directions spanning single-cell lipidomics, imaging mass spectrometry, and therapeutic lipid engineering. Together, available evidence positions PA as a conserved, tunable molecular switch that coordinates membrane mechanics with signal transduction to enable realisation of a wide range of function within cells.