NLRC3 deficiency promotes cutaneous wound healing due to the inhibition of p53 signaling

Aging Impairs Implant Osseointegration Through a Novel Reactive Oxygen Species-Hypoxia-Inducible Factor 1α/p53 Axis

Enhancing bone-vessel coupling to form high-quality vascular-rich peri-implant bone is crucial for improving implant prognosis in elder patients. Notably, hypoxia-inducible factor 1α (HIF1α) is known to promote osteogenesis-angiogenesis coupling; however, this effect remains to be investigated in aged bone owing to the dual effect of HIF1α in different aged organs. In this study, HIF1α inhibitor or activator was applied to aged mice and their bone mesenchymal stem cells (BMSCs) to investigate the effects and inner mechanism of HIF1α on the peri-implant osteogenesis and angiogenesis in senescent status. Cell senescence, along with osteogenic and angiogenic abilities of aged BMSCs, was detected, respectively. Meanwhile, a femur implant implantation model was constructed on aged mice, and the bone-vessel coupling of peri-implant bone was observed. Mandibular bone morphology was also detected to further provide evidence for clinical oral implantation. Furthermore, p53 expression was examined in vivo and in vitro following HIF1α intervention. A reactive oxygen species (ROS) scavenger was also adopted to further investigate the roles of ROS in the HIF1α-p53 axis. Results showed that the suppression of HIF1α alleviated senescence and osteogenesis-angiogenesis coupling of aged BMSCs, while its activation aggravated these effects. The mandible phenotype and bone-vessel coupling in aged peri-implant bone also changed accordingly upon regulation of HIF1α. Mechanistically, p53 changed in the same direction as HIF1α in vivo and in vitro. Moreover, the ROS scavenger reversed the HIF1α-p53 relationship and weakened the effect of HIF1α inhibitor on peri-implant bone improvement. In conclusion, in aged mice, highly expressed HIF1α impaired peri-implant bone-vessel coupling and implant osseointegration through p53, and accumulated ROS was a prerequisite for HIF1α to positively regulate p53. These findings provide new insights into the role of HIF1α and the ROS-HIF1α/p53 signaling axis, offering potential therapeutic targets to improve implant outcomes in elderly patients.

Molecular mechanisms of ubiquitination in wound healing

Wound healing is a complex biological process involving multiple cellular and molecular mechanisms. Ubiquitination, a crucial post-translational modification, plays a vital role in regulating various aspects of wound healing through protein modification and degradation. This review comprehensively examines the molecular mechanisms of ubiquitination in wound healing, focusing on its regulation of inflammatory responses, macrophage polarization, angiogenesis, and the activities of fibroblasts and keratinocytes. We discuss how ubiquitination modifies key signaling pathways, including TGF-β/Smad3, NF-κB, and HIF-α, which are essential for proper wound healing. Understanding these mechanisms provides insights into potential therapeutic strategies for treating impaired wound healing, particularly in conditions such as diabetes. The review highlights recent advances in understanding ubiquitination's role in wound healing and discusses future research directions for developing targeted therapeutic approaches.

Porcine NLRC3 specially binds short dsDNA to regulate cGAS activation

Host immune system has evolved multiple sensors to detect pathogenic and damaged DNA, where precise regulation is critical for distinguishing self from non-self. Our previous studies showed that NLRC3 is an inhibitory nucleic acid sensor that binds to viral DNA and thereby unleashing STING activation. In this study, we demonstrate that human NLRC3 favors long dsDNA, while porcine NLRC3 shows an affinity for shorter dsDNA. Mechanistically, a conserved arginine residue within the leucine-rich repeats of primates NLRC3 forms a structural bridge facilitating the binding of long dsDNA. Conversely, a glycine residue that replaces the arginine in non-primates disrupts this bridge. Furthermore, porcine NLRC3 negatively regulates type I interferon by interacting with cyclic GMP-AMP synthase (cGAS) to inhibit its DNA binding, thereby preventing cGAS activation. These results reveal an unrecognized mechanism by which a species-specific amino acid variation of NLRC3 influences nucleic acid recognition, providing insights into the evolution of innate immunity to pathogens.

What is slough? Defining the proteomic and microbial composition of slough and its implications for wound healing

Slough is a well-known feature of non-healing wounds. This pilot study aims to determine the proteomic and microbiologic components of slough as well as interrogate the associations between wound slough components and wound healing. Ten subjects with slow-to-heal wounds and visible slough were enrolled. Aetiologies included venous stasis ulcers, post-surgical site infections and pressure ulcers. Patient co-morbidities and wound healing outcome at 3-months post-sample collection was recorded. Debrided slough was analysed microscopically, through untargeted proteomics, and high-throughput bacterial 16S-ribosomal gene sequencing. Microscopic imaging revealed wound slough to be amorphous in structure and highly variable. 16S-profiling found slough microbial communities to associate with wound aetiology and location on the body. Across all subjects, slough largely consisted of proteins involved in skin structure and formation, blood-clot formation and immune processes. To predict variables associated with wound healing, protein, microbial and clinical datasets were integrated into a supervised discriminant analysis. This analysis revealed that healing wounds were enriched for proteins involved in skin barrier development and negative regulation of immune responses. While wounds that deteriorated over time started off with a higher baseline Bates-Jensen Wound Assessment Score and were enriched for anaerobic bacterial taxa and chronic inflammatory proteins. To our knowledge, this is the first study to integrate clinical, microbiome, and proteomic data to systematically characterise wound slough and integrate it into a single assessment to predict wound healing outcome. Collectively, our findings underscore how slough components can help identify wounds at risk of continued impaired healing and serves as an underutilised biomarker.

Understanding the complexity of p53 in a new era of tumor suppression

p53 was discovered 45 years ago as an SV40 large T antigen binding protein, coded by the most frequently mutated TP53 gene in human cancers. As a transcription factor, p53 is tightly regulated by a rich network of post-translational modifications to execute its diverse functions in tumor suppression. Although early studies established p53-mediated cell-cycle arrest, apoptosis, and senescence as the classic barriers in cancer development, a growing number of new functions of p53 have been discovered and the scope of p53-mediated anti-tumor activity is largely expanded. Here, we review the complexity of different layers of p53 regulation, and the recent advance of the p53 pathway in metabolism, ferroptosis, immunity, and others that contribute to tumor suppression. We also discuss the challenge regarding how to activate p53 function specifically effective in inhibiting tumor growth without harming normal homeostasis for cancer therapy.

Bioactive glass 1393 promotes angiogenesis and accelerates wound healing through ROS/P53/MMP9 signaling pathway

Compared to bioactive glass 45S5, bioactive glass 1393 has shown greater potential in activating tissue cells and promoting angiogenesis for bone repair. Nevertheless, the effect of bioactive glass 1393 in the context of wound healing remains extensively unexplored, and its mechanism in wound healing remains unclear. Considering that angiogenesis is a critical stage in wound healing, we hypothesize that bioactive glass 1393 may facilitate wound healing through the stimulation of angiogenesis. To validate this hypothesis and further explore the mechanisms underlying its pro-angiogenic effects, we investigated the impact of bioactive glass 1393 on wound healing angiogenesis through both in vivo and in vitro studies. The research demonstrated that bioactive glass 1393 accelerated wound healing by promoting the formation of granulation, deposition of collagen, and angiogenesis. The results of Western blot analysis and immunofluorescence staining revealed that bioactive glass 1393 up-regulated the expression of angiogenesis-related factors. Additionally, bioactive glass 1393 inhibited the expression of ROS and P53 to promote angiogenesis. Furthermore, bioactive glass 1393 stimulated angiogenesis through the P53 signaling pathway, as evidenced by P53 activation assays. Collectively, these findings indicate that bioactive glass 1393 accelerates wound healing by promoting angiogenesis via the ROS/P53/MMP9 signaling pathway.

Probiotic Pediococcus pentosaceus restored gossypol-induced intestinal barrier injury by increasing propionate content in Nile tilapia

BACKGROUND

Intestinal barrier is a dynamic interface between the body and the ingested food components, however, dietary components or xenobiotics could compromise intestinal integrity, causing health risks to the host. Gossypol, a toxic component in cottonseed meal (CSM), caused intestinal injury in fish or other monogastric animals. It has been demonstrated that probiotics administration benefits the intestinal barrier integrity, but the efficacy of probiotics in maintaining intestinal health when the host is exposed to gossypol remains unclear. Here, a strain (YC) affiliated to Pediococcus pentosaceus was isolated from the gut of Nile tilapia (Oreochromis niloticus) and its potential to repair gossypol-induced intestinal damage was evaluated.

RESULTS

A total of 270 Nile tilapia (2.20 ± 0.02 g) were allotted in 3 groups with 3 tanks each and fed with 3 diets including CON (control diet), GOS (control diet containing 300 mg/kg gossypol) and GP (control diet containing 300 mg/kg gossypol and 108 colony-forming unit (CFU)/g P. pentosaceus YC), respectively. After 10 weeks, addition of P. pentosaceus YC restored growth retardation and intestinal injury induced by gossypol in Nile tilapia. Transcriptome analysis and siRNA interference experiments demonstrated that NOD-like receptors (NLR) family caspase recruitment domain (CARD) domain containing 3 (Nlrc3) inhibition might promote intestinal stem cell (ISC) proliferation, as well as maintaining gut barrier integrity. 16S rRNA sequencing and gas chromatography-mass spectrometry (GC-MS) revealed that addition of P. pentosaceus YC altered the composition of gut microbiota and increased the content of propionate in fish gut. In vitro studies on propionate's function demonstrated that it suppressed nlrc3 expression and promoted wound healing in Caco-2 cell model.

CONCLUSIONS

The present study reveals that P. pentosaceus YC has the capacity to ameliorate intestinal barrier injury by modulating gut microbiota composition and elevating propionate level. This finding offers a promising strategy for the feed industry to incorporate cottonseed meal into fish feed formulations.

Metabolism-related biomarkers, molecular classification, and immune infiltration in diabetic ulcers with validation

Diabetes mellitus (DM) can lead to diabetic ulcers (DUs), which are the most severe complications. Due to the need for more accurate patient classifications and diagnostic models, treatment and management strategies for DU patients still need improvement. The difficulty of diabetic wound healing is caused closely related to biological metabolism and immune chemotaxis reaction dysfunction. Therefore, the purpose of our study is to identify metabolic biomarkers in patients with DU and construct a molecular subtype-specific prognostic model that is highly accurate and robust. RNA-sequencing data for DU samples were obtained from the Gene Expression Omnibus (GEO) database. DU patients and normal individuals were compared regarding the expression of metabolism-related genes (MRGs). Then, a novel diagnostic model based on MRGs was constructed with the random forest algorithm, and classification performance was evaluated utilizing receiver operating characteristic (ROC) analysis. The biological functions of MRGs-based subtypes were investigated using consensus clustering analysis. A principal component analysis (PCA) was conducted to determine whether MRGs could distinguish between subtypes. We also examined the correlation between MRGs and immune infiltration. Lastly, qRT-PCR was utilized to validate the expression of the hub MRGs with clinical validations and animal experimentations. Firstly, 8 metabolism-related hub genes were obtained by random forest algorithm, which could distinguish the DUs from normal samples validated by the ROC curves. Secondly, DU samples could be consensus clustered into three molecular classifications by MRGs, verified by PCA analysis. Thirdly, associations between MRGs and immune infiltration were confirmed, with LYN and Type 1 helper cell significantly positively correlated; RHOH and TGF-β family remarkably negatively correlated. Finally, clinical validations and animal experiments of DU skin tissue samples showed that the expressions of metabolic hub genes in the DU groups were considerably upregulated, including GLDC, GALNT6, RHOH, XDH, MMP12, KLK6, LYN, and CFB. The current study proposed an auxiliary MRGs-based DUs model while proposing MRGs-based molecular clustering and confirmed the association with immune infiltration, facilitating the diagnosis and management of DU patients and designing individualized treatment plans.

Human Parathyroid Hormone Analog (3-34/29-34) promotes wound re-epithelialization through inducing keratinocyte migration and epithelial-mesenchymal transition via PTHR1-PI3K/AKT activation

BACKGROUND

Re-epithelialization is important in the process of wound healing. Various methods have been identified to expedite the process, but their clinical application remains limited. While parathyroid hormone (PTH) has shown promising results in wound healing due to its role in promoting collagen deposition and cell migration, application is limited by its potentially inhibitive effects when being continuously and locally administrated. Herein, we developed a novel PTH analog, Human parathyroid hormone (hPTH) (3-34/29-34) (henceforth MY-1), by partially replacing and repeating the amino acid sequences of hPTH (1-34), and evaluated its effect on skin wound re-epithelialization.

METHODS

CCK-8, colony formation unit assay, and Ki67 immunofluorescent staining were performed to evaluate the effect of MY-1 on HaCaT cell proliferation. Then, wound scratch assay, Transwell assay and lamellipodia staining were carried out to evaluate the effect of MY-1 on cell migration. Moreover, the epithelial-mesenchymal transition (EMT) markers were measured using qPCR and western blot analysis. For in-vivo drug delivery, gelatin methacryloyl (GelMA) hydrogel was employed to load the MY-1, with the physicochemical characteristics evaluated prior to its application in wound models. Then, MY-1's role in wound healing was determined via acute skin wound models. Finally, the mechanism that MY-1 activated was also detected on HaCaT cells and in-vivo wound models.

RESULTS

In-vitro, MY-1 accelerated the migration and EMT of HaCaT cells, while having little effect on cell proliferation. GelMA and MY-1-incorporated GelMA hydrogels showed similar physicochemical characteristics and were used in the in-vivo studies, where the results revealed that MY-1 led to a stronger re-epithelialization by inducing basal keratinocyte migration and EMT. Further studies on in-vivo wound models and in-vitro HaCaT cells revealed that MY-1 regulated cell migration and EMT through activating PI3K/AKT signaling. The parathyroid hormone type 1 receptor (PTHR1), the main receptor of PTH, was found to be the upstream of PI3K/AKT signaling, through interfering PTHR1 expression with a small interference RNA following detection of the PI3K/AKT activation.

CONCLUSION

Collectively, our study demonstrated that MY-1 accelerates skin wound re-epithelialization by inducing keratinocyte migration and EMT via PTHR1-PI3K/AKT axis activation. Video Abstract.

Genetic Variants in PHACTR1 & LPL Mediate Restenosis Risk in Coronary Artery Patients

Background and Objective

Coronary artery disease (CAD) is a major cause of death worldwide. Revascularization via stent placement or coronary artery bypass grafting (CABG) are standard treatments for CAD. Despite a high success rate, these approaches are associated with long-term failure due to restenosis. Risk factors associated with restenosis were investigated using a case-control association study design.

Methods

Five thousand two hundred and forty-two patients were enrolled in this study and were assigned as follows: Stenosis Group: 3570 patients with CAD >50% without a prior stent or CABG (1394 genotyped), and Restenosis Group: 1672 patients with CAD >50% and prior stent deployment or CABG (705 genotyped). Binomial regression models were applied to investigate the association of restenosis with diabetes, hypertension, and dyslipidemia. The genetic association with restenosis was conducted using PLINK 1.9.

Results

Dyslipidemia is a major risk factor (Odds Ratio (OR) = 2.14, P-value <0.0001) for restenosis particularly among men (OR = 2.32, P < 0.0001), while type 2 diabetes (T2D) was associated with an increased risk of restenosis in women (OR = 1.36, P = 0.01). The rs9349379 (PHACTR1) and rs264 (LPL) were associated with an increased risk of restenosis in our patients. PHACTR1 variant was associated with increased risk of restenosis mainly in women and in diabetic patients, while the LPL variant was associated with increased risk of restenosis in men.

Conclusion

The rs9349379 in PHACTR1 gene is significantly associated with restenosis, this association is more pronounced in women and in diabetic patients. The rs264 in LPL gene was associated with increased risk of restenosis in male patients.

Negative regulator NLRC3: Its potential role and regulatory mechanism in immune response and immune-related diseases

NLRC3 is a member of the pattern recognition receptors nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) family, and plays a pivotal regulatory role in modulating the activation of immune cells. In macrophages, NLRC3 inhibits the activation of the NF-κB signaling pathway, the STING/TBK1 signaling pathway, and the formation of the inflammasome. In the context of T cells immune response, NLRC3 prevents the activation of T cells by regulating the function of dendritic cells and directly influencing the function of T cells. Different from other pattern recognition receptors, NLRC3 is more closely associated with regulatory activity than pathogens recognition, it influences the fates of cells, for example, prevents proliferation, promotes apoptosis and inhibits pyroptosis. These cellular functions regulated by NLRC3 are involved in the development processes of a variety of diseases, such as infectious disease, sterile inflammatory diseases, and cancer. However, its characteristics, function and regulatory mechanism in immune response and immune-related diseases have not been addressed fully. In this review, we elaborate the potential roles of NLRC3 from several different levels, include molecular mechanism, cellular functions in the immune-related diseases.