Acta Biochimica et Biophysica Sinica

This study investigates the therapeutic potential of secretomes derived from Adipose-derived Mesenchymal Stem Cells (ADMSC-CM) and Limbal-derived Mesenchymal Stem Cells (LMSC-CM) against oxidative stress-induced damage in Retinal Pigment Epithelium (RPE-1) cells. RPE dysfunction, often triggered by oxidative stress, is a hallmark of various retinal degenerations. Here, we induced RPE-1 injury using H2O2 and evaluated the restorative effects of both MSC-conditioned media (CM). Our results demonstrated that both ADMSC-CM and LMSC-CM significantly enhanced cell viability and successfully reversed H2O2-induced G2/M phase cell cycle arrest. While oxidative stress triggered a pro-inflammatory response characterized by elevated IL-1{beta}, IL-6, and IL-10 expression, MSC-CM treatment, particularly ADMSC-CM, effectively modulated these levels and suppressed the p38 MAPK signaling pathway. Furthermore, MSC-CM reduced the Bax/Bcl-2 ratio, indicating an anti-apoptotic effect, and appeared to stabilize autophagic flux. To investigate the impact of oxidative-stress induced alterations in retinal pigment epithelial cells on angiogenesis, the effects of RPE-derived secreted factors on endothelial cell function were evaluated. Crucially, in terms of safety and secondary complications, neither secretome exhibited pro-angiogenic tendencies; instead, they significantly inhibited HUVEC migration and invasion compared to the H2O2 damaged group. These findings suggest that both ADMSC and LMSC secretomes provide a potent multi-targeted therapeutic effect, making them promising candidates for cell-free therapies in retinal diseases.

Astrocytes play a key role in neuronal homeostasis and in various neural disorders. The generation of astrocytes from neural progenitor cells (NPCs) and its functions are under a complex control of several signaling networks and transcription factors. In this study, we demonstrate that the transcription factor, GLIS similar 3 (GLIS3), which has been implicated in several neurodegenerative diseases, is highly expressed in astrocytes, and is required for the efficient differentiation of human NPCs into astrocytes. Loss of GLIS3 function greatly impairs astrocytes differentiation, resulting in reduced expression of astrocyte markers, whereas expression of exogenous GLIS3 restores the induction of astrocyte specific genes indicating a critical role for GLIS3 in astrocyte differentiation. Integrated transcriptomic and cistromic analyses revealed that GLIS3 directly regulates the transcription of several astrocyte-associated genes, including GFAP, SLC1A2, NFIA, and ATF3, in coordination with lineage-determining factors, such as STAT3, NFIA, and SOX9. We hypothesize that GLIS3 dysfunction disrupts this transcriptional network thereby contributing to astrocyte-associated neurological disorders. Identification of GLIS3 as a key regulator of astrocyte differentiation and gene expression will advance our understanding of its role in neurodegenerative diseases and may provide a new therapeutic target.

G-quadruplexes (G4s) are critical nucleic acid secondary structures that play pivotal roles in regulating gene expression. In this study, we conducted a proteome-wide in silico analysis across multiple viruses causing hemorrhagic fevers to identify candidate proteins containing a conserved G4-binding motif. Four peptides belonging to Marburg, Ebola, Hantaan and Yellow fever viruses were shown to bind to G4 in vitro. We selected the NS3 protease domain of Yellow Fever virus for further validation. Biochemical assays demonstrated that the NS3 protease domain binds G4 structures with high specificity and affinity, particularly favoring the parallel conformation. Molecular docking and simulations further revealed that the NS3 protease domain interacts with the terminal G-tetrads and loop regions of G4 via key residues, including PHE40, adopting an insertion and stacking composite binding mode. These findings expand our understanding of virus - G4 interactions and offer novel potential targets for G4-based antiviral strategies. Bullet points- We screened viruses causing hemorrhagic fevers for potential G4-binding peptides. - Four peptides belonging to Marburg, Ebola, Hantaan and Yellow fever viruses were shown to bind to G4 in vitro. - Biochemical assays demonstrated that the NS3 protease domain of YFV binds G4 structures with high specificity and affinity.

Long noncoding RNAs (LncRNAs) have emerged as a class of important regulatory ncRNAs and are known to fine-tune numerous cellular processes including proliferation, differentiation and development; however, their role in quiescence still remains largely unexplored. A miRNA host gene lncRNA, MIR503HG, has been reported to play important role in cancer development. Here, we demonstrate the role of MIR503HG lncRNA in regulating cellular quiescence. MIR503HG displays elevated levels in human diploid fibroblasts induced to undergo quiescence. Depletion of MIR503HG in HDFs affects the entry of cells into quiescence but has no effect on cell cycle progression, suggesting its role in quiescence attainment and/or maintenance. Additionally, MIR503HG depletion led to a drastic decrease in the levels of miR508 target, PTEN with a concomitant increase in pAkt levels, indicating its role in negative regulation of miR508. Further, we demonstrate that the lncRNA MIR503HG regulates PTEN levels by acting as a ceRNA for miR508 to maintain cellular quiescence. Our studies illustrate that MIR503HG can function synergistically with miR503 to maintain cells under quiescence and both the miRNA-HG and the miRNA encoded by its gene locus synergistically control the same biological process in different ways by regulating different downstream genes.

SGLT2 inhibitor (SGLT2i)-induced diabetic hyperketonemia is a life-threatening acute complication of diabetes. While Celastrol has been reported to exert beneficial effects on obesity; its potential role in ketogenesis remains unclear. In this study, Celastrol administration significantly attenuates the fasting-induced elevation of blood {beta}-hydroxybutyrate. Moreover, a 7-day course of Celastrol (1 mg/kg/day) leads to reductions in body weight and fat mass. Mechanistically, Celastrol specifically downregulates HMGCS2 expression and suppressess hepatic ketogenesis through inhibiting PPAR expression in the short term ([≤] 2 days). However, after prolonged treatment for 7 days, Celastrol modulates both PPARand serum free fatty acids (FFAs) levels. Furthermore, anti-ketogenic effect of Celastrol is abolished in Ppar{square} /{square} mice. Importantly, Celastrol effectively ameliorates SGLT2i-induced hyperketonemia. In summary, Celastrol curbs hepatic ketone overproduction in a PPAR-dependent manner, indicating its protective potential against SGLT2i-induced hyperketonemia.

During viral infection, viral replication perturbs endoplasmic reticulum (ER) homeostasis and triggers the unfolded protein response (UPR). XBP1s, a transcription factor generated by one branch of the UPR, is known to potentiate both innate and adaptive immunity, but its role in antiviral responses remains incompletely understood beyond its ability to augment type I interferon (IFN) mRNA induction. Here, we show that XBP1s positively regulates the RIG-I-like receptors (RLRs), ribonuclease L (RNase L), and protein kinase R (PKR) pathways, indicating that it enhances all three major antiviral response pathways. We further show that RNase L activation rapidly decreases XBP1 mRNA levels in an RNase activity-dependent manner, leading to a prompt reduction in XBP1s expression. Consistent with this, RNase L deletion significantly increased both thapsigargin-mediated XBP1s induction and XBP1s expression following Japan encephalitis virus infection. Poly(I:C)-induced IFNB mRNA expression was significantly enhanced in RNase L-knockout cells. This enhancement was completely abolished by RNase L reconstitution. XBP1 knockdown also significantly attenuated IFNB mRNA expression in RNase L-knockout cells. These findings suggest a negative-feedback loop in which RNase L suppresses XBP1s, thereby fine-tuning antiviral responsiveness during viral infection. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=77 SRC="FIGDIR/small/713401v1_ufig1.gif" ALT="Figure 1000"> View larger version (19K): org.highwire.dtl.DTLVardef@112d312org.highwire.dtl.DTLVardef@df79a9org.highwire.dtl.DTLVardef@1ac571borg.highwire.dtl.DTLVardef@18ac610_HPS_FORMAT_FIGEXP M_FIG C_FIG

MicroRNAs (miRNAs) play essential roles in the posttranscriptional regulation of gene expression in organisms. In the process of synthesizing mature miRNAs from miRNA precursors, the miRNA precursors are cleaved via Dicer at their loop structure, after which the miRNA precursors become mature and regulate transcription. However, the consequences of altering the loop sequence are not fully understood. The silkworm Bombyx mori is a lepidopteran insect with many genetic strains. We identified a mutant of the miRNA miR-3260 whose the part of the loop structure was lacking in a silkworm strain with translucent larval skin. Here, we aimed to analyze the role of wild-type miR-3260 and the influence of the mutation of the loop structure in B. mori. First, we identified the genomic region responsible for the translucent larval skin phenotype and determined that the mutated miR-3260 nucleotide sequences. Then, we predicted the binding partners of wild-type miR-3260 using the RNA hybrid tool and found two juvenile hormone (JH)-related genes as targets of wild-type miR-3260. Next, we assessed the relationships between miR-3260 and JH and found that miR-3260 was highly expressed in the Corpora allata and its expression responded to JH treatment. Meanwhile, miR-3260 mimic and inhibitor did not induce the typical phenotypes associated with JH in B. mori. Then, we compared the dicing products from wild-type and mutant miR-3260 precursors and observed that neither form underwent Dicer-mediated cleavage when the loop structure was altered. These results suggest that loop mutations in the miR-3260 precursor may not influence dicing activity, consistent with the lack of observable phenotypic effects.

NLRP3 inflammasome is a cytosolic multi-protein complex that plays a crucial role in the immune system, responding to various exogenous and endogenous stimuli by triggering protective inflammatory responses. However, aberrant NLRP3 inflammasome activation is implicated in numerous inflammatory diseases. Therefore, the NLRP3 inflammasome is an important pharmacological target for the treatment of multiple diseases. In this context, we screened various US-FDA-approved drugs for NLRP3 inflammasome inhibition. We found that among various drugs, minoxidil hydrochloride (MXL) effectively inhibits NLRP3 inflammasome, evidenced by reduced secretion of IL-1{beta} and IL-18 in J774A.1 cells treated with MXL. The IC50 values of MXL for inhibition of IL-1{beta} and IL-18 were calculated to be 1.2 and 1.06 {micro}M, respectively. MXL was found to prevent ASC oligomerization, thereby inhibiting the NLRP3 inflammasome and leading to CASP1 cleavage. Further investigation revealed that MXL also utilizes AMPK-mediated autophagy to modulate NLRP3 inflammasome activity. Using siAMPK and bafilomycin A1, an end-stage autophagy inhibitor, we elucidated crosstalk between the NLRP3 inflammasome and autophagic pathways, which was modulated by MXL. Furthermore, we demonstrated the efficacy of MXL in two different mouse models of inflammation, involving the NLRP3 inflammasome. MXL at doses of 10 and 20 mg/kg effectively inhibited the activation of NLRP3 inflammasome by monosodium urate in the air pouch model and by ATP in the peritoneal inflammation model, as evidenced by reduced secretion of 1{beta} and IL-18 in the lavage. Our study identifies MXL as a potent NLRP3 inflammasome inhibitor, warranting further investigation as a potential therapeutic agent for inflammatory diseases.

Nitrogen mustard (NM)-caused severe cutaneous damage lacks effective targeted therapies. Vitamin D3 (VD3) shows promise as a therapy for NM-induced dermal toxicity; however, the underlying mechanisms remain elusive. Herein, we initially confirmed that NM induced gut flora dysbiosis, characterized by a decrease of Akkermansia muciniphila (AKK) abundance, thereby leading to butyrate reduction. Antibiotics (ABX) significantly promoted NM-induced skin injury, whereas fecal microbiota transplantation of the controls feces (HC-FMT) or AKK administration attenuated NM-induced dermal toxicity. HC-FMT or AKK significantly increased butyrate levels in feces and serum of NM-treated mice. Butyrate notably attenuated ABX-caused acceleration of NM-induced skin injury. Meanwhile, NM markedly decreased the expression of -defensins, MMP7, and VDR. NM failed to further decrease AKK abundance and BA contents in intestinal MMP7-deficient mice, which was abolished by human alpha defensin 5 (HD5) overexpression. And intestinal MMP7 deficiency enhanced NM-caused skin injury, which was markedly attenuated by HD5 overexpression, AKK transplantation, or BA supplementation. Moreover, NM also failed to further reduce MMP7 and -defensin expression, AKK abundance, and butyrate levels in intestinal VDR-silenced mice. Finally, VD3 remodeled the gut microbiome particularly enriching AKK, increased butyrate contents and promoted the expression of -defensins, MMP7, and VDR, thereby attenuating NM-induced skin damage. The protective effect of VD3 against NM-caused dermal toxicity was abolished by either ABX or intestinal-specific knockdown of MMP7 or VDR in mice; however, this impairment was reversed by butyrate or AKK. In conclusion, VD3 attenuated NM-caused dermal toxicity by promoting BA production via remodeling the gut microbiota, and this effect was partially mediated by the intestinal VDR--defensin signaling pathway. These highlight that targeting the gut flora or supplementing with BA could be potential therapies for NM-induced dermal toxicity.

Background & aimsConstitutive activation of the {beta}-catenin pathway is a determining feature in the pathogenesis of two primary liver cancers, namely HCC and hepatoblastoma (HB). Activating alterations in CTNNB1 gene and, to a lesser extent, inhibiting alterations in APC gene are observed in 30 to 40% of HCC cases and 80 to 90% of HB cases. For both tumours, therapeutic management is far from optimal. Therefore, relevant experimental models are needed to increase our knowledge and test new therapeutic approaches. MethodsOrganoids and tumouroids were established from APC{Delta}hep and {beta}cat{Delta}ex3 mouse models, which are clinically relevant models for {beta}-catenin-activated HCC and mesenchymal HB. We developed a new methodological approach based on a dynamic suspension culture in a rotating bioreactor. Morphological and molecular characteristics and sensitivity to WNTinib, a treatment already successfully tested on human HCC and HB tumouroids, were evaluated by histology, immunohistochemistry, immunofluorescence, and RT-qPCR. ResultsThis easy-to-implement methodology allows for the rapid generation of a large number of organoids and tumouroids that are uniform in size and show no signs of cell death in their core. The robustness of the methodology is illustrated by the maintenance of the histological architecture, cell diversity and gene expression in organoids and tumouroids in comparison with the native liver tissues. In addition, the value of the HCC-derived tumouroids for evaluating cancer treatment was assessed based on their responsiveness to the {beta}-catenin antagonist WNTinib. ConclusionsThe organoids and tumouroids that we present here are new reliable in vitro cancer models, recapitulating the main features of {beta}-catenin-driven HCC and mesenchymal HB. They can be integrated into an appropriate platform for drug screening and could enable the development of "a la carte" therapies that are urgently needed for these indications. Impact and implicationsThis study addresses the critical need for representative in vitro models to investigate {beta}-catenin-driven liver cancers. The organoids and tumouroids developed here are particularly valuable for researchers seeking robust, reproducible models that accurately reflect the cellular diversity and gene expression profiles of native liver tumours. These findings have practical applications in exploring cancer mechanisms, screening new drugs, optimizing personalized treatment strategies, and reducing reliance on animal models, which ultimately benefits patients. HighlightsO_LIEasy and rapid generation of mouse liver organoids and tumouroids from {beta}-catenin activated tumours using culture in a bioreactor C_LIO_LITumouroids preserve histology, cell diversity, and gene expression of native tissue C_LIO_LIHCC-derived tumouroids respond to {beta}-catenin inhibitor WNTinib C_LIO_LIThese reliable 3D models reduce reliance on animal experiments for drug testing C_LI

Despite of the highly potent antiretroviral therapies, HIV-1 establishes persistent infection and causes chronic inflammation in AIDS patients. Beyond CD4+ T cells, HIV-1 infects myeloid cells, including circulating monocytes and tissue-resident macrophages, and integrates with host genomes to form stable viral reservoirs. To achieve a functional HIV cure, latency-promoting agents (LPAs) have been developed for the "block-and-lock" strategy to reinforce deep HIV-1 latency and permanently silence proviruses. However, most LPAs have been tested mainly in CD4+ T cells, and their efficacy in myeloid cells remains unclear. In this study, we reported that levosimendan (LSM), a drug approved for clinic use to treat heart failures, is able to inhibit HIV lytic infection and reactivation in myeloid cells. LSM blocked viral lytic reactivation in HIV-1 latently infected monocytic cells (TH89GFP, U1) and microglial cells (HC69). LSM also inhibited HIV infection in human induced pluripotent stem cell (iPSC) derived microglia (iMG), primary human resident liver macrophages (Kupffer cells) as well as human monocyte-derived macrophages (MDMs). Furthermore, we demonstrated that overexpression of a predicted drug target of LSM, the conserved serine/threonine kinase RIOK1 (RIO kinase 1), overcomes LSMs anti-HIV effect. Overall, our studies concluded that LSM is a promising LPA to inhibit HIV-1 infection in myeloid cells in the RIOK1-dependent manner.

Glioma is the most common primary malignant tumor of the brain, and accumulating evidence indicates that neuronal activity plays a pivotal role in tumor progression. In this study, neuronal activity is modulated in vitro using potassium chloride (KCl)-induced depolarization and midazolam (MDZ)-mediated suppression. MDZ is a neuronal activity modulation medication, commonly used for sedation, anxiolysis, and amnesia in clinics. After treatment, conditioned media derived from these neuronal cultures are subsequently co-cultured with glioma cells. EdU incorporation assays demonstrate that MDZ significantly inhibits glioma cell proliferation in vitro. Furthermore, an orthotopic xenograft glioma model is established to assess the anti-tumor efficacy of MDZ in vivo, as evaluated by tumor volume and Ki-67 immunostaining. Mechanistically, insulin-like growth factor 1 (IGF1) is identified as the neuronal-activity-regulated factor that promotes glioma growth through activation of the PI3K/AKT signaling pathway. Moreover, transcriptomic profiling of brain tissues reveals that MDZ attenuates neuronal activity and downregulates neuron-derived growth factors in both glioma and non-tumor regions, thereby exerting anti-tumor effects in vivo. Collectively, these findings demonstrate that MDZ suppresses glioma progression by suppressing neuronal activity and inhibiting neuron-derived trophic factors, providing new insights into the development of therapeutic strategies for glioma.

The use of decellularized diseased livers in regenerative medicine is a promising approach for eliminating organ shortages. Bioengineering studies have shown that ECM can impact cell physiology, inducing cell activation, function, and ECM deposition, which suggests that the ECM has a "memory" that is involved in the outcome after recellularization. However, the effect of diseased ECM memory on new cells in vitro and in vivo has not been thoroughly investigated. Since it has been increasingly recognized that liver ECM changes due to different factors, it is comprehensively that diseased ECM obtained from discarded organs will ensure a distinct environment and impact cell survival and physiology. Thus, we aimed at investigating the impact of the memory of diseased ECM obtained from metabolic dysfunction-associated steatohepatitis (MASH)-derived organs on steatohepatitis establishment. To address this aim, we explored decellularized ECM obtained from rats and humans with MASH in different contexts. First, MASH ECM was characterized and then submitted to transplantation to investigate whether a MASH-derived ECM could be used as a scaffold for transplantation and to promote steatohepatitis features in control animals. Histological analysis revealed that the MASH-ECM was completely recellularized after transplantation in both control and MASH recipient rats. However, steatosis and fibrosis were observed in MASH ECM after transplantation in both groups. Molecular analysis showed that MASH ECM stimulates de novo lipogenesis and fibrosis 30 days after transplantation. Untargeted metabolomic analysis revealed that cells grown on MASH ECM had a similar metabolic profile, even when transplanted into healthy or MASH recipient rats. In addition, we observed that MASH ECM promoted impaired lipid oxidation and mitochondrial dysfunction when transplanted into healthy recipients. Altered lipid turnover and inflammatory signaling were observed in MASH ECM transplanted in MASH recipients. In vitro analysis revealed that MASH ECM induced lipid accumulation in HepG2 cells after 10 days of culture. Calcium signalling experiments obtained from HepG2 cells cultured in MASH ECM showed a lower response to ATP, a reduced calcium signalling amplitude, and a distinct response profile than that observed in healthy ECM. On the other hand, a diseased human-derived ECM could still provide an environment that allows cell development. Taken together, our data showed that MASH ECM impacts cell metabolism, promoting steatohepatitis maintenance. In conclusion, our data confirm that diseased ECM memory can impact cell physiology contributing to disease progression.

African swine fever (ASF) is a highly pathogenic disease caused by the African swine fever virus (ASFV) infection, which can affect pigs of all ages and breeds, posing significant threat to the global pig farming industry. The ASFV p30 protein is an early-expressed viral structural protein; however, its function is not fully understood. In this study, the interaction of viral p30 with host TRIM21 was identified. The ectopic TRIM21 inhibited ASFV replication, while knockdown or knockout of TRIM21 promoted ASFV replication. Further, p30 was found to interact with RIG-I-like receptor (RLR) signaling adaptor MAVS, and during ASFV infection, p30-TRIM21-MAVS interacted with each other. Mechanistically, TRIM21 activated the K27 polyubiquitination of MAVS to induce IRF3 mediated type I interferon (IFN) production, whereas p30 counteracted TRIM21 activated MAVS K27 polyubiquitination to evade RLR signaling mediated antiviral IFN induction. In summary, our study revealed a novel function of ASFV p30, and provided new insights into the immune evasion of ASFV.

Maladaptive repair of acute kidney injury (AKI) may lead to the development of chronic kidney disease (CKD) characterized by renal fibrosis. Macrophages play roles in AKI-to-CKD progression; however, the interplay between inflammation and fibrosis after AKI remains controversial and the precise role of the distinct macrophage subsets remains elusive. In the present study we identified a unique population of Trem2hi macrophages derived from the bone marrow as a mediator bridging inflammation resolution and fibrosis establishment after kidney injury. Trem2 deficient mice exhibited mitigated renal fibrosis after ischemia-reperfusion injury (IRI) while the renal injury and inflammation persisted. Mechanistically, Trem2 promoted renal inflammation resolution by facilitating macrophage efferocytosis to remove apoptotic tubule cells and reshaping the macrophage cytokine production profile. Loss of Trem2 expression led to excessive cholesterol accumulation in macrophages via Lxr-Abca1/Abcg1 axis and thus sustained pro-inflammatory cytokines production. Moreover, Trem2hi macrophages orchestrated the pro-fibrotic tubular epithelial cells and the activation of myofibroblasts through SPP1 to promote the establishment of renal fibrotic niche. Based on our findings, Trem2hi macrophages may serve as a potential therapeutic target for AKI-to-CKD in combination with anti-inflammatory remedies.

Recurrent hypoglycemia increases cognitive impairment in diabetes mellitus patients. Following cerebral neuron injury, endothelial cells provide morphological, metabolic and immune support to damaged neurons. We investigated the inflammatory mechanism involved in hippocampal neuron degeneration. Behavioral experiments, including the open field test (OFT) and the Morris water maze test, were performed to measure cognitive changes. Using a vascular ring experiment, we evaluated vasodilation of the carotid artery. ZBP1 expression was knocked down after transfection with small interfering RNA in a brain endothelial cell line (bEnd3). In this study, PANoptosis, a recently defined form of programmed cell death (PCD), was found to be increased by hypoglycemia in the hippocampus of type 2 diabetic mice in vivo and by low glucose in bEnd3 cells in vitro. ZBP1 knockdown decreased PANoptosis induced by low-glucose stimulation in high-glucose-cultivated bEnd3 cells. RNA transcriptomics sequencing revealed that AGE-RAGE signaling significantly changed after ZBP1 was knocked down in bEnd3 cells. Corresponding biochemical data confirmed that ZBP1 knockdown regulated the advanced glycation end products (AGEs)-Receptor for Advanced Glycation End Products (RAGE) axis in bEnd3 cells. We present the first evidence that hypoglycemia impaired cognition in mice with type 2 diabetes by activating brain endothelial ZBP1-mediated PANoptosis via the AGE-RAGE axis. ARTICLE HIGHLIGHTSO_LIPANoptosis, a newly defined form of programmed cell death, is induced in the hippocampus after recurrent hypoglycemia in male db/db mice. C_LIO_LIZBP1, a sensor of the PANoptosome, was activated in low glucose cultured brain endothelial cells. C_LIO_LIHypoglycemia impairs vasodilation and cognitive function in type 2 diabetic mice. C_LIO_LIOur study indicates that inhibiting ZBP1-PANoptosis and the AGE-RAGE axis may be a potential approach to prevent hypoglycemia-induced cognitive degeneration in individuals with type 2 diabetes. C_LI

ObjectiveThis study aimed to investigate the anti-gastric cancer effect of Patchouli alcohol (PA), especially its influence on PD-L1-mediated immune evasion, and to elucidate the underlying molecular mechanisms. MethodsA CCK-8 assay was used to evaluate the effects of PA on the viability of the gastric cancer cell lines HGC-27 and MKN-45. RT-qPCR and western blotting were performed to analyze the mRNA and protein levels of NF-{kappa}B and PD-L1, respectively. In a coculture system of gastric cancer cells and peripheral blood mononuclear cells (PBMCs), the effect of PA pretreatment on the PBMC-induced apoptosis of cancer cells was analyzed by flow cytometry, and the cytotoxic activity of the PBMCs was assessed by a lactate dehydrogenase (LDH) release assay. Flow cytometry was also used to determine the proportions of CD3CD8 T cells and IFN-{gamma}CD8 T cells. ELISA was used to measure the levels of IFN-{gamma}, TNF-, and granzyme B in the coculture supernatants. Immunofluorescence staining was conducted to assess NF-{kappa}B nuclear translocation. In a mouse xenograft model, tumor volume and weight were measured after 14 days of PA treatment. Histopathological changes and apoptosis were analyzed by HE and TUNEL staining. A luciferase reporter assay was used to examine the transcriptional regulation of PD-L1 by NF-{kappa}B. ResultsPA inhibited the viability of HGC-27 and MKN-45 cells in a dose- and time-dependent manner and significantly downregulated the expression of NF-{kappa}B and PD-L1 at both the mRNA and protein levels. In a PBMC coculture model, PA pretreatment enhanced the ability of PBMCs to induce apoptosis and directly kill gastric cancer cells. Furthermore, PA pretreatment increased the proportions of CD3CD8 T cells and IFN-{gamma}CD8 T cells in a dose-dependent manner. Consistent with this immunostimulatory effect, PA increased the levels of IFN-{gamma}, TNF-, and granzyme B in the coculture supernatants. Mechanistically, western blotting analysis demonstrated that PA significantly reduced the protein levels of AKT, NF-{kappa}B, and PD-L1 in gastric cancer cells. Immunofluorescence staining further indicated that PA suppressed the nuclear translocation of NF-{kappa}B. In a mouse xenograft model, PA treatment significantly inhibited tumor growth, induced apoptosis, and downregulated NF-{kappa}B and PD-L1 protein expression in tumor tissues. Flow cytometry of tumor-infiltrating lymphocytes revealed increased proportions of CD3CD8 and IFN-{gamma}CD8 T cells following PA treatment. Finally, luciferase reporter assays demonstrated that NF-{kappa}B directly regulates PD-L1 transcription by binding to its promoter region. ConclusionPA exerts antitumor effects in gastric cancer by suppressing the NF-{kappa}B/PD-L1 axis, thereby enhancing CD8 T-cell-mediated cytotoxicity and inhibiting immune evasion.

Sirtuins (SIRTs), which remove protein lysine acyl modifications, play crucial roles in diverse cellular processes, including metabolism, gene transcription, DNA damage repair, cell survival, and stress response. Several sirtuins are considered non-oncogene addiction of cancer cells and promising targets for anticancer drug development. High-throughput screening (HTS) methods for sirtuins are critical for the development of potent and isoform-selective sirtuin inhibitors, which are needed to validate the therapeutic potential. Herein, we designed and synthesized a fluorescent polarization (FP) tracer, KP-SC-1. Using this high-affinity tracer, we developed a robust, high-throughput FP competition assay for screening SIRT1-3 inhibitors. The assay was validated by testing known SIRT1-3 inhibitors. The assay can detect NAD+-independent SIRT1-3 inhibitors, as well as NAD+-dependent inhibitors, such as Ex-527 and TM. Finally, our assay showed satisfactory stability and outstanding performance in a pilot library screening. Compared to previous assays, the FP assay uses much less SIRT1-3 enzymes, a feature important for high-throughput library screening. We believe that the FP assay developed here will accelerate the discovery and development of SIRT1-3 inhibitors.

Background: Human papillomaviruses (HPVs) pose a severe threat to global public health by driving nonmelanoma skin cancer (NMSC) and cervical cancer, with NMSC being one of the most common cancers worldwide. Epidermodysplasia verruciformis (EV) is an inborn error of immunity characterized by an increased susceptibility to persistent infection of cutaneous HPV and a high risk of NMSC. The genetic basis remains unknown in many patients with EV. Methods: We collected four unrelated pedigrees with EV. Genetic analysis identified five variants in JAK1 encoding the Janus kinase 1. Ex vivo models and patient-derived tissue were employed to evaluate the functional effects of JAK1 variants and delineate the pathogenic mechanisms. Results: We identified different variants in JAK1 in four pedigrees with dominant EV. Genetic analysis revealed five novel variants in JAK1, three of which resulted in nonsense-mediated mRNA decay (NMD). Functional assays identified a decreased phosphorylation of the signal transducers and activators of transcription (STATs), impaired interferon responses, and defective T cell activation. Immune dysregulation in patients, characterized by a reduced CD4/CD8 T cell ratio, decreased CD8 naive T cell proportion, and accumulated memory T cells, implies impaired antiviral immunity against HPV. Conclusions: Our findings confirm that JAK1 loss-of-function (LOF) variants underlie susceptibility to cutaneous HPV infection. [Funded by the National Natural Science Foundation of China (81788101, 81230015, 82394420, and 82394423), the National Key Research and Development Program of China (2022YFC2703900), the CAMS Innovation Fund for Medical Sciences (2021-I2M-1-018), and the Regione Lombardia, Italy (Innovative Research Project 1137-2010)].

Hyperuricemia, a major risk factor for gout and kidney disease, arises from the evolutionary loss of human uricase and remains a significant medical challenge due to its high prevalence. However, limited therapeutic options are available for refractory hyperuricemia that typically require long-term treatment. Here we developed a circRNA-based uricase replacement strategy and evaluated its efficacy in uricase-knockout mice as a model for severe hyperuricemia. Lipid nanoparticle-mediated delivery of circRNA enabled efficient in vivo expression of an engineered human-like uricase, which rapidly reduced serum urate levels after a single injection and maintained the urate-lowering effect for up to 10 days. Repeated administration led to sustained urate reduction for 10 weeks, mitigated renal injury, and exhibited favorable biosafety. These findings highlight the therapeutic potential of circRNA-based uricase replacement for the long-term treatment of hyperuricemia and its associated complications.