The Long Pentraxin PTX3 as a Link Between Innate Immunity, Tissue Remodeling, and Cancer

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.

Transcriptome analysis in mouse skin after exposure to ultraviolet radiation from a canopy sunbed

Exposure to ultraviolet radiation (UV-R), from both natural and artificial tanning, heightens the risk of skin cancer by inducing molecular changes in cells and tissues. Despite established transcriptional alterations at a molecular level due to UV-R exposure, uncertainties persist regarding UV radiation characterization and subsequent genomic changes. Our study aimed to mechanistically explore dose- and time-dependent gene expression changes, that may drive short-term (e.g., sunburn) and long-term actinic (e.g., skin cancer) consequences. Using C57BL/6N mouse skin, we analyzed transcriptomic expression following exposure to five erythemally weighted UV-R doses (0, 5, 10, 20, and 40 mJ/cm2) emitted by a UV-R tanning device. At 96 h post-exposure, 5 mJ/cm2 induced 116 statistically significant differentially expressed genes (DEGs) associated with structural changes from UV-R damage. The highest number of significant gene expression changes occurred at 6 and 48 h post-exposure in the 20 and 40 mJ/cm2 dose groups. Notably, at 40 mJ/cm2, 13 DEGs related to skin barrier homeostasis were consistently perturbed across all timepoints. UV-R exposure activated pathways involving oxidative stress, P53 signaling, inflammation, biotransformation, skin barrier maintenance, and innate immunity. This in vivo study's transcriptional data offers mechanistic insights into both short-term and potential non-threshold-dependent long-term health effects of UV-R tanning.

Proteomic insights into breast cancer response to brain cell-secreted factors

The most devastating feature of cancer cells is their ability to metastasize to distant sites in the body. HER2 + and TN breast cancers frequently metastasize to the brain and stay potentially dormant for years until favorable conditions support their proliferation. The sheltered and delicate nature of the brain prevents, however, early disease detection and effective delivery of therapeutic drugs. Moreover, the challenges associated with the acquisition of brain biopsies add compounding difficulties to exploring the mechanistic aspects of tumor development. To provide insights into the determinants of cancer cell behavior at the brain metastatic site, this study was aimed at exploring the early response of HER2 + breast cancer cells (SKBR3) to factors present in the brain perivascular niche. The neural microenvironment was simulated by using the secretome of a set of brain cells that come first in contact with the cancer cells upon crossing the blood brain barrier, i.e., endothelial cells, astrocytes, and microglia. Cytokine microarrays were used to investigate the secretome mediators of intercellular communication, and proteomic technologies for assessing the changes in the behavior of cancer cells upon exposure to the brain cell-secreted factors. The cytokines detected in the brain secretomes were supportive of inflammatory conditions, while the SKBR3 cells secreted numerous cancer-promoting growth factors that were either absent or present in lower abundance in the brain cell cultures, indicating that upon exposure the SKBR3 cells may have been deprived of favorable conditions for optimal growth. Altogether, the results suggest that the exposure of SKBR3 cells to the brain cell-secreted factors altered their growth potential and drove them toward a state of quiescence, with broader overall outcomes that affected cellular metabolism, adhesion and immune response processes. The findings of this study underscore the key role played by the neural niche in shaping the behavior of metastasized cancer cells, provide insights into the cellular cross-talk that may lead cancer cells into dormancy, and highlight novel opportunities for the development of metastatic breast cancer therapeutic strategies.

Interplay between host humoral pattern recognition molecules controls undue immune responses against Aspergillus fumigatus

Pentraxin 3 (PTX3), a long pentraxin and a humoral pattern recognition molecule (PRM), has been demonstrated to be protective against Aspergillus fumigatus, an airborne human fungal pathogen. We explored its mode of interaction with A. fumigatus, and the resulting implications in the host immune response. Here, we demonstrate that PTX3 interacts with A. fumigatus in a morphotype-dependent manner: (a) it recognizes germinating conidia through galactosaminogalactan, a surface exposed cell wall polysaccharide of A. fumigatus, (b) in dormant conidia, surface proteins serve as weak PTX3 ligands, and (c) surfactant protein D (SP-D) and the complement proteins C1q and C3b, the other humoral PRMs, enhance the interaction of PTX3 with dormant conidia. SP-D, C3b or C1q opsonized conidia stimulated human primary immune cells to release pro-inflammatory cytokines and chemokines. However, subsequent binding of PTX3 to SP-D, C1q or C3b opsonized conidia significantly decreased the production of pro-inflammatory cytokines/chemokines. PTX3 opsonized germinating conidia also significantly lowered the production of pro-inflammatory cytokines/chemokines while increasing IL-10 (an anti-inflammatory cytokine) released by immune cells when compared to the unopsonized counterpart. Overall, our study demonstrates that PTX3 recognizes A. fumigatus either directly or by interplaying with other humoral PRMs, thereby restraining detrimental inflammation. Moreover, PTX3 levels were significantly higher in the serum of patients with invasive pulmonary aspergillosis (IPA) and COVID-19-associated pulmonary aspergillosis (CAPA), supporting previous observations in IPA patients, and suggesting that it could be a potential panel-biomarker for these pathological conditions caused by A. fumigatus.

Functional variants of the pentraxin 3 gene are associated with the metastasis and progression of prostate cancer

Age, ethnic background and genetic components have been identified as the established risks for prostate cancer (PCa). Pentraxin 3 (PTX3), originally identified as a pattern-recognition molecule for defence against infectious agents, has multiple functions in tissue repair and in the regulation of cancer-associated inflammation. In this study, we sought to investigate the impact of PTX3 gene variants on the development of PCa. Genotypes of four common single-nucleotide polymorphisms (SNPs) of PTX3 gene, including rs1840680, rs2305619, rs3816527 and rs2120243, were profiled among 705 PCa patients and 705 ethnicity-matched controls. In this study, we found that patients who carry at least one minor allele (C) of rs3816527 (AC and CC) tended to develop advanced forms of diseases (clinical large T stage, OR, 1.593, p = 0.032; pathologically-confirmed nodal spread, OR, 1.987, p = 0.011; metastatic tumour, OR, 3.896, p = 0.032) as compared with those homologous for the major allele (AA). Further stratification analysis showed that such association of rs3816527 with lymphatic and distal metastasis of PCa was accentuated in the younger age group (≤65 at diagnosis) but not seen in the older age group (>65 at diagnosis), suggesting an age-specific effect of PTX3 variants. Prediction of PTX3 protein structure implied that polymorphism may alter the quaternary organization and oligomerization of PTX3 protein. Moreover, our gene silencing experiments and survey of public datasets revealed that elevation of PTX3 levels in PCa was required for cell migration and associated with tumour metastasis. Our results highlight an association of PTX3 rs3816527 with the progression of PCa.

Exploring gut microbiota's role in rheumatic valve disease: insights from a Mendelian randomization study and mediation analysis

Background

Investigating the relationship between gut microbiota and Rheumatic Valve Disease (RVD) is crucial for understanding the disease's etiology and developing effective interventions. Our study adopts a novel approach to examine the potential causal connections between these factors.

Methods

Utilizing a two-sample Mendelian Randomization (MR) framework, we incorporated a multi-variable MR (MVMR) strategy to assess the mediatory mechanisms involved. This approach involved analyzing data from the MiBioGen consortium for gut microbiota and the FinnGen for RVD, among other sources. Instrumental variables (IVs) were carefully selected based on rigorous MR principles, and statistical analysis was conducted using bidirectional two-sample MR, such as inverse variance-weighted (IVW), weighted median, MR-Egger regression and MR Steiger Test methods. The MR-PRESSO strategy was employed for outlier detection, and MVMR was used to untangle the complex relationships between multiple microbiota and RVD.

Results

Our analysis highlighted several gut microbiota classes and families with potential protective effects against RVD, including Lentisphaerae, Alphaproteobacteria, and Streptococcaceae. In contrast, certain genera, such as Eubacterium eligens and Odoribacter, were identified as potential risk factors. The MVMR analysis revealed significant mediation effects of various immune cell traits and biomarkers, such as CD4-CD8- T cells, CD3 on Terminally Differentiated CD8+ T cell and Pentraxin-related protein PTX, elucidating the complex pathways linking gut microbiota to RVD.

Conclusion

This study underscores the intricate and potentially causal relationship between gut microbiota and RVD, mediated through a range of immune and hormonal factors. The use of MVMR in our methodological approach provides a more comprehensive understanding of these interactions, highlighting the gut microbiota's potential as therapeutic targets in RVD management. Our findings pave the way for further research to explore these complex relationships and develop targeted interventions for RVD.

Molecular characterization of a short-chained pentraxin gene from kuruma shrimp Marsupenaeus japonicus hemocytes

Pentraxins (PTXs) are a family of pattern recognition proteins (PRPs) that play a role in pathogen recognition during infection via pathogen-associated molecular patterns (PAMPs). Here, we characterized a short-chained pentraxin isolated from kuruma shrimp (Marsupenaeus japonicus) hemocytes (MjPTX). MjPTX contains the pentraxin signature HxCxS/TWxS (where x can be any amino acid), although the second conserved residue of this signature differed slightly (L instead of C). In the phylogenetic analysis, MjPTX clustered closely with predicted sequences from crustaceans (shrimp, lobster, and crayfish) displaying high sequence identities exceeding 52.67 %. In contrast, MjPTX showed minimal sequence identity when compared to functionally similar proteins in other animals, with sequence identities ranging from 20.42 % (mouse) to 28.14 % (horseshoe crab). MjPTX mRNA transcript levels increased significantly after artificial infection with Vibrio parahaemolyticus (48 h), White Spot Syndrome Virus (72 h) and Yellow Head Virus (24 and 48 h). Assays done in vitro revealed that recombinant MjPTX (rMjPTX) has an ability to agglutinate Gram-negative and Gram-positive bacteria and to bind microbial polysaccharides and bacterial suspensions in the presence of Ca2+. Taken together, our results suggest that MjPTX functions as a classical pattern recognition protein in the presence of calcium ions, that is capable of binding to specific moieties present on the surface of microorganisms and facilitating their clearance.

Association between blood Pentraxin-3 concentrations and rheumatic diseases: A systematic review and meta-analysis

BACKGROUND

Among the Pentraxins, the long Pentraxin-3 (PTX-3) is associated with several processes, particularly in the earliest phases of the innate humoral response. Increased blood PTX-3 concentrations have been observed in a wide range of conditions, from infectious to cardiovascular disorders. Since its increase is more rapid than C-reactive protein (CRP), PTX-3 can be useful to detect and monitor early inflammation. To dissect its pathophysiological role in rheumatic diseases (RD), we conducted a systematic review and meta-analysis comparing blood PTX-3 concentrations in RD patients and healthy individuals and investigating possible associations with clinical, demographic, and study characteristics.

METHODS

We performed a search of published evidence until April 2024 in PubMed, Web of Science and Scopus, which led to the selection of 60 relevant manuscripts from a total of 1072 records.

RESULTS

Our synthesis revealed a statistically significant difference in PTX-3 concentrations between RD patients and controls (standard mean difference, SMD = 1.02, 95% CI 0.77-1.26, p < .001), that correlated with CRP concentrations. The effect size was associated with geographical region of study conduction, RD type, with a reduction of the observed heterogeneity in patients with low LDL-cholesterol and triglycerides concentrations.

CONCLUSIONS

Our study has shown a significant increase in blood PTX-3 concentrations in RD patients, which was associated with specific patient characteristics. Nevertheless, additional studies are needed to better define the utility of measuring PTX-3 in the early phase of RD. Our study was conducted in compliance with the PRISMA 2020 statement (study protocol available at PROSPERO CRD42024516600).

Canine Amniotic Fluid at Birth Holds Information about Neonatal Antibody Titres against Core Vaccine Viruses

There is a growing interest in the composition of amniotic fluid (AF) in both humans and animals. In addition to its nutritional and protective functions for the foetus, current knowledge demonstrates that AF also serves advanced diagnostic, prognostic, and therapeutic roles. Newborn dogs have an underdeveloped immune system, making them highly susceptible to dangerous pathogens such as canine parvovirus (CPV-2), canine infectious hepatitis virus (CAdV-1), and canine distemper virus (CDV), thus exposing them to a high risk of mortality in the first weeks of life. Immunoglobulins G (IgGs) represent the only antibody isotype capable of crossing the placenta in a small amount and have been detected also in canine AF. The primary aim of this study was to investigate the reliability of AF collected at birth as a marker of passive immunity in canine species. For this purpose, total and specific IgGs against CPV-2, CAdV-1, and CDV were investigated and quantified in both maternal plasma and AF collected at the time of caesarean section. The vaccination status of the bitches was also taken into consideration. Since the immune system can be influenced by gestational age, with preterm infants having immature innate and adaptive immunity, IgG concentrations were correlated with amniotic lecithin, sphingomyelin, cortisol, surfactant protein A, and pentraxin 3 levels. In a previous study from our group on foetal maturity these molecules were measured in the same samples. Finally, correlations between their amniotic content and neonatal outcomes were investigated. This study demonstrates that AF analysis at birth can provide valuable insights into neonatal immunity in puppies, offering a non-invasive method to detect potential early health risks, for improved puppy care and management.

Pentraxin 3: A Main Driver of Inflammation and Immune System Dysfunction in the Tumor Microenvironment of Glioblastoma

Brain tumors are a heterogeneous group of brain neoplasms that are highly prevalent in individuals of all ages worldwide. Within this pathological framework, the most prevalent and aggressive type of primary brain tumor is glioblastoma (GB), a subtype of glioma that falls within the IV-grade astrocytoma group. The death rate for patients with GB remains high, occurring within a few months after diagnosis, even with the gold-standard therapies now available, such as surgery, radiation, or a pharmaceutical approach with Temozolomide. For this reason, it is crucial to continue looking for cutting-edge therapeutic options to raise patients' survival chances. Pentraxin 3 (PTX3) is a multifunctional protein that has a variety of regulatory roles in inflammatory processes related to extracellular matrix (ECM). An increase in PTX3 blood levels is considered a trustworthy factor associated with the beginning of inflammation. Moreover, scientific evidence suggested that PTX3 is a sensitive and earlier inflammation-related marker compared to the short pentraxin C-reactive protein (CRP). In several tumoral subtypes, via regulating complement-dependent and macrophage-associated tumor-promoting inflammation, it has been demonstrated that PTX3 may function as a promoter of cancer metastasis, invasion, and stemness. Our review aims to deeply evaluate the function of PTX3 in the pathological context of GB, considering its pivotal biological activities and its possible role as a molecular target for future therapies.

ptx3a+ fibroblast/epicardial cells provide a transient macrophage niche to promote heart regeneration

Macrophages conduct critical roles in heart repair, but the niche required to nurture and anchor them is poorly studied. Here, we investigated the macrophage niche in the regenerating heart. We analyzed cell-cell interactions through published single-cell RNA sequencing datasets and identified a strong interaction between fibroblast/epicardial (Fb/Epi) cells and macrophages. We further visualized the association of macrophages with Fb/Epi cells and the blockage of macrophage response without Fb/Epi cells in the regenerating zebrafish heart. Moreover, we found that ptx3a+ epicardial cells associate with reparative macrophages, and their depletion resulted in fewer reparative macrophages. Further, we identified csf1a expression in ptx3a+ cells and determined that pharmacological inhibition of the csf1a pathway or csf1a knockout blocked the reparative macrophage response. Moreover, we found that genetic overexpression of csf1a enhanced the reparative macrophage response with or without heart injury. Altogether, our studies illuminate a cardiac Fb/Epi niche, which mediates a beneficial macrophage response after heart injury.

PTX3 activates POSTN and promotes the progression of glioblastoma via the MAPK/ERK signalling axis

BACKGROUND

Intrinsic brain tumours such as glioblastoma (GBM) are believed to develop from neuroglial stem or progenitor cells. GBM accounts for approximately half of gliomas. GBM has a poor prognosis and a low 5-year survival rate. Pentraxin 3 (PTX3) is overexpressed in GBM, but the potential mechanism is unclear.

METHODS

Glioblastoma data from the TCGA and CGGA databases were used to analyse PTX3 expression. Subsequently, in vivo and in vitro experiments were conducted to verify the effect of PTX3 silencing in glioma cells on EMT like process and GSC maintenance. The JASPAR database was used to predict the downstream genes of PTX3. POSTN is a novel target gene of PTX3 in gliomas, and this finding was validated using a luciferase reporter gene assay. Western blotting and KEGG enrichment analysis were used to predict the downstream pathway of POSTN, and it was found that the MAPK/ERK pathway might be related to the function of POSTN.

RESULTS

GBM tissues have higher levels of PTX3 expression than normal brain tissues (NBTs). In functional tests, PTX3 promoted the EMT like process of GBM cells while maintaining the stem cell characteristics of GBM stem cells and enhancing their self-renewal. Moreover, we performed a dual luciferase reporter experiment to confirm that PTX3 binds to the POSTN promoter region. In addition, the expression of key proteins in the MAPK/ERK signalling pathway was increased after PTX3 overexpression.

CONCLUSION

POSTN is a direct target of PTX3 that promotes GBM growth via the MAPK/ERK signalling pathway.

Th17 Cell and Inflammatory Infiltrate Interactions in Cutaneous Leishmaniasis: Unraveling Immunopathogenic Mechanisms

The inflammatory response during cutaneous leishmaniasis (CL) involves immune and non-immune cell cooperation to contain and eliminate Leishmania parasites. The orchestration of these responses is coordinated primarily by CD4+ T cells; however, the disease outcome depends on the Th cell predominant phenotype. Although Th1 and Th2 phenotypes are the most addressed as steers for the resolution or perpetuation of the disease, Th17 cell activities, especially IL-17 release, are recognized to be vital during CL development. Th17 cells perform vital functions during both acute and chronic phases of CL. Overall, Th17 cells induce the migration of phagocytes (neutrophils, macrophages) to the infection site and CD8+ T cells and NK cell activation. They also provoke granzyme and perforin secretion from CD8+ T cells, macrophage differentiation towards an M2 phenotype, and expansion of B and Treg cells. Likewise, immune cells from the inflammatory infiltrate have modulatory activities over Th17 cells involving their differentiation from naive CD4+ T cells and further expansion by generating a microenvironment rich in optimal cytokines such as IL-1β, TGF-β, IL-6, and IL-21. Th17 cell activities and synergies are crucial for the resistance of the infection during the early and acute stages; however, if unchecked, Th17 cells might lead to a chronic stage. This review discusses the synergies between Th17 cells and the inflammatory infiltrate and how these interactions might destine the course of CL.

The role of pentraxin 3 and oxidative status in the prognosis of multiple myeloma

Multiple myeloma (MM) is a bone marrow malignancy characterized by plasma cell proliferation. It was aimed to investigate pentraxin 3 (PTX3) levels, oxidative/antioxidative status, and their correlation in MM. In the study, four groups were established, including newly diagnosed MM (NDMM), MM in remission (Rem-MM), relapsed/refractory MM (RRMM) patients, and a healthy control group. PTX3 levels were measured using enzyme-linked immunosorbent assay, and the total antioxidant status (TAS) and total oxidant status (TOS) were assessed with an autoanalyzer. The oxidative stress index (OSI) was calculated using the formula: OSI (arbitrary unit) = TOS (µmol H2O2 Eq/L)/TAS (mmol Trolox Eq/L) × 100. The study involved comparing PTX3, TAS, TOS, and OSI levels among these four groups. PTX3 levels were significantly elevated in NDMM and RRMM groups compared to controls and the Rem-MM group (NDMM vs control; p < 0.001, NDMM vs Rem-MM; p < 0.001, RRMM vs control; p < 0.001, and RRMM vs Rem-MM; p = 0.006). TAS was higher in NDMM and RRMM groups versus controls (p = 0.009 and p < 0.001, respectively), and TOS was higher in rem-MM group versus NDMM and control groups (p < 0.001 and p = 0.016, respectively). OSI was higher in the Rem-MM group than in NDMM and RRMM groups (p < 0.001 and p = 0.009, respectively). Multivariate analysis confirmed associations between MM groups and PTX3 levels. Receiver operating characteristic analysis revealed high specificity (90%) and sensitivity (79%) for PTX3 in NDMM at a >0.56 ng/mL cut-off value. This study suggests that PTX3 levels may have diagnostic and prognostic potential in MM and its relationship with oxidative stress requires further exploration.

Differential gene expression in two consecutive pregnancies between same sex siblings and implications on maternal constraint

The objective of this study was to investigate how placental gene expression differs in two consecutive pregnancies in same sex siblings, and its possible association with the "maternal constraint" hypothesis. Material was gathered from the BASIC study (Biological, Affect, Stress, Imaging, and Cognition in Pregnancy and the Puerperium), a population based prospective study that was started in 2009 in Uppsala. Over 900 specimens of placenta biopsies were collected and out of these 10 women gave birth twice, to the same sex child, and were included in this study. The total RNA was isolated and prepared from frozen villous tissue from the placenta and further analyzed by use of Ion AmpliSeq Human Transcriptome Gene Expression kit. A total of 234 genes differed significantly between the first and second pregnancy placentas, when adjusting for delivery mode, maternal BMI and gestational age. Of special interest was the down-regulated group of genes in the second pregnancy. Exemplified by Pentraxin 3, SRY-Box Transcription Factor 9, and Serum Amyloid A1, which all were associated with biological processes involved in the immune system and inflammation. Further, protein-protein interaction analysis visualized them as hub genes interacting with several of the other differentially expressed genes. How these altered gene expressions affect maternal constraint during pregnancy needs further validation in lager study cohorts and also future validation in functional assays.

A dual role of lysophosphatidic acid type 2 receptor (LPAR2) in nonsteroidal anti-inflammatory drug-induced mouse enteropathy

Lysophosphatidic acid (LPA) is a bioactive phospholipid mediator that has been found to ameliorate nonsteroidal anti-inflammatory drug (NSAID)-induced gastric injury by acting on lysophosphatidic acid type 2 receptor (LPAR2). In this study, we investigated whether LPAR2 signaling was implicated in the development of NSAID-induced small intestinal injury (enteropathy), another major complication of NSAID use. Wild-type (WT) and Lpar2 deficient (Lpar2-/-) mice were treated with a single, large dose (20 or 30 mg/kg, i.g.) of indomethacin (IND). The mice were euthanized at 6 or 24 h after IND treatment. We showed that IND-induced mucosal enteropathy and neutrophil recruitment occurred much earlier (at 6 h after IND treatment) in Lpar2-/- mice compared to WT mice, but the tissue levels of inflammatory mediators (IL-1β, TNF-α, inducible COX-2, CAMP) remained at much lower levels. Administration of a selective LPAR2 agonist DBIBB (1, 10 mg/kg, i.g., twice at 24 h and 30 min before IND treatment) dose-dependently reduced mucosal injury and neutrophil activation in enteropathy, but it also enhanced IND-induced elevation of several proinflammatory chemokines and cytokines. By assessing caspase-3 activation, we found significantly increased intestinal apoptosis in IND-treated Lpar2-/- mice, but it was attenuated after DBIBB administration, especially in non-obese diabetic/severe combined immunodeficiency (NOD/SCID) mice. Finally, we showed that IND treatment reduced the plasma activity and expression of autotaxin (ATX), the main LPA-producing enzyme, and also reduced the intestinal expression of Lpar2 mRNA, which preceded the development of mucosal damage. We conclude that LPAR2 has a dual role in NSAID enteropathy, as it contributes to the maintenance of mucosal integrity after NSAID exposure, but also orchestrates the inflammatory responses associated with ulceration. Our study suggests that IND-induced inhibition of the ATX-LPAR2 axis is an early event in the pathogenesis of enteropathy.

Association of PTX3 gene polymorphisms and PTX3 plasma levels with leprosy susceptibility

BACKGROUND

Pentraxin 3 (PTX3) is a soluble pattern recognition receptor that plays a crucial role in modulating the inflammatory response and activating the complement system. Additionally, plasma PTX3 has emerged as a potential biomarker for various infectious diseases. The aim of this study was to evaluate the association of PTX3 gene polymorphisms and PTX3 plasma levels with susceptibility to leprosy and clinical characteristics.

METHODS

Patients with leprosy from a hyperendemic area in the Northeast Region of Brazil were included. Healthy household contacts and healthy blood donors from the same geographical area were recruited as a control group. The rs1840680 and rs2305619 polymorphisms of PTX3 were determined by real-time PCR. Plasma levels of PTX3 were determined by ELISA.

RESULTS

A total of 512 individuals were included. Of these, 273 were patients diagnosed with leprosy; 53 were household contacts, and 186 were healthy blood donors. No association was observed between PTX3 polymorphisms and susceptibility to leprosy or development of leprosy reaction or physical disability. On the other hand, plasma levels of PTX3 were significantly higher in patients with leprosy when compared to household contacts (p = 0.003) or blood donors (p = 0.04). It was also observed that PTX3 levels drop significantly after multidrug therapy (p < 0.0001).

CONCLUSIONS

Our results suggest that PTX3 may play an important role in the pathogenesis of leprosy and point to the potential use of this molecule as an infection marker.

Extracellular vesicle storm during the course of Ebola virus infection in primates

Introduction

Ebola virus (EBOV) is an RNA virus of the Filoviridae family that is responsible for outbreaks of hemorrhagic fevers in primates with a lethality rate as high as 90%. EBOV primarily targets host macrophages leading to cell activation and systemic cytokine storm, and fatal infection is associated with an inhibited interferon response, and lymphopenia. The EBOV surface glycoprotein (GP) has been shown to directly induce T cell depletion and can be secreted outside the virion via extracellular vesicles (EVs), though most studies are limited to epithelial cells and underlying mechanisms remain poorly elucidated.

Methods

To assess the role of GP on EBOV-induced dysregulation of host immunity, we first utilized EBOV virus-like particles (VLPs) expressing VP40 and NP either alone (Bald-VLP) or in conjunction with GP (VLP-GP) to investigate early inflammatory responses in THP-1 macrophages and in a murine model. We then sought to decipher the role of non-classical inflammatory mediators such as EVs over the course of EBOV infection in two EBOV-infected rhesus macaques by isolating and characterizing circulatory EVs throughout disease progression using size exclusion chromatography, nanoparticle tracking-analysis, and LC-MS/MS.

Results

While all VLPs could induce inflammatory mediators and recruit small peritoneal macrophages, pro-inflammatory cytokine and chemokine gene expression was exacerbated by the presence of GP. Further, quantification of EVs isolated from infected rhesus macaques revealed that the concentration of vesicles peaked in circulation at the terminal stage, at which time EBOV GP could be detected in host-derived exosomes. Moreover, comparative proteomics conducted across EV populations isolated from serum at various time points before and after infection revealed differences in host-derived protein content that were most significantly pronounced at the endpoint of infection, including significant expression of mediators of TLR4 signaling.

Discussion

These results suggest a dynamic role for EVs in the modification of disease states in the context of EBOV. Overall, our work highlights the importance of viral factors, such as the GP, and host derived EVs in the inflammatory cascade and pathogenesis of EBOV, which can be collectively further exploited for novel antiviral development.

PTX3 shapes profibrotic immune cells and epithelial/fibroblast repair and regeneration in a murine model of pulmonary fibrosis

The long pentraxin 3 (PTX3) is protective in different pathologies but was not analyzed in-depth in Idiopathic Pulmonary Fibrosis (IPF). Here, we have explored the influence of PTX3 in the bleomycin (BLM)-induced murine model of IPF by looking at immune cells (macrophages, mast cells, T cells) and stemness/regenerative markers of lung epithelium (SOX2) and fibro-blasts/myofibroblasts (CD44) at different time points that retrace the progression of the disease from onset at day 14, to full-blown disease at day 21, to incomplete regression at day 28. We took advantage of transgenic PTX3 overexpressing mice (Tie2-PTX3) and Ptx3 null ones (PTX3-KO) in which pulmonary fibrosis was induced. Our data have shown that PTX3 overexpression in Tie2-PTX3 compared to WT or PTX3-KO: reduced CD68+ and CD163+ macrophages and the Tryptase+ mast cells during the whole experimental time; on the contrary, CD4+ T cells are consistently present on day 14 and dramatically decreased on day 21; CD8+ T cells do not show significant differences on day 14, but are significantly reduced on day 21; SOX2 is reduced on days 14 and 21; CD44 is reduced on day 21. Therefore, PTX3 could act on the proimmune and fibrogenic microenvironment to prevent fibrosis in BLM-treated mice.

A cohort-based study of host gene expression: tumor suppressor and innate immune/inflammatory pathways associated with the HIV reservoir size

The major barrier to an HIV cure is the HIV reservoir: latently-infected cells that persist despite effective antiretroviral therapy (ART). There have been few cohort-based studies evaluating host genomic or transcriptomic predictors of the HIV reservoir. We performed host RNA sequencing and HIV reservoir quantification (total DNA [tDNA], unspliced RNA [usRNA], intact DNA) from peripheral CD4+ T cells from 191 ART-suppressed people with HIV (PWH). After adjusting for nadir CD4+ count, timing of ART initiation, and genetic ancestry, we identified two host genes for which higher expression was significantly associated with smaller total DNA viral reservoir size, P3H3 and NBL1, both known tumor suppressor genes. We then identified 17 host genes for which lower expression was associated with higher residual transcription (HIV usRNA). These included novel associations with membrane channel (KCNJ2, GJB2), inflammasome (IL1A, CSF3, TNFAIP5, TNFAIP6, TNFAIP9, CXCL3, CXCL10), and innate immunity (TLR7) genes (FDR-adjusted q<0.05). Gene set enrichment analyses further identified significant associations of HIV usRNA with TLR4/microbial translocation (q = 0.006), IL-1/NRLP3 inflammasome (q = 0.008), and IL-10 (q = 0.037) signaling. Protein validation assays using ELISA and multiplex cytokine assays supported these observed inverse host gene correlations, with P3H3, IL-10, and TNF-α protein associations achieving statistical significance (p<0.05). Plasma IL-10 was also significantly inversely associated with HIV DNA (p = 0.016). HIV intact DNA was not associated with differential host gene expression, although this may have been due to a large number of undetectable values in our study. To our knowledge, this is the largest host transcriptomic study of the HIV reservoir. Our findings suggest that host gene expression may vary in response to the transcriptionally active reservoir and that changes in cellular proliferation genes may influence the size of the HIV reservoir. These findings add important data to the limited host genetic HIV reservoir studies to date.

Plasma-Derived Exosome Proteins as Novel Diagnostic and Prognostic Biomarkers in Neuroblastoma Patients

Neuroblastoma (NB) is the most common extracranial solid tumor during infancy, causing up to 10% of mortality in children; thus, identifying novel early and accurate diagnostic and prognostic biomarkers is mandatory. NB-derived exosomes carry proteins (Exo-prots) reflecting the status of the tumor cell of origin. The purpose of this study was to characterize, for the first time, the Exo-prots specifically expressed in NB patients associated with tumor phenotype and disease stage. We isolated exosomes from plasma specimens of 24 HR-NB patients and 24 low-risk (LR-NB) patients at diagnosis and of 24 age-matched healthy controls (CTRL). Exo-prot expression was measured by liquid chromatography-mass spectrometry. The data are available via ProteomeXchange (PXD042422). The NB patients had a different Exo-prot expression profile compared to the CTRL. The deregulated Exo-prots in the NB specimens acted mainly in the tumor-associated pathways. The HR-NB patients showed a different Exo-prot expression profile compared to the LR-NB patients, with the modulation of proteins involved in cell migration, proliferation and metastasis. NCAM, NCL, LUM and VASP demonstrated a diagnostic value in discriminating the NB patients from the CTRL; meanwhile, MYH9, FN1, CALR, AKAP12 and LTBP1 were able to differentiate between the HR-NB and LR-NB patients with high accuracy. Therefore, Exo-prots contribute to NB tumor development and to the aggressive metastatic NB phenotype.

Proteomic Insights into Metastatic Breast Cancer Response to Brain Cell-Secreted Factors

The most devastating feature of cancer cells is their ability to metastasize to distant sites in the body. HER2+ and triple negative breast cancers frequently metastasize to the brain and stay potentially dormant for years, clinging to the microvasculature, until favorable environmental conditions support their proliferation. The sheltered and delicate nature of the brain prevents, however, early disease detection, diagnosis, and effective delivery of therapeutic drugs. Moreover, the challenges associated with the acquisition of brain tissues and biopsies add compounding difficulties to exploring the mechanistic aspects of tumor development, leading to slow progress in understanding the drivers of disease progression and response to therapy. To provide insights into the determinants of cancer cell behavior at the brain metastatic site, this study was aimed at exploring the growth and initial response of HER2+ breast cancer cells (SKBR3) to factors present in the brain perivascular niche. The neural microenvironment conditions were simulated by using the secretome of a set of brain cells that come first in contact with the cancer cells upon crossing the blood brain barrier, i.e., human endothelial cells (HBEC5i), human astrocytes (NHA) and human microglia (HMC3) cells. Cytokine microarrays were used to investigate the cell secretomes and explore the mediators responsible for cell-cell communication, and proteomic technologies for assessing the changes in the behavior of cancer cells upon exposure to the brain cell-secreted factors. The results of the study suggest that the exposure of SKBR3 cells to the brain secretomes altered their growth potential and drove them towards a state of quiescence. The cytokines, growth factors and enzymes detected in the brain cell-conditioned medium were supportive of mostly inflammatory conditions, indicating a collective functional contribution to cell activation, defense, inflammatory responses, chemotaxis, adhesion, angiogenesis, and ECM organization. The SKBR3 cells, on the other hand, secreted numerous cancer-promoting growth factors that were either absent or present in lower abundance in the brain cell culture media, suggesting that upon exposure the SKBR3 cells were deprived of favorable environmental conditions required for optimal growth. The findings of this study underscore the key role played by the neural niche in shaping the behavior of metastasized cancer cells, providing insights into the cancer-host cell cross-talk that contributes to driving metastasized cancer cells into dormancy and into the opportunities that exist for developing novel therapeutic strategies that target the brain metastases of breast cancer.

ECM-Focused Proteomic Analysis of Ear Punch Regeneration in Acomys Cahirinus

In mammals, significant injury is generally followed by the formation of a fibrotic scar which provides structural integrity but fails to functionally restore damaged tissue. Spiny mice of the genus Acomys represent the first example of full skin autotomy in mammals. Acomys cahirinus has evolved extremely weak skin as a strategy to avoid predation and is able to repeatedly regenerate healthy tissue without scar after severe skin injury or full-thickness ear punches. Extracellular matrix (ECM) composition is a critical regulator of wound repair and scar formation and previous studies have suggested that alterations in its expression may be responsible for the differences in regenerative capacity observed between Mus musculus and A. cahirinus , yet analysis of this critical tissue component has been limited in previous studies by its insolubility and resistance to extraction. Here, we utilize a 2-step ECM-optimized extraction to perform proteomic analysis of tissue composition during wound repair after full-thickness ear punches in A. cahirinus and M. musculus from weeks 1 to 4 post-injury. We observe changes in a wide range of ECM proteins which have been previously implicated in wound regeneration and scar formation, including collagens, coagulation and provisional matrix proteins, and matricryptic signaling peptides. We additionally report differences in crosslinking enzyme activity and ECM protein solubility between Mus and Acomys. Furthermore, we observed rapid and sustained increases in CD206, a marker of pro-regenerative M2 macrophages, in Acomys, whereas little or no increase in CD206 was detected in Mus. Together, these findings contribute to a comprehensive understanding of tissue cues which drive the regenerative capacity of Acomys and identify a number of potential targets for future pro-regenerative therapies.

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.

The PTX3/TLR4 autocrine loop as a novel therapeutic target in triple negative breast cancer

BACKGROUND

The pattern recognition receptor long pentraxin-3 (PTX3) plays conflicting roles in cancer by acting as an oncosuppressor or as a pro-tumor mediator depending on tumor context. Triple negative breast cancer (TNBC) represents the most aggressive histotype of breast cancer, characterized by the lack of efficacious therapeutic targets/approaches and poor prognosis. Thus, the characterization of new molecular pathways and/or alternative druggable targets is of great interest in TNBC.

METHODS

The expression of PTX3 in BC tumor samples and in BC cell lines has been analyzed using the Gene Expression-Based Outcome for Breast Cancer Online (GOBO), qPCR, Western blot and ELISA assay. The contribution of tumor and stromal cells to PTX3 production in TNBC was assessed by analyzing single cell RNA sequencing data and RNAscope performed on TNBC tumor samples. In order to investigate the effects of PTX3 in TNBC, different cell lines were engineered to knock-down (MDA-MB-231 and BT549 cells) or overexpress (MDA-MB-468 and E0771 cells) PTX3. Finally, using these engineered cells, in vitro (including gene expression profiling and gene set enrichment analyses) and in vivo (orthotopic tumor models in immune-compromised and immune competent mice) analyses were performed to assess the role and the molecular mechanism(s) exerted by PTX3 in TNBC.

RESULTS

In silico and experimental data indicate that PTX3 is mainly produced by tumor cells in TNBC and that its expression levels correlate with tumor stage. Accordingly, gene expression and in vitro results demonstrate that PTX3 overexpression confers a high aggressive/proliferative phenotype and fosters stem-like features in TNBC cells. Also, PTX3 expression induces a more tumorigenic potential when TNBC cells are grafted orthotopically in vivo. Conversely, PTX3 downregulation results in a less aggressive behavior of TNBC cells. Mechanistically, our data reveal that PTX3 drives the activation of the pro-tumorigenic Toll-like receptor 4 (TLR4) signaling pathway in TNBC, demonstrating for the first time that the PTX3/TLR4 autocrine stimulation loop contributes to TNBC aggressiveness and that TLR4 inhibition significantly impacts the growth of PTX3-producing TNBC cells.

CONCLUSION

Altogether, these data shed light on the role of tumor-produced PTX3 in TNBC and uncover the importance of the PTX3/TLR4 axis for therapeutic and prognostic exploitation in TNBC.

A Supportive Role of Mesenchymal Stem Cells on Insulin-Producing Langerhans Islets with a Specific Emphasis on The Secretome

Type 1 Diabetes (T1D) is a chronic autoimmune disease characterized by a gradual destruction of insulin-producing β-cells in the endocrine pancreas due to innate and specific immune responses, leading to impaired glucose homeostasis. T1D patients usually require regular insulin injections after meals to maintain normal serum glucose levels. In severe cases, pancreas or Langerhans islet transplantation can assist in reaching a sufficient β-mass to normalize glucose homeostasis. The latter procedure is limited because of low donor availability, high islet loss, and immune rejection. There is still a need to develop new technologies to improve islet survival and implantation and to keep the islets functional. Mesenchymal stem cells (MSCs) are multipotent non-hematopoietic progenitor cells with high plasticity that can support human pancreatic islet function both in vitro and in vivo and islet co-transplantation with MSCs is more effective than islet transplantation alone in attenuating diabetes progression. The beneficial effect of MSCs on islet function is due to a combined effect on angiogenesis, suppression of immune responses, and secretion of growth factors essential for islet survival and function. In this review, various aspects of MSCs related to islet function and diabetes are described.

Serum Pentraxin 3 as Promising Biomarker for the Long-Lasting Inflammatory Response of COVID-19

Currently, biological markers for COVID-19 disease severity still constitute the main goal of enhancing an efficient treatment to reduce critical consequences such as an abnormal systemic inflammatory response. In this regard, the latest research has shown that Pentraxin 3 (PTX3), a highly conserved innate immunity protein, may serve as a valuable biochemical marker. Based on this evidence, we conducted a case-control study to compare the PTX3 serum levels and several immune-inflammatory mediators of 80 healthcare workers who were subdivided into subjects who were previously infected with SARS-CoV-2 (n = 40) and individuals who were never infected (n = 40). Using a commercially available Enzyme-Linked Immunosorbent Assay (ELISA), PTX3 and various immune-inflammatory protein levels were assessed in serum samples, while also considering possible variables (e.g., gender-related differences). We have shown elevated levels of PTX3 and other inflammatory proteins in previously infected COVID-19-positive subjects (p < 0.001). Moreover, the obtained data also indicate a degree of severity influenced by gender, as shown by the subgroup analysis, in which PTX3 expression was more pronounced in previously COVID-19-positive males (p < 0.001) than in females (p < 0.05) compared to the respective controls. In addition, our data further validate, through a direct comparison of previously COVID-19-positive subjects, greater pro-inflammatory levels in males than in females. Overall, our results may support the validity of PTX3 as a systemic biomarker in prolonged systemic inflammatory responses in the context of COVID-19. Thus, PTX3 modulation could constitute an effective therapeutic strategy for improving the recovery from COVID-19 and its systemic long-term consequences.

Machine learning-based immune prognostic model and ceRNA network construction for lung adenocarcinoma

PURPOSE

Lung adenocarcinoma (LUAD) is a malignant tumor with a high lethality rate. Immunotherapy has become a breakthrough in cancer treatment and improves patient survival and prognosis. Therefore, it is necessary to find new immune-related markers. However, the current research on immune-related markers in LUAD is not sufficient. Therefore, there is a need to find new immune-related biomarkers to help treat LUAD patients.

METHODS

In this study, a bioinformatics approach combined with a machine learning approach screened reliable immune-related markers to construct a prognostic model to predict the overall survival (OS) of LUAD patients, thus promoting the clinical application of immunotherapy in LUAD. The experimental data were obtained from The Cancer Genome Atlas (TCGA) database, including 535 LUAD and 59 healthy control samples. Firstly, the Hub gene was screened using a bioinformatics approach combined with the Support Vector Machine Recursive Feature Elimination algorithm; then, a multifactorial Cox regression analysis by constructing an immune prognostic model for LUAD and a nomogram to predict the OS rate of LUAD patients. Finally, the regulatory mechanism of Hub genes in LUAD was analyzed by ceRNA.

RESULTS

Five genes, ADM2, CDH17, DKK1, PTX3, and AC145343.1, were screened as potential immune-related genes in LUAD. Among them, ADM2 and AC145343.1 had a good prognosis in LUAD patients (HR < 1) and were novel markers. The remaining three genes screened were associated with poor prognosis in LUAD patients (HR > 1). In addition, the experimental results showed that patients in the low-risk group had better OS rates than those in the high-risk group (P < 0.001).

CONCLUSION

In this paper, we propose an immune prognostic model to predict OS rate in LUAD patients and show the correlation between five immune genes and the level of immune-related cell infiltration. It provides new markers and additional ideas for immunotherapy in patients with LUAD.

Circulating Profiles of Serum Proguanylin, S100A12 Protein and Pentraxin 3 as Diagnostic Markers of Ulcerative Colitis

The aim of this research was to investigate potential new biomarkers which could be used in the clinical practice of ulcerative colitis (UC). Given the crucial role of intestinal barrier integrity and inflammation in the pathogenesis of UC, the serum profile of proteins linked to intestinal barrier and pro-inflammatory neutrophil products may be useful in diagnosing and monitoring the activity of the disease. We measured serum levels of proguanylin (pro-GN), S100A12, and pentraxin 3 (PTX3) in 31 patients with UC before and after a year of biological treatment, as well as in 20 healthy individuals. Significant differences in the serum profiles of pro-GN (5.27 vs. 11.35, p < 0.001), S100A12 (39.36 vs. 19.74, p < 0.001) and PTX3 (3197.05 vs. 1608.37, p < 0.001) were observed between pre-treatment patients with UC and healthy individuals. Furthermore, in UC patients prior to treatment, the levels of S100A12 (p < 0.0005; r = 0.628) and PTX3 (p < 0.05; r = 0.371) were correlated with disease activity as measured by the Mayo scale. Following a year of biological treatment with adalimumab, the concentration of pro-GN significantly increased (5.27 vs. 6.68, p < 0.005) in the blood of UC patients, while the level of PTX-3 decreased (3197.05 vs. 1946.4, p < 0.0001). Our study demonstrates the usefulness of pro-GN, S100A12, and PTX3 measurements in diagnosing and monitoring the activity of UC.

Deletion of the mRNA stability factor ELAVL1 (HuR) in pancreatic cancer cells disrupts the tumor microenvironment integrity

Stromal cells promote extensive fibrosis in pancreatic ductal adenocarcinoma (PDAC), which is associated with poor prognosis and therapeutic resistance. We report here for the first time that loss of the RNA-binding protein human antigen R (HuR, ELAVL1) in PDAC cells leads to reprogramming of the tumor microenvironment. In multiple in vivo models, CRISPR deletion of ELAVL1 in PDAC cells resulted in a decrease of collagen deposition, accompanied by a decrease of stromal markers (i.e. podoplanin, α-smooth muscle actin, desmin). RNA-sequencing data showed that HuR plays a role in cell-cell communication. Accordingly, cytokine arrays identified that HuR regulates the secretion of signaling molecules involved in stromal activation and extracellular matrix organization [i.e. platelet-derived growth factor AA (PDGFAA) and pentraxin 3]. Ribonucleoprotein immunoprecipitation analysis and transcription inhibition studies validated PDGFA mRNA as a novel HuR target. These data suggest that tumor-intrinsic HuR supports extrinsic activation of the stroma to produce collagen and desmoplasia through regulating signaling molecules (e.g. PDGFAA). HuR-deficient PDAC in vivo tumors with an altered tumor microenvironment are more sensitive to the standard of care gemcitabine, as compared to HuR-proficient tumors. Taken together, we identified a novel role of tumor-intrinsic HuR in its ability to modify the surrounding tumor microenvironment and regulate PDGFAA.

Transcriptional space-time mapping identifies concerted immune and stromal cell patterns and gene programs in wound healing and cancer

Tissue repair responses in metazoans are highly coordinated by different cell types over space and time. However, comprehensive single-cell-based characterization covering this coordination is lacking. Here, we captured transcriptional states of single cells over space and time during skin wound closure, revealing choreographed gene-expression profiles. We identified shared space-time patterns of cellular and gene program enrichment, which we call multicellular "movements" spanning multiple cell types. We validated some of the discovered space-time movements using large-volume imaging of cleared wounds and demonstrated the value of this analysis to predict "sender" and "receiver" gene programs in macrophages and fibroblasts. Finally, we tested the hypothesis that tumors are like "wounds that never heal" and found conserved wound healing movements in mouse melanoma and colorectal tumor models, as well as human tumor samples, revealing fundamental multicellular units of tissue biology for integrative studies.

Complementing Testicular Immune Regulation: The Relationship between Sertoli Cells, Complement, and the Immune Response

Sertoli cells within the testis are instrumental in providing an environment for spermatogenesis and protecting the developing germ cells from detrimental immune responses which could affect fertility. Though these immune responses consist of many immune processes, this review focuses on the understudied complement system. Complement consists of 50+ proteins including regulatory proteins, immune receptors, and a cascade of proteolytic cleavages resulting in target cell destruction. In the testis, Sertoli cells protect the germ cells from autoimmune destruction by creating an immunoregulatory environment. Most studies on Sertoli cells and complement have been conducted in transplantation models, which are effective in studying immune regulation during robust rejection responses. In grafts, Sertoli cells survive activated complement, have decreased deposition of complement fragments, and express many complement inhibitors. Moreover, the grafts have delayed infiltration of immune cells and contain increased infiltration of immunosuppressive regulatory T cells as compared to rejecting grafts. Additionally, anti-sperm antibodies and lymphocyte infiltration have been detected in up to 50% and 30% of infertile testes, respectively. This review seeks to provide an updated overview of the complement system, describe its relationship with immune cells, and explain how Sertoli cells may regulate complement in immunoprotection. Identifying the mechanism Sertoli cells use to protect themselves and germ cells against complement and immune destruction is relevant for male reproduction, autoimmunity, and transplantation.

Long Pentraxin 3 as a New Biomarker for Diagnosis of Hip and Knee Periprosthetic Joint Infections

BACKGROUND

Preoperative diagnosis of periprosthetic joint infections (PJIs) poses an unmet clinical challenge. The long pentraxin PTX3 is a component of the innate immune system involved in infection immunity. This study evaluated the potential of synovial and plasmatic PTX3 in the diagnosis of hip and knee PJIs.

METHODS

Consecutive total hip and knee arthroplasty (THA/TKA) revisions were prospectively included and classified as septic or aseptic according to the European Bone and Joint Infection Society (EBJIS) and Musculoskeletal Infection Society (MSIS) criteria. The concentration of PTX3 in plasma and synovial fluid samples was measured with ELISA. The AUC, threshold value, sensitivity, specificity, and positive and negative likelihood ratios were calculated using the ROC (receiver operating characteristic) curve method.

RESULTS

The study population included 128 patients (94 THAs; 34 TKAs). The AUC of the synovial PTX3 based on EBJIS criteria was 0.85 (p < 0.0001), with a sensitivity of 81.13% and a specificity of 93.33%. The AUC based on MSIS criteria was 0.95 (p < 0.001), with a sensitivity of 91.43% and a specificity of 89.25%. Plasmatic PTX3 failed to discriminate infected from non-infected patients.

CONCLUSIONS

Synovial PTX3 demonstrated an excellent diagnostic potential in hip and knee PJIs, with a very high specificity irrespective of the diagnostic criteria for PJI.

The Sertoli Cell Complement Signature: A Suspected Mechanism in Xenograft Survival

The complement system is an important component of transplant rejection. Sertoli cells, an immune regulatory testicular cell, survive long-term when transplanted across immunological barriers; thus, understanding the mechanisms behind this unique survival would be of great benefit to the transplantation field. This study focused on Sertoli cell inhibition of complement as relevant in xenotransplantation. Neonatal pig Sertoli cells (NPSCs) survived activated human complement in vitro while neonatal pig islet (NPI) aggregates and pig aortic endothelial cell (PAEC) survival were diminished to about 65% and 12%, respectively. PAECs cultured in NPSC-conditioned media and human complement demonstrated a 200% increase in survival suggesting that NPSCs secrete complement-inhibiting substances that confer protection. Bioinformatic and molecular analyses identified 21 complement inhibitors expressed by NPSCs with several significantly increased in NPSCs compared to NPIs or PAECs. Lastly, RNA sequencing revealed that NPSCs express 25 other complement factors including cascade components and receptors. Overall, this study identified the most comprehensive Sertoli cell complement signature to date and indicates that the expression of a variety of complement inhibitors ensures a proper regulation of complement through redundant inhibition points. Understanding the regulation of the complement system should be further investigated for extending xenograft viability.

Differences in expression of tumor suppressor, innate immune, inflammasome, and potassium/gap junction channel host genes significantly predict viral reservoir size during treated HIV infection

The major barrier to an HIV cure is the persistence of infected cells that evade host immune surveillance despite effective antiretroviral therapy (ART). Most prior host genetic HIV studies have focused on identifying DNA polymorphisms (e.g., CCR5Δ32 , MHC class I alleles) associated with viral load among untreated "elite controllers" (~1% of HIV+ individuals who are able to control virus without ART). However, there have been few studies evaluating host genetic predictors of viral control for the majority of people living with HIV (PLWH) on ART. We performed host RNA sequencing and HIV reservoir quantification (total DNA, unspliced RNA, intact DNA) from peripheral CD4+ T cells from 191 HIV+ ART-suppressed non-controllers. Multivariate models included covariates for timing of ART initiation, nadir CD4+ count, age, sex, and ancestry. Lower HIV total DNA (an estimate of the total reservoir) was associated with upregulation of tumor suppressor genes NBL1 (q=0.012) and P3H3 (q=0.012). Higher HIV unspliced RNA (an estimate of residual HIV transcription) was associated with downregulation of several host genes involving inflammasome ( IL1A, CSF3, TNFAIP5, TNFAIP6, TNFAIP9 , CXCL3, CXCL10 ) and innate immune ( TLR7 ) signaling, as well as novel associations with potassium ( KCNJ2 ) and gap junction ( GJB2 ) channels, all q<0.05. Gene set enrichment analyses identified significant associations with TLR4/microbial translocation (q=0.006), IL-1β/NRLP3 inflammasome (q=0.008), and IL-10 (q=0.037) signaling. HIV intact DNA (an estimate of the "replication-competent" reservoir) demonstrated trends with thrombin degradation ( PLGLB1 ) and glucose metabolism ( AGL ) genes, but data were (HIV intact DNA detected in only 42% of participants). Our findings demonstrate that among treated PLWH, that inflammation, innate immune responses, bacterial translocation, and tumor suppression/cell proliferation host signaling play a key role in the maintenance of the HIV reservoir during ART. Further data are needed to validate these findings, including functional genomic studies, and expanded epidemiologic studies in female, non-European cohorts.

Author Summary

Although lifelong HIV antiretroviral therapy (ART) suppresses virus, the major barrier to an HIV cure is the persistence of infected cells that evade host immune surveillance despite effective ART, "the HIV reservoir." HIV eradication strategies have focused on eliminating residual virus to allow for HIV remission, but HIV cure trials to date have thus far failed to show a clinically meaningful reduction in the HIV reservoir. There is an urgent need for a better understanding of the host-viral dynamics during ART suppression to identify potential novel therapeutic targets for HIV cure. This is the first epidemiologic host gene expression study to demonstrate a significant link between HIV reservoir size and several well-known immunologic pathways (e.g., IL-1β, TLR7, TNF-α signaling pathways), as well as novel associations with potassium and gap junction channels (Kir2.1, connexin 26). Further data are needed to validate these findings, including functional genomic studies and expanded epidemiologic studies in female, non-European cohorts.

The crossroad between autoimmune disorder, tissue remodeling and cancer of the thyroid: The long pentraxin 3 (PTX3)

Thyroid is at the crossroads of immune dysregulation, tissue remodeling and oncogenesis. Autoimmune disorders, nodular disease and cancer of the thyroid affect a large amount of general population, mainly women. We wondered if there could be a common factor behind three processes (immune dysregulation, tissue remodeling and oncogenesis) that frequently affect, sometimes coexisting, the thyroid gland. The long pentraxin 3 (PTX3) is an essential component of the humoral arm of the innate immune system acting as soluble pattern recognition molecule. The protein is found expressed in a variety of cell types during tissue injury and stress. In addition, PTX3 is produced by neutrophils during maturation in the bone-marrow and is stored in lactoferrin-granules. PTX3 is a regulator of the complement cascade and orchestrates tissue remodeling and repair. Preclinical data and studies in human tumors indicate that PTX3 can act both as an extrinsic oncosuppressor by modulating complement-dependent tumor-promoting inflammation, or as a tumor-promoter molecule, regulating cell invasion and proliferation and epithelial to mesenchymal transition, thus suggesting that this molecule may have different functions on carcinogenesis. The involvement of PTX3 in the regulation of immune responses, tissue remodeling and oncosuppressive processes led us to explore its potential role in the development of thyroid disorders. In this review, we aimed to highlight what is known, at the state of the art, regarding the connection between the long pentraxin 3 and the main thyroid diseases i.e., nodular thyroid disease, thyroid cancer and autoimmune thyroid disorders.

Insights into the Relationship between Pentraxin-3 and Cancer

Although cancer can be cured if detected early and treated effectively, it is still a leading cause of death worldwide. Tumor development can be limited by an appropiate immune response, but it can be promoted by chronic extensive inflammation through metabolic dysregulation and angiogenesis. In the past decade, numerous efforts have been made in order to identify novel candidates with predictive values in cancer diagnostics. In line with this, researchers have investigated the involvement of pentraxin-3 (PTX-3) in cellular proliferation and immune escape in various types of cancers, although it has not been clearly elucidated. PTX-3 is a member of the long pentraxin subfamily which plays an important role in regulating inflammation, innate immunity response, angiogenesis, and tissue remodeling. Increased synthesis of inflammatory biomarkers and activation of different cellular mechanisms can induce PTX-3 expression in various types of cells (neutrophils, monocytes, lymphocytes, myeloid dendritic cells, fibroblasts, and epithelial cells). PTX-3 has both pro- and anti-tumor functions, thus dual functions in oncogenesis. This review elucidates the potential usefulness of PTX-3 as a serum biomarker in cancer. While future investigations are needed, PTX-3 is emerging as a promising tool for cancer's diagnosis and prognosis, and also treatment monitoring.

Blockade of the pentraxin 3/CD44 interaction attenuates lung injury-induced fibrosis

BACKGROUND

Fibrosing interstitial lung diseases (fILD) are potentially fatal with limited therapeutic options and no effective strategies to reverse fibrogenesis. Myofibroblasts are chief effector cells in fibrosis that excessively deposit collagen in the pulmonary interstitium and lead to progressive impairment of gaseous exchange.

METHODS

Plasma and lung specimens from patients with fILD were applied for detecting pentraxin 3 (PTX3) abundance by ELISA and Immunohistochemistry. Masson's trichrome and Sirius red stains and hydroxyproline assay were performed for assessing collagen accumulation in the lungs of bleomycin-exposed conditional Ptx3-deficient and PTX3-neutralizing antibody (αPTX3i)-treated mice. Downstream effectors including signaling pathways and fibrotic genes were examined for assessing CD44-involved PTX3-induced fibrosis in HFL1 and primary mouse fibroblasts.

RESULTS

PTX3 was upregulated in the lungs and plasma of bleomycin-exposed mice and correlated with disease severity and adverse outcomes in fILD patients. Decreased collagen accumulation, attenuation of alveolar fibrosis and fibrotic markers, and improved lung function were observed in bleomycin-exposed conditional Ptx3-deficient mice. PTX3 activates lung fibroblasts to differentiate towards migrative and highly collagen-expressing myofibroblasts. Lung fibroblasts with CD44 inactivation attenuated the PI3K-AKT1, NF-κB, and JNK signaling pathways and fibrotic markers. αPTX3i mimic-based therapeutic studies demonstrated abrogation of the migrative fibroblast phenotype and myofibroblast activation in vitro. Notably, αPTX3i inhibited lung fibrosis, reduced collagen deposition, increased mouse survival, and improved lung function in bleomycin-induced pulmonary fibrosis.

CONCLUSIONS

The present study reveals new insights into the involvement of the PTX3/CD44 axis in fibrosis and suggests PTX3 as a promising therapeutic target in fILD patients.

Profound Effects of Dexamethasone on the Immunological State, Synthesis and Secretion Capacity of Human Testicular Peritubular Cells

The functions of human testicular peritubular cells (HTPCs), forming a small compartment located between the seminiferous epithelium and the interstitial areas of the testis, are not fully known but go beyond intratesticular sperm transport and include immunological roles. The expression of the glucocorticoid receptor (GR) indicates that they may be regulated by glucocorticoids (GCs). Herein, we studied the consequences of the GC dexamethasone (Dex) in cultured HTPCs, which serves as a unique window into the human testis. We examined changes in cytokines, mainly by qPCR and ELISA. A holistic mass-spectrometry-based proteome analysis of cellular and secreted proteins was also performed. Dex, used in a therapeutic concentration, decreased the transcript level of proinflammatory cytokines, e.g., IL6, IL8 and MCP1. An siRNA-mediated knockdown of GR reduced the actions on IL6. Changes in IL6 were confirmed by ELISA measurements. Of note, Dex also lowered GR levels. The proteomic results revealed strong responses after 24 h (31 significantly altered cellular proteins) and more pronounced ones after 72 h of Dex exposure (30 less abundant and 42 more abundant cellular proteins). Dex also altered the composition of the secretome (33 proteins decreased, 13 increased) after 72 h. Among the regulated proteins were extracellular matrix (ECM) and basement membrane components (e.g., FBLN2, COL1A2 and COL3A1), as well as PTX3 and StAR. These results pinpoint novel, profound effects of Dex in HTPCs. If transferrable to the human testis, changes specifically in ECM and the immunological state of the testis may occur in men upon treatment with Dex for medical reasons.

Amaryllidaceae Alkaloids Decrease the Proliferation, Invasion, and Secretion of Clinically Relevant Cytokines by Cultured Human Colon Cancer Cells

Alkaloids isolated from members of the Amaryllidaceae plant family are promising anticancer agents. The purpose of the current study was to determine if the isocarbostyrils narciclasine, pancratistatin, lycorane, lycorine, crinane, and haemanthamine inhibit phenomena related to cancer progression in vitro. To achieve this, we examined the proliferation, adhesion, and invasion of cultured human colon cancer cells via MTT assay and Matrigel-coated Boyden chambers. In addition, Luminex assays were used to quantify the secretion of matrix metalloproteinases (MMP) and cytokines associated with poor clinical outcomes. We found that all alkaloids decreased cell proliferation regardless of TP53 status, with narciclasine exhibiting the greatest potency. The effects on cell proliferation also appear to be specific to cancer cells. Narciclasine, lycorine, and haemanthamine decrease both adhesion and invasion but with various potencies depending on the cell line. In addition, narciclasine, lycorine, and haemanthamine decreased the secretion of MMP-1, -2, and -7, as well as the secretion of the cytokines pentraxin 3 and vascular endothelial growth factor. In conclusion, the present study shows that Amaryllidaceae alkaloids decrease phenomena and cytokines associated with colorectal cancer progression, supporting future investigations regarding their potential as multifaceted drug candidates.

Lung fibroblasts facilitate pre-metastatic niche formation by remodeling the local immune microenvironment

Primary tumors are drivers of pre-metastatic niche formation, but the coordination by the secondary organ toward metastatic dissemination is underappreciated. Here, by single-cell RNA sequencing and immunofluorescence, we identified a population of cyclooxygenase 2 (COX-2)-expressing adventitial fibroblasts that remodeled the lung immune microenvironment. At steady state, fibroblasts in the lungs produced prostaglandin E2 (PGE2), which drove dysfunctional dendritic cells (DCs) and suppressive monocytes. This lung-intrinsic stromal program was propagated by tumor-associated inflammation, particularly the pro-inflammatory cytokine interleukin-1β, supporting a pre-metastatic niche. Genetic ablation of Ptgs2 (encoding COX-2) in fibroblasts was sufficient to reverse the immune-suppressive phenotypes of lung-resident myeloid cells, resulting in heightened immune activation and diminished lung metastasis in multiple breast cancer models. Moreover, the anti-metastatic activity of DC-based therapy and PD-1 blockade was improved by fibroblast-specific Ptgs2 deletion or dual inhibition of PGE2 receptors EP2 and EP4. Collectively, lung-resident fibroblasts reshape the local immune landscape to facilitate breast cancer metastasis.

Utility of Pentraxin-3 as a biomarker for diagnosis of acute appendicitis: a systematic review and meta-analysis

PURPOSE

To systematically summarize all relevant data and to define the current evidence on the utility of Pentraxin-3 (PTX3) as a biomarker for acute appendicitis (AA) in children.

METHODS

This review was conducted in accordance with the PRISMA guidelines. PubMed, Embase, Scopus, and Web of Science databases were systematically searched for studies comparing the levels of PTX3 in patients with AA vs healthy controls or non-specific abdominal pain (NSAP). Mean differences were calculated for all outcomes and the inverse variance method was used for weighted mean difference. The methodological quality of the included studies was assessed using the Downs and Black scale.

RESULTS

Five comparative studies were included. Significantly elevated levels of PTX3 in cases with AA vs healthy controls (WMD: 9.56, 95% CI 7.24-11.88, p < 0.00001), and patients with AA vs NSAP (WMD: 8.05, 95% CI 6.81-9.29, p < 0.00001) were demonstrated. Similarly, in separate meta-analyses, the levels of PTX3 were significantly elevated in children with AA vs healthy controls (WMD: 11.18, 95% CI 10.03-12.34, p < 0.00001), and children with AA vs NSAP (WMD: 8.35, 95% CI 6.88-9.82, p < 0.00001).

CONCLUSIONS

PTX3-levels are elevated in AA, but differentiation between perforated and non-perforated appendicitis demands other methods.

Links between ectopic and abdominal fat and systemic inflammation: New insights from the SHIP-Trend study

BACKGROUND

Excessive fat accumulation in adipose tissue depots and organs such as the pancreas and the liver is associated with systemic low-grade chronic inflammation.

AIMS

To investigate the association between abdominal, hepatic, and pancreatic fat and the circulating level of inflammatory biomarkers.

METHODS

We used data from a subsample of the Study of Health in Pomerania (SHIP-Trend, n = 469). The plasma concentration of 37 inflammatory biomarkers was measured using the Bio-Plex-Pro™-Human-Inflammation-Panel-1. Subcutaneous and visceral adipose tissue (SAT and VAT), as well as hepatic and pancreatic fat, were determined by magnetic resonance imaging. We assessed the associations between fat content and inflammatory biomarkers using multiple linear regression.

RESULTS

Hepatic fat was associated with MMP-2 (β -0.11), PTX3 (β -0.14), and TNFSF12 (β -0.06). Pancreatic fat was associated with sTNFR1 (β 0.15), sTNFR2 (β 0.11), and sCD163 (β 0.13). VAT and SAT were associated with sCD163 (βVAT 0.20, βSAT 0.16), MMP-2 (βVAT -0.12, βSAT -0.10), OSTCN (βVAT -0.16, βSAT -0.10), sTNFR1 (βVAT 0.13, βSAT 0.13), sTNFR2 (βVAT 0.13, βSA 0.12), TNFSF12 (βVAT -0.11, βSAT -0.08), and TNFSF14 (βVAT 0.21, βSAT 0.20). VAT was additionally associated with TNFSF13B (β 0.08) and CHI3L1 (β 0.07).

CONCLUSIONS

Our findings provide new insights into the involvement of hepatic and pancreatic fat on systemic inflammation.

Conditioned media of pancreatic cancer cells and pancreatic stellate cells induce myeloid-derived suppressor cells differentiation and lymphocytes suppression

As pancreatic cancer cells (PCCs) and pancreatic stellate cells (PSCs) are the two major cell types that comprise the immunosuppressive tumor microenvironment of pancreatic cancer, we aimed to investigate the role of conditioned medium derived from PCCs and PSCs co-culture on the viability of lymphocytes. The conditioned medium (CM) collected from PCCs and/or PSCs was used to treat peripheral blood mononuclear cells (PBMCs) to determine CM ability in reducing lymphocytes population. A proteomic analysis has been done on the CM to investigate the differentially expressed protein (DEP) expressed by two PCC lines established from different stages of tumor. Subsequently, we investigated if the reduction of lymphocytes was directly caused by CM or indirectly via CM-induced MDSCs. This was achieved by isolating lymphocyte subtypes and treating them with CM and CM-induced MDSCs. Both PCCs and PSCs were important in suppressing lymphocytes, and the PCCs derived from a metastatic tumor appeared to have a stronger suppressive effect than the PCCs derived from a primary tumor. According to the proteomic profiles of CM, 416 secreted proteins were detected, and 13 DEPs were identified between PANC10.05 and SW1990. However, CM was found unable to reduce lymphocytes viability through a direct pathway. In contrast, CM that contains proteins secreted by PCC and/or PSC appear immunogenic as they increase the viability of lymphocytes subtypes. Lymphocyte subtype treated with CM-induced MDSCs showed reduced viability in T helper 1 (Th1), T helper 2 (Th2), and T regulatory (Treg) cells, but not in CD8+ T cells, and B cells. As a conclusion, the interplay between PCCs and PSCs is important as their co-culture displays a different trend in lymphocytes suppression, hence, their co-culture should be included in future studies to better mimic the tumor microenvironment.

Vasculature atrophy causes a stiffened microenvironment that augments epidermal stem cell differentiation in aged skin

Stem cell loss causes tissue deterioration associated with aging. The accumulation of genomic and oxidative stress-induced DNA damage is an intrinsic cue for stem cell loss^1,2; however, whether there is an external microenvironmental cue that triggers stem cell loss remains unclear. Here we report that the involution of skin vasculature causes dermal stiffening that augments the differentiation and hemidesmosome fragility of interfollicular epidermal stem cells (IFESCs) in aged mouse skin. Aging-related IFESC dysregulation occurs in plantar and tail skin, and is correlated with prolonged calcium influx, which is contributed by the mechanoresponsive ion channel Piezo1 (ref. ³). Epidermal deletion of Piezo1 ameliorated IFESC dysregulation in aged skin, whereas Piezo1 activation augmented IFESC differentiation and hemidesmosome fragility in young mice. The dermis stiffened with age, which was accompanied by dermal vasculature atrophy. Conversely, induction of the dermal vasculature softened the dermis and ameliorated IFESC dysregulation in aged skin. Single-cell RNA sequencing of dermal fibroblasts identified an aging-associated anti-angiogenetic secretory molecule, pentraxin 3 (ref. ⁴), which caused dermal sclerotization and IFESC dysregulation in aged skin. Our findings show that the vasculature softens the microenvironment for stem cell maintenance and provide a potential mechanobiology-based therapeutic strategy against skin disorders in aging.

STAT3 Activates the Pentraxin 3 Gene in Chronic Lymphocytic Leukemia Cells

Pentraxin-related protein 3 (PTX3), commonly produced by myeloid and endothelial cells, is a humoral pattern recognition protein of the innate immune system. Because PTX3 plasma levels of patients with chronic lymphocytic leukemia (CLL) are high and most circulating cells in patients with CLL are CLL cells, we reasoned that CLL cells produce PTX3. Western immunoblotting revealed that low-density cells from seven of seven patients with CLL produce high levels of PTX3, flow cytometry analysis revealed that the PTX3-producing cells are B lymphocytes coexpressing CD19 and CD5, and confocal microscopy showed that PTX3 is present in the cytoplasm of CLL cells. Because STAT3 is constitutively activated in CLL cells, and because we identified putative STAT3 binding sites within the PTX3 gene promoter, we postulated that phosphorylated STAT3 triggers transcriptional activation of PTX3. Immunoprecipitation analysis of CLL cells' chromatin fragments showed that STAT3 Abs precipitated PTX3 DNA. STAT3 knockdown induced a marked reduction in PTX3 expression, indicating a STAT3-induced transcriptional activation of the PTX3 gene in CLL cells. Using an EMSA, we established and used a dual-reporter luciferase assay to confirm that STAT3 binds the PTX3 gene promoter. Downregulation of PTX3 enhanced apoptosis of CLL cells, suggesting that inhibition of PTX3 might benefit patients with CLL.

ST08 Altered NF-κB Pathway in Breast Cancer Cells In Vitro as Revealed by miRNA-mRNA Analysis and Enhanced the Effect of Cisplatin on Tumour Reduction in EAC Mouse Model

ST08 is a novel curcumin derivative that exhibited apoptotic and anti-migratory activity in MDA-MB-231, triple-negative breast cancer cells reported earlier. In this study, we further explored the anticancer properties of ST08. ST08 reduced tumor burden in vivo and induced apoptosis through the mitochondrial pathway both in vitro and in vivo. ST08 potentiated the effect of cisplatin in vitro and in vivo in mouse EAC breast cancer models with minimal toxicity. ST08 induced alterations in the gene expression were studied by parallel analysis of miRNA and mRNA. 74 differentially expressed miRNA regulated 114 mRNA in triple-negative (MDA-MB-231) cancer cells. Pathway related to the ECM was altered in mesenchymal MDA-MB-231 cells. We constructed a unique miRNA-mRNA interaction network, and one of the pathways regulated by miRNA was NF-κB. Targets of NF-κB like MMP1, PTX3, and MMP2 were downregulated in MDA-MB-231 in response to ST08 treatment. PMA induced cell proliferation was abrogated by ST08 treatment, and no additional cell cytotoxicity was observed when used in combination with IKK-16 indicating ST08 regulation of NF-κB pathway in MDA-MB-231 cells.

Pentraxin 3 depletion (PTX3 KD) inhibited myocardial fibrosis in heart failure after myocardial infarction

Background: HF is a common complication of MI. The underlying mechanisms of myocardial fibrosis in HF after MI are incompletely defined. Here, this study aims to investigate the role of PTX3 KD in HF after MI.

Methods: Bioinformatics analysis based on GSE86569 dataset was performed to explore the potential role of PTX3 in HF. Male C57/BL6J mice were administered with lentiviral vector encoding PTX3 KD or empty vector, and then underwent either coronary ligation or sham surgery. Echocardiography, Masson staining, and immunofluorescence counterstaining were conducted to evaluate the cardiac function and fibrosis. Cardiac fibroblasts were isolated and transfected with lentiviral vector encoding PTX3 KD in vitro to verify the in vivo findings.

Results: Bioinformatics analysis based on GSE86569 revealed the aberrant expression of PTX3 in HF patients. Echocardiography showed that PTX3 KD reversed the HF-induced cardiac dysfunction with better cardiac function parameters. Masson staining demonstrated that the obvious infarct and high fibrosis ratio in HF mice were remarkably improved after PTX3 KD. Immunofluorescence staining indicated that the HF-induced increase expression of α-SMA was significantly suppressed by PTX3 KD. Additionally, both in vivo and in vitro results confirmed that PTX3 KD decreased the fibrosis-related up-regulation of collagen I, collagen III, and p-STAT3. However, the result was opposite after IL-6 treatment.

Conclusions: PTX3 KD protects the cardiac function and counteracts the myocardial fibrosis by down-regulating IL-6/STAT3 pathway in HF.