Targeting and exploitation of tumor-associated neutrophils to enhance immunotherapy and drug delivery for cancer treatment

Neutrophils,the most abundant leukocytes in human blood,are essential fighter immune cells against microbial infection.Based on the finding that neutrophils can either restrict or promote cancer progression,tumor-associated neutrophils(TAN)are classified into anti-tumor N1 and pro-tumor N2 subsets.One of the major mechanisms underlying the tumor-promoting function of N2-TANs is suppression of adaptive immune cells,in particular,cytotoxic T lymphocytes.Currently,no established methodologies are available that can unequivocally distinguish immunosuppressive TANs and granulocytic/polymorphonuclear myeloid-derived suppressor cells(G/PMN-MDSC).In view of the critical role of PMN-MDSCs in immune evasion and resistance to cancer immunotherapy,as established from data obtained with diverse cancer models,therapeutic strategies targeting these cells have been actively developed to enhance the efficacy of immunotherapy.Here,we have reviewed the available literature on strategies targeting PMN-MDSCs and summarized the findings into four categories:(1)depletion of existing PMN-MDSCs,(2)blockade of the development of PMNMDSCs,(3)blockade of PMN-MDSC recruitment,(4)inhibition of immunosuppressive function.Owing to their high mobility to inflamed organs and ability to trespass the blood-brain barrier,neutrophils are outstanding candidate carriers in nanoparticle-based therapies.Another attractive application of neutrophils in cancer therapy is the use of neutrophil membrane-derived nanovesicles as a surrogate of extracellular vesicles for more efficient and scalable drug delivery.In the second part of the review,we have highlighted recent advances in the field of neutrophil-based cancer drug delivery.Overall,we believe that neutrophil-based therapeutics are a rapidly growing area of cancer therapy with significant potential benefits.

Nomogram based on tumor-associated neutrophil-tolymphocyte ratio to predict survival of patients with gastric neuroendocrine neoplasms

AIM To assess the predictive value of the tumor-associated neutrophil-to-lymphocyte ratio in terms of the clinical outcomes of patients with gastric neuroendocrine neoplasms after radical surgery.METHODS Data were retrospectively collected from 142 patients who were diagnosed with gastric neuroendocrine neoplasms and who underwent radical gastrectomy at our department from March 2006 to March 2015. These data were retrospectively analyzed, and a receiver operating characteristic curve analysis was used to identify the optimal value of the tumorassociated neutrophil-to-lymphocyte ratio. Univariate and multivariate survival analyses were used to identify prognostic factors. A nomogram was then applied to predict clinical outcomes after surgery.RESULTS The tumor-associated neutrophil-to-lymphocyte ratio was significantly associated with tumor recurrence, especially with liver metastasis and lymph node metastasis(P < 0.05 for both), but not with clinical characteristics(P > 0.05 for all). A multivariate Cox regression analysis identified the tumor-associatedneutrophil-to-lymphocyte ratio as an independent prognostic factor for recurrence-free survival and overall survival(P < 0.05 for both). The concordance index of the nomograms, which included the tumorassociated neutrophil-to-lymphocyte ratio, Ki-67 index, and lymph node ratio, was 0.788(0.759) for recurrence-free survival(overall survival) and was higher than the concordance index of the traditional TNM staging system [0.672(0.663)].CONCLUSION The tumor-associated neutrophil-to-lymphocyte ratio is an independent prognostic factor in patients with gastric neuroendocrine neoplasms. Nomograms that include the tumor-associated neutrophil-to-lymphocyte ratio, Ki-67 index, and lymph node ratio have a superior ability to predict clinical outcomes of postoperative patients.

Pancreatic melatonin enhances anti-tumor immunity in pancreatic adenocarcinoma through regulating tumor-associated neutrophils infiltration and NETosis

Tumor microenvironment contributes to poor prognosis of pancreatic adenocarcinoma(PAAD)patients.Proper regulation could improve survival.Melatonin is an endogenous hormone that delivers multiple bioactivities.Here we showed that pancreatic melatonin level is associated with patients'survival.In PAAD mice models,melatonin supplementation suppressed tumor growth,while blockade of melatonin pathway exacerbated tumor progression.This anti-tumor effect was independent of cytotoxicity but associated with tumor-associated neutrophils(TANs),and TANs depletion reversed effects of melatonin.Melatonin induced TANs infiltration and activation,therefore induced cell apoptosis of PAAD cells.Cytokine arrays revealed that melatonin had minimal impact on neutrophils but induced secretion of Cxcl2 from tumor cells.Knockdown of Cxcl2 in tumor cells abolished neutrophil migration and activation.Melatonin-induced neutrophils presented an N1-like anti-tumor phenotype,with increased neutrophil extracellular traps(NETs)causing tumor cell apoptosis through cell-to-cell contact.Proteomics analysis revealed that this reactive oxygen species(ROS)-mediated inhibition was fueled by fatty acid oxidation(FAO)in neutrophils,while FAO inhibitor abolished the anti-tumor effect.Analysis of PAAD patient specimens revealed that CXCL2 expression was associated with neutrophil infiltration.CXCL2,or TANs,combined with NET marker,can better predict patients'prognosis.Collectively,we discovered an anti-tumor mechanism of melatonin through recruiting N1-neutrophils and beneficial NET formation.

Calculus bovis inhibits M2 tumor-associated macrophage polarization via Wnt/β-catenin pathway modulation to suppress liver cancer

BACKGROUND Calculus bovis(CB),used in traditional Chinese medicine,exhibits anti-tumor effects in various cancer models.It also constitutes an integral component of a compound formulation known as Pien Tze Huang,which is indicated for the treatment of liver cancer.However,its impact on the liver cancer tumor microenvironment,particularly on tumor-associated macrophages(TAMs),is not well understood.AIM To elucidate the anti-liver cancer effect of CB by inhibiting M2-TAM polarization via Wnt/β-catenin pathway modulation.METHODS This study identified the active components of CB using UPLC-Q-TOF-MS,evaluated its anti-neoplastic effects in a nude mouse model,and elucidated the underlying mechanisms via network pharmacology,transcriptomics,and molecular docking.In vitro assays were used to investigate the effects of CB-containing serum on HepG2 cells and M2-TAMs,and Wnt pathway modulation was validated by real-time reverse transcriptase-polymerase chain reaction and Western blot analysis.RESULTS This study identified 22 active components in CB,11 of which were detected in the bloodstream.Preclinical investigations have demonstrated the ability of CB to effectively inhibit liver tumor growth.An integrated approach employing network pharmacology,transcriptomics,and molecular docking implicated the Wnt signaling pathway as a target of the antineoplastic activity of CB by suppressing M2-TAM polarization.In vitro and in vivo experiments further confirmed that CB significantly hinders M2-TAM polarization and suppresses Wnt/β-catenin pathway activation.The inhibitory effect of CB on M2-TAMs was reversed when treated with the Wnt agonist SKL2001,confirming its pathway specificity.CONCLUSION This study demonstrated that CB mediates inhibition of M2-TAM polarization through the Wnt/β-catenin pathway,contributing to the suppression of liver cancer growth.

The heterogeneity of tumor-associated macrophages and strategies to target it

Tumor-associated macrophages(TAMs)are emerging as targets for tumor therapy because of their primary role in promoting tumor progression.Several studies have been conducted to target TAMs by reducing their infiltration,depleting their numbers,and reversing their phenotypes to suppress tumor progression,leading to the development of drugs in preclinical and clinical trials.However,the heterogeneous characteristics of TAMs,including their ontogenetic and functional heterogeneity,limit their targeting.Therefore,in-depth exploration of the heterogeneity of TAMs,combined with immune checkpoint therapy or other therapeutic modalities could improve the efficiency of tumor treatment.This review focuses on the heterogeneous ontogeny and function of TAMs,as well as the current development of tumor therapies targeting TAMs and combination strategies.

Research progress of tumor-associated macrophages in immune checkpoint inhibitor tolerance in colorectal cancer

The relevant mechanism of tumor-associated macrophages(TAMs)in the treatment of colorectal cancer patients with immune checkpoint inhibitors(ICIs)is discussed,and the application prospects of TAMs in reversing the treatment tolerance of ICIs are discussed to provide a reference for related studies.As a class of drugs widely used in clinical tumor immunotherapy,ICIs can act on regulatory molecules on cells that play an inhibitory role-immune checkpoints-and kill tumors in the form of an immune response by activating a variety of immune cells in the immune system.The sensitivity of patients with different types of colorectal cancer to ICI treatment varies greatly.The phenotype and function of TAMs in the colorectal cancer microenvironment are closely related to the efficacy of ICIs.ICIs can regulate the phenotypic function of TAMs,and TAMs can also affect the tolerance of colorectal cancer to ICI therapy.TAMs play an important role in ICI resistance,and making full use of this target as a therapeutic strategy is expected to improve the immunotherapy efficacy and prognosis of patients with colorectal cancer.

MicroRNA-206 as a promising epigenetic approach to modulate tumor-associated macrophages in hepatocellular carcinoma

This letter comments on the recently published manuscript by Huang et al in the World Journal of Gastroenterology,which focused on the immunomodulatory effect of Calculus bovis on hepatocellular carcinoma(HCC)tumor microenvironments(TME)by inhibiting M2-tumor-associated macrophage(M2-TAM)polarization via Wnt/β-catenin pathway modulation.Recent research highlights the crucial role of TAMs and their polarization towards the M2 phenotype in promoting HCC progression.Epigenetic regulation,particularly through microRNAs(miR),has emerged as a key factor in modulating immune responses and TAM polarization in the TME,influencing treatment responses and tumor progression.This editorial focuses on miR-206,which has been found to inhibit HCC cell proliferation and migration and promote apoptosis.Moreover,miR-206 enhances anti-tumor immune responses by promoting M1-polarization of Kupffer cells,facilitating CD8+T cell recruitment and suppressing liver cancer stem cell expansion.However,challenges remain in understanding the precise mechanisms regulating miR-206 and its potential as a therapeutic agent.Targeting epigenetic mechanisms and improving strategies,whether through pharmacological or genetic approaches,offer promising avenues to sensitize tumor cells to chemotherapy.Understanding the intricate interactions between cancer and non-coding RNA regulation opens new avenues for developing targeted therapies,potentially improving HCC prognosis.

Abnormally activated wingless/integrated signaling modulates tumor-associated macrophage polarization and potentially promotes hepatocarcinoma cell growth

In this article,we comment on the article by Huang et al.The urgent development of new therapeutic strategies targeting macrophage polarization is critical in the fight against liver cancer.Tumor-associated macrophages(TAMs),primarily of the M2 subtype,are instrumental in cellular communication within the tumor microenvironment and are influenced by various signaling pathways,including the wingless/integrated(Wnt)pathway.Activation of the Wnt signaling pathway is pivotal in promoting M2 TAMs polarization,which in turn can exacerbate hepatocarcinoma cell proliferation and migration.This manuscript emphasizes the burgeoning significance of the Wnt signaling pathway and M2 TAMs polarization in the pathogenesis and progression of liver cancer,highlighting the potential therapeutic benefits of inhibiting the Wnt pathway.Lastly,we point out areas in Huang et al’s study that require further research,providing guidance and new directions for similar studies.

Concerting magnesium implant degradation facilitates local chemotherapy in tumor-associated bone defect

Effective management of malignant tumor-induced bone defects remains challenging due to severe systemic side effects,substantial tumor recurrence,and long-lasting bone reconstruction post tumor resection.Magnesium and its alloys have recently emerged in clinics as orthopedics implantable metals but mostly restricted to mechanical devices.Here,by deposition of calcium-based bilayer coating on the surface,a Mg-based composite implant platform is developed with tailored degradation characteristics,simultaneously integrated with chemotherapeutic(Taxol)loading capacity.The delicate modulation of Mg degradation occurring in aqueous environment is observed to play dual roles,not only in eliciting desirable osteoinductivity,but allows for modification of tumor microenvironment(TME)owing to the continuous release of degradation products.Specifically,the sustainable H2 evolution and Ca2+from the implant is distinguished to cooperate with local Taxol delivery to achieve superior antineoplastic activity through activating Cyt-c pathway to induce mitochondrial dysfunction,which in turn leads to significant tumor-growth inhibition in vivo.In addition,the local chemotherapeutic delivery of the implant minimizes toxicity and side effects,but markedly fosters osteogenesis and bone repair with appropriate structure degradation in rat femoral defect model.Taken together,a promising intraosseous administration strategy with biodegradable Mg-based implants to facilitate tumor-associated bone defect is proposed.

Correlation of tumor-associated macrophage density and proportion of M2 subtypes with the pathological stage of colorectal cancer

BACKGROUND Colorectal cancer(CRC)is a prevalent global malignancy with complex prognostic factors.Tumor-associated macrophages(TAMs)have shown paradoxical associations with CRC survival,particularly concerning the M2 subset.AIM We aimed to establish a simplified protocol for quantifying M2-like TAMs and explore their correlation with clinicopathological factors.METHODS A cross-sectional study included histopathological assessment of paraffinembedded tissue blocks obtained from 43 CRC patients.Using CD68 and CD163 immunohistochemistry,we quantified TAMs in tumor stroma and front,focusing on M2 proportion.Demographic,histopathological,and clinical parameters were collected.RESULTS TAM density was significantly higher at the tumor front,with the M2 proportion three times greater in both zones.The tumor front had a higher M2 proportion,which correlated significantly with advanced tumor stage(P=0.04),pathological nodal involvement(P=0.04),and lymphovascular invasion(LVI,P=0.01).However,no significant association was found between the M2 proportion in the tumor stroma and clinicopathological factors.CONCLUSION Our study introduces a simplified protocol for quantifying M2-like TAMs in CRC tissue samples.We demonstrated a significant correlation between an increased M2 proportion at the tumor front and advanced tumor stage,nodal involvement,and LVI.This suggests that M2-like TAMs might serve as potential indicators of disease progression in CRC,warranting further investigation and potential clinical application.

Inhibition of M2 tumor-associated macrophages polarization by modulating the Wnt/β-catenin pathway as a possible liver cancer therapy method

The problem of liver cancer is becoming increasingly important due to the epi-demic of metabolic diseases and persistent high alcohol consumption.This deter-mines great attention to the development and improvement of methods for early diagnosis and treatment of liver cancer.Huang et al presented a study in the World Journal of Gastroenterology,in which they showed that the use of the traditional Chinese medicine Calculus bovis(CB)can suppress tumor growth in mice by inhibiting M2 tumor-associated macrophages(TAM)through modulating the activity of the Wnt/β-catenin pathway.The interaction of CB components with the Wnt/β-catenin pathway,M2 TAM polarization,and tumor dynamics were studied using network pharmacology,transcriptomics,and molecular docking.It is now generally accepted that the polarization of TAM and the differentiation of the functions of M1 and M2 phagocytes are of great importance for the progression of neoplasms.It is assumed that M2 TAM promote proliferation and migration of tumor cells.Attempts to medicinally influence the Wnt/β-catenin pathway in order to modulate phagocyte polarization now belong to one of the most promising areas of immunotherapy of oncological diseases.Undoubtedly,the work of the Chinese authors deserves attention and further development.

Role of tumor-associated macrophages in common digestive system malignant tumors

Many digestive system malignant tumors are characterized by high incidence and mortality rate.Increasing evidence has revealed that the tumor microenvironment(TME)is involved in cancer initiation and tumor progression.Tumor-associated macrophages(TAMs)are a predominant constituent of the TME,and participate in the regulation of various biological behaviors and influence the prognosis of digestive system cancer.TAMs can be mainly classified into the antitumor M1 phenotype and protumor M2 phenotype.The latter especially are crucial drivers of tumor invasion,growth,angiogenesis,metastasis,immunosuppression,and resistance to therapy.TAMs are of importance in the occurrence,development,diagnosis,prognosis,and treatment of common digestive system malignant tumors.In this review,we summarize the role of TAMs in common digestive system malignant tumors,including esophageal,gastric,colorectal,pancreatic and liver cancers.How TAMs promote the development of tumors,and how they act as potential therapeutic targets and their clinical applications are also described.

The neutrophil–osteogenic cell axis promotes bone destruction in periodontitis

The immune-stromal cell interactions play a key role in health and diseases. In periodontitis, the most prevalent infectious disease in humans, immune cells accumulate in the oral mucosa and promote bone destruction by inducing receptor activator of nuclear factor-κB ligand (RANKL) expression in osteogenic cells such as osteoblasts and periodontal ligament cells. However, the detailed mechanism underlying immune–bone cell interactions in periodontitis is not fully understood. Here, we performed single-cell RNAsequencing analysis on mouse periodontal lesions and showed that neutrophil–osteogenic cell crosstalk is involved in periodontitis-induced bone loss. The periodontal lesions displayed marked infiltration of neutrophils, and in silico analyses suggested that the neutrophils interacted with osteogenic cells through cytokine production. Among the cytokines expressed in the periodontal neutrophils, oncostatin M (OSM) potently induced RANKL expression in the primary osteoblasts, and deletion of the OSM receptor in osteogenic cells significantly ameliorated periodontitis-induced bone loss. Epigenomic data analyses identified the OSM-regulated RANKL enhancer region in osteogenic cells, and mice lacking this enhancer showed decreased periodontal bone loss while maintaining physiological bone metabolism. These findings shed light on the role of neutrophils in bone regulation during bacterial infection, highlighting the novel mechanism underlying osteoimmune crosstalk.

Neutrophil extracellular traps mediate neuro-immunothrombosis

Neutrophil extracellular traps are primarily composed of DNA and histones and are released by neutrophils to promote inflammation and thrombosis when stimulated by various inflammato ry reactions.Neutrophil extracellular trap formation occurs through lytic and non-lytic pathways that can be further classified by formation mechanisms.Histones,von Willebrand factor,fibrin,and many other factors participate in the interplay between inflammation and thrombosis.Neuroimmunothrombosis summarizes the intricate interplay between inflammation and thrombosis during neural development and the pathogenesis of neurological diseases,providing cutting-edge insights into post-neurotrauma thrombotic events.The blood-brain barrier defends the brain and spinal cord against external assaults,and neutrophil extracellular trap involvement in blood-brain barrier disruption and immunothrombosis contributes substantially to secondary injuries in neurological diseases.Further research is needed to understand how neutrophil extracellular traps promote blood-brain barrier disruption and immunothrombosis,but recent studies have demonstrated that neutrophil extracellular traps play a crucial role in immunothrombosis,and identified modulators of neuro-immunothrombosis.However,these neurological diseases occur in blood vessels,and the mechanisms are unclear by which neutrophil extracellular traps penetrate the blood-brain barrier to participate in immunothrombosis in traumatic brain injury.This review discusses the role of neutrophil extracellular traps in neuro-immunothrombosis and explores potential therapeutic interventions to modulate neutrophil extracellular traps that may reduce immunothrombosis and improve traumatic brain injury outcomes.

Neutrophil peptide 1 accelerates the clearance of degenerative axons during Wallerian degeneration by activating macrophages after peripheral nerve crush injury

Macrophages play an important role in peripheral nerve regeneration,but the specific mechanism of regeneration is still unclear.Our preliminary findings indicated that neutrophil peptide 1 is an innate immune peptide closely involved in peripheral nerve regeneration.However,the mechanism by which neutrophil peptide 1 enhances nerve regeneration remains unclear.This study was designed to investigate the relationship between neutrophil peptide 1 and macrophages in vivo and in vitro in peripheral nerve crush injury.The functions of RAW 264.7 cells we re elucidated by Cell Counting Kit-8 assay,flow cytometry,migration assays,phagocytosis assays,immunohistochemistry and enzyme-linked immunosorbent assay.Axonal debris phagocytosis was observed using the CUBIC(Clear,Unobstructed Brain/Body Imaging Cocktails and Computational analysis)optical clearing technique during Wallerian degeneration.Macrophage inflammatory factor expression in different polarization states was detected using a protein chip.The results showed that neutrophil peptide 1 promoted the prolife ration,migration and phagocytosis of macrophages,and CD206 expression on the surfa ce of macrophages,indicating M2 polarization.The axonal debris clearance rate during Wallerian degeneration was enhanced after neutrophil peptide 1 intervention.Neutrophil peptide 1 also downregulated inflammatory factors interleukin-1α,-6,-12,and tumor necrosis factor-αin invo and in vitro.Thus,the results suggest that neutrophil peptide 1 activates macrophages and accelerates Wallerian degeneration,which may be one mechanism by which neutrophil peptide 1 enhances peripheral nerve regeneration.

Role of Cyclin D1b in Inducing Macrophages Toward a Tumor-associated Macrophage-like Phenotype in Murine Breast Cancer

Objective:Tumor-associated macrophages(TAMs)of the M2 phenotype are frequently associated with cancer progression.Invasive cancer cells undergoing epithelial-mesenchymal transition(EMT)have a selective advantage as TAM activators.Cyclin D1b is a highly oncogenic splice variant of cyclin D1.We previously reported that cyclin D1b enhances the invasiveness of breast cancer cells by inducing EMT.However,the role of cyclin D1b in inducing macrophage differentiation toward tumor-associated macrophage-like cells remains unknown.This study aimed to explore the relationship between breast cancer cells overexpressing cyclin Dlb and TAMs.Methods:Mouse breast cancer 4T1 cells were transfected with cyclin D1b variant and co-cultured with macrophage cells in a Transwell coculture system.The expression of characteristic cytokines in differentiated macrophages was detected using qRT-PCR,ELISA and zymography assay.Tumor-associated macrophage distribution in a transplanted tumor was detected by immunofluorescence staining.The proliferation and migration ability of breast cancer cells was detected using the cell counting kit-8(CCK-8)assay,wound healing assay,Transwell invasion assay,and lung metastasis assay.Expression levels of mRNAs were detected by qRT-PCR.Protein expression levels were detected by Western blotting.The integrated analyses of The Cancer Genome Atlas(TCGA)datasets and bioinformatics methods were adopted to discover gene expression,gene coexpression,and overall survival in patients with breast cancer.Results:After co-culture with breast cancer cells overexpressing cyclin D1b,RAW264.7 macrophages were differentiated into an M2 phenotype.Moreover,differentiated M2-like macrophages promoted the proliferation and migration of breast cancer cells in turn.Notably,these macrophages facilitated the migration of breast cancer cells in vivo.Further investigations indicated that differentiated M2-like macrophages induced EMT of breast cancer cells accompanied with upregulation of TGF-β1 and integrinβ3 expression.Conclusion:Breast cancer cells transfected with cyclin D1b can induce the differentiation of macrophages into a tumor-associated macrophage-like phenotype,which promotes tumor metastasis in vitro and in vivo.

Correlation of neutrophil to lymphocyte ratio to severity of coronary artery disease and in-hospital clinical outcomes in patients with acute coronary syndrome: A prospective observational study

Objective:To explore correlation of neutrophil-to-lymphocyte ratio(NLR)to severity of coronary artery disease(CAD)and in-hospital clinical outcomes in patients with acute coronary syndrome(ACS).Methods:In this prospective and observational study,we recruited 500 patients with ACS.For all the eligible patients,demographic details were collected,and laboratory parameters were evaluated.The CAD severity was evaluated in terms of the number of involved vessels.The NLR was calculated based on neutrophils and lymphocytes and the correlation of various risk factors and severity and outcome of CAD was performed.Results:77.2%of Patients was male,and 52%of the patients aged between 55-70 years.Based on the type of ACS,396 out of 500 patients had ST-elevation myocardial infarction.An ascending trend in the white blood cell levels and NLR value was noted as the severity of the ACS increased and the highest white blood cell levels and NLR was noted among classⅣpatients.The mean NLR value among the non-survivors were higher compared to the survivors(9.52±5.72 vs.4.76±2.36;P<0.01).Receiver operating curve showed that the cut-off NLR value was 5.76 with a sensitivity of 75.0%and a specificity of 77.3%.Conclusions:The NLR can be used as an independent prognostic marker in ACS.An elevated NLR value serves as a reliable predictor for short-term complications,notably in-hospital mortality.

Complex role of neutrophils in the tumor microenvironment: an avenue for novel immunotherapies

Neutrophils,which originate from the bone marrow and are characterized by a segmented nucleus and a brief lifespan,have a crucial role in the body’s defense against infections and acute inflammation.Recent research has uncovered the complex roles of neutrophils as regulators in tumorigenesis,during which neutrophils exhibit a dualistic nature that promotes or inhibits tumor progression.This adaptability is pivotal within the tumor microenvironment(TME).In this review,we provide a comprehensive characterization of neutrophil plasticity and heterogeneity,aiming to illuminate current research findings and discuss potential therapeutic avenues.By delineating the intricate interplay of neutrophils in the TME,this review further underscores the urgent need to understand the dual functions of neutrophils with particular emphasis on the anti-tumor effects to facilitate the development of effective therapeutic strategies against cancer.

The Combined Effect of Lumenato and Ceramide in the Protection of Collagen Damage Induced by Neutrophils in Normal Human Dermal Fibroblasts

Introduction: Collagen is the primary structural protein fibroblasts produce in the skin’s extracellular matrix. Infiltration of neutrophils into the epidermis and dermis by exposure to UV causes collagen damage and contributes to photoaging. Methods: To study the combined effect of Lumenato and ceramide in preventing collagen-1 damage induced by phagocytes, we used co-cultures of normal human dermal fibroblasts (fibroblasts) and activated human neutrophils. The present study aimed to determine the protective effect of the combination of Lumenato and ceramide on fibroblast collagen-1 damage induced by neutrophils. Results: Lumenato (in the range of 6.5 - 208 μg/ml) or ceramide (in the range of 0.1 - 50 μM) inhibited the production of superoxides and MPO by TNFα-stimulated neutrophils, as well as the production of NO by LPS-stimulated macrophages in a dose-dependent manner. The combinations of Lumenato and ceramide, in low concentrations, caused synergistic prevention of fibroblasts’ collagen-1 damage induced by TNFα-activated neutrophils, detected by fluorescence immunostaining and WB analysis. MPO activity in the supernatants of the co-cultures was also synergistically inhibited. Adding Lumenato or ceramide singly or in combinations in these low concentrations to the fibroblast cultures did not affect the expression of collagen-1. The combinations of Lumenato or ceramide in these concentrations also caused a synergistic inhibition of NO production by activated macrophages. Conclusions: The results suggest that combining low concentrations of Lumenato and ceramide results in synergistic protection against fibroblasts’ collagen-1 damage induced by neutrophils, thus indicating their possible potential for enhanced skin health.

Phagocytosis: A Practical Approach for Evaluating Neutrophil Function in Health and Disease

Neutrophils, crucial players in the effector phase of the immune response, are recognized as important mediators of both innate and adaptive immune responses. Through the production of pro- and anti-inflammatory cytokines, they modulate the function of T and other lymphoid cells. Countless reports have highlighted the importance of these cells as efficient antimicrobial agents and annotated their involvement in the pathology of infectious and noninfectious diseases. The development of modern, sophisticated technologies has allowed the study of the functions of these cells in clinical settings. These advanced technologies include fluorescence-activated cell sorters, confocal microscopy, automated cell image analyzers, and live cell analysis instruments. Unfortunately, the cost of these modern instruments, maintenance, reagents, and the need for qualified technicians prohibit their use in low-income laboratories and universities in developing countries. With this in mind, we propose a series of basic tests that can be used in low-input clinical laboratories and universities to evaluate the function of neutrophils in health and disease. Our methodology allows us to assess in a practical and low-cost manner the functions of neutrophils in the phagocytic process, including opsonization, ingestion, ROI production (NBT reduction), myeloperoxidase content, phagosome-lysosome fusion, microbicidal activity, and NET production. Thus, under a disadvantageous ambiance, this may guide physicians in deciding whether a patient’s illness involves phagocytic defects without imposing a heavy financial burden.Graphical Abstract[-rId13-]