The cGAS-STING pathway as a therapeutic target in inflammatory diseases

Update on the correlation between mitochondrial function and osteonecrosis of the femoral head osteocytes

Mitochondrial health is maintained in a steady state through mitochondrial dynamics and autophagy processes. Recent studies have identified healthy mitochondria as crucial regulators of cellular function and survival. This process involves adenosine triphosphate (ATP) synthesis by mitochondrial oxidative phosphorylation (OXPHOS), regulation of calcium metabolism and inflammatory responses, and intracellular oxidative stress management. In the skeletal system, they participate in the regulation of cellular behaviors and the responses of osteoblasts, osteoclasts, chondrocytes, and osteocytes to external stimuli. Indeed, mitochondrial damage or dysfunction occurs in the development of a few bone diseases. For example, mitochondrial damage may lead to an imbalance in osteoblasts and osteoclasts, resulting in osteoporosis, osteomalacia, or poor bone production, and chondrocyte death and inflammatory infiltration in osteoarthritis are the main causes of cartilage degeneration due to mitochondrial damage. However, the opposite exists for osteosarcoma, where overactive mitochondrial metabolism is able to accelerate the proliferation and migration of osteosarcoma cells, which is a major disease feature. Bone is a dynamic organ and osteocytes play a fundamental role in all regions of bone tissue and are involved in regulating bone integrity. This review examines the impact of mitochondrial physiological function on osteocyte health and summarizes the microscopic molecular mechanisms underlying its effects. It highlights that targeted therapies focusing on osteocyte mitochondria may be beneficial for osteocyte survival, providing a new insight for the diagnosis, prevention, and treatment of diseases associated with osteocyte death.

Helicobacter pylori infection induces DNA double-strand breaks through the ACVR1/IRF3/POLD1 signaling axis to drive gastric tumorigenesis

Helicobacter pylori (H. pylori) infection plays a pivotal role in gastric carcinogenesis through inflammation-related mechanisms. Activin A receptor type I (ACVR1), known for encoding the type I receptor for bone morphogenetic proteins (BMPs), has been identified as a cancer diver gene across various tumors. However, the specific role of AVCR1 in H. pylori-induced gastric tumorigenesis remains incompletely understood. We conducted a comprehensive analysis of the clinical relevance of ACVR1 by integrating data from public databases and our local collection of human gastric tissues. In vitro cell cultures, patient-derived gastric organoids, and transgenic INS-GAS mouse models were used for Western blot, qRT-PCR, immunofluorescence, immunohistochemistry, luciferase assays, ChIP, and comet assays. Furthermore, to investigate the therapeutic potential, we utilized the ACVR1 inhibitor DM3189 in our in vivo studies. H. pylori infection led to increased expression of ACVR1 in gastric epithelial cells, gastric organoid and gastric mucosa of INS-GAS mice. ACVR1 activation led to DNA double-strand break (DSB) accumulation by inhibiting POLD1, a crucial DNA repair enzyme. The activation of POLD1 was facilitated by the transcription factor IRF3, with identified binding sites. Additionally, treatment with the ACVR1 inhibitor DM3189 significantly ameliorated H. pylori-induced gastric pathology and reduced DNA damage in INS-GAS mice. Immunohistochemistry analysis showed elevated levels of ACVR1 in H. pylori-positive gastritis tissues, showing a negative correlation with POLD1 expression. This study uncovers a novel signaling axis of AVCR1/IRF3/POLD1 in the pathogenesis of H. pylori infection. The upregulation of ACVR1 and the suppression of POLD1 upon H. pylori infection establish a connection between the infection, genomic instability, and the development of gastric carcinogenesis.

Inhibition of the cGAS-STING pathway: contributing to the treatment of cerebral ischemia-reperfusion injury

The cGAS-STING pathway plays an important role in ischemia-reperfusion injury in the heart, liver, brain, and kidney, but its role and mechanisms in cerebral ischemia-reperfusion injury have not been systematically reviewed. Here, we outline the components of the cGAS-STING pathway and then analyze its role in autophagy, ferroptosis, cellular pyroptosis, disequilibrium of calcium homeostasis, inflammatory responses, disruption of the blood-brain barrier, microglia transformation, and complement system activation following cerebral ischemia-reperfusion injury. We further analyze the value of cGAS-STING pathway inhibitors in the treatment of cerebral ischemia-reperfusion injury and conclude that the pathway can regulate cerebral ischemia-reperfusion injury through multiple mechanisms. Inhibition of the cGAS-STING pathway may be helpful in the treatment of cerebral ischemia-reperfusion injury.

Photochemical bomb: Precision nuclear targeting to activate cGAS-STING pathway for enhanced bladder cancer immunotherapy

Activating the cGAS-STING pathway presents a promising strategy to enhance the innate immunity and combat the immunosuppressive tumor microenvironment. One key mechanism for triggering this pathway involves the release of damaged DNA fragments caused by nuclear DNA damage. However, conventional cGAS-STING agonists often suffer from limited nucleus-targeting efficiency and potential biotoxicity. In this study, we develop a novel nucleus-targeting theranostic nanoplatform designed to synergistically activate the cGAS-STING pathway through the combination of photodynamic therapy (PDT) and cisplatin chemotherapy for orthotopic bladder cancer treatment. The nanoplatform integrates a new high-performance type-I photosensitizer with near-infrared-II emission, a TATSA peptide for enhanced nuclear targeting, and a biosafe platinum (IV) cisplatin prodrug. Upon NIR laser irradiation, the nanoagent delivers synergistic nucleus-targeted PDT and chemotherapy, causing substantial DNA damage and the release of double-stranded DNA, which subsequently activates the cGAS-STING pathway and triggers potent immunomodulation. This activation promotes dendritic cells maturation, enhances cytotoxic T infiltration, and facilitates the formation of memory T cells, leading to immune microenvironment remodeling, and long-lasting immune memory, thus effectively inhibiting orthotopic bladder tumors and reducing the risk of metastasis. These findings highlight the substantial potential of this strategy to overcome the limitations of current immunotherapies by leveraging nucleus-targeted PDT to activate the cGAS-STING pathway for cancer treatment.

Regulation of mitochondrial apoptosis via siRNA-loaded metallo-alginate hydrogels: A localized and synergistic antitumor therapy

Preventing relapse after resection of a primary tumor continues to be an unmet clinical need. Development of adjuvant biomaterials with the capacity to kill residual cancer cells after tumor resection is of clinical importance. Here we developed a library of metallo-alginate hydrogels containing high concentrations of metallic ions such as Ca2+ in combination with Zn2+, Li+, or Mg2+ to disrupt Ca2+ homeostasis in the mitochondria of cancer cells by local hyperthermia. To synergistically kill tumor cells and suppress the growth of rechallenged tumors, we embedded oncogene-silencing nucleic acids (mTOR siRNA) loaded into polymerc nanoparticles (NPs) composed of poly (β-amino esters) in the metallo-alginate hydrogels, targeting cancer cells that activate multi-drug resistance pathways such PI3K/AKT/mTOR. Metabolomic studies showed alterations in the Warburg effect, mitochondrial transport, and the TCA cycle, confirming cancer cell damage. In vivo studies of this targeted therapy in mice demonstrated a sex-dependent effect. Male B16F10-tumor-bearing mice treated with the synergistic therapy showed restrained tumor growth. In contrast, no therapeutic effect was observed in female counterparts. Our results demonstrate that in situ-formed NP-loaded metallo-alginate hydrogels can modulate two distinct immune signaling networks that are relevant for enhancing cancer cell death. On the basis of our findings, this combination therapy emerges as a promising sex-dependent strategy for clinical translation.

Type I Interferon Signalling and Ischemic Stroke: Mechanisms and Therapeutic Potentials

Type I interferon (IFN-I) signalling is intricately involved in the pathogenesis of multiple infectious diseases, autoimmune diseases, and neurological diseases. Acute ischemic stroke provokes overactivation of IFN-I signalling within the injured brain, particularly in microglia. Following cerebral ischemia, damage-associated molecular patterns (DAMPs) released from injured neural cells elicit marked proinflammatory episodes within minutes. Among these, self-nucleic acids, including nuclear DNA and mitochondrial DNA (mtDNA), have been recognized as a critical alarm signal to fan the flames of neuroinflammation, predominantly via inducing IFN-I signalling activation in microglia. The concept of interferon-responsive microglia (IRM), marked by upregulation of a plethora of IFN-stimulated genes, has been emergingly elucidated in ischemic mouse brains, particularly in aged ones. Among the pattern recognition receptors responsible for IFN-I induction, cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) plays integral roles in potentiating microglia-driven neuroinflammation and secondary brain injury after cerebral ischemia. Here, we aim to provide an up-to-date review on the multifaceted roles of IFN-I signalling, the detailed molecular and cellular mechanisms leading to and resulting from aberrant IFN-I signalling activation after cerebral ischemia, and the therapeutic potentials. A thorough exploration of these above points will inform our quest for IFN-based therapies as effective immunomodulatory therapeutics to complement the limited repertoire of thrombolytic agents, thereby facilitating the translation from bench to bedside.

The cGAS-STING-mediated ROS and ferroptosis are involved in manganese neurotoxicity

Manganese (Mn) has been characterized as an environmental pollutant. Excessive releases of Mn due to human activities have increased Mn levels in the environment over the years, posing a threat to human health and the environment. Long-term exposure to high concentrations of Mn can induce neurotoxicity. Therefore, toxicological studies on Mn are of paramount importance. Mn induces oxidative stress through affecting the level of reactive oxygen species (ROS), and the overabundance of ROS further triggers ferroptosis. Additionally, Mn2+ was found to be a novel activator of the cyclic guanosine-adenosine synthase (cGAS)-stimulator of interferon genes (STING) pathway in the innate immune system. Thus, we speculate that Mn exposure may promote ROS production by activating the cGAS-STING pathway, which further induces oxidative stress and ferroptosis, and ultimately triggers Mn neurotoxicity. This review discusses the mechanism between Mn-induced oxidative stress and ferroptosis via activation of the cGAS-STING pathway, which may offer a prospective direction for future in-depth studies on the mechanism of Mn neurotoxicity.

Leucine enhances the cGAS-STING-NLRP3 pathway in autoimmune thyroiditis

Background

Branched-chain amino acids (BCAAs), including isoleucine (Ile), leucine (Leu), and valine (Val), are substrates for synthesising nitrogenous compounds and signalling molecules involved in regulating immunity. To date, data on the role of BCAAs in autoimmune thyroiditis (AIT) are lacking; therefore, this study aimed to determine the causality using two-sample Mendelian randomisation (MR) and explored the role of BCAAs in the cGAS-STING-NLRP3 pathway in vitro.

Methods

The causal relationship between BCAAs and the pathogenesis of AIT were identified using a two-sample MR study. The anti-inflammatory effects of BCAAs and their role in the cGAS-STING-NLRP3 pathway were investigated in lipopolysaccharide (LPS)- induced thyroid follicular cells (TFCs).

Results

Our findings indicate that BCAAs are a pathogenic factor for AIT (IVW OR = 4.960; 95 % CI = (1.54,15.940); P = 0.007). Leu significantly exacerbated the inflammatory response of thyroid cells, as evidenced by the up-regulation of tumour necrosis factor-alpha (TNF-α) and interleukin (IL)-6 and down-regulation of TGF-β1; simultaneously aggravated cellular injury and oxidative stress; significantly increased the expression of Sestrin2/p-mTOR and cGAS/STING/NLRP3 in AIT cells. Furthermore, the expression of IL-18 and IL-1β was significantly increased. Conversely, Leu deprivation induced cell injury, decreased oxidative stress, and inhibited Sestrin2/p-mTOR and cGAS/STING/NLRP3 pathways.

Conclusion

Our findings suggest a potential causal effect of genetically predicted Leu on AIT; Leu significantly exacerbated the inflammatory response and cellular damage in AIT cells. The mechanism by which Leu induces inflammation involves activating the promoted Sestrin2/mTOR and cGAS-STING-NLRP3 signalling pathways. Our study proposes a novel mechanism for the contributions of Leu in AIT and potential therapeutic strategies involving Leu deprivation in treating AIT.

Marine-derived STING inhibitors, excavatolide B promote wound repair in full-thickness-incision rats

The process of wound healing encompasses both inflammatory and proliferative stages. Excessive inflammation is known to impede the healing of chronic wounds. Activation of the cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway causes inflammation during cellular stress and tissue damage. Herein, we examined the anti-inflammatory effects of the marine-derived STING antagonist excavatolide B (EXCB) and its derivatives, EXCB-61 and EXCB-79, in full-thickness-incision rats. Wound area measurements, histopathological observations, and immunohistochemical analyses were performed to evaluate the roles of these compounds in wound healing. These three compounds were found to have low toxicity, with EXCB promoting Hs68 human dermal fibroblast migration and proliferation. EXCB and EXCB61 treatments, but not EXCB79, reduced the wound area. The histopathological results showed a significant decrease in immune cell infiltration and mast cell accumulation in all compound-treated groups. Immunohistochemical analysis revealed that EXCB and its derivatives reduced cGAS-STING pathway factors such as STING, phosphorylated TANK-binding kinase 1, nuclear factor kappa-light-chain-enhancer of activated B cells, and M1 macrophages while increasing the expression of angiogenic factors vascular endothelial growth factor and CD31, as well as M2 macrophages and collagen I/III deposition. We conclude that marine-derived STING antagonists can attenuate inflammatory responses by inhibiting the cGAS-STING pathway and promoting angiogenesis, thereby aiding wound healing.

Timely administration of drug combination improves chemoimmunotherapy of an immune-cold tumor

An immunoactive complex consisting of a polyethyleneimine derivative (2E'), paclitaxel (PTX), and cyclic dinucleotide (CDN) was developed for chemoimmunotherapy of solid tumors. Each component uniquely contributes to stimulating innate immune response to tumors: 2E' carries PTX and CDN while stimulating antigen-presenting cells, PTX induces immunogenic cell death, and CDN activates the STING pathway. A single intratumoral injection of 2E'/PTX/CDN inhibited the growth of MOC1 oral squamous cell carcinoma and KPCY (2838c3) pancreatic tumors, achieving complete tumor regression in 80-100 % of mice. However, 2E'/PTX/CDN showed limited therapeutic efficacy with immune-cold B16F10 melanoma, accompanied by the increase of innate immune cells in the tumor draining lymph nodes peaking on day 5 post-administration and subsiding thereafter. The addition of a complex of 2E' and siRNA targeting PD-L1 (siPD-L1) at an optimal 5-d interval improved the response in B16F10 melanoma, resulting in tumor-free survival in 50 % of mice and rejection of live tumor rechallenge in 67 % of surviving animals. Consistent with the function of each component, the timed combination of 2E'/PTX/CDN and 2E'/siPD-L1 increased the fractions of mature dendritic cells and M1 macrophages, prevented the increase of regulatory T cells in tumor-draining lymph nodes, and increased melanoma antigen-specific CD8+ T cells in the spleen. These results demonstrate the effectiveness of the 2E'/PTX/CDN complex in the chemoimmunotherapy of solid tumors and highlight the significance of timely intervention to sustain the immunoactive phenotype in its application to immune-cold tumors.

Unraveling the cGAS-STING pathway in Alzheimer's disease: A new Frontier in neuroinflammation and therapeutic strategies

Alzheimer's disease (AD) is the most prevalent type of neurological disorder characterized by cognitive decline and memory loss, marked by the accumulation of amyloid beta (Aβ) plaques and hyperphosphorylated tau protein, causing extensive neuronal death and neuroinflammation. There is growing evidence that AD development extends beyond the neuronal compartment and has a major impact on the immunological functions of the brain. The cyclic GMP-AMP synthase (cGAS) detects cytosolic DNA, including pathogenic foreign DNA and self-DNA from cellular injury, triggering a type I interferon (IFN-I) response through activation of the stimulator of interferon genes (STING). The activation of the cGAS-STING pathway in response to mitochondrial dysfunction drives neuroinflammation in AD, which is mediated by the release of IFN-I cytokines. Furthermore, the release of oxidized mtDNA is necessary for the stimulation of the nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 (NLRP3) inflammasome, which is a family of protein complexes that macrophages can produce to induce inflammation. AD becomes severe by the stimulation of the cGAS-STING pathway, which results in sterile inflammation and microglial dysfunction. This review aims to explore the potential impact of the cGAS-STING signaling pathway in the pathogenesis and progression of AD. Additionally; after overviewing recent findings, this article highlights the molecular mechanism involved in the onset of disease and its modulation regarding the therapeutic approach of AD. Finally, deliberated a deep insight, the cGAS-STING axis could provide novel therapeutic avenues for slowing or halting the progression of AD, thereby offering new prospects for treatment development.

STING regulates porphyromonas gingivalis lipopolysaccharide-induced pyroptosis and inflammatory response through the NF-κB/NLRP3 signaling pathway in human gingival fibroblasts

OBJECTIVE

The production of reactive oxygen species caused by antimicrobial response during periodontitis leads to the activation of NOD-like receptor protein 3 (NLRP3) inflammasome and pyroptosis. Stimulator of interferon genes (STING) has been found to be involved in regulating pyroptosis and inflammation in a variety of diseases. The present study aimed to investigate whether STING is involved in Porphyromonas gingivalis lipopolysaccharide (P.g LPS)-stimulated human gingival fibroblasts (HGFs) by regulating pyroptosis and inflammation.

DESIGN

After culturing and identifying HGFs, HGFs were treated with P.g LPS. Constructs of si-STING were transfected into HGFs, which were then stimulated with P.g LPS for 24 h. Subsequently, cell viability, pyroptosis, inflammation, oxidative stress and alterations in the STING/TANK-binding kinase 1 (TBK1)/interferon regulatory factor 3 (IRF3)/nuclear factor-kappaB (NF-κB)/NLRP3 signalling pathway were detected.

RESULTS

P.g LPS significantly enhanced STING expression in HGFs. Downregulation of STING rescued P.g LPS-enhanced pyroptosis, oxidative stress and inflammation in HGFs. Moreover, STING was found to bind directly to TBK1 to increase IRF3 phosphorylation and nuclear translocation of NF-κB, thus promoting NLRP3 inflammasome activation. Downregulation of STING rescued P.g LPS-enhanced TBK1/IRF3/NF-κB/NLRP3 pathway activation.

CONCLUSION

STING/TBK1/IRF3/NF-κB/NLRP3 is a key pathway governing pyroptosis, oxidative stress and inflammation of HGFs induced by LPS.

Red blood cell metabolism: a window on systems health towards clinical metabolomics

PURPOSE OF REVIEW

This review focuses on recent advances in the understanding of red blood cell (RBC) metabolism as a function of hypoxia and oxidant stress. In particular, we will focus on RBC metabolic alterations during storage in the blood bank, a medically relevant model of erythrocyte responses to energy and redox stress.

RECENT FINDINGS

Recent studies on over 13 000 healthy blood donors, as part of the Recipient Epidemiology and Donor Evaluation Study (REDS) III and IV-P RBC omics, and 525 diversity outbred mice have highlighted the impact on RBC metabolism of biological factors (age, BMI), genetics (sex, polymorphisms) and exposure (dietary, professional or recreational habits, drugs that are not grounds for blood donor deferral).

SUMMARY

We review RBC metabolism from basic biochemistry to storage biology, briefly discussing the impact of inborn errors of metabolism and genetic factors on RBC metabolism, as a window on systems metabolic health. Expanding on the concept of clinical chemistry towards clinical metabolomics, monitoring metabolism at scale in large populations (e.g., millions of blood donors) may thus provide insights into population health as a complementary tool to genetic screening and standard clinical measurements.

Dihydroartemisinin Attenuates Radiation-Induced Lung Injury by Inhibiting the cGAS/STING/NF-κB Signaling Pathway

Dihydroartemisinin (DHA) is a derivative of artemisinin, which affects inflammation, oxidative stress, and immune regulation. However, the mechanism underlying its effects remains largely unknown. This study aims to explore the mechanism by which DHA affects radiation-induced lung injury (RILI), providing new insights for lung radiotherapy. To elucidate its mechanism of action, C57BL/6 J mice were irradiated with 15 Gy whole chest. RILI was evaluated by qRT-PCR, ELISA, histology, Western blot analysis, immunohistochemistry, and RILI signaling cascade studies. In addition, small interfering RNAs were employed to knockdown cGAS proteins in the cGAS-STING signaling pathway in the human bronchial epithelium cell line (BEAS-2B). Both In Vivo and Vitro experiments were conducted to investigate the specific mechanism by which DHA alleviated RILI. We observed the activation of the cGAS-STING pathway, along with the phosphorylation of the downstream target NF-κB and an increase in inflammatory factor levels in the mouse model following radiation exposure. In the cell model, irradiation also triggered the activation of the cGAS-STING signaling pathway and its downstream targets, leading to elevated levels of inflammatory factors. Notably, knocking down the cGAS using small interfering RNA in the BEAS-2B cells significantly alleviated RILI in the cell model. Our study elucidated the mechanism of DHA reducing RILI through the cGAS/STING/NF-κB signaling pathway, and revealed that the GAS/STING/NF-κB axis may be a potential therapeutic target for RILI.

EZH2 inhibits senescence-associated inflammation and attenuates intervertebral disc degeneration by regulating the cGAS/STING pathway via H3K27me3

OBJECTIVE

Senescent nucleus pulposus mesenchymal stem cells (NPMSCs) are key instigators of local chronic inflammation and disruptions in nucleus pulposus tissue repair in intervertebral disc degeneration (IVDD). This study aimed to investigate the interplay between EZH2 and NPMSCs senescence-associated inflammation.

METHODS

Nucleus pulposus samples were collected from IVDD patients (n = 15, F/M = 7/8, average age 47.9 (21-72) year-old). Multiplex immunohistochemistry was conducted to detect the expression of EZH2 and the cGAS/STING pathway. Subsequently, NPMSCs were isolated from 7 patients (n = 7, F/M = 4/3, average age 49.4 (36-68) year-old). After treatment with tert-butyl hydroperoxide and lentivirus-overexpression-EZH2 (Lv-OE-EZH2), real time fluorescent quantitative PCR, immunofluorescence, western blot, and ChIP were used to detect the expression of EZH2 and the cGAS/STING pathway. Micro-CT, magnetic resonance imaging, and histological staining were performed to assess the therapeutic effects of Lv-OE-EZH2 and a STING inhibitor on rat IVDD. All experiment designs were independent.

RESULTS

In both human nucleus pulposus tissues and an in vitro cell model, EZH2 expression decreased while the cGAS/STING pathway became activated in senescent NPMSCs. ChIP assays and Lv-OE-EZH2 experiments validated that EZH2 epigenetically inhibited STING expression via H3K27me3, thereby impairing the cGAS/STING pathway and attenuating senescence-associated inflammation. Moreover, overexpression of EZH2 (Pfirrmann grade means difference -1.375, p = 0.0089) and inhibition of STING effectively attenuated rat IVDD.

CONCLUSION

The decreased expression of EZH2 in senescent NPMSCs promotes senescence-associated inflammation and the progression of IVDD, possibly by relieving the transcriptional inhibition of STING and enabling the activation of the cGAS/STING pathway.

Inhibition of the cGAS-STING pathway via an endogenous copper ion-responsive covalent organic framework nanozyme for Alzheimer's disease treatment

Inhibition of cGAS-STING overactivation has recently emerged as a promising strategy to counteract Alzheimer's disease (AD). However, current cGAS-STING inhibitors as immunosuppressants suffer from instability, non-specific targeting, and innate immune disruption. Here, an endogenous AD brain copper ion-responsive covalent organic framework (COF)-based nanozyme (denoted as TP@PB-COF@NADH) has been designed for targeted inhibition of the cGAS-STING pathway for AD treatment. The effective trapping of excess brain endogenous copper ions by TP@PB-COF@NADH not only inhibits the Cu2+-induced harmful reactive oxygen species (ROS) production which is one of the mediators of cGAS-STING activation, but also activates the nanozyme activity of TP@PB-COF@NADH. Furthermore, the well-prepared nanozyme catalytically generates NAD+ and consumes hydrogen peroxide (H2O2) through second near-infrared (NIR-II) enhanced nicotinamide adenine dinucleotide (NADH) peroxidase (NPX)-like activity, realizing the efficient inhibition of the cGAS-STING pathway and associated neuroinflammation. Moreover, replenishing NAD+ levels efficiently restores mitochondrial function and ATP supply. In vivo studies demonstrate that TP@PB-COF@NADH with NIR-II irradiation significantly improves cognitive function in 3× Tg-AD mice, with a reduction in amyloid-β (Aβ) plaque, neuroinflammation and neuronal damage. Collectively, this work presents a promising approach for AD treatment by using an AD brain harmful excess endogenous copper ion-responsive and efficient nanozyme.

Smart Organic-Inorganic Copolymer Nanoparticles Distinguish Between Microglia and Cancer Cells for Synergistic Immunotherapy in Glioma

The stimulator of interferon genes (STING) pathway has emerged as a new immunotherapy strategy with potent local stimulation specificity, showing promising potential to counteract the immunosuppression in glioma. Herein, a tumor microenvironment (TME) responsive nanoagonists are developed based on an organic-inorganic copolymer composed of the polymer PC6AB coupled with manganous phosphate ionic oligomers (MnP). The degradation of nanoagonists into PC6AB and MnP in the acidic TME enables spatiotemporal control of their delivery to tumor cells and immune cells, respectively. PC6AB with membranolytic activity selectively interacts with tumor cell membranes to induce immunogenic cell death, while manganese metal can activate the STING pathway in immune cells and trigger downstream immunostimulatory signals. Nanoagonists can stimulate robust antitumor immunity after local injection into the brain extracellular space (ECS), showing significant therapeutic efficacy in mouse glioma. Nanoagonists can achieve spatiotemporal orchestration of STING activation in response to TME and enhance immune response against "cold" solid tumors, providing a promising approach for clinical immunotherapy.

Signal Converter-Based Therapy Platform Promoting Aging Bone Healing by Improving Permeability of the Mitochondrial Membrane

The aging microenvironment promotes persistent inflammation and loss of intrinsic regenerative capacity. These are major obstacles to effective bone tissue repair in older adults. This study aims to explore how physical thermal stimulation can effectively delay the bone marrow mesenchymal stem cells (BMSCs) aging process. Based on this, an implantable physical signal-converter platform is designed as a therapeutic system that enables stable heat signals at the bone injury site under ultrasound stimulation (US). It is found that the therapeutic platform controllably reduces the mitochondrial outer membrane permeabilization of aging BMSCs, bidirectionally inhibiting mitochondrial reactive oxygen species and mitochondrial DNA (mtDNA) leakage. The leakage ratio of mtDNA decreases by 22.7%. This effectively mitigates the activation of the cGAS-STING pathway and its downstream NF-κB signaling induced by oxidative stress in aging BMSCs, thereby attenuating the pathological advancement of chronic inflammation. Thus, it effectively restores the metabolism and osteogenic differentiation of aging BMSCs in vitro, which is further confirmed in a rat model. In the GMPG/US group, the bone mineral density increases 2-3 times at 4 weeks in the rats femoral defect model. Therefore, this ultrasound-based signal-conversion platform provides a promising strategy for aging bone defect repair.

RNA interference-mediated osteoprotegerin silencing increases the receptor activator of nuclear factor-kappa B ligand/osteoprotegerin ratio and promotes osteoclastogenesis

BACKGROUND

In vivo degradation of bone scaffolds is significantly influenced by osteoclast (OC) activity, which is orchestrated by the interplay between receptor activator of nuclear factor-kappa B ligand (RANKL) and osteoprotegerin (OPG). The ratio of RANKL/OPG is a crucial determinant of OC-mediated bone resorption, which plays an integral role in bone remodeling and scaffold degradation. Elevated levels of RANKL relative to OPG enhance osteoclastogenesis, thereby accelerating the degradation process essential for integrating bone scaffolds into the host tissue.

AIM

To elucidate the effects of OPG gene silencing on osteoclastogenesis within rat bone marrow-derived mesenchymal stem cells (BMSCs). By investigating these effects, the study aimed to provide deeper insights into the regulatory mechanisms that influence bone scaffold degradation, potentially leading to improved bone repair and regeneration strategies.

METHODS

We employed recombinant lentiviral plasmids to silence the OPG gene in rat BMSCs to achieve the aims. The efficacy of gene silencing was assessed using quantitative reverse transcription polymerase chain reaction and western blot analysis to measure the expression levels of OPG and RANKL. Tartrate-resistant acid phosphatase staining was utilized to evaluate the formation of OCs. Additionally, co-immunoprecipitation assays were conducted to explore the interactions between RANKL and OPG proteins, further assessing the biochemical pathways involved in osteoclastogenesis.

RESULTS

The silencing of the OPG gene in BMSCs resulted in a significant increase in the RANKL/OPG ratio, evidenced by decreased expression levels of OPG and increased levels of RANKL. Enhanced osteoclastogenesis was observed through tartrate-resistant acid phosphatase staining, which indicated a substantial rise in OC formation in response to the altered RANKL/OPG balance. The co-immunoprecipitation assays provided concrete evidence of the direct interaction between RANKL and OPG proteins, substantiating their pivotal roles in regulating OC activity.

CONCLUSION

The findings from this study underscore the critical role of the RANKL/OPG axis in osteoclastogenesis. Silencing of the OPG gene in BMSCs effectively increases the RANKL/OPG ratio, promoting OC activity and potentially enhancing bone scaffold degradation. This regulatory mechanism offers a promising avenue for modulating bone remodeling processes, which is essential for effective bone repair and the successful integration of bone scaffolds into damaged sites. Future research might focus on optimizing the control of this axis to better facilitate bone tissue engineering and regenerative therapies.

Mitochondria-targeted manganese-based mesoporous silica nanoplatforms trigger cGAS-STING activation and sensitize anti PD-L1 therapy in triple-negative breast cancer

Activation of the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway could effectively initiate antitumor immunity in triple-negative breast cancer. However, current nuclear DNA-mediated activation of STING pathway remains constrained by the tight protection of nuclear membrane and histones, highlighting the need for new strategies to enhance its efficacy. Mitochondrial DNA (mtDNA), in contrast, is more vulnerable to damage. Herein, our nanoplatforms exploited the high glutathione (GSH) environment characteristic of tumors to release abundant Mn2+, which induced mitochondrial dysfunction and the release of endogenous mtDNA. The released mtDNA, in conjunction with Mn2+ itself functioning as a strong cGAS agonist, effectively activated cGAS-STING pathway. Consequently, the cGAS-STING-dependent secretion of type I interferon successively enhanced the maturation of dendritic cells and cross-priming of CD8+ T cells. In a poorly immunogenic 4T1 tumor model, TPP-MMONs efficiently primed systemic antitumor immunity and significantly enhanced the therapeutic efficacy of αPD-L1 therapy, suppressing tumor growth in both localized and metastatic tumor models. These findings provided an innovative and straightforward strategy to enhance TNBC immunogenicity by targeting mitochondrial damage to induce mtDNA-mediated cGAS-STING activation, thereby sensitizing tumors to immune checkpoint inhibitor therapy. STATEMENT OF SIGNIFICANCE: The cGAS-STING pathway is a promising target for overcoming immunoresistance in TNBC. However, current nuclear DNA-based activation strategies are limited by the tight protection of nuclear membrane and histones. Herein, we reported novel manganese-rich, mitochondria-targeting nanoplatforms (TPP-MMONs), which can release abundant Mn²⁺ and significantly induce mitochondrial dysfunction, leading to the release of mtDNA. As a result, the nanoplatforms can effectively stimulate the cGAS-STING pathway, thereby enhancing immune responses and improving the therapeutic efficacy of αPD-L1 therapy, offering new insights into TNBC treatments.

Epigenetic modulation of the NLRP6 inflammasome sensor as a therapeutic modality to reduce necroptosis-driven gastrointestinal mucosal dysfunction in HIV/SIV infection

BACKGROUND

Gastrointestinal (GI) disease/dysfunction persists in people living with HIV (PLWH) receiving suppressive combination anti-retroviral therapy (ART) leading to epithelial barrier breakdown, microbial translocation and systemic inflammation that can drive non-AIDS associated comorbidities. Although epigenetic mechanisms are predicted to drive GI dysfunction, they remain unknown and unaddressed in HIV/SIV infection. The present study investigated genome-wide changes in DNA methylation, and gene expression exclusively in colon epithelial cells (CE) in response to simian immunodeficiency virus infection (SIV) and long-term low-dose delta-9-tetrahydrocannabinol (THC).

METHODS

Using reduced-representation bisulfite sequencing, we characterized DNA methylation changes in colonic epithelium (CE) of uninfected controls (n=5) and SIV-infected rhesus macaques (RMs) administered vehicle (VEH/SIV; n=7) or THC (THC/SIV; n=6). Intact jejunum resection segments (~5cm) were collected from sixteen ART treated SIV-infected RMs [(VEH/SIV/ART; n=8) and (THC/SIV/ART; n=8)] to confirm protein expression data identified in the colon of ART-naïve SIV-infected RMs. Transcriptomics data was used to confirm expression of differentially methylated genes. Protein expression of differentially methylated genes and their downstream targets was assessed using Immunofluorescence followed by HALO quantification.

RESULTS

SIV infection in ART-naïve RMs induced marked hypomethylation throughout promoter-associated CpG islands (paCGIs) in genes related to inflammatory response (NLRP6, cGAS), cellular adhesion (PCDH17, CDH7) and proliferation (WIF1, SFRP1, TERT, and HAND2) in CEs. Moreover, low-dose THC reduced NLRP6 protein expression in CE by hypermethylating the NLRP6 paCGI and blocked polyI:C induced NLRP6 upregulation in vitro. In ART suppressed SIV-infected RMs, significant NLRP6 protein upregulation during acute infection was unaffected by long-term ART administration during chronic infection despite successful plasma and tissue viral suppression. In this group, NLRP6 protein upregulation was associated with significantly increased expression of necroptosis-driving proteins; phosphorylated-RIPK3(Ser199), phosphorylated-MLKL(Thr357/Ser358), and HMGB1. Most strikingly, adding ART to THC-treated SIV-infected RMs effectively reduced NLRP6 and necroptosis-driving protein expression to pre-infection levels.

CONCLUSIONS

We conclude that DNA hypomethylation-assisted NLRP6 upregulation can lead to its constitutively high expression resulting in the activation of necroptosis signaling via the RIPK3/p-MLKL pathway that can eventually drive intestinal epithelial loss/death. From a clinical standpoint, low-dose phytocannabinoids in combination with ART could safely and successfully reduce/reverse persistent GI inflammatory responses via modulating DNA methylation.

A20 attenuates oxidized self-DNA-mediated inflammation in acute kidney injury

The ubiquitin-editing enzyme A20 is known to regulate inflammation and maintain homeostasis, but its role in self-DNA-mediated inflammation in acute kidney injury (AKI) is not well understood. Here, our study demonstrated that oxidized self-DNA accumulates in the serum of AKI mice and patients. This oxidized self-DNA exacerbates the progression of AKI by activating the cGAS-STING pathway and NLRP3 inflammasome. While inhibition of the STING pathway only slightly attenuates AKI progression, suppression of NLRP3 inflammasome-mediated pyroptosis significantly alleviates AKI progression and improves the survival of AKI mice. Subsequently, we found that Tnfaip3 (encoding A20) is significantly upregulated following oxidized self-DNA treatment. A20 significantly alleviates AKI development by dampening STING signaling pathway and NLRP3-mediated pyroptosis. Moreover, A20-derived peptide (P-II) also significantly alleviates ox-dsDNA-induced pyroptosis and improves the survival and renal injury of AKI mice. Mechanistically, A20 competitively binds with NEK7 and thus inhibiting NLRP3 inflammasome. A20 and P-II interfere with the interaction between NEK7 and NLRP3 through Lys140 of NEK7. Mutation of Lys140 effects on the interaction of NEK7 with A20 and/or NLRP3 complex. Conditional knockout of NEK7 in macrophages or pharmacological inhibition of NEK7 both significantly rescue AKI mouse models. This study reveals a new mechanism by which A20 attenuates oxidized self-DNA-mediated inflammation and provides a new therapeutic strategy for AKI.

Rebalancing redox homeostasis: A pivotal regulator of the cGAS-STING pathway in autoimmune diseases

Autoimmune diseases (ADs) arise from the breakdown of immune tolerance to self-antigens, leading to pathological tissue damage. Proinflammatory cytokine overproduction disrupts redox homeostasis across diverse cell populations, generating oxidative stress that induces DNA damage through multiple mechanisms. Oxidative stress-induced alterations in membrane permeability and DNA damage can lead to the recognition of double-stranded DNA (dsDNA), mitochondrial DNA (mtDNA) and micronuclei-DNA(MN-DNA) by DNA sensors, thereby initiating activation of the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway. While previous reviews have characterized cGAS-STING activation in autoimmunity, the reciprocal regulation between redox homeostasis and cGAS-STING activation remains insufficiently defined. This narrative review examines oxidative stress-mediated DNA damage as a critical driver of pathological cGAS-STING signaling and delineates molecular mechanisms linking redox homeostasis to autoimmune pathogenesis. Furthermore, we propose therapeutic strategies that combine redox restoration with the attenuation of aberrant cGAS-STING activation, thereby establishing a mechanistic foundation for precision interventions in autoimmune disorders. METHODS: The manuscript is formatted as a narrative review. We conducted a comprehensive search strategy using electronic databases such as PubMed, Google Scholar and Web of Science. Various keywords were used, such as "cGAS-STING," "Redox homeostasis," "Oxidative stress," "pentose phosphate pathway," "Ferroptosis," "mtDNA," "dsDNA," "DNA damage," "Micronuclei," "Reactive oxygen species," "Reactive nitrogen species," "Nanomaterial," "Autoimmune disease," "Systemic lupus erythematosus," "Type 1 diabetes," "Rheumatoid arthritis," "Multiple sclerosis," "Experimental autoimmune encephalomyelitis," "Psoriasis," etc. The titles and abstracts were reviewed for inclusion into this review. After removing duplicates and irrelevant studies, 174 articles met inclusion criteria (original research, English language).

Double-stranded DNA enhances platelet activation, thrombosis, and myocardial injury via cyclic GMP-AMP synthase

AIMS

Elevated dsDNA levels in ST-elevated myocardial infarction (STEMI) patients are associated with increased infarct size and worse clinical outcomes. However, the direct effect of dsDNA on platelet activation remains unclear. This study aims to investigate the direct influence of dsDNA on platelet activation, thrombosis, and the underlying mechanisms.

METHODS AND RESULTS

Analysis of clinical samples revealed elevated plasma dsDNA levels in STEMI patients, which positively correlated with platelet aggregation and markers of neutrophil extracellular traps such as MPO-DNA and CitH3. Platelet assays demonstrated the activation of the cGAS-STING pathway in platelets from STEMI patients. DsDNA directly potentiated platelet activation and thrombus formation. Mechanistic studies using G150 (cGAS inhibitor), H151 (STING inhibitor), and MCC950 (NLRP3 inhibitor), as well as cGAS-/-, STING-/-, and NLRP3-/- mice, showed that dsDNA activated cGAS, a previously unreported DNA sensor in platelets, and induced activation of the STING/NLRP3/caspase-1/IL-1β axis. This cascade enhanced platelet activation and thrombus formation. Platelet cGAS depletion or Palbociclib, a cGAS-STING inhibitor, approved by the FDA for advanced breast cancer, ameliorated myocardial ischaemia-reperfusion injury in ApoE-/- mice fed with a high-fat diet for 12 weeks.

CONCLUSIONS

These results suggested that dsDNA is a novel driver of platelet activation and thrombus formation in STEMI patients.

Impact of radiation therapy on the immunological tumor microenvironment

External beam radiation therapy (RT) is a cornerstone of modern cancer management, being utilized in both curative and palliative settings due to its safety, efficacy, and widespread availability. A primary biological effect of RT is DNA damage, which leads to significant cytostatic and cytotoxic effects. Importantly, malignant cells possess a limited capacity for DNA repair compared to normal cells, and when combined with irradiation techniques that minimize damage to healthy tissues, this creates an advantageous therapeutic window. However, the clinical effectiveness of RT also appears to involve both direct and indirect interactions between RT and non-transformed components of the tumoral ecosystem, particularly immune cells. In this review, we describe the molecular and cellular mechanisms by which irradiated cancer cells modify the immunological tumor microenvironment and how such changes ultimately impact tumor growth.

The induction of type I interferonopathy in Trex1-P212fs mice is mediated by activation of the cGAS-STING pathway

The cGAS-STING pathway is crucial for immune tolerance, pathogen resistance, and tumor immunity. Knocking out the cGAS gene can reverse the type I interferonopathy seen in Trex1-/- and Trex1D18N/D18N mice. TREX1, a key DNA-specific exonuclease in mammalian cells, degrades cytoplasmic DNA to prevent excessive immune activation. Mutations in TREX1 are linked to various autoimmune diseases. In prior research, we generated a Trex1-P212fs mouse model associated with systemic lupus erythematosus (SLE) using CRISPR-Cas9 gene editing. This model displays systemic inflammation that mirrors numerous characteristics of both Aicardi-Goutières syndrome (AGS) and SLE in humans. In this study, we found that the TREX1-P212fs mutation resulted in reduced dsDNA enzyme activity. DNA accumulation was present in the cytoplasm of Trex1P212fs/P212fs MEFs. Nonetheless, the role of the cGAS-STING pathway in mediating the disease phenotype in Trex1-P212fs mice associated with SLE has yet to be elucidated. We observed that cGas knockout mitigated systemic inflammation, lymphocyte proliferation, vasculitis, renal disease, and spontaneous T cell activation in Trex1-P212fs mice. Similarly, inhibition of STING with C-176 treatment ameliorated the disease phenotype in Trex1-P212fs mice. These findings elucidate the pathogenesis of TREX1-P212fs-associated type I interferonopathy and offer potential therapeutic targets for their treatment.

TFAM Deficiency Triggers mtDNA Leakage and cGAS-STING-Mediated Intestinal Ischemia-Reperfusion Injury

Intestinal Ischemia-Reperfusion (IIR) injury is a common clinical pathophysiological condition, yet the complex molecular mechanisms underlying its pathology remain incompletely understood. This study aims to explore the precise molecular mechanisms of IIR injury, with a focus on the role of the cGAS-STING signaling pathway. Using a mouse IIR model and hypoxia/reoxygenation (HR) model in HT-29 cells and small intestinal organoids, we observed that IIR significantly induces oxidative stress and activates the cGAS-STING pathway, which is associated with exacerbated small intestinal tissue damage and enhanced inflammatory responses. Further investigation revealed that mitochondrial DNA (mtDNA) leakage is a critical trigger for the activation of the cGAS-STING pathway. The introduction of exogenous mtDNA into cells activated the STING pathway and exacerbated cellular damage. In contrast, the depletion of intracellular mtDNA effectively suppressed HR-induced activation of the cGAS-STING pathway. Mechanistically, we found that IIR downregulates mitochondrial transcription factor A (TFAM), which subsequently affects mtDNA stability, promoting the release of mtDNA into the cytoplasm and triggering the cGAS-STING pathway. Overexpression of TFAM stabilized mtDNA, reduced the accumulation of cytoplasmic mtDNA, inhibited cGAS-STING pathway activation, and alleviated cellular damage. Moreover, STING-deficient mice exhibited reduced inflammation, less tissue damage, and improved survival rates following IIR, highlighting the critical role of the STING pathway in IIR-induced injury. Our findings elucidate the close association between oxidative stress, inflammation, and cGAS-STING pathway activation in IIR. mtDNA leakage and TFAM downregulation are key mechanisms driving this activation. Importantly, TFAM plays a crucial role in stabilizing mtDNA and reducing mtDNA leakage during IIR. These results not only deepen our understanding of the molecular pathogenesis of IIR injury but also provide potential therapeutic strategies targeting the cGAS-STING pathway for treating IIR-related diseases.

Accurate and Efficient Detection of Nasopharyngeal Carcinoma Using Multi-Dimensional Features of Plasma Cell-Free DNA

BACKGROUND

The incidence of Nasopharyngeal carcinoma (NPC) is rising in recent years, especially in some non-developed parts of the world. Hence, cost-efficient means for sensitive detection of NPC are vital.

METHODS

We recruited 646 participants, including healthy individuals, patients with benign nasopharyngeal diseases, and NPC patients for plasma cell-free DNA(cfDNA), which underwent low-depth whole-genome sequencing (WGS) to extract multi-dimensional molecular features, including fragmentation pattern, end motif, copy number variation(CNV), and transcription factors(TF). Based on these features, we employed a machine learning algorithm to build prediction models for NPC detection.

RESULTS

We achieved a sensitivity of 95.8% and a specificity of 99.4% to discriminate NPC patients from healthy individuals.

CONCLUSIONS

This study can be a proof-of-concept for these multi-dimensional molecular features to be implemented as a noninvasive approach for the detection and even early detection of NPC.

TFEB and TFE3 regulate STING1-dependent immune responses by controlling type I interferon signaling

STING1 is an essential component of the innate immune defense against a wide variety of pathogens. Whereas induction of type I interferon (IFN) responses is one of the best-defined functions of STING1, our transcriptomic analysis revealed IFN-independent activities of STING1 in macrophages, including transcriptional upregulation of numerous lysosomal and autophagic genes. This upregulation was mediated by the STING1-induced activation of the transcription factors TFEB and TFE3, and led to increased autophagy, lysosomal biogenesis, and lysosomal acidification. TFEB and TFE3 also modulated IFN-dependent STING1 signaling by controlling IRF3 activation. IFN production and cell death were increased in TFEB- and TFE3-depleted iBMDMs. Conversely, TFEB overexpression led to reduced IRF3 activation and an almost complete inhibition of IFN synthesis and secretion, resulting in decreased CASP3 activation and increased cell survival. Our study reveals a key role of TFEB and TFE3 as regulators of STING1-mediated innate antiviral immunity.Abbreviation: ACOD1/IRG1, aconitate decarboxylase 1; cGAMP, cyclic guanosine monophosphate-adenosine monophosphate; CGAS, cyclic GMP-AMP synthase; DMXAA, 5,6-dimethylxanthenone-4-acetic acid; EIF4EBP1, eukaryotic translation initiation factor 4E binding protein 1; GABARAP, GABA type A receptor-associated protein; HSV-1, herpes simplex virus type; iBMDMs, immortalized bone marrow-derived macrophages; IFN, type I interferon; IFNB, interferon beta; IKBKE, inhibitor of nuclear factor kappa B kinase subunit epsilon; IRF3, interferon regulatory factor 3; LAMP1, lysosomal associated membrane protein 1; LAMP2, lysosomal associated membrane protein 2; MTORC1, mechanistic target of rapamycin kinase complex 1; RPS6, ribosomal protein S6; STING1, stimulator of interferon response cGAMP interactor 1; TBK1, TANK binding kinase 1; TFE3, transcription factor binding to IGHM enhancer 3; TFEB, transcription factor EB.

Optimized electroporation buffer improves transfection and prime editing efficiency in adult bovine fibroblasts

For livestock breeding, using somatic cells from adult animals for gene editing and subsequent cloning allows the preservation and enhancement of superior traits from the parent directly in the offspring, while avoiding the loss of genetic gain that can occur through crossbreeding. However, primary cells generally more difficult to transfect and perform gene editing. To date, most related studies have used more vigorous fetal fibroblasts as donor cells, while using somatic cells from adult animals requires more post-editing screening efforts due to the low yield of edited cells. Here, we performed electroporation on adult bovine ear fibroblasts (BEFs) under various conditions such as electrical pulse settings, plasmid dosage, cell density, and concentration of electroporation buffer, and evaluated the transfect efficiency using flow cytometry analysis. We confirmed that the 270 V-10-10 program (270 V, 10 ms, 10 cycles) using 1.5 million cells and 5 µg of EGFP plasmid yielded the highest number of EGFP positive cells. Additionally, we used prime editor (PE) to edit the MSTN locus in BEFs. More importantly, we discovered that lowering the osmolarity of the electroporation buffer improves both electroporation and gene editing efficiency, which relate to the repression of cGAS-STING pathway. Our finding provides valuable references for using electroporation methods in adult bovine primary cell gene editing.

Targeting mitochondrial DNA-STING-NF-κB Axis-mediated microglia activation by cryptotanshinone alleviates ischemic retinopathy

BACKGROUND

Ischemic retinopathy, a leading cause of vision impairment, involves oxidative stress and dysregulated inflammation, with microglia playing a key role. Cryptotanshinone (CTS), a bioactive compound from Salvia miltiorrhiza, exhibits anti-inflammatory and antioxidant properties and thus has the potential for development as a therapeutic agent. However, the actual mechanism of action of CTS in ischemic retinopathy is not known. Overactivation of the STING pathway in microglia is critical in ischemic retinopathy pathogenesis and a potential target of CTS.

PURPOSE

This study aimed to explore whether CTS alleviates ischemic retinopathy by modulating microglial STING signaling.

METHODS

Oxygen-induced retinopathy (OIR) mice and hypoxia-induced microglial cells were used. CTS efficacy in ischemic retinopathy was evaluated at multiple stages using fluorescein fundus angiography, electroretinogram, H&E staining, and Western blotting of relevant proteins. Network pharmacology and RNA sequencing identified STING as a key target. Furthermore, surface plasmon resonance (SPR), molecular docking, and site-directed mutagenesis were systematically employed to elucidate the precise binding interface between CTS and the STING protein. STING activation and knockout models were employed to further investigate the mechanisms of action of CTS.

RESULTS

CTS treatment reduced microglial activation and pathological retinal angiogenesis, and protected both retinal function and structure in OIR mice. Network pharmacology, RNA sequencing, and experimental validation demonstrated a significant link between the protective effect of CTS and the inhibition of STING signaling. Mechanistically, CTS suppressed cytosolic mtDNA release, blocked STING translocation from the ER to the Golgi, and enhanced lysosomal STING degradation. These CTS-mediated effects were abolished by STING activation and absent in Sting-deficient OIR mice. Notably, CTS combined with anti-VEGF therapy showed synergistic efficacy in suppressing pathological retinal neovascularization.

CONCLUSION

CTS, a natural inhibitor of STING, alleviated ischemic retinopathy by inhibiting the mtDNA-STING-NF-κB signaling pathway via multifaceted mechanisms in microglia.

Death domain-associated protein (Daxx) impairs colon cancer chemotherapy by inhibiting the cGAS-STING pathway

Background

Colorectal cancer (CRC) holds the third position in global cancer prevalence mortality. Although chemotherapy is a conventional treatment, recent investigations have shed light on the therapeutic potential of the cGAS cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway in CRC management. Despite the primary role of the death domain-associated protein (Daxx) in cellular apoptosis, its influence on the regulation of cGAS-STING activation remains elusive.

Methods

The Daxx degradation and speck formation were conducted using immunofluorescence and Western blotting. The Daxx knock-down and over-expression in CRC cells were performed to detect in vivo and in vitro migration, proliferation, cGAS-STING activation, and immune responses.

Results

Our study reveals that treatment with irinotecan (CPT-11) and oxaliplatin (OXA) significantly accelerated the Daxx degradation and diminished the formation of Daxx specks within the nucleus of CRC cells. Genetic elimination of Daxx enhanced the irinotecan and oxaliplatin-induced suppression of proliferation and migration in CRC cells, and overexpression of Daxx resulted in similar results. Mechanistically, Daxx overexpression reduced DNA damage repair by restraining homologous recombination (HR) over non-homologous end-joining (NHEJ), which suppressed TBK1 and IRF3 phosphorylation downstream of the cGAS-STING signal. In a murine model of CT-26 tumors, Daxx knockdown amplified the OXA-mediated tumor growth inhibition by promoting STING activation and immune responses.

Conclusions

Our findings show that the degradation of nuclear Daxx potentiates the cGAS-STING pathway, thereby bolstering the efficacy of chemotherapy.

AUP1 and UBE2G2 complex targets STING signaling and regulates virus-induced innate immunity

Stimulator of interferon genes (STING) is an endoplasmic reticulum (ER) signaling adaptor that is essential for the host immune response triggered by DNA pathogens. Precise regulation of STING is crucial for maintaining a balanced immune response and preventing harmful autoinflammation. Activation of STING requires its translocation from the ER to the Golgi apparatus. However, the mechanisms that maintain STING in its resting state remain largely unclear. Here, we find that deficiency of the ancient ubiquitous protein 1 (AUP1) causes spontaneous activation of STING and enhances the expression of type I interferons (IFNs) under resting conditions. Furthermore, deficiency of UBE2G2, a cofactor of AUP1, also promotes the abnormal activation of STING. AUP1 deficiency significantly enhances STING signaling induced by DNA virus, and AUP1 deficiency exhibits increased resistance to DNA virus infection in vitro and in vivo. Mechanistically, AUP1 may form a complex with UBE2G2 to interact with STING, preventing its exit from the ER membrane. Notably, infection with the RNA virus vesicular stomatitis virus (VSV) promotes the accumulation of lipid droplets (LDs) and AUP1 proteins. Additionally, AUP1 deficiency markedly inhibits the replication of VSV because AUP1 deficiency reduces lipid accumulation and alters the expression of lipid metabolism genes, such as carnitine palmitoyltransferase 1A (CPT1A), monoglyceride lipase (MGLL), and sterol regulatory element-binding transcription factor 1 (SREBF1). This study uncovers the essential roles of AUP1 in the STING signaling pathway and lipid metabolism pathway, highlighting its dual role in regulating virus replication.IMPORTANCEThe stimulator of interferon genes (STING) signaling cascade plays an essential role in coordinating innate immunity against DNA pathogens and autoimmunity. Precise regulation of the innate immune response is essential for maintaining homeostasis. In this study, we demonstrate that ancient ubiquitous protein 1 (AUP1) and UBE2G2 act as negative regulators of the innate immune response by targeting STING. Notably, AUP1 interacts with STING to retain STING in the endoplasmic reticulum (ER), preventing STING translocation and thereby limiting STING signaling in the resting state. In addition, deficiency of AUP1 markedly inhibits the replication of DNA virus and RNA virus. Our findings provide new insights into the regulation of STING signaling and confirm AUP1 has a dual role in regulating virus replication.

Leptin attenuates diabetic cardiomyopathy-induced cardiac remodeling via regulating cGAS/STING signaling and Opa1-mediated mitochondrial fusion

PURPOSE

This investigation seeks to elucidate the contribution of leptin to the pathogenesis of diabetic cardiomyopathy (DCM).

METHODS

Mice were rendered diabetic through the administration of streptozotocin (STZ). Leptin was delivered via subcutaneously implanted osmotic pumps. Assessments of cardiac performance, hypertrophy, and fibrosis were conducted using echocardiography, Hematoxylin and Eosin (H&E), Wheat Germ Agglutinin (WGA), and Masson trichrome staining. Myocardial apoptosis and oxidative stress were quantified through TUNEL assay and biochemical markers of oxidative stress, including Malondialdehyde (MDA), 4-Hydroxynonenal (4-HNE), and 3-Nitrotyrosine (3NT). Mitochondrial structure was examined using Transmission Electron Microscopy (TEM). Primary neonatal cardiomyocytes were subjected to high glucose (HG) conditions. The fluorescent indicators MitoTracker Green and MitoSOX Red were employed to evaluate mitochondrial morphology and function within the cardiomyocytes.

RESULTS

Mice with diabetes displayed marked cardiac hypertrophy and fibrosis, as indicated by H&E, WGA, and Masson staining. The administration of leptin significantly mitigated the cardiac pathological manifestations in diabetic mice. Leptin increased the expression of Opa1 and enhanced mitochondrial fusion and function in cardiomyocytes exposed to HG. The cGAS/STING signaling pathway may serve as a pivotal intermediary for leptin to facilitate Opa1-driven mitochondrial fusion.

CONCLUSIONS

Leptin appears to safeguard against hyperglycemia-induced mitochondrial oxidative damage and DCM by modulating the cGAS/STING signaling cascade and Opa1-mediated mitochondrial fusion. These results propose that leptin could be a promising agent for promoting mitochondrial fusion and preventing diabetes-associated cardiac pathologies.

Harnessing Nanomaterials for Enhanced DNA-Based Biosensing and Therapeutic Performance

The integration of nanomaterials with DNA-based systems has emerged as a transformative approach in biosensing and therapeutic applications. Unique features of DNA, like its programmability and specificity, complement the diverse functions of nanomaterials, leading to the creation of advanced systems for detecting biomarkers and delivering treatments. Here, we review the developments in DNA-nanomaterial conjugates, emphasizing their enhanced functionalities and potential across various biomedical applications. We first discuss the methodologies for synthesizing these conjugates, distinguishing between covalent and non-covalent interactions. We then categorize DNA-nanomaterials conjugates based on the properties of the DNA and nanomaterials involved, respectively. DNA probes are classified by their application into biosensing or therapeutic uses, and, several nanomaterials are highlighted by their recent progress in living biological. Finally, we discuss the current challenges and future prospects in this field, anticipating that significant progress in DNA-nanomaterial conjugates will greatly enhance precision medicine.

The dilemma of nuclear mechanical forces in DNA damage and repair

Genomic stability, encompassing DNA damage and repair mechanisms, plays a pivotal role in the onset of diseases and the aging process. The stability of DNA is intricately linked to the chemical and mechanical forces exerted on chromatin, particularly within lamina-associated domains (LADs). Mechanical stress can induce DNA damage through the deformation and rupture of the nuclear envelope, leading to DNA bending and cleavage. However, DNA can evade such mechanical stress-induced damage by relocating away from the nuclear membrane, a process facilitated by the depletion of H3K9me3-marked heterochromatin and its cleavage from the lamina. When DNA double-stranded breaks occur, they prompt the rapid recruitment of Lamin B1 and the deposition of H3K9me3. Despite these insights, the precise mechanisms underlying DNA damage and repair under mechanical stress remain unclear. In this review, we explore the interplay between mechanical forces and the nuclear envelope in the context of DNA damage, elucidate the molecular pathways through which DNA escapes force-induced damage, and discuss the corresponding repair strategies involving the nuclear cytoskeleton. By summarizing the mechanisms of force-induced DNA damage and repair, we aim to underscore the potential for developing targeted therapeutic strategies to bolster genomic stability and alleviate the impacts of aging and disease.

The role of ubiquitination and deubiquitination in the pathogenesis of non-alcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases and is closely associated with metabolic abnormalities. The causes of NAFLD are exceedingly complicated, and it is known that a variety of signaling pathways, endoplasmic reticulum stress, and mitochondrial dysfunction play a role in the pathogenesis of NAFLD. Recent studies have shown that ubiquitination and deubiquitination are involved in the regulation of the NAFLD pathophysiology. Protein ubiquitination is a dynamic and diverse post-translational alteration that affects various cellular biological processes. Numerous disorders, including NAFLD, exhibit imbalances in ubiquitination and deubiquitination. To highlight the significance of this post-translational modification in the pathogenesis of NAFLD and to aid in the development of new therapeutic approaches for the disease, we will discuss the role of enzymes involved in the processes of ubiquitination and deubiquitination, specifically E3 ubiquitin ligases and deubiquitinating enzymes that are important in the regulation of NAFLD.

Distinct oligomeric assemblies of STING induced by non-nucleotide agonists

STING plays essential roles coordinating innate immune responses to processes that range from pathogenic infection to genomic instability. Its adaptor function is activated by cyclic dinucleotide (CDN) secondary messengers originating from self (2'3'-cGAMP) or bacterial sources (3'3'-CDNs). Different classes of CDNs possess distinct binding modes, stabilizing STING's ligand-binding domain (LBD) in either a closed or open conformation. The closed conformation, induced by the endogenous ligand 2'3'-cGAMP, has been extensively studied using cryo-EM. However, significant questions remain regarding the structural basis of STING activation by open conformation-inducing ligands. Using cryo-EM, we investigate potential differences in conformational changes and oligomeric assemblies of STING for closed and open conformation-inducing synthetic agonists. While we observe a characteristic 180° rotation for both classes, the open-LBD inducing agonist diABZI-3 uniquely induces a quaternary structure reminiscent but distinct from the reported autoinhibited state of apo-STING. Additionally, we observe slower rates of activation for this ligand class in functional assays, which collectively suggests the existence of a potential additional regulatory mechanism for open conformation-inducing ligands that involves head-to-head interactions and restriction of curved oligomer formation. These observations have potential implications in the selection of an optimal class of STING agonist in the context of a defined therapeutic application.

In silico pan-cancer analysis of VRAC subunits and their prognostic roles in human cancers

The study focuses on the VRAC channel and its significant roles in cancer development. It addresses a research gap by conducting a pan-cancer analysis with multi-omics bioinformatics tools, integrating data from the Human Protein Atlas (HPA) and Genotype-Tissue Expression (GTEx) datasets to examine mRNA expression patterns of its Leucine Rich Repeat Containing 8 (LRRC8) subunits in various tissues and cancers. The study links variations in LRRC8s expression with patient outcomes and includes analyses of DNA and RNA methylation. The study reveals significant correlations between LRRC8s expression and immune cell infiltration, as well as a positive association with cancer-associated fibroblasts and key immune regulators such as major histocompatibility complex (MHCs) and chemokines. Furthermore, the research suggests that LRRC8s are involved in cancer-signalling pathways, which may offer new therapeutic targets. Additionally, a drug sensitivity analysis shows that LRRC8 subunits affect drug responses differently, supporting the use of personalized therapeutic strategies. In conclusion, the study emphasizes the significance of VRAC subunits in cancer biology and suggests their potential as biomarkers and targets in cancer immunotherapy and personalized medicine.

A novel STING1-activating mutation is identified in a patient with childhood-onset systemic lupus erythematosus

Gain-of-function variants in stimulator of interferon genes (STING1) are known to cause STING-associated vasculopathy with onset in infancy (SAVI), a disorder characterized by cutaneous vasculopathy, interstitial lung disease (ILD), and systemic inflammation. Here, we report a novel STING1 N188H variant in a patient who met the classification criteria for systemic lupus erythematosus (SLE) but lacked typical SAVI features. In vitro assays demonstrated that the N188H variant drives constitutive STING activation and enhances type I interferon signaling. Consistent with this, the patient exhibited elevated interferon-stimulated genes (ISGs) expression, and RNA sequencing confirmed significant upregulation of type I IFN signaling compared to healthy controls. Our findings expand the molecular spectrum of STING-associated disease.

High-Resolution Tracking of Aging-Related Small Molecules: Bridging Pollutant Exposure, Brain Aging Mechanisms, and Detection Innovations

Brain aging is a complex process regulated by genetic, environmental, and metabolic factors, and increasing evidence suggests that environmental pollutants can significantly accelerate this process by interfering with oxidative stress, neuroinflammation, and mitochondrial function-related signaling pathways. Traditional studies have focused on the direct damage of pollutants on macromolecules (e.g., proteins, DNA), while the central role of senescence-associated small molecules (e.g., ROS, PGE2, lactate) in early regulatory mechanisms has been long neglected. In this study, we innovatively proposed a cascade framework of "small molecule metabolic imbalance-signaling pathway dysregulation-macromolecule collapse", which reveals that pollutants exacerbate the dynamics of brain aging through activation of NLRP3 inflammatory vesicles and inhibition of HIF-1α. Meanwhile, to address the technical bottleneck of small molecule spatiotemporal dynamics monitoring, this paper systematically reviews the cutting-edge detection tools such as electrochemical sensors, genetically encoded fluorescent probes and antioxidant quantum dots (AQDs). Among them, AQDs show unique advantages in real-time monitoring of ROS fluctuations and intervention of oxidative damage by virtue of their ultra-high specific surface area, controllable surface modification, and free radical scavenging ability. By integrating multimodal detection techniques and mechanism studies, this work provides a new perspective for analyzing pollutant-induced brain aging and lays a methodological foundation for early intervention strategies based on small molecule metabolic networks.

Effective design of therapeutic nanovaccines based on tumor neoantigens

Neoantigen vaccines are among the most potent immunotherapies for personalized cancer treatment. Therapeutic vaccines containing tumor-specific neoantigens that elicit specific T cell responses offer the potential for long-term clinical benefits to cancer patients. Unlike immune-checkpoint inhibitors (ICIs), which rely on pre-existing specific T cell responses, personalized neoantigen vaccines not only promote existing specific T cell responses but importantly stimulate the generation of neoantigen-specific T cells, leading to the establishment of a persistent specific memory T cell pool. The review discusses the current state of clinical research on neoantigen nanovaccines, focusing on the application of vectors, adjuvants, and combinational strategies to address a range of challenges and optimize therapeutic outcomes.

AMPK is dispensable for physiological podocyte and glomerular functions but prevents glomerular fibrosis in experimental diabetes

AMP-activated protein kinase (AMPK) has been postulated to be crucial in regulating various renal physiology and pathophysiology processes, including energy metabolism, ion and water transport, inflammation, and hypertrophy. However, the specific roles of AMPK in the podocyte, a cell critical for maintaining glomerular filtration, have not been fully explored using genetic model animals. In this study, we generated mice lacking both AMPK α1 and α2 catalytic subunits in glomerular podocytes (pmut). Our findings revealed that, surprisingly, AMPK is dispensable for normal podocyte function. These knockout mice could live as long as their wild-type littermates without showing any pathological alterations in their glomeruli or glomerular function at two years of age. However, under type 1 diabetic conditions, the diabetic pmut mice exhibited increased lipid and collagen accumulation and an elevated expression of mesenchymal proteins in their glomeruli. They also showed more significant albuminuria compared to control diabetic mice. Under high glucose culture conditions, glomeruli isolated from pmut mice demonstrated a reduced expression of mitochondrial genes (e.g., Ndufv2) and increased leakage of mitochondrial components. Additionally, there was heightened expression of genes associated with nucleotide sensing and pro-inflammatory pathways (including mb21d2, IL-1 beta, and NF-kB). These observations suggest that while AMPK is not necessary for podocyte function in healthy kidneys, it is crucial for preventing glomerular fibrosis resulting from lipotoxicity and inflammation under diabetic conditions.

The common HAQ STING allele prevents clinical penetrance of COPA syndrome

COPA syndrome, an autosomal-dominant inborn error of immunity, is nonpenetrant in ∼20% of individuals, with no known mediators of protection. Recent studies implicate STING in the pathogenesis of COPA syndrome. We show that the common HAQ STING allele mediates complete clinical protection. We sequenced 35 individuals with COPA mutations, 26 affected patients and 9 unaffected carriers, finding HAQ STING co-segregation with clinical nonpenetrance. Exome sequencing identified only the mutations comprising HAQ STING as variants shared by unaffected carriers and absent in patients. Experimentally, we found that HAQ STING acts dominantly to dampen COPA-dependent STING signaling. Expressing HAQ STING in patient cells rescued the molecular phenotype of COPA syndrome. Our study is the first report of a common and well-tolerated allele mediating complete clinical protection from a severe genetic disorder. Our findings redefine the diagnostic criteria for COPA syndrome, expose functional differences among STING alleles with broad scientific and clinical implications, and reveal a potential universal gene therapy approach for patients.

Oral Lipid-Based Nanomedicine for the Inhibition of the cGAS-STING Pathway in Inflammatory Bowel Disease Treatment

Harnessing the effect of the cyclic GMP-AMP Synthase-STimulator of INterferon Genes (cGAS-STING) signaling pathway has emerged as a promising approach to developing novel strategies for the oral treatment of inflammatory bowel disease (IBD). In this work, we screened different cGAS-STING inhibitors in vitro in murine macrophages. Then, we encapsulated the cGAS-STING inhibitor H-151 within lipid nanocapsules (LNCs), owing to their inherent ability to induce the secretion of glucagon-like peptide 2 (GLP-2), a re-epithelizing peptide, upon oral administration. We demonstrated that our formulation (LNC(H-151)) could induce GLP-2 secretion and selectively target the cGAS-STING pathway and its downstream key markers (including TBK1 and pTBK1) while reducing the expression of pro-inflammatory cytokines associated with the cGAS-STING pathway (TNF-α and CXCL10) in murine macrophages. In an in vivo acute dextran sodium sulfate (DSS)-induced colitis mouse model, the oral administration of LNC(H-151) significantly reduced pro-inflammatory cytokines to levels comparable to the CTRL Healthy group while promoting mucosal healing. The therapeutic potential of this scalable and cost-effective nanomedicine warrants further investigation as an alternative for the oral treatment of IBD.

CMPK2 promotes microglial activation through the cGAS-STING pathway in the neuroinflammatory mechanism

The activation of microglia and the resulting neuroinflammation play crucial regulatory roles in the pathogenesis and progression of neurological diseases, although the specific mechanisms remain incompletely understood. Cytidine monophosphate kinase 2 (CMPK2) is a key mitochondrial nucleotide kinase involved in cellular energy metabolism and nucleotide synthesis. Recent studies suggest that CMPK2 plays a role in microglial-mediated neuroinflammation; however, its specific impact on microglial activation remains unclear. In this study, we hypothesize that CMPK2 promotes microglial-mediated neuroinflammation by activating the cGAS-STING signaling pathway. To investigate this mechanism, we employed lipopolysaccharide (LPS)-treated microglial cells to investigate the detailed mechanisms by which CMPK2 regulates neuroinflammation. Our experimental results indicate that in the BV2 and mouse primary microglial neuroinflammation model, both CMPK2 protein and transcript levels were significantly elevated, accompanied by microglial activation phenotypes such as increased cell size, shortened processes, transformation to round or rod-like shapes, and elevated CD40 expression. Concurrently, there was an increase in pro-inflammatory cytokine levels and a decrease in anti-inflammatory cytokine levels. Further investigation revealed that in the microglial, the expression of cGAS and STING was elevated, along with an increase in oxidative products and inflammatory responses. CMA stimulation further intensified these changes, while cGAS knockdown mitigated them. Finally, we demonstrated that cGAS knockdown inhibited the oxidative stress, cell activation-related changes, and neuroinflammatory responses induced by CMPK2 overexpression in the BV2 neuroinflammation model. Molecular docking experiments showed that CMPK2 stably binds to cGAS at the protein level. These findings suggest that the cGAS-STING pathway mediates CMPK2-induced microglial activation. In summary, our study demonstrates that LPS-induced CMPK2 overactivity promotes microglial activation and neuroinflammatory through the cGAS-STING pathway.

Remdesivir alleviates joint damage in collagen-induced arthritis and inhibits inflammatory cell death of RA synovial fibroblasts

BACKGROUND

The antiviral agent, remdesivir, is adenosine analogue which is currently also used as anti-coronavirus disease 2019. Remdesivir also had anti-inflammatory effect which reduced pro-inflammatory cytokine production, and inhibition of the cyclic GMP-AMP synthase-STING pathway.

METHODS

We evaluated the antiarthritic effects of remdesivir in a mouse model of High-fat diet (HFD) collagen-induced arthritis (CIA) and in fibroblast-like synoviocytes from patients with RA. Type II collagen was administered to DBA/1J mice to induce CIA. Vehicle or remdesivir was injected subcutaneously three times a week. During 7 weeks of treatment, the arthritis score and incidence were evaluated twice a week. Flow cytometry and confocal imaging were used to evaluate CD4 + T cells in the spleen. FLSs from patients with RA were stimulated in vitro with remdesivir and tumor necrosis factor (TNF)-α, and western blotting was used to measure the expression of STING and necroptosis-related markers.

RESULTS

Remdesivir administration suppressed the incidence and progression of arthritis in mice with CIA. Histological analysis revealed lower inflammation and cartilage damage scores in remdesivir-treated than in vehicle groups. Interleukin (IL)-17 + CD4 + T-cell differentiation was inhibited in the remdesivir-treated group. Furthermore, IL-17/-6/-1β, monocyte chemoattractant protein -1, and TNF-α expression was reduced in the remdesivir group. In vitro, remdesivir suppressed the expression of STING, nuclear factor-κB, RIPK3, and phosphorylated MLKL in RA-FLSs under TNF-α stimulation.

CONCLUSIONS

The antiviral agent remdesivir suppressed arthritis by regulating Th cell differentiation, pro-inflammatory cytokine expression, the STING pathway, and necroptosis.

A non-canonical cGAS-STING pathway drives cellular and organismal aging

Accumulation of cytosolic DNA has emerged as a hallmark of aging, inducing sterile inflammation. STING (Stimulator of Interferon Genes) protein translates the sensing of cytosolic DNA by cGAS (cyclic-GMP-AMP synthase) into an inflammatory response. However, the molecular mechanisms whereby cytosolic DNA-induced cGAS-STING pathway leads to aging remain poorly understood. We show that STING does not follow the canonical pathway of activation in human fibroblasts passaged (aging) in culture, senescent fibroblasts, or progeria fibroblasts (from Hutchinson Gilford Progeria Syndrome patients). Despite cytosolic DNA buildup, features of the canonical cGAS-STING pathway like increased cGAMP production, STING phosphorylation, and STING trafficking to perinuclear compartment are not observed in progeria/senescent/aging fibroblasts. Instead, STING localizes at endoplasmic reticulum, nuclear envelope, and chromatin. Despite the non-conventional STING behavior, aging/senescent/progeria cells activate inflammatory programs such as the senescence-associated secretory phenotype (SASP) and the interferon (IFN) response, in a cGAS and STING-dependent manner, revealing a non-canonical pathway in aging. Importantly, progeria/aging/senescent cells are hindered in their ability to activate the canonical cGAS-STING pathway with synthetic DNA, compared to young cells. This deficiency is rescued by activating vitamin D receptor signaling, unveiling new mechanisms regulating the cGAS-STING pathway in aging. Significantly, in HGPS, inhibition of the non-canonical cGAS-STING pathway ameliorates cellular hallmarks of aging, reduces tissue degeneration, and extends the lifespan of progeria mice. Our study reveals that a new feature of aging is the progressively reduced ability to activate the canonical cGAS-STING pathway in response to cytosolic DNA, triggering instead a non-canonical pathway that drives senescence/aging phenotypes.

Significance Statement

Our study provides novel insights into the mechanisms driving sterile inflammation in aging and progeria. We reveal a previously unrecognized characteristic of aging cells: the progressive loss of ability to activate the canonical response to foreign or self-DNA at the cytoplasm. Instead, aging, senescent, and progeria cells activate inflammatory programs via a non-conventional pathway driven by cGAS and the adaptor protein STING. Importantly, pharmacological inhibition of the non-canonical cGAS-STING pathway ameliorates cellular, tissue and organismal decline in a devastating accelerated aging disease (Hutchinson Gilford Progeria Syndrome), highlighting it as a promising therapeutic target for age-related pathologies.

Lycopene: A potent antioxidant to alleviate kidney disease

Kidney disease is a major public health problem worldwide and one of the common causes of death in patients. How to effectively treat or alleviate renal diseases has not only attracted the attention of a large number of scholars, but is likewise a great challenge. Oxidative stress is the main mechanism leading to kidney injury. Natural antioxidant substances not only have efficient antioxidant capacity, but also have the advantage of high safety and low side effects. Lycopene is a naturally occurring carotenoid found mainly in tomatoes or tomato products. Epidemiologic investigations have shown that lycopene has potent antioxidant properties, scavenges reactive substances, and has a protective role in kidney disease. This paper summarizes the biochemical properties and antioxidant mechanisms of lycopene in the context of animal experiments and clinical studies of lycopene in renal diseases. We found that lycopene exerts its protective effects against kidney injury mainly through anti-oxidative stress and anti-inflammatory effects. Meanwhile, lycopene has been found to reduce the incidence of Chronic Kidney Disease (CKD) as well as mortality in some CKD patients. In addition to this, lycopene intake is negatively correlated with the incidence of kidney cancer and also mitigates the nephrotoxic damage of cisplatin. Therefore, lycopene has a promising application in the treatment of kidney diseases. However, there are relatively few clinical studies on lycopene in renal diseases, and subsequent research studies in large-scale populations are still needed to determine the value of lycopene in renal diseases even further.

ZNFX1 Functions as a Master Regulator of Epigenetically Induced Pathogen Mimicry and Inflammasome Signaling in Cancer

DNA methyltransferase (DNMT) and PARP inhibitors induce a stimulator of IFN gene-dependent pathogen mimicry response (PMR) in ovarian and other cancers. In this study, we showed that combining DNMT and PARP inhibitors upregulates expression of the nucleic acid sensor NFX1-type zinc finger-containing 1 (ZNFX1) protein. ZNFX1 mediated the induction of PMR in mitochondria, serving as a gateway for stimulator of IFN gene-dependent IFN/inflammasome signaling. Loss of ZNFX1 in ovarian cancer cells promoted proliferation and spheroid formation in vitro and tumor growth in vivo. In patient ovarian cancer databases, expression of ZNFX1 was elevated in advanced stage disease, and ZNFX1 expression alone significantly correlated with an increase in overall survival in a phase III trial for patients with therapy-resistant ovarian cancer receiving bevacizumab in combination with chemotherapy. RNA sequencing revealed an association between inflammasome signaling through ZNFX1 and abnormal vasculogenesis. Together, this study identified that ZNFX1 is a tumor suppressor that controls PMR signaling through mitochondria and may serve as a biomarker to facilitate personalized therapy in patients with ovarian cancer. Significance: DNMT and PARP inhibitors induce a nucleic acid sensor, ZNFX1, that serves as a mitochondrial gateway to STING-dependent inflammasome signaling with tumor suppressor properties in ovarian cancer.