Discovery of novel disulfide-containing PD-1/PD-L1 inhibitor with in vivo influenza therapeutic efficacy
Monoclonal antibody-based immune checkpoint inhibitors,which have brought breakthrough effects in cancer treatments,are expected to assist in the treatment of viral diseases. However,antibody therapies may cause immune-related side effects,such as inflammation and pneumonia,due to cytokine storms. Small-molecule PD-1/PD-L1 inhibitors are an alternative to monoclonal antibody-based therapeutics. We have identified a novel small-molecule PD-1/PD-L1 inhibitor having a functional group (disulfide group),namely compound 2 (molecular weight: 456.6),from our library of sulfur-containing protein–protein interaction inhibitor compounds. Compound 2 selectively bound to PD-L1 over PD-1,with the dissociation rate constant (K D ) of 77.60 ± 4.44 nM (obtained by affinity analysis) and showed promising T cell activation recovery. A molecular docking simulation study between 2 and PD-L1 suggested that 2 binds to PD-L1 in a binding mode different from those of other small-molecule PD-L1/PD-1 inhibitors. Notably,oral administration of 2 to mice pre-infected with influenza A virus (A/NWS/33,H1N1 subtype) caused a significant increase in the neutralizing antibody titers,as well as recovery from influenza-induced pneumonia. Overall,2 provides insight for the development of therapeutic drugs against early viral infections,with both virus titer-reducing and antibody titer-boosting effects. Moreover,2 is widely used as a rubber peptizing agent in the production process of tires and other rubber products. Our findings may provide useful information for investigating its influence on living organisms. The online version contains supplementary material available at 10.1038/s41598-025-17982-3. Subject terms: Drug discovery and development,Pharmacology,Screening,Structure-based drug design
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Z. Li et al. (Sep 2025)
Journal of Asthma and Allergy 18 4
Inhibition of LOXL2 Suppresses Nasal Mucosal Inflammation and Remodeling in Allergic Rhinitis
Tissue remodeling is a key feature of allergic rhinitis (AR),but its underlying molecular mechanisms remain unclear. Lysyl oxidase-like 2 (LOXL2),a regulator of tissue remodeling,has not been studied in AR. Proteomic analysis was performed on nasal mucosal tissues from 8 AR patients and 8 healthy controls (HCs) to identify differentially expressed proteins (DEPs). The top three upregulated DEPs and their association with tissue remodeling markers were validated by immunofluorescence,Western blot,and RT-qPCR in an independent cohort of 30 AR patients and 30 HCs. In vitro,human nasal epithelial cells (HNECs) were treated with IL-4,and the effects of candidate protein inhibitors on remodeling were assessed. An AR mouse model was used to evaluate the impact of these inhibitors on nasal inflammation and remodeling. Proteomic analysis revealed a disease-specific protein expression profile in the nasal mucosa of AR patients,with the top three upregulated proteins being LOXL2,TGF-β1,and TIRAP. Tissue validation showed that LOXL2 was significantly upregulated in the nasal mucosa of AR patients compared to HCs and was significantly correlated with EMT markers (TGF-β1,α-SMA,and E-cadherin). In vitro,IL-4 stimulation significantly upregulated LOXL2,TGF-β1,and α-SMA,while downregulating E-cadherin in a dose-dependent manner in human nasal epithelial cells. These effects were reversed by inhibition of LOXL2. Further investigations demonstrated that LOXL2 promotes tissue remodeling through activation of the TGF-β1/Smad signaling pathway. In the AR mouse model,LOXL2 inhibitors significantly reduced nasal mucosal inflammation and tissue remodeling. Our proteomic analysis suggests that LOXL2 may be involved in the pathological remodeling processes of AR,potentially through modulation of the TGF-β1/Smad signaling pathway. These findings provide preliminary evidence that LOXL2 could serve as a candidate biomarker and a possible therapeutic target in AR,warranting further investigation.
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S. Trushin et al. (Sep 2025)
eBioMedicine 120 4
Therapeutic assessment of a novel mitochondrial complex I inhibitor in in vitro and in vivo models of Alzheimer's disease
Despite recent approval of monoclonal antibodies that reduce amyloid (Aβ) accumulation,the development of disease-modifying strategies targeting the underlying mechanisms of Alzheimer's disease (AD) is urgently needed. We demonstrate that mitochondrial complex I (mtCI) represents a druggable target,where its weak inhibition activates neuroprotective signalling,benefiting AD mouse models with Aβ and p-Tau pathologies. Rational design and structure‒activity relationship studies yielded mtCI inhibitors profiled in a drug discovery funnel designed to address safety,selectivity,and efficacy. The lead compound C458 is highly protective against Aβ toxicity,has favourable pharmacokinetics,and minimal off-target effects. C458 exhibited excellent brain penetrance,activating neuroprotective pathways with a single dose. Preclinical studies in APP/PS1 mice were conducted using functional tests,metabolic assessment,in vivo 31 P-NMR spectroscopy,blood cytokine panels,ex vivo electrophysiology,and Western blotting. Chronic oral administration improved long-term potentiation,reduced oxidative stress and inflammation,and enhanced mitochondrial biogenesis,antioxidant signalling,and cellular energetics. Efficacy against Aβ and p-Tau was confirmed in human organoids. These studies provide further evidence that the restoration of mitochondrial function in response to mild energetic stress represents a promising disease-modifying strategy for AD. This research was supported by grants from NIH AG 5549-06,NS1 07265,AG 062135,UG3/UH3 NS 113776,and ADDF 291204 (all to ET); U19 AG069701 (to TK); the Alzheimer’s Association Research Fellowship grant 23AARF-1027342 (to TKON).
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A. Chakraborty et al. (Aug 2025)
International Journal of Molecular Sciences 26 17
Cholesterol is an essential plasma membrane component,and altered cholesterol metabolism has been linked to cholesterol accumulation in the airways of COPD and cystic fibrosis patients. However,its role in airway epithelial differentiation is not well understood. Tandem mass spectrometry-based proteomic analysis of differentiating primary human bronchial epithelial cells (phBECs) revealed an overall inhibition of the cholesterol biosynthesis pathway. We hypothesized that excess cholesterol impairs the differentiation of phBECs into a fully functional bronchial epithelium. PhBECs were differentiated in the presence of 80 µM cholesterol for 21 days,the main airway cell type populations monitored using qRT-PCR and immunofluorescent stainings,and epithelial barrier integrity was analyzed via transepithelial electrical resistance measurements. Chronic cholesterol exposure led to a significant increase in CC10 + secretory cells at the expense of ciliated cells. Pathway enrichment analysis suggested the tumor protein p53 as a master regulator of genes during normal differentiation of phBECs. Chronic cholesterol exposure drastically impaired the nuclear translocation of p53. Our findings suggest that this inhibition underlies the cholesterol-induced expansion of CC10 + secretory cell populations at the expense of ciliated cells. In conclusion,we identify cholesterol as an important regulator of normal bronchial epithelial cell differentiation through inhibition of p53 nuclear translocation.
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W. Yang et al. (Aug 2025)
Cancers 17 17
A Polyomavirus-Positive Merkel Cell Carcinoma Mouse Model Supports a Unified Origin for Somatic and Germ Cell Cancers
Cancer research has long focused on mutations in normal body cells,but this approach has not produced major breakthroughs for most cancers. Our study explores a different concept that some aggressive cancers may actually arise from early reproductive cells called primordial germ cells,which normally develop into eggs and sperm. We created a new experimental model showing how a virus can transform human primordial germ cell-like cells into virus-positive Merkel cell carcinoma,a rare but deadly skin cancer. This model shows that cancers can emerge through changes in developmental states rather than relying solely on genetic mutations. By linking cancer development to early germ cells,our findings suggest a unifying explanation for both germ cell cancers and body cancers. This new perspective may guide more effective approaches to study,diagnose,and treat cancer by focusing on early human development rather than only DNA mutations and later developmental stages.
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K. Chang et al. (Sep 2025)
Nature Communications 16
Modulating the PPARγ pathway upregulates NECTIN4 and enhances chimeric antigen receptor (CAR) T cell therapy in bladder cancer
With the approval of the antibody-drug conjugate enfortumab vedotin (EV),NECTIN4 has emerged as a bona fide therapeutic target in urothelial carcinoma (UC). Here,we report the development of a NECTIN4-directed chimeric antigen receptor (CAR) T cell,which exhibits reactivity across cells expressing a range of endogenous NECTIN4,with enhanced activity in high expressors. We demonstrate that the PPARγ pathway,critical for luminal differentiation,transcriptionally controls NECTIN4,and that the PPARγ agonist rosiglitazone primes and augments NECTIN4 expression,thereby increasing sensitivity to NECTIN4-CAR T cell-mediated killing. NECTIN4-CAR T cells have potent anti-tumor activity even against EV resistant cells,which largely retain NECTIN4 expression,including in a post-EV biopsy cohort. Our results elucidate a therapeutically actionable mechanism that UC cells use to control NECTIN4 expression and suggest therapeutic approaches that leverage PPARγ agonists for rational combinations with NECTIN4-targeting agents in UC,as well as future potential treatment options for EV-refractory patients. Subject terms: Bladder cancer,Cancer immunotherapy,Cancer therapeutic resistance,Oncology,Bladder cancer
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E. Yamashita et al. (Sep 2025)
The FASEB Journal 39 17
Red Blood Cell‐Mediated Enhancement of Hematopoietic Stem Cell Functions via a Hes1‐Dependent Pathway
In bone marrow,cell numbers are balanced between production and loss. After chemotherapy,blood cell counts decrease initially but later recover as hematopoietic progenitor cells expand,although the mechanisms underlying this recovery are still unclear. We investigated the influence of red blood cells (RBCs) on hematopoietic stem cell (HSC) function during bone marrow recovery. Following chemotherapy,RBC concentrations in bone marrow peaked on day 5 posttreatment,coinciding with the recovery of hematopoiesis. Coculture of HSCs with RBCs resulted in a significant increase in hematopoiesis. Direct contact between RBCs and HSCs was essential for enhancement of hematopoiesis,and HSCs precultured with RBCs resulted in greater numbers of donor‐derived mature hematopoietic cells after transplantation. RNA‐sequencing analysis showed that Hes1 was the most significantly upregulated transcription factor in RBC coculture,and the response to RBC‐induced hematopoiesis of Hes1‐deficient HSCs was reduced. These findings imply a role of RBCs and Hes1 in the enhancement of hematopoietic recovery following bone marrow stress.
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H. Steppuhn et al. (Aug 2025)
Frontiers in Immunology 16
Particulate matters such as diesel exhaust particles induce oxidative stress in cells and thereby have a negative impact on health. The aim of this study was to test whether the membrane-permeable,anti-inflammatory metabolite 4-Octyl Itaconate can counteract the oxidative stress induced by diesel exhaust particles and to analyze the downstream-regulated pathways both in human nasal epithelial cells and PBMCs. Human nasal epithelial cells were cultured from nasal swabs,and the response of the cells to diesel exhaust particles either alone or in combination with 4-Octyl Itaconatee was investigated using RNA sequencing,qPCR,and cytokine measurement. The presence of reactive oxygen species in the cells was analyzed using CellROX staining and flow cytometric DCFDA assay. Diesel exhaust particles caused an upregulation of CYP1A1 in nasal epithelial cells. The administration of 4-Octyl Itaconate reduced the reactive oxygen species and increased the expression of antioxidant genes regulated by the transcription factor NRF2,which was also confirmed in PBMCs. IL-6 secretion from NEC was elevated by diesel exhaust particles and reduced when 4-Octyl Itaconate was administered. 4-Octyl Itaconate can reduce the diesel-exhaust-particle-induced oxidative damage by the activation of NRF2-regulated antioxidative pathways.
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V. Joris et al. (Aug 2025)
NPJ Regenerative Medicine 10
FGF9 treatment reduces off-target chondrocytes from iPSC-derived kidney organoids
Renal failure due to drug nephrotoxicity or disease is frequently observed in patients. The development of in vitro models able to recapitulate kidney biology offers new possibilities to study drug toxicity or model diseases. Induced pluripotent stem cell–derived kidney organoids already show promise,but several drawbacks must be overcome to maintain them in culture,among which is the presence of non-renal cell populations such as cartilage. We modified the culture protocol and maintained kidney organoids in medium containing FGF9 for 1 additional week compared to the control protocol (Takasato). In comparison to the control,the FGF9-treated kidney organoids had reduced cartilage at day 7 + 25 and diminished chondrocyte marker expression. Importantly,the renal structures assessed by immunofluorescence were unaffected by the FGF9 treatment. This reduction of cartilage produces a higher quality kidney organoid that can be maintained longer in culture to improve their maturation for further in vivo work. Subject terms: Pluripotent stem cells,Stem-cell differentiation,Kidney
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O. V. Volodina et al. (Aug 2025)
International Journal of Molecular Sciences 26 16
Prime Editing Modification with FEN1 Improves F508del Variant Editing in the CFTR Gene in Airway Basal Cells
Prime editing is a promising approach for correcting pathogenic variants,but its efficiency remains variable across genomic contexts. Here,we systematically evaluated 12 modifications of the PEmax system for correcting the CFTR F508del pathogenic variant that caused cystic fibrosis in patient-derived airway basal cells. We chose EXO1 and FEN1 nucleases to improve the original system. While all tested variants showed comparatively low efficiency in this AT-rich genomic region,4-FEN modification demonstrated significantly improved editing rates (up to 2.13 fold) compared to standard PEmax. Our results highlight two key findings: first,the persistent challenge of AT-rich target sequence correction even with optimized editors,and second,the performance of 4-FEN suggests its potential value for other genomic targets.
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F. Efendic et al. (Aug 2025)
Cells 14 16
Disrupted Myelination in FAHN: Insights from a Patient-Specific hiPSC Neuron–Oligodendrocyte Model
Fatty-acid-hydroxylase-associated neurodegeneration (FAHN) is a rare neurodegenerative disorder caused by loss-of-function mutations in the FA2H gene,leading to impaired enzymatic activity and resulting in myelin sheath instability,demyelination,and axonal degeneration. In this study,we established a human in vitro model using neurons and oligodendrocytes derived from induced pluripotent stem cells (hiPSCs) of a FAHN patient. This coculture system enabled the investigation of myelination processes and myelin integrity in a disease-relevant context. Analyses using immunofluorescence and Western blot revealed impaired expression and localisation of key myelin proteins in oligodendrocytes and cocultures. FA2H-deficient cells showed reduced myelination,shortened internodes,and disrupted formation of the nodes of Ranvier. Additionally,we identified autophagy defects—a hallmark of many neurodegenerative diseases—including reduced p62 expression,elevated LC3B levels,and impaired fusion of autophagosomes with lysosomes. This study presents a robust hiPSC-based model to study FAHN,offering new insights into the molecular pathology of the disease. Our findings suggest that FA2H mutations compromise both the structural integrity of myelin and the efficiency of the autophagic machinery,highlighting potential targets for future therapeutic interventions.
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A. Ferrelli et al. (Aug 2025)
HemaSphere 9 8
Mesenchymal stromal cells from JAK2 V617F myeloproliferative neoplasms support healthy and malignant hematopoiesis in a humanized scaffold model in vivo
Myeloproliferative Neoplasms (MPN) are malignancies of hematopoietic stem and progenitor cells (HSPCs) that lead to the overproduction of mature blood cells. These disorders include Essential Thrombocythemia (ET),Polycythemia Vera (PV),and Primary Myelofibrosis (PMF),primarily driven by somatic mutations such as JAK2 V617F . Research indicates that mesenchymal stromal cells (MSCs) support fibrosis in PMF,though their role in ET and PV remains less clear. Furthermore,in vivo studies of ET/PV HSPCs remain a challenge due to low engraftment levels in xenograft models. We employed a 3D scaffold model to create an MPN humanized xenograft mouse model,enabling in vivo functional studies of primary MPN progenitor cells and the supportive role of human MSCs. Using this model,we first demonstrated robust hematopoietic support of healthy (HD) HSPCs by PV and ET MSCs. We then investigated the role of MSCs in sustaining JAK2 V617F mutant cells by using a CRISPR‐Cas9 editing model,along with primary PV and ET HSPCs. Our results showed consistent engraftment of CRISPR‐edited JAK2 V617F mutant HSPCs and PV and ET patient‐derived HSPCs in scaffolds seeded with HD,PV,and ET stroma,providing the first in vivo evidence that PV and ET MSCs can sustain both healthy and MPN‐associated hematopoiesis. Furthermore,HD MSCs were also capable of sustaining PV and ET HSPCs in vivo. Overall,we present the first humanized MPN xenograft model that offers valuable insights into how human BM MSCs interact with JAK2 V617F mutant clones.
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