PTX3 promotes osteogenic differentiation by triggering HA/CD44/FAK/AKT positive feedback loop in an inflammatory environment

PTX3 Deficiency Aggravates Periodontitis by the Complement C5a-C5aR1 Axis

Dysregulation of the complement system plays a critical role in periodontitis progression. In addition to the harmful effects of biofilm, aberrant expression of complement regulatory proteins is also a potential cause of periodontitis. Pentraxin 3 (PTX3) is involved in complement activation and regulation, seeking a balance between amplifying complement-mediated immune responses and avoiding complement-mediated tissue damage. However, its role in periodontitis remains unexplored. This study aimed to investigate the effects of PTX3 on inflammation onset and resolution, with a particular emphasis on its complement regulatory function. We found that PTX3 is predominantly expressed in human and mouse inflammatory monocytes and is significantly upregulated during periodontitis. In vivo experiments showed that PTX3 deficiency led to the accumulation of complement C5a, massive infiltration of inflammatory monocytes, and alveolar bone loss in a ligation-induced mouse periodontitis model. Inhibition of C5a signaling with PMX53 or NLRP3 inflammasome with MCC950 significantly alleviated these adverse effects. In addition, PTX3 deficiency delayed the resolution of inflammation and alveolar bone repair during the recovery phase of periodontitis. In vitro studies showed that PTX3 deficiency promoted C5a conversion and release in monocytes, thereby activating the NLRP3 inflammasome via the C5a-C5aR1 axis-mediated mitogen-activated protein kinase and nuclear factor κB signaling in an inflammatory environment. In conclusion, these data elucidate the link between PTX3 in regulating complement activation and periodontitis progression, providing a potential target for innate immune-based therapy of periodontitis.

Nf2-FAK signaling axis is critical for cranial bone ossification and regeneration

Skeletal mesenchymal stem cells (MSCs) possess self-renewal capacities and play a leading role in the craniofacial system. However, their engagement in controlling cranial bone development and regeneration remains largely unidentified. Herein, we discovered the neurofibromin 2 (Nf2)-encoded regulator Merlin, demonstrating indispensableness in the craniofacial system. Mice lacking Nf2 in MSCs exhibit malformed cranial bones, diminished proliferation, increased apoptosis, and more severe osteogenesis impairment. Mechanically, we substantiate that Nf2 physically interacts with focal adhesion kinase (FAK) to preferentially mediate Erk1/2 and PI3K catalytic p110 subunit/Akt signaling. Meanwhile, Nf2-FAK disturbance in MSCs results in deficient migration, cytoskeletal organization and focal adhesion dynamics, and develops retarded regeneration of cranial bone defects. Collectively, our findings underscore an unrecognized scaffolding role for Nf2-FAK as upstream element in regulating PI3K/Akt and Erk1/2 action in osteoblasts, and illuminate its essentialness in coordinating cell migration, osteogenic lineage development, cranial bone ossification and regeneration.

PTX3-assembled pericellular hyaluronan matrix enhances endochondral ossification during fracture healing and heterotopic ossification

Endochondral ossification (EO) is a pivotal process during fracture healing and traumatic heterotopic ossification (HO), involving the cartilaginous matrix synthesis and mineralization. Unlike the extracellular matrix, the hyaluronan (HA)-rich pericellular matrix (PCM) directly envelops chondrocytes, serving as the frontline for extracellular signal reception and undergoing dynamic remodeling. Pentraxin 3 (PTX3), a secreted glycoprotein, facilitates HA matrix assembly and remodeling. However, it remains unclear whether PTX3 affects EO by regulating HA-rich PCM assembly of chondrocytes, thereby impacting fracture healing and traumatic HO. This study demonstrates that PTX3 deficiency impairs fracture healing and inhibits traumatic HO, but dose not affect growth plate development in mice. PTX3 expression is up-regulated during chondrocyte matrix synthesis and maturation and is localized in the HA-rich PCM. PTX3 promotes the assembly of HA-rich PCM in a serum- and TSG6-dependent manner, fostering CD44 receptor clustering, activating the FAK/AKT signaling pathway, and promoting chondrocyte matrix synthesis and maturation. Local injection of PTX3/TSG6 matrix protein mixture effectively promotes fracture healing in mice. In conclusion, PTX3-assembled HA-rich PCM promotes chondrocyte matrix synthesis and maturation via CD44/FAK/AKT signaling. This mechanism facilitates EO during fracture healing and traumatic HO in mice.

KAT3B-mediated succinylation of DERL3 suppresses osteogenic differentiation by promoting M1/M2 macrophage polarization

Periodontitis is a chronic inflammatory disease influenced by macrophage polarization. Additionally, succinylation-enriched Porphyromonas gingivalis is a pathogenic factor of periodontitis. However, the role of succinylation in the pathogenesis of periodontitis remains unclear. This study aimed to investigate the effects of a succinyltransferase KAT3B on macrophage polarization, osteogenic differentiation, and the molecular mechanism. Macrophages RAW264.7 were cocultured with MC3T3-E1-differentiated osteoblasts, and macrophage polarization and osteogenic differentiation were evaluated. iTRAQ-based proteomic analysis identified that DERL3 was highly expressed in lipopolysaccharide (LPS)-treated MC3T3-E1 cells. The TLR4/MyD88 pathway is closely related to inflammatory response. Thus, the succinylation of DERL3 and the TLR4/MyD88 pathway were assessed using immunoblotting. The results showed that KAT3B-mediated succinylation was increased in LPS-treated MC3T3-E1 cells and patients with periodontitis. Knockdown of KAT3B inhibited macrophage M1-like polarization and promoted M2-like polarization, thereby promoting osteogenic differentiation in LPS-treated osteoblasts. Mechanically, overexpression of KAT3B promoted the succinylation of DERL3 and stabilized this protein, thereby upregulating DERL3 expression. Rescue experiments showed that DERL3 reversed the promotion of osteogenic differentiation and M2/M1 macrophage polarization caused by KAT3B knockdown. Moreover, DERL3 activated the TLR4/MyD88 pathway, and inhibition of this pathway reversed macrophage polarization and osteogenesis mediated by DERL3. In vivo experiments showed that KAT3B knockdown attenuated experimental periodontitis in rats. In conclusion, silencing of KAT3B promotes osteogenic differentiation by inducing M2/M1 macrophage polarization through the succinylation DERL3, which regulates the TLR4/MyD88 pathway, thereby attenuating periodontitis. These findings suggest that KAT3B may be a promising therapeutic target for periodontitis.

Prolonged cultivation enhances the stimulatory activity of hiPSC mesenchymal progenitor-derived conditioned medium

BACKGROUND

Human induced pluripotent stem cells represent a scalable source of youthful tissue progenitors and secretomes for regenerative therapies. The aim of our study was to investigate the potential of conditioned medium (CM) from hiPSC-mesenchymal progenitors (hiPSC-MPs) to stimulate osteogenic differentiation of human bone marrow-derived mesenchymal stromal cells (MSCs). We also investigated whether prolonged cultivation or osteogenic pre-differentiation of hiPSC-MPs could enhance the stimulatory activity of CM.

METHODS

MSCs were isolated from 13 donors (age 20-90 years). CM derived from hiPSC-MPs was added to the MSC cultures and the effects on proliferation and osteogenic differentiation were examined after 14 days and 6 weeks. The stimulatory activity of hiPSC-MP-CM was compared with the activity of MSC-derived CM and with the activity of CM prepared from hiPSC-MPs pre-cultured in growth or osteogenic medium for 14 days. Comparative proteomic analysis of CM was performed to gain insight into the molecular components responsible for the stimulatory activity.

RESULTS

Primary bone marrow-derived MSC exhibited variability, with a tendency towards lower proliferation and tri-lineage differentiation in older donors. hiPSC-MP-CM increased the proliferation and alkaline phosphatase activity of MSC from several adult/aged donors after 14 days of continuous supplementation under osteogenic conditions. However, CM supplementation failed to improve the mineralization of MSC pellets after 6 weeks under osteogenic conditions. hiPSC-MP-CM showed greater enhancement of proliferation and ALP activity than CM derived from bone marrow-derived MSCs. Moreover, 14-day cultivation but not osteogenic pre-differentiation of hiPSC-MPs strongly enhanced CM stimulatory activity. Quantitative proteomic analysis of d14-CM revealed a distinct profile of components that formed a highly interconnected associations network with two clusters, one functionally associated with binding and organization of actin/cytoskeletal components and the other with structural constituents of the extracellular matrix, collagen, and growth factor binding. Several hub proteins were identified that were reported to have functions in cell-extracellular matrix interaction, osteogenic differentiation and development.

CONCLUSIONS

Our data show that hiPSC-MP-CM enhances early osteogenic differentiation of human bone marrow-derived MSCs and that prolonged cultivation of hiPSC-MPs enhances CM-stimulatory activity. Proteomic analysis of the upregulated protein components provides the basis for further optimization of hiPSC-MP-CM for bone regenerative therapies.

A systematic review of mesenchymal stem cell secretome: Functional annotations, gene clusters and proteomics analyses for bone formation

The regenerative capacity of mesenchymal stem cells (MSCs) is now attributed to their ability to release paracrine factors into the extracellular matrix that boost tissue regeneration, reduce inflammation and encourage healing. Understanding the MSC secretome is crucial for shifting the prototypic conventional cell-based therapies to cell-free regenerative treatments. This systematic review aimed to analyse the functional annotations of the secretome of human adult adipose tissue and bone marrow MSCs and unveil the gene clusters responsible for bone formation. Bioinformatics tools were used to identify the biological processes, molecular functions, hallmarks and KEGG pathways of adipose and bone marrow MSC secretome proteins. We found a substantial overlap in the functional annotations and protein compositions of both adipose and bone marrow MSC secretome indicating that MSC source may be noninfluencial with regards to tissue regeneration. Additionally, a novel network pharmacology-based analysis of the secreted proteins revealed that the commonly secreted proteins within a single source interact with multiple drugable targets of bone diseases and regulate various KEGG pathway. This study unravels the secretome profile of human adult adipose and bone marrow MSCs based on the current literature and provides valuable insights into the therapeutic use of the MSC secretome for cell-free therapies.

PTX3 promotes cementum formation and cementoblast differentiation via HA/ITGB1/FAK/YAP1 signaling pathway

Cementum is a vital component of periodontium, yet its regeneration remains a challenge. Pentraxin 3 (PTX3) is a multifunctional glycoprotein involved in extracellular matrix remodeling and bone metabolism regulation. However, the role of PTX3 in cementum formation and cementoblast differentiation has not been elucidated. In this study, we initially observed an increase in PTX3 expression during cementum formation and cementoblast differentiation. Then, overexpression of PTX3 significantly enhanced the differentiation ability of cementoblasts. While conversely, PTX3 knockdown exerted an inhibitory effect. Moreover, in Ptx3-deficient mice, we found that cementum formation was hampered. Furthermore, we confirmed the presence of PTX3 within the hyaluronan (HA) matrix, thereby activating the ITGB1/FAK/YAP1 signaling pathway. Notably, inhibiting any component of this signaling pathway partially reduced the ability of PTX3 to promote cementoblast differentiation. In conclusion, our study indicated that PTX3 promotes cementum formation and cementoblast differentiation, which is partially dependent on the HA/ITGB1/FAK/YAP1 signaling pathway. This research will contribute to our understanding of cementum regeneration after destruction.

Advances in Hydrogels for Periodontitis Treatment

Periodontitis is a common condition characterized by a bacterial infection and the disruption of the body's immune-inflammatory response, which causes damage to the teeth and supporting tissues and eventually results in tooth loss. Current therapy involves the systemic and local administration of antibiotics. However, the existing treatments cannot exert effective, sustained release and maintain an effective therapeutic concentration of the drug at the lesion site. Hydrogels are used to treat periodontitis due to their low cytotoxicity, exceptional water retention capability, and controlled drug release profile. Hydrogels can imitate the extracellular matrix of periodontal cells while offering suitable sites to load antibiotics. This article reviews the utilization of hydrogels for periodontitis therapy based on the pathogenesis and clinical manifestations of the disease. Additionally, the latest therapeutic strategies for smart hydrogels and the main techniques for hydrogel preparation have been discussed. The information will aid in designing and preparing future hydrogels for periodontitis treatment.

Trauma diagnostic-related target proteins and their detection techniques

Trauma is a significant health issue that not only leads to immediate death in many cases but also causes severe complications, such as sepsis, thrombosis, haemorrhage, acute respiratory distress syndrome and traumatic brain injury, among trauma patients. Target protein identification technology is a vital technique in the field of biomedical research, enabling the study of biomolecular interactions, drug discovery and disease treatment. It plays a crucial role in identifying key protein targets associated with specific diseases or biological processes, facilitating further research, drug design and the development of treatment strategies. The application of target protein technology in biomarker detection enables the timely identification of newly emerging infections and complications in trauma patients, facilitating expeditious medical interventions and leading to reduced post-trauma mortality rates and improved patient prognoses. This review provides an overview of the current applications of target protein identification technology in trauma-related complications and provides a brief overview of the current target protein identification technology, with the aim of reducing post-trauma mortality, improving diagnostic efficiency and prognostic outcomes for patients.

Genetic Deficiency of the Long Pentraxin 3 Affects Osteogenesis and Osteoclastogenesis in Homeostatic and Inflammatory Conditions

The long pentraxin 3 (PTX3) is a soluble glycoprotein made by immune and nonimmune cells endowed with pleiotropic functions in innate immunity, inflammation, and tissue remodeling. PTX3 has recently emerged as a mediator of bone turnover in both physiological and pathological conditions, with direct and indirect effects on osteoblasts and osteoclasts. This notwithstanding, its role in bone biology, with major regard to the osteogenic potential of osteoblasts and their interplay with osteoclasts, is at present unclear. Here, we investigated the contribution of this pentraxin to bone deposition in the osteogenic lineage by assessing collagen production, mineralization capacity, osteoblast maturation, extracellular matrix gene expression, and inflammatory mediators' production in primary osteoblasts from the calvaria of wild-type (WT) and Ptx3-deficient (Ptx3-/-) mice. Also, we evaluated the effect of PTX3 on osteoclastogenesis in cocultures of primary osteoblasts and bone marrow-derived osteoclasts. Our investigations were carried out both in physiological and inflammatory conditions to recapitulate in vitro aspects of inflammatory diseases of the bone. We found that primary osteoblasts from WT animals constitutively expressed low levels of the protein in osteogenic noninflammatory conditions, and genetic ablation of PTX3 in these cells had no major impact on collagen and hydroxyapatite deposition. However, Ptx3-/- osteoblasts had an increased RANKL/OPG ratio and CD44 expression, which resulted in in enhanced osteoclastogenesis when cocultured with bone marrow monocytes. Inflammation (modelled through administration of tumor necrosis factor-α, TNF-α) boosted the expression and accumulation of PTX3 and inflammatory mediators in WT osteoblasts. In these conditions, Ptx3 genetic depletion was associated with reduced collagen deposition and immune modulators' production. Our study shed light on the role of PTX3 in osteoblast and osteoclast biology and identified a major effect of inflammation on the bone-related properties of this pentraxin, which might be relevant for therapeutic and/or diagnostic purposes in musculoskeletal pathology.

Focal adhesion kinase (FAK): its structure, characteristics, and signaling in skeletal system

Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase and distributes important regulatory functions in skeletal system. Mesenchymal stem cell (MSC) possesses significant migration and differentiation capacity, is an important source of distinctive bone cells production and a prominent bone development pathway. MSC has a wide range of applications in tissue bioengineering and regenerative medicine, and is frequently employed for hematopoietic support, immunological regulation, and defect repair, although current research is insufficient. FAK has been identified to cross-link with many other keys signaling pathways in bone biology and is considered as a fundamental "crossroad" on the signal transduction pathway and a "node" in the signal network to mediate MSC lineage development in skeletal system. In this review, we summarized the structure, characteristics, cellular signaling, and the interactions of FAK with other signaling pathways in the skeletal system. The discovery of FAK and its mediated molecules will lead to a new knowledge of bone development and bone construction as well as considerable potential for therapeutic use in the treatment of bone-related disorders such as osteoporosis, osteoarthritis, and osteosarcoma.

Structural insights into the biological functions of the long pentraxin PTX3

Soluble pattern recognition molecules (PRMs) are a heterogenous group of proteins that recognize pathogen- and danger-associated molecular patterns (PAMPs and DAMPs, respectively), and cooperate with cell-borne receptors in the orchestration of innate and adaptive immune responses to pathogenic insults and tissue damage. Amongst soluble PRMs, pentraxins are a family of highly conserved proteins with distinctive structural features. Originally identified in the early 1990s as an early inflammatory gene, PTX3 is the prototype of long pentraxins. Unlike the short pentraxin C reactive protein (CRP), whose expression is mostly confined to the liver, PTX3 is made by several immune and non-immune cells at sites of infection and inflammation, where it intercepts fundamental aspects of infection immunity, inflammation, and tissue remodeling. Of note, PTX3 cross talks to components of the complement system to control cancer-related inflammation and disposal of pathogens. Also, it is an essential component of inflammatory extracellular matrices (ECMs) through crosslinking of hyaluronic acid and turn-over of provisional fibrin networks that assemble at sites of tissue injury. This functional diversity is mediated by unique structural characteristics whose fine details have been unveiled only recently. Here, we revisit the structure/function relationships of this long pentraxin in light of the most recent advances in its structural biology, with a focus on the interplay with complement and the emerging roles as a component of the ECM. Differences to and similarities with the short pentraxins are highlighted and discussed.

Renal cancer secretome induces migration of mesenchymal stromal cells

BACKGROUND

Advanced renal cell carcinoma (RCC) is therapeutically challenging. RCC progression is facilitated by mesenchymal stem/stromal cells (MSCs) that exert remarkable tumor tropism. The specific mechanisms mediating MSCs' migration to RCC remain unknown. Here, we aimed to comprehensively analyze RCC secretome to identify MSCs attractants.

METHODS

Conditioned media (CM) were collected from five RCC-derived cell lines (Caki-1, 786-O, A498, KIJ265T and KIJ308T) and non-tumorous control cell line (RPTEC/TERT1) and analyzed using cytokine arrays targeting 274 cytokines in addition to global CM proteomics. MSCs were isolated from bone marrow of patients undergoing standard orthopedic surgeries. RCC CM and the selected recombinant cytokines were used to analyze their influence on MSCs migration and microarray-targeted gene expression. The expression of genes encoding cytokines was evaluated in 100 matched-paired control-RCC tumor samples.

RESULTS

When compared with normal cells, CM from advanced RCC cell lines (Caki-1 and KIJ265T) were the strongest stimulators of MSCs migration. Targeted analysis of 274 cytokines and global proteomics of RCC CM revealed decreased DPP4 and EGF, as well as increased AREG, FN1 and MMP1, with consistently altered gene expression in RCC cell lines and tumors. AREG and FN1 stimulated, while DPP4 attenuated MSCs migration. RCC CM induced MSCs' transcriptional reprogramming, stimulating the expression of CD44, PTX3 and RAB27B. RCC cells secreted hyaluronic acid (HA), a CD44 ligand mediating MSCs' homing to the kidney. AREG emerged as an upregulator of MSCs' transcription.

CONCLUSIONS

Advanced RCC cells secrete AREG, FN1 and HA to induce MSCs migration, while DPP4 loss prevents its inhibitory effect on MSCs homing. RCC secretome induces MSCs' transcriptional reprograming to facilitate their migration. The identified components of RCC secretome represent potential therapeutic targets.

EXOSOMES AND MICROVESICLES FROM ADIPOSE-DERIVED MESENCHYMAL STEM CELLS PROTECTS THE ENDOTHELIAL GLYCOCALYX FROM LPS INJURY

ABSTRACT

Introduction: Endothelial glycocalyx damage occurs in numerous pathological conditions and results in endotheliopathy. Extracellular vesicles, including exosomes and microvesicles, isolated from adipose-derived mesenchymal stem cells (ASCs) have therapeutic potential in multiple disease states; however, their role in preventing glycocalyx shedding has not been defined. We hypothesized that ASC-derived exosomes and microvesicles would protect the endothelial glycocalyx from damage by LPS injury in cultured endothelial cells. Methods : Exosomes and microvesicles were collected from ASC conditioned media by centrifugation (10,000 g for microvesicles, 100,000 g for exosomes). Human umbilical vein endothelial cells (HUVECs) were exposed to 1 μg/mL lipopolysaccharide (LPS). LPS-injured cells (n = 578) were compared with HUVECS with concomitant LPS injury plus 1.0 μg/mL of exosomes (n = 540) or microvesicles (n = 510) for 24 hours. These two cohorts were compared with control HUVECs that received phosphate-buffered saline only (n = 786) and HUVECs exposed to exosomes (n = 505) or microvesicles (n = 500) alone. Cells were fixed and stained with FITC-labeled wheat germ agglutinin to quantify EGX. Real-time quantitative reverse-transcription polymerase chain reaction was used on HUVECs cell lystate to quantify hyaluron synthase-1 (HAS1) expression. Results: Exosomes alone decreased endothelial glycocalyx staining intensity when compared with control (4.94 vs. 6.41 AU, P < 0.001), while microvesicles did not cause a change glycocalyx staining intensity (6.39 vs. 6.41, P = 0.99). LPS injury resulted in decreased glycocalyx intensity as compared with control (5.60 vs. 6.41, P < 0.001). Exosomes (6.85 vs. 5.60, P < 0.001) and microvesicles (6.35 vs. 5.60, P < 0.001) preserved endothelial glycocalyx staining intensity after LPS injury. HAS1 levels were found to be higher in the exosome (1.14 vs. 3.67 RE, P = 0.02) and microvesicle groups (1.14 vs. 3.59 RE, P = 0.02) when compared with LPS injury. Hyaluron synthase-2 and synthase-3 expressions were not different in the various experimental groups. Conclusions: Exosomes alone can damage the endothelial glycocalyx. However, in the presence of LPS injury, both exosomes and microvesicles protect the glycocalyx layer. This effect seems to be mediated by HAS1. Level of Evidence : Basic science study.

Retrospective Case-Control Study Genes Related to Bone Metabolism That Justify the Condition of Periodontal Disease and Failure of Dental Implants in Patients with down Syndrome

Down syndrome patients show success rates in dental implants much lower than those observed in the general population. This retrospective case-control study aimed to identify possible genes that are related to the regulation of inflammatory responses and bone metabolism related to periimplantitis and implant loss, as well as genes related to bone quality. This process involved using the functional analysis of the gene expression software Transcriptome Analysis Console (TAC version 4.0 Applied Biosystems^TM, Thermo Fisher Scientific, Waltham, MA, USA) and a search for possible candidate genes involved. The focus was placed on the 93 genes related to periodontitis, periimplantitis, bone loss, implant loss, and genes related to bone quality and regulators underlying the establishment and maintenance of osseointegration. Five genes showed statistically significant results (p < 0.05) in our comparison. Four of them, IL1B (p = 0.023), IL1RN (p = 0.048), BGLAP (p = 0.0372) and PTK2 (p = 0.0075) were down-regulated in the periodontal disease and implant rejection group, and only one was overexpressed: FOXO1A (p = 0.0552). The genes with statistically significant alterations described in this article determine that the group of Down syndrome patients with periodontal disease and implant failure is a group of patients genetically susceptible to suffering from both conditions together.

Oxidative Stress Inhibits Endotoxin Tolerance and May Affect Periodontitis

Periodontal disease is caused by dysbiosis of the dental biofilm and the host inflammatory response. Various pathogenic factors, such as proteases and lipopolysaccharides (LPSs) produced by bacteria, are involved in disease progression. Endotoxin tolerance is a function of myeloid cells, which sustain inflammation and promote tissue regeneration upon prolonged stimulation by endotoxins such as LPS. The role of endotoxin tolerance is gaining attention in various chronic inflammatory diseases, but its role in periodontal disease remains elusive. Oxidative stress, one of the major risk factors for periodontal disease, promotes disease progression through various mechanisms, of which only some are known. The effect of oxidative stress on endotoxin tolerance has not yet been studied, and we postulated that endotoxin tolerance regulation may be an additional mechanism through which oxidative stress influences periodontal disease. This study aimed to reveal the effect of oxidative stress on endotoxin tolerance and that of endotoxin tolerance on periodontitis progression. The effect of oxidative stress on endotoxin tolerance was analyzed in vitro using peritoneal macrophages of mice and hydrogen peroxide (H₂O₂). The results showed that oxidative stress inhibits endotoxin tolerance induced by Porphyromonas gingivalis LPS in macrophages, at least partially, by downregulating LPS-elicited negative regulators of Toll-like receptor (TLR) signaling. A novel oxidative stress mouse model was established using SMP30KO mice incapable of ascorbate biosynthesis. Using this model, we revealed that oxidative stress impairs endotoxin tolerance potential in macrophages in vivo. Furthermore, gingival expression of endotoxin tolerance-related genes and TLR signaling negative regulators was decreased, and symptoms of ligature-induced periodontitis were aggravated in the oxidative stress mouse model. Our findings suggest that oxidative stress may contribute to periodontitis progression through endotoxin tolerance inhibition.

Molecular insight into pentraxin-3: Update advances in innate immunity, inflammation, tissue remodeling, diseases, and drug role

Pentraxin-3 (PTX3) is the prototype of the long pentraxin subfamily, an acute-phase protein consisting of a C-terminal pentraxin domain and a unique N-terminal domain. PTX3 was initially isolated from human umbilical vein endothelial cells and human FS-4 fibroblasts. It was subsequently found to be also produced by synoviocytes, chondrocytes, osteoblasts, smooth muscle cells, myeloid dendritic cells, epithelial cells, and tumor cells. Various modulatory factors, such as miRNAs, cytokines, drugs, and hypoxic conditions, could regulate the expression level of PTX3. PTX3 is essential in regulating innate immunity, inflammation, angiogenesis, and tissue remodeling. Besides, PTX3 may play dual (pro-tumor and anti-tumor) roles in oncogenesis. PTX3 is involved in the occurrence and development of many non-cancerous diseases, including COVID-19, and might be a potential biomarker indicating the prognosis, activity,and severity of diseases. In this review, we summarize and discuss the potential roles of PTX3 in the oncogenesis and pathogenesis of non-cancerous diseases and potential targeted therapies based on PTX3.