Chronic inflammation is central to the pathogenesis of autoimmune disorders, metabolic syndromes, and cancers. Current therapeutic strategies include nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, and Janus kinase (JAK) inhibitors. However, these treatments can have broad downstream effects and may not adequately address parallel compensatory mechanisms that contribute to chronic inflammation. Dual-drug strategies offer the potential to improve therapeutic efficacy by simultaneously modulating complementary inflammatory pathways. However, their successful clinical translation requires careful evaluation of both safety and efficacy. Here, we discuss representative strategies spanning the translational spectrum, from mechanistic proof-of-concept studies to clinically evaluated and approved therapies, highlighting the opportunities and limitations of dual-drug approaches. We also examine emerging candidates with clinical potential and identify key challenges that must be addressed to facilitate their broader therapeutic application.

Adipogenin (Adig) is a lipid droplet-associated protein that promotes lipid droplet growth. CCAAT/enhancer-binding protein α (C/EBPα) is a transcription factor enriched in white adipose tissue and liver and is a key regulator of hepatic gene expression. In this study, we investigated the molecular mechanism by which C/EBPα regulates Adig gene expression in the liver of type 2 diabetic model (ob/ob) mice. Although hepatic C/EBPα expression levels were comparable between control and ob/ob mice, both Adig mRNA levels and the putative ADIG signal were significantly elevated in the fatty liver of ob/ob mice. This induction of Adig was markedly repressed by liver-specific C/EBPα deficiency. Analysis of publicly available chromatin immunoprecipitation sequencing (ChIP-seq) data revealed a C/EBPα-binding peak within the Adig promoter region in the mouse liver. Within this peak, we identified a putative C/EBP response element (Adig-CEBPRE, located at positions -87 to -79) that was relatively well conserved across multiple species, suggesting an evolutionarily conserved role of C/EBPα in Adig regulation. Reporter assays demonstrated that luciferase activity driven by Adig-CEBPRE was significantly induced by either C/EBPα or C/EBPβ, whereas this induction was abolished upon deletion of Adig-CEBPRE. Collectively, these findings indicate that Adig is a novel C/EBPα target gene in the steatotic liver of ob/ob mice, providing a mechanistic link between hepatic transcriptional regulation and lipid droplet homeostasis.

The vacuolar ATPase (V-ATPase) is essential for lysosomal acidification and autophagy, and its activity is regulated by nutrient-sensitive reversible assembly of its V1 and Vo domains. While mTORC1 is known to inhibit V-ATPase assembly, the precise molecular mechanisms remain incompletely understood. Here, using TurboID-based proximity labeling and quantitative mass spectrometry, we identified the R2TP complex subunits RPAP3 and PIH1D1 as novel autophagy-responsive interactors of the V-ATPase V1A subunit (encoded by ATP6V1A). We found that mTORC1 inhibition disrupts the R2TP-V1A interaction, promoting the relocation of the V1 domain to lysosomes and its assembly with the Vo domain to form active proton pumps. Functionally, knockdown of RPAP3 or PIH1D1 enhanced autophagic flux, increased lysosomal proteolytic activity, and promoted the clearance of soluble α-synuclein in a cellular model of Parkinson's disease (PD). Our study reveals the R2TP complex as a critical molecular switch that couples mTORC1 signaling to V-ATPase assembly and lysosomal function, thereby identifying a new pathway for regulating lysosomal catabolism with significant therapeutic potential for neurodegenerative disorders.

Kenny-Caffey syndrome type II (KCS2) is a rare genetic disorder characterized by skeletal abnormalities, impaired growth, and developmental delay. This study investigates a novel heterozygous FAM111A variant's role in a patient presenting with KCS2-like features. An 11-year-old patient with clinical features consistent with KCS2-like syndrome underwent whole exome sequencing, which identified a novel heterozygous variant in the FAM111A gene. In vitro experiments and protein structure analysis were performed to elucidate the contribution of this mutation to KCS2-like syndrome. To confirm the diagnosis, whole exome sequencing revealed a novel heterozygous variant (c.405delA/p.E136Sfs*3) in the FAM111A gene in an 11-year-old patient. Additionally, we found the clinical features of this patient were consistent with KCS2-like syndrome. Our in vitro studies revealed that the variant led to a significant increase in necroptosis of osteoclasts. Furthermore, variant osteoclasts displayed a significant down-regulation of autophagy, which may contribute to the onset of KCS2-like syndrome. Consequently, the augmented necroptosis may result in the up-regulation of inflammatory cytokines such as IL-1β, IL-17, IL-12p70, MCP-1, IFN-γ and TNF-α. Protein structure analysis suggests that the truncated FAM111A (p.E136Sfs*3) retains an ubiquitin-like domain, which might explain the up-regulated ubiquitination in variant osteoclasts. Therefore, the enhanced ubiquitination in variant osteoclasts may lead to the excessive degradation of intracellular proteins, resulting in irreversible necroptosis. Our findings suggest that the novel variant FAM111A (c.405delA) may be a pathogenic factor in KCS2-like syndrome, likely through mechanisms involving increased necroptosis and inflammation. This expands understanding of FAM111A variant's role in skeletal and immune dysregulation.

Chronic stress (CS) acts as both an initiating and aggravating factor for depression and osteoporosis. Cumulative evidence indicates that Cathepsin K (Cat K), a cysteine protease, is functionally linked to chronic stress and exerts critical regulatory roles in bone metabolism. Nevertheless, the molecular mechanisms whereby CS promotes osteoporosis in the background of mood-related disturbances remain poorly defined. In the present work, we established a combined mouse model of osteoporosis and chronic stress. We evaluated anxiety- and depression-like behaviors, the expression profiles of Cat K, autophagy-, apoptosis-, and inflammation-associated proteins in bone tissue, as well as vascular senescence in experimental animals. Furthermore, we investigated the biological effects of serum collected from chronically-stressed mice on MC3T3-E1 osteoblast-like cells. Following 8-week chronic stress exposure, ovariectomized (OVX) mice developed prominent anxiety- and depression-like behaviors, accompanied by deteriorated osteoporosis and aortic senescence. Meanwhile, bone tissues exhibited elevated levels of Cat K, p62, pro-inflammatory mediators, and apoptosis-related proteins, whereas the autophagy marker LC3B/A was down-regulated. Administration of E64d, a cysteine protease inhibitor, markedly reversed these pathological alterations. In vitro culture revealed that serum from chronically-stressed mice suppressed the viability of MC3T3-E1 osteoblast-like cells. Pharmacological inhibition of Cat K restored autophagic activity, mitigated the overexpression of pro-inflammatory and pro-apoptotic mediators, and rescued MC3T3-E1 cells from stress-triggered injury. Collectively, our findings demonstrate that chronic stress induces anxiety- and depression-like phenotypes in OVX mice and accelerates bone loss, at least partially via Cat K activation and autophagy suppression.

Chondrocyte senescence is a central driver of osteoarthritis (OA) pathogenesis. While bone marrow mesenchymal stem cell-derived exosomes (BMSCs-Exos) exhibit therapeutic potential, their key functional components remain unclear. We therefore investigated whether Exportin-7 (XPO7), a protein enriched in BMSCs-Exos, alleviates OA by ameliorating chondrocyte senescence-associated changes and explores the underlying mechanism. Using an IL-1β-induced in vitro OA model in rat chondrocytes, we treated cells with exosomes from BMSCs with modulated XPO7 overexpression or knockdown; KDM2B was overexpressed in chondrocytes. Senescence, apoptosis, viability, senescence-associated secretory phenotype (SASP) markers, and extracellular matrix (ECM) metabolism were evaluated. We found that BMSCs-Exos significantly mitigated IL-1β-induced chondrocyte senescence-like changes, apoptosis, SASP (p16, p21, p53, IL-1β, IL-6, TNF-α), and ECM degradation, as evidenced by the reversal of IL-1β-induced suppression of anabolic genes SOX9, COL2, ACAN and elevated catabolic gene MMP13. These protective effects were enhanced by XPO7 overexpression and diminished by its knockdown. Co-immunoprecipitation and immunofluorescence further showed that XPO7 physically interacted with and negatively regulated the histone demethylase KDM2B, and overexpressing KDM2B abolished the protective effects of XPO7-enriched exosomes. In an in vivo rat OA model induced by anterior cruciate ligament transection (ACLT), systemic administration of BMSCs-Exos overexpressing XPO7 attenuated cartilage destruction and improved mechanical allodynia (increased paw withdrawal threshold). These therapeutic benefits were significantly reversed by concurrent intra-articular injection with a KDM2B overexpressing plasmid. Collectively, BMSCs-Exos deliver XPO7, which negatively regulates KDM2B to attenuate chondrocyte senescence-associated phenotypes and OA progression. The XPO7-KDM2B axis may represent a promising therapeutic target for OA intervention.

Cellular senescence is a complex biological process characterized by irreversible cell-cycle arrest and acquisition of the senescence-associated secretory phenotype (SASP). Beyond biochemical stress, increasing evidence indicates that mechanical cues from the extracellular microenvironment contribute to the regulation of senescence; however, the molecular mechanisms linking mechanotransduction to senescent phenotypes remain incompletely understood. SERPINE1 (plasminogen activator inhibitor-1, PAI-1) has emerged as a key mechanosensitive effector induced downstream of mechanotransduction signaling pathways. In this review, we discuss SERPINE1 as both a hallmark of cellular senescence and a functional mediator linking mechanotransduction to senescence-associated processes. Once induced, SERPINE1 contributes to cell-cycle arrest and extracellular matrix (ECM) remodeling by inhibiting plasmin-dependent proteolysis. The resulting ECM accumulation and matrix stiffening further enhance integrin-dependent mechanotransduction, promoting further SERPINE1 expression and establishing a self-reinforcing mechanobiological feedback loop. SERPINE1 also contributes to senescence-associated inflammatory signaling, which may further support the maintenance of the senescent phenotype. Together, these findings identify SERPINE1 as a mechanistic link between mechanotransduction, ECM remodeling, and cellular senescence. Pharmacological studies using PAI-1 inhibitors further support the biological importance of this pathway and suggest that SERPINE1 may represent a potential therapeutic target for senescence-associated fibrotic diseases.

Ferroptosis, an iron-dependent form of regulated cell death, is frequently dysregulated in both tumor and immune cells, contributing to tumor progression and limiting the effectiveness of cancer immunotherapy. Defining the molecular mechanisms that govern ferroptosis and its effects within the tumor immune microenvironment is critical for understanding its dual role in cancer biology. While modulation of ferroptosis presents a promising therapeutic strategy, non-specific targeting may also impair normal tissues and tumor-infiltrating immune cells. In this context, nanoparticle-based delivery systems offer a potential approach to selectively regulate ferroptosis within tumors. Such strategies may enable precise remodeling of the tumor microenvironment and enhance antitumor immune responses, thereby improving immunotherapy outcomes. This review highlights the regulatory mechanisms linking ferroptosis and the tumor immune microenvironment, provides a critical discussion of recent developments in bionanomaterial-based therapeutic platforms, and outlines the challenges and prospects for clinical application of these platforms for immunotherapy.

Topologically knotted proteins are emerging as functional elements of the proteome rather than structural curiosities. Among the recurring protein knot types, the 31 trefoil, 52 Gordian and 71 septoil knots provide useful models for understanding how topology may reshape catalysis, substrate recognition, folding and mechanical behaviour. This review focuses on two systems in which these links can already be made with unusual clarity: the 31-knotted SPOUT methyltransferase superfamily and the 52-knotted ubiquitin C-terminal hydrolases (UCHs). In SPOUT methyltransferases, the knot defines a compact S-adenosyl-l-methionine (SAM)-binding pocket and enforces the bent cofactor geometry required for efficient methyl transfer. In UCH deubiquitinases, the 52 knot stabilises catalytic architecture, constrains the crossover loop that gates substrate access, and helps explain how mutations, regulatory elements and disease-linked perturbations alter function. Beyond catalysis, knotted topology may also modulate how some proteins respond to force, although the range of mechanostabilities across the knotted proteome is broad and many knotted proteins show moderate resistance to mechanical unfolding. Comparisons between 52-knotted UCH paralogs and the 71-knotted protein Q9PR55 raise the possibility that knot geometry contributes to resilience to withstand vectorial pulling, that is, mechanical unfolding, by a AAA+ protease, ClpXP, alongside local folding stability. In the context of folding mechanisms, knotted proteins are challenging systems in that many populate long-lived intermediates or misthreaded states along parallel or bifurcated folding pathways. Although populated intermediates and slow folding are also well documented in numerous unknotted systems, the question of how knotted topologies contribute to the formation of folding intermediates together with knotting/threading events adds to an extra layer of complexity to the analyses. Together, these examples support a broader view in which topology is not merely descriptive geometry, but a mechanistic variable that links structure, dynamics and biological function.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with multi-system involvement, and its pathogenesis is complex, involving abnormalities of multiple immune cells and molecules. In recent years, the role of the transcription factor Forkhead Box P3 (FOXP3) in SLE has attracted much attention. FOXP3, a crucial indicator of regulatory T cells (Tregs), is essential for maintaining immune tolerance and suppressing excessive immune responses. This review systematically elucidates the multi-tiered regulatory networks that control FOXP3 expression at the transcriptional, epigenetic, and post-translational levels. It further examines the specific phenotypic alterations and molecular mechanisms responsible for the dysregulation of Treg quantity, function, and stability within the SLE milieu, including factors such as interleukin (IL)-2 deficiency, cytokine storms, and epigenetic abnormalities. Building upon this foundation, the article explores a range of emerging therapeutic strategies targeting FOXP3 and Tregs as central elements, highlighting recent advances and clinical translation prospects in low-dose IL-2 therapy, adoptive Treg cell transfer, and epigenetic drug interventions. Ultimately, we propose that the precise modulation and enhancement of Treg function to restore stable immune tolerance in SLE patients constitutes a novel therapeutic paradigm, transitioning from broad immunosuppression toward targeted immune modulation. This strategy holds significant promise for fundamentally improving the therapeutic landscape of this complex autoimmune disorder.

The Warburg effect-induced lactate production in T-cell acute lymphoblastic leukemia (T-ALL) cell proliferation is well established, however, the role of lactate-mediated protein lactylation in this process remains poorly understood. In this study, we demonstrated that inhibiting lactate levels through the lactate dehydrogenase A (LDHA) inhibitor significantly reduced both cell proliferation and protein lactylation levels in T-ALL cells. Lactate deficiency led to a marked decrease in protein lactylation, accompanied by impaired cell proliferation. Meanwhile, lactate deficiency also induced the S‑phase cell cycle arrest and reduced DNA synthesis, which collectively impaired cell proliferation. Mechanistically, we observed that the decreased expression of lactylation in histone H3 at lysine 18 (H3K18lac) reduced the enrichment of this mark on the promoter region of neurotrophic receptor tyrosine kinase 3 (NTRK3), which supported the cell proliferation of T-ALL cells. Moreover, the overexpression of NTRK3 rescued the lactate deficiency-induced proliferation inhibition of T-ALL cells. Furthermore, exogenous lactate supplementation dramatically restored the decreased cell proliferation in T-ALL cells and restored H3K18lac levels. Our findings reveal a novel role of lactate-mediated protein lactylation in regulating T-ALL cell proliferation.

N-glycanase 1 (NGLY1) is involved in intracellular misfolded protein degradation, releasing a de-N-glycosylated protein and a complete N-oligosaccharide. Enzymatic defects in NGLY1 may cause NGLY1-related congenital disorder of deglycosylation (NGLY1-CDDG). NGLY1 patients exhibit cognition and coordination defects, and the regulatory impact of NGLY1 in the organism deserves in-depth investigation. In this study, we established NGLY1-knockdown human foreskin fibroblasts-1 (HFF-1) cells and observed mitochondrial function impairments. We conservatively suggest that NGLY1 has global regulatory roles within cells. The Calnexin/IP3R/VDAC1 axis acts as a communication bridge and represents one mechanism underlying NGLY1-mediated modulation of mitochondrial function. This has significant implications for addressing the clinical disease problems presented by NGLY1-CDDG.