Macrophage Polarization in Chronic Inflammatory Diseases: Killers or Builders? J Immunol Res. 2018;2018:8917804. [PMID: 29507865 PMCID: PMC5821995 DOI: 10.1155/2018/8917804]

Tetrahedral framework nucleic acids-based delivery of microRNA-155 inhibits choroidal neovascularization by regulating the polarization of macrophages

Choroidal neovascularization (CNV) is a common pathological feature of various eye diseases and an important cause of visual impairment in middle-aged and elderly patients. In previous studies, tetrahedral framework nucleic acids (tFNAs) showed good carrier performance. In this experiment, we developed microRNA-155-equipped tFNAs (T-155) and explored its biological effects on CNV. Based on the results of in-vitro experiments, T-155 could regulate macrophages into the antiangiogenic M1 type. Then, we injected T-155 into the vitreous of laser-induced CNV model mice and found that T-155 significantly reduced the size and area of CNV, inhibited blood vessel leakage. In summary, we prove that T-155 could regulate the inflammatory process of CNV by polarizing macrophages, thereby improving the symptoms of CNV. Thus, T-155 might become a new DNA-based drug with great potential for treating CNV.

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T-155 could regulate the inflammatory process of CNV by polarizing macrophages, thereby improving the symptoms of CNV.

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Thus, T-155 might become a new DNA-based drug with great potential for treating CNV.

Interrogation of the microenvironmental landscape in spinal ependymomas reveals dual functions of tumor-associated macrophages

Spinal ependymomas are the most common spinal cord tumors in adults, but their intratumoral cellular heterogeneity has been less studied, and how spinal microglia are involved in tumor progression is still unknown. Here, our single-cell RNA-sequencing analyses of three spinal ependymoma subtypes dissect the microenvironmental landscape of spinal ependymomas and reveal tumor-associated macrophage (TAM) subsets with distinct functional phenotypes. CCL2+ TAMs are related to the immune response and exhibit a high capacity for apoptosis, while CD44+ TAMs are associated with tumor angiogenesis. By combining these results with those of single-cell ATAC-sequencing data analysis, we reveal that TEAD1 and EGR3 play roles in regulating the functional diversity of TAMs. We further identify diverse characteristics of both malignant cells and TAMs that might underlie the different malignant degrees of each subtype. Finally, assessment of cell-cell interactions reveal that stromal cells act as extracellular factors that mediate TAM diversity. Overall, our results reveal dual functions of TAMs in tumor progression, providing valuable insights for TAM-targeting immunotherapy.

Morus alba L. (Sangzhi) alkaloids (SZ-A) exert anti-inflammatory effects via regulation of MAPK signaling in macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

Morus alba L. (Sangzhi) alkaloids (SZ-A) tablets have been approved by the China National Medical Products Administration for T2DM treatment. Our previous study (Liu et al., 2021) revealed that SZ-A protected against diabetes and inflammation in KKAy mice. However, the mechanism and components in SZ-A exerting anti-inflammatory effects are unclear.

AIM OF THE STUDY

Investigate the effects and molecular mechanisms of SZ-A on inflammation, and identify anti-inflammatory active components in SZ-A.

MATERIALS AND METHODS

The major ingredients in SZ-A were analyzed by HPLC and sulfuric acid - anthrone spectrophotometry. The inhibitory activities of SZ-A on lipopolysaccharide (LPS)-stimulated inflammation were determined in bone marrow-derived macrophage (BMDM) and RAW264.7 cells. The cytokine levels of IL-6 and TNF-α in cell culture supernatant were measured by enzyme-linked immunosorbent assay (ELISA). Gene expression levels of IL-6 and TNF-α were detected by qRT-PCR. The levels of protein phosphorylation of p38 MAPK, ERK, and JNK were analyzed by Western blot.

RESULTS

The main components in SZ-A were found to be 1-deoxynojirimycin (DNJ), 1,4-dideoxy-1,4-imino-D-arabinitol (DAB), fagomine (FAG), polysaccharide (APS), and arginine (ARG). SZ-A reduced the levels of IL-6 and TNF-α secreted by LPS-induced RAW264.7 and BMDM cells. Simultaneously, the mRNA expression levels of IL-6 and TNF-α were all significantly suppressed by SZ-A in a concentration-dependent manner. Furthermore, SZ-A inhibited the phosphorylation of p38 MAPK, ERK, and JNK in BMDM and the activation of ERK and JNK signaling in RAW264.7 cells. We also observed that DNJ, DAB, FAG, and ARG markedly downregulated IL-6 and TNF-α cytokine levels, while APS did not have an obvious effect.

CONCLUSIONS

SZ-A attenuates inflammation at least partly by blocking the activation of p38 MAPK, ERK, and JNK signaling pathways. DNJ, FAG, DAB, and ARG are the main constituents in SZ-A that exert anti-inflammatory effects.

Nicaraven prevents the fast growth of inflamed tumors by an anti-inflammatory mechanism

Inflammatory microenvironment is known to accelerate the progression of malignant tumors. We investigated the possible anti-inflammatory effect of nicaraven on slowing tumor growth. Tumor-bearing mice randomly received nicaraven injection (50 mg/kg daily, i.p, n = 8) or placebo treatment (n = 8) for 10 days, and then sacrificed for evaluations. Nicaraven administration effectively inhibited the fast growth of tumor, as a large tumor (> 1.0 g) developed finally in three of the eight mice received placebo treatment. Cytokines/chemokines array indicated that nicaraven reduced the levels of CXCL10 and SDF-1 in the tumor as well as the levels of IL-2 and MIP-2 in serum. Immunofluorescence staining showed that nicaraven significantly reduced the recruitment of macrophages and neutrophils in the tumor. Interestingly, western blot indicated that the expression of CD86, CD206, and NIMP-R14 was especially enhanced in the three large-size tumors, suggesting the potential role of nicaraven in preventing the hyper-inflammatory tumor microenvironment. Moreover, the expression of PARP-1 was downregulated, but the expression of phospho-p38 MAPK, phospho-MKK-3/6, and phospho-MSK-1 was upregulated in the large-size tumors, suggesting the involvement of p38 MAPK pathway in the anti-inflammatory effect of nicaraven. Taken together, our study suggests that nicaraven may effectively prevent the fast growth of inflamed tumors by an anti-inflammatory mechanism.

TLR-4 Agonist Induces IFN-γ Production Selectively in Proinflammatory Human M1 Macrophages through the PI3K-mTOR- and JNK-MAPK-Activated p70S6K Pathway

IFN-γ, a proinflammatory cytokine produced primarily by T cells and NK cells, activates macrophages and engages mechanisms to control pathogens. Although there is evidence of IFN-γ production by murine macrophages, IFN-γ production by normal human macrophages and their subsets remains unknown. Herein, we show that human M1 macrophages generated by IFN-γ and IL-12- and IL-18-stimulated monocyte-derived macrophages (M0) produce significant levels of IFN-γ. Further stimulation of IL-12/IL-18-primed macrophages or M1 macrophages with agonists for TLR-2, TLR-3, or TLR-4 significantly enhanced IFN-γ production in contrast to the similarly stimulated M0, M2a, M2b, and M2c macrophages. Similarly, M1 macrophages generated from COVID-19-infected patients' macrophages produced IFN-γ that was enhanced following LPS stimulation. The inhibition of M1 differentiation by Jak inhibitors reversed LPS-induced IFN-γ production, suggesting that differentiation with IFN-γ plays a key role in IFN-γ induction. We subsequently investigated the signaling pathway(s) responsible for TLR-4-induced IFN-γ production in M1 macrophages. Our results show that TLR-4-induced IFN-γ production is regulated by the ribosomal protein S6 kinase (p70S6K) through the activation of PI3K, the mammalian target of rapamycin complex 1/2 (mTORC1/2), and the JNK MAPK pathways. These results suggest that M1-derived IFN-γ may play a key role in inflammation that may be augmented following bacterial/viral infections. Moreover, blocking the mTORC1/2, PI3K, and JNK MAPKs in macrophages may be of potential translational significance in preventing macrophage-mediated inflammatory diseases.

Selective Induction of Cell Death in Human M1 Macrophages by Smac Mimetics Is Mediated by cIAP-2 and RIPK-1/3 through the Activation of mTORC

Inflammatory macrophages have been implicated in many diseases, including rheumatoid arthritis and inflammatory bowel disease. Therefore, targeting macrophage function and activation may represent a potential strategy to treat macrophage-associated diseases. We have previously shown that IFN-γ-induced differentiation of human M0 macrophages toward proinflammatory M1 state rendered them highly susceptible to the cytocidal effects of second mitochondria-derived activator of caspases mimetics (SMs), antagonist of the inhibitors of apoptosis proteins (IAPs), whereas M0 and anti-inflammatory M2c macrophages were resistant. In this study, we investigated the mechanism governing SM-induced cell death during differentiation into M1 macrophages and in polarized M1 macrophages. IFN-γ stimulation conferred on M0 macrophages the sensitivity to SM-induced cell death through the Jak/STAT, IFN regulatory factor-1, and mammalian target of rapamycin complex-1 (mTORC-1)/ribosomal protein S6 kinase pathways. Interestingly, mTORC-1 regulated SM-induced cell death independent of M1 differentiation. In contrast, SM-induced cell death in polarized M1 macrophages is regulated by the mTORC-2 pathway. Moreover, SM-induced cell death is regulated by cellular IAP (cIAP)-2, receptor-interacting protein kinase (RIPK)-1, and RIPK-3 degradation through mTORC activation during differentiation into M1 macrophages and in polarized M1 macrophages. In contrast to cancer cell lines, SM-induced cell death in M1 macrophages is independent of endogenously produced TNF-α, as well as the NF-κB pathway. Collectively, selective induction of cell death in human M1 macrophages by SMs may be mediated by cIAP-2, RIPK-1, and RIPK-3 degradation through mTORC activation. Moreover, blocking cIAP-1/2, mTORC, or IFN regulatory factor-1 may represent a promising therapeutic strategy to control M1-associated diseases.

Melittin-loaded Iron Oxide Nanoparticles Prevent Intracranial Arterial Dolichoectasia Development through Inhibition of Macrophage-mediated Inflammation

Rationale: In intracranial arterial dolichoectasia (IADE) development, the feedback loop between inflammatory cytokines and macrophages involves TNF-α and NF-κB signaling pathways and leads to subsequent MMP-9 activation and extracellular matrix (ECM) degeneration. In this proof-of-concept study, melittin-loaded L-arginine-coated iron oxide nanoparticle (MeLioN) was proposed as the protective measure of IADE formation for this macrophage-mediated inflammation and ECM degeneration.

Methods: IADE was created in 8-week-old C57BL/6J male mice by inducing hypertension and elastase injection into a basal cistern. Melittin was loaded on the surface of ION as a core-shell structure (hydrodynamic size, 202.4 nm; polydispersity index, 0.158). Treatment of MeLioN (2.5 mg/kg, five doses) started after the IADE induction, and the brain was harvested in the third week. In the healthy control, disease control, and MeLioN-treated group, the morphologic changes of the cerebral arterial wall were measured by diameter, thickness, and ECM composition. The expression level of MMP-9, CD68, MCP-1, TNF-α, and NF-κB was assessed from immunohistochemistry, polymerase chain reaction, and Western blot assay.

Results: MeLioN prevented morphologic changes of cerebral arterial wall related to IADE formation by restoring ECM alterations and suppressing MMP-9 expression. MeLioN inhibited MCP-1 expression and reduced CD68-positive macrophage recruitments into cerebral arterial walls. MeLioN blocked TNF-α activation and NF-κB signaling pathway. In the Sylvian cistern, co-localization was found between the CD68-positive macrophage infiltrations and the MeLioN distributions detected on Prussian Blue and T2* gradient-echo MRI, suggesting the role of macrophage harboring MeLioN.

Conclusions: The macrophage infiltration into the arterial wall plays a critical role in the MMP-9 secretion. MeLioN, designed for ION-mediated melittin delivery, effectively prevents IADE formation by suppressing macrophage-mediated inflammations and MMP activity. MeLioN can be a promising strategy preventing IADE development in high-risk populations.

The Microenvironment's Role in Mycosis Fungoides and Sézary Syndrome: From Progression to Therapeutic Implications

BACKGROUND

Mycosis fungoides (MF) and Sezary Syndrome (SS) are the most common cutaneous T-cell lymphomas. It has been hypothesized that the interaction between the immune system, cutaneous cells, and neoplastic elements may play a role in MF/SS pathogenesis and progression.

METHODS

This paper aims to revise in a narrative way our current knowledge of the microenvironment's role in MF/SS.

RESULTS AND CONCLUSIONS

Literature data support a possible implication of microenvironment cells in MF/SS pathogenesis and progression, opening up new therapeutic avenues.

Bacterial Cellulose as a Potential Bio-Scaffold for Effective Re-Epithelialization Therapy

Currently, there are several therapeutic approaches available for wound injury management. However, a better understanding of the underlying mechanisms of how biomaterials affect cell behavior is needed to develop potential repair strategies. Bacterial cellulose (BC) is a bacteria-produced biopolymer with several advantageous qualities for skin tissue engineering. The aim here was to investigate BC-based scaffold on epithelial regeneration and wound healing by examining its effects on the expression of scavenger receptor-A (SR-A) and underlying macrophage behavior. Full-thickness skin wounds were generated on Sprague-Dawley rats and the healing of these wounds, with and without BC scaffolds, was examined over 14 days using Masson’s trichome staining. BC scaffolds displayed excellent in vitro biocompatibility, maintained the stemness function of cells and promoted keratinocyte differentiation of cells, which are vital in maintaining and restoring the injured epidermis. BC scaffolds also exhibited positive in vivo effects on the wound microenvironment, including improved skin extracellular matrix deposition and controlled excessive inflammation by reduction of SR-A expression. Furthermore, BC scaffold significantly enhanced epithelialization by stimulating the balance of M1/M2 macrophage re-programming for beneficial tissue repair relative to that of collagen material. These findings suggest that BC-based materials are promising products for skin injury repair.

Mechanisms, Pathophysiology and Currently Proposed Treatments of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is one of the leading global causes of morbidity and mortality. A hallmark of COPD is progressive airflow obstruction primarily caused by cigarette smoke (CS). CS exposure causes an imbalance favoring pro- over antioxidants (oxidative stress), leading to transcription factor activation and increased expression of inflammatory mediators and proteases. Different cell types, including macrophages, epithelial cells, neutrophils, and T lymphocytes, contribute to COPD pathophysiology. Alteration in cell functions results in the generation of an oxidative and inflammatory microenvironment, which contributes to disease progression. Current treatments include inhaled corticosteroids and bronchodilator therapy. However, these therapies do not effectively halt disease progression. Due to the complexity of its pathophysiology, and the risk of exacerbating symptoms with existing therapies, other specific and effective treatment options are required. Therapies directly or indirectly targeting the oxidative imbalance may be promising alternatives. This review briefly discusses COPD pathophysiology, and provides an update on the development and clinical testing of novel COPD treatments.

Macrophages and Foam Cells: Brief Overview of Their Role, Linkage, and Targeting Potential in Atherosclerosis

Atherosclerosis is still one of the main causes of death around the globe. This condition leads to various life-threatening cardiovascular complications. However, no effective preventive measures are known apart from lifestyle corrections, and no cure has been developed. Despite numerous studies in the field of atherogenesis, there are still huge gaps in already poor understanding of mechanisms that underlie the disease. Inflammation and lipid metabolism violations are undoubtedly the key players, but many other factors, such as oxidative stress, endothelial dysfunction, contribute to the pathogenesis of atherosclerosis. This overview is focusing on the role of macrophages in atherogenesis, which are at the same time a part of the inflammatory response, and also tightly linked to the foam cell formation, thus taking part in both crucial for atherogenesis processes. Being essentially involved in atherosclerosis development, macrophages and foam cells have attracted attention as a promising target for therapeutic approaches.

Acute HIV-1 and SARS-CoV-2 Infections Share Slan+ Monocyte Depletion-Evidence from an Hyperacute HIV-1 Case Report

Monocytes are key modulators in acute viral infections, determining both inflammation and development of specific B- and T-cell responses. Recently, these cells were shown to be associated to different SARS-CoV-2 infection outcome. However, their role in acute HIV-1 infection remains unclear. We had the opportunity to evaluate the mononuclear cell compartment in an early hyper-acute HIV-1 patient in comparison with an untreated chronic HIV-1 and a cohort of SARS-CoV-2 infected patients, by high dimensional flow cytometry using an unsupervised approach. A distinct polarization of the monocyte phenotype was observed in the two viral infections, with maintenance of pro-inflammatory M1-like profile in HIV-1, in contrast to the M2-like immunosuppressive shift in SARS-CoV-2. Noticeably, both acute infections had reduced CD14^low/−CD16⁺ non-classical monocytes, with depletion of the population expressing Slan (6-sulfo LacNac), which is thought to contribute to immune surveillance through pro-inflammatory properties. This depletion indicates a potential role of these cells in acute viral infection, which has not previously been explored. The inflammatory state accompanied by the depletion of Slan+ monocytes may provide new insights on the critical events that determine the rate of viral set-point in acute HIV-1 infection and subsequent impact on transmission and reservoir establishment.

Genipin guides and sustains the polarization of macrophages to the pro-regenerative M2 subtype via activation of the pSTAT6-PPAR-gamma pathway

M2 macrophages are associated with deposition of interstitial collagen and other extracellular matrix proteins during the course wound healing and also inflammatory response to biomaterials. Developing advanced biomaterials to promote the M2 subtype may be an effective way to improve tissue reinforcement surgery outcomes. In this study, the effect of genipin, a naturally derived crosslinking agent, on M0 → M2-polarization was investigated. Genipin was introduced either indirectly by seeding cells on aligned collagen biotextiles that are crosslinked by the agent or in soluble form by direct addition to the culture medium. Cellular elongation effects on macrophage polarization induced by the collagen biotextile were also investigated as a potential inducer of macrophage polarization. M0 and M2 macrophages demonstrated significant elongation on the surface of aligned collagen threads, while cells of the M1 subtype-maintained a round phenotype. M0 → M2 polarization, as reflected by arginase and Ym-1 production, was observed on collagen threads only when the threads were crosslinked by genipin, implicating genipin as a more potent inducer of the regenerative phenotype compared to cytoskeletal elongation. The addition of genipin to the culture medium directly also drove the emergence of pro-regenerative phenotype as measured by the markers (arginase and Ym-1) and through the activation of the pSTAT6-PPAR-gamma pathway. This study indicates that genipin-crosslinked collagen biotextiles can be used as a delivery platform to promote regenerative response after biomaterial implantation. STATEMENT OF SIGNIFICANCE: The immune response is one of the key determinants of tissue repair and regeneration rate, and outcome. The M2 macrophage subtype is known to resolve the inflammatory response and support tissue repair by producing pro-regenerative factors. Therefore, a biomaterial that promotes M2 sub-type can be a viable strategy to enhance tissue regeneration. In this study, we investigated genipin-crosslinked electrochemically aligned collagen biotextiles for their capacity to induce pro-regenerative polarization of M0 macrophages. The results demonstrated that genipin, rather than matrix-induced cellular elongation, was responsible for M0 → M2 polarization in the absence of other bioinductive factors and maintaining the M2 polarized status of macrophages. Furthermore, we identified that genipin polarizes the M2 macrophage phenotype via activation of the pSTAT6-PPAR-gamma pathway.

Comprehensive Integrative Analysis Reveals the Association of KLF4 with Macrophage Infiltration and Polarization in Lung Cancer Microenvironment

Macrophage polarization and infiltration to the tumor microenvironment (TME) is a critical determining factor for tumor progression. Macrophages are polarized into two states—M1 (pro-inflammatory, anti-tumorigenic and stimulated by LPS or IFN-γ) and M2 (anti-inflammatory pro-tumorigenic and stimulated by IL-4) phenotypes. Specifically, M2 macrophages enhance tumor cell growth and survival. Recent evidences suggest the pivotal role of microRNAs in macrophage polarization during the development of Non-small cell lung cancer (NSCLC), thus proposing a new therapeutic option to target lung cancer. In silico analysis determined cogent upregulation of KLF4, downregulation of IL-1β and miR-34a-5p in NSCLC tissues, consequently worsening the overall survival of NSCLC patients. We observed a significant association of KLF4 with macrophage infiltration and polarization in NSCLC. We found that KLF4 is critically implicated in M2 polarization of macrophages, which, in turn, promotes tumorigenesis. KLF4 expression correlated with miR-34a-5p and IL-1β in a feed-forward loop (FFL), both of which are implicated in immune regulation. Mechanistic overexpression of miR-34a-5p in macrophages (IL-4 stimulated) inhibits KLF4, along with downregulation of ARG1, REL-1MB (M2 macrophage specific markers), and upregulation of IL-1β, IL-6, (M1 macrophage specific markers), demonstrating macrophage polarization switch from M2 to M1 phenotype. Moreover, co-culture of these macrophages with NSCLC cells reduces their proliferation, wound healing, clonogenic capacity and enhanced NO-mediated apoptosis. Further, transfection of miR-34a-5p in NSCLC cells, also degrades KLF4, but enhances the expression of KLF4 regulated genes—IL-1β, IL-6 (pro-inflammatory mediators), which is further enhanced upon co-culture with IL-4 stimulated macrophages. Additionally, we observed a significant increase in i-NOS/NO content upon co-culture, suggesting polarization reversion of macrophages from M2 to M1, and eventually leading to anti-tumor effects. Our findings thus show a significant role of KLF4 in tumorigenesis and TAM polarization of NSCLC. However, miR-34a-5p mediated targeting of these molecular networks will provide a better therapeutic intervention for NSCLC.

A Machine-Generated View of the Role of Blood Glucose Levels in the Severity of COVID-19

SARS-CoV-2 started spreading toward the end of 2019 causing COVID-19, a disease that reached pandemic proportions among the human population within months. The reasons for the spectrum of differences in the severity of the disease across the population, and in particular why the disease affects more severely the aging population and those with specific preconditions are unclear. We developed machine learning models to mine 240,000 scientific articles openly accessible in the CORD-19 database, and constructed knowledge graphs to synthesize the extracted information and navigate the collective knowledge in an attempt to search for a potential common underlying reason for disease severity. The machine-driven framework we developed repeatedly pointed to elevated blood glucose as a key facilitator in the progression of COVID-19. Indeed, when we systematically retraced the steps of the SARS-CoV-2 infection, we found evidence linking elevated glucose to each major step of the life-cycle of the virus, progression of the disease, and presentation of symptoms. Specifically, elevations of glucose provide ideal conditions for the virus to evade and weaken the first level of the immune defense system in the lungs, gain access to deep alveolar cells, bind to the ACE2 receptor and enter the pulmonary cells, accelerate replication of the virus within cells increasing cell death and inducing an pulmonary inflammatory response, which overwhelms an already weakened innate immune system to trigger an avalanche of systemic infections, inflammation and cell damage, a cytokine storm and thrombotic events. We tested the feasibility of the hypothesis by manually reviewing the literature referenced by the machine-generated synthesis, reconstructing atomistically the virus at the surface of the pulmonary airways, and performing quantitative computational modeling of the effects of glucose levels on the infection process. We conclude that elevation in glucose levels can facilitate the progression of the disease through multiple mechanisms and can explain much of the differences in disease severity seen across the population. The study provides diagnostic considerations, new areas of research and potential treatments, and cautions on treatment strategies and critical care conditions that induce elevations in blood glucose levels.

Study of immune-mediated mechanisms in patients tested positive for SARS-CoV-2: phenotypic and functional analysis of monocytes, NK and T cells in the blood of subjects affected by COVID 19

Background

The novel coronavirus has a high mortality rate (over 1% for patients older than 50 years). This can only be partially ascribed to other comorbidities. A possible explanation is a factor that assures a prompt response to SARS-CoV-2 in younger people, independent from the novelty of the virus itself. A factor is believed to stimulate the immune system and provide immunity against more antigens. The only external stimulation received by healthy people is vaccination (eg, the diphtheria, tetanus, and pertussis [DTP] vaccine). One hypothesis is that vaccination helps develop specific immunity but generates sprouting immunity against antigens in transit. The underlying immunological phenomena are the “bystander effect” and “trained immunity.” The developed immunity gives protection for years until it naturally fades out. After the fifth decade of life, the immune system is almost incompetent when a viral infection occurs, and thus, at this stage, the novel coronavirus can enter the body and cause acute respiratory distress syndrome.

Objective

The initial aim is to demonstrate that blood monocytes and natural killer cells show overpowering hyperactivity, while CD4+ and CD8+ T cells experience impediments to their defensive functions in patients with severe SARS-CoV-2 infection. The secondary objectives are to correlate clinical data and vaccination history with laboratory immune patterns in order to identify protective factors. Subsequently, we are also interested in characterizing the phenotypes and state of the degree of activation of peripheral blood mononuclear cells, including monocytes, natural killer cells, and CD4+ and CD8+ T cells, in healthy subjects vaccinated with the Pfizer vaccine.

Methods

Data will be collected using the following 3 approaches: (1) an experimental analysis to study the innate immune response and to identify genetic profiles; (2) an epidemiological analysis to identify the patients’ vaccination history; and (3) a clinical analysis to detect the immunological profile.

Results

The protocol was approved by the Ethics Committee on April 16, 2020, and the study started on April 27, 2020. As of February 2021, enrollment has been completed. Immunological analysis is ongoing, and we expect to complete this analysis by December 2022.

Conclusions

We will recognize different populations of patients, each one with a specific immunological pattern in terms of cytokines, soluble factor serum levels, and immune cell activity. Anamnestic data, such as preceding vaccinations and comorbidities, biochemical findings like lymphocyte immunophenotyping, and pre-existing persistent cytomegalovirus infection, allow depicting the risk profile of severe COVID-19. Proof of the roles of these immunological phenomena in the development of COVID-19 can be the basis for the implementation of therapeutic immunomodulatory treatments.

Trial Registration

ClinicalTrials.gov NCT04375176; https://clinicaltrials.gov/ct2/show/NCT04375176

International Registered Report Identifier (IRRID)

DERR1-10.2196/29892

Mechanisms and Pharmaceutical Action of Lipid Nanoformulation of Natural Bioactive Compounds as Efficient Delivery Systems in the Therapy of Osteoarthritis

Osteoarthritis (OA) is a degenerative joint disease. An objective of the nanomedicine and drug delivery systems field is to design suitable pharmaceutical nanocarriers with controllable properties for drug delivery and site-specific targeting, in order to achieve greater efficacy and minimal toxicity, compared to the conventional drugs. The aim of this review is to present recent data on natural bioactive compounds with anti-inflammatory properties and efficacy in the treatment of OA, their formulation in lipid nanostructured carriers, mainly liposomes, as controlled release systems and the possibility to be intra-articularly (IA) administered. The literature regarding glycosaminoglycans, proteins, polyphenols and their ability to modify the cell response and mechanisms of action in different models of inflammation are reviewed. The advantages and limits of using lipid nanoformulations as drug delivery systems in OA treatment and the suitable route of administration are also discussed. Liposomes containing glycosaminoglycans presented good biocompatibility, lack of immune system activation, targeted delivery of bioactive compounds to the site of action, protection and efficiency of the encapsulated material, and prolonged duration of action, being highly recommended as controlled delivery systems in OA therapy through IA administration. Lipid nanoformulations of polyphenols were tested both in vivo and in vitro models that mimic OA conditions after IA or other routes of administration, recommending their clinical application.

Induction of microRNA hsa-let-7d-5p, and repression of HMGA2, contribute protection against lipid accumulation in macrophage 'foam' cells

Accumulation of excess cholesterol and cholesteryl ester in macrophage 'foam' cells within the arterial intima characterises early 'fatty streak' atherosclerotic lesions, and is accompanied by epigenetic changes, including altered expression of microRNA sequences which determine of gene and protein expression. This study established that exposure to lipoproteins, including acetylated LDL, induced macrophage expression of microRNA hsa-let-7d-5p, a sequence previously linked with tumour suppression, and repressed expression of one of its target genes, high mobility group AT hook 2 (HMGA2). A let-7d-5p mimic repressed expression of HMGA2 (18%; p < 0.05) while a marked increase (2.9-fold; p < 0.05) in expression of HMGA2 was noted in the presence of let-7d-5p inhibitor. Under these conditions, let-7d-5p mimic significantly (p < 0.05) decreased total (10%), free (8%) and cholesteryl ester (21%) mass, while the inhibitor significantly (p < 0.05) increased total (29%) and free cholesterol (29%) mass, compared with the relevant controls. Let-7d-5p inhibition significantly (p < 0.05) increased endogenous biosynthesis of cholesterol (38%) and cholesteryl ester (39%) pools in macrophage 'foam' cells, without altering the cholesterol efflux pathway, or esterification of exogenous radiolabelled oleate. Let-7d-5p inhibition in sterol-loaded cells increased the level of HMGA2 protein (32%; p < 0.05), while SiRNA knockdown of this protein (29%; p < 0.05) resulted in a (21%, p < 0.05) reduction in free cholesterol mass. Thus, induction of let-7d-5p, and repression of its target HMGA2, in macrophages is a protective response to the challenge of increased cholesterol influx into these cells; dysregulation of this response may contribute to atherosclerosis and other disorders such as cancer.

HIF-1α activator DMOG inhibits alveolar bone resorption in murine periodontitis by regulating macrophage polarization

Periodontitis is initiated by serious and sustained bacterial infection and ultimately results in chronic immune-mediated inflammation, tissue destruction, and bone loss. The pathogenesis of periodontitis remains unclear. Host immunological responses to periodontal bacteria ultimately determine the severity and mechanisms governing periodontitis progression. This study aimed to clarify the effect of the hypoxia-inducible factor-1α (HIF-1α) activator dimethyloxalylglycine (DMOG) on a mouse periodontitis model and its underlying role in macrophage polarization. qRT-PCR analysis showed that DMOG inhibited the M1-like polarization of both RAW264.7 macrophages and murine bone marrow macrophages (BMMs) and downregulated TNF-α, IL-6, CD86, and MCP-1 expression in vitro. Immunofluorescence staining and flow cytometry also confirmed the less percentage of F4/80 + CD86 + cells after DMOG treatment. The phosphorylation of NF-κB pathway was also inhibited by DMOG with higher level of HIF-1α expression. Furthermore, mice treated with DMOG showed decreased alveolar bone resorption in the experimental periodontitis model, with significant increases in alveolar bone volume/tissue volume (BV/TV) and bone mineral density (BMD). DMOG treatment of mice decreased the ratio of M1/M2 (CD86+/CD206+) macrophages in periodontal tissues, resulting in the downregulation of proinflammatory cytokines such as TNF-α and IL-6 and increased levels of anti-inflammatory factors such as IL-4 and IL-10. DMOG treatment promoted the number of HIF-1α-positive cells in periodontal tissues. This study demonstrated the cell-specific roles of DMOG in macrophage polarization in vitro and provided insight into the mechanism underlying the protective effect of DMOG in a model of periodontitis.

TLR4 and TNFR1 blockade dampen M1 macrophage activation and shifts them towards an M2 phenotype

The Gram-negative bacterial lipopolysaccharide (LPS)-induced sepsis has emerged as major concern worldwide due to the pressing need to develop its effective treatment strategies which is not available yet. LPS is the major causative agent in the pathogenesis of septic shock. In macrophages, LPS interacts with cell surface TLR4 leading to reactive oxygen species (ROS), TNF-α, IL-1β production, oxidative stress and markedly activated the MAPKs and NF-kB pathway. Post cell isolation, the macrophages were subjected to administration with neutralizing antibodies to TLR4 and TNFR1 either alone or in combination prior to LPS challenge. Subsequently, we performed flow cytometric analysis along with Western blots, reactive oxygen species production, and TNF-α, IL-1β release. Outcomes suggested that the dual blockade of TLR4 and TNFR1 was indeed beneficial in shifting the LPS-induced M1 polarization towards M2. Both TLR4 and TNFR1 exhibited dependency during LPS stimulation. Furthermore, the switch towards the M2 phenotype might be responsible for the decreased levels of TNF-α, IL-1β, NO, and superoxide anion and the simultaneous elevation in the activity level of anti-oxidant enzymes like SOD, CAT (catalase), and GSH content in the isolated peritoneal macrophages. Simultaneous blocking of both TLR4 and TNFR1 also showed reduced expression of NF-kB, JNK, and COX-2 by promoting TNFR2-mediated TNF-α signaling. The increased arginase activity further confirmed the polarization towards M2. Thus it may be inferred that dual blockade of TLR4 and TNFR1 might be an alternative therapeutic approach for regulating of sepsis in future.

Lung macrophages are involved in lung injury secondary to repetitive diving

This study aimed to establish an animal model of decompression-induced lung injury (DILI) secondary to repetitive diving in mice and explore the role of macrophages in DILI and the protective effects of high-concentration hydrogen (HCH) on DILI. Mice were divided into three groups: control group, DILI group, and HCH group. Mice were exposed to hyperbaric air at 600 kPa for 60 min once daily for consecutive 3 d and then experienced decompression. In HCH group, mice were administered with HCH (66.7% hydrogen and 33.3% oxygen) for 60 min after each hyperbaric exposure. Pulmonary function tests were done 6 h after decompression; the blood was harvested for cell counting; the lung tissues were harvested for the detection of inflammatory cytokines, hematoxylin and eosin (HE) staining, and immunohistochemistry; western blotting and polymerase chain reaction (PCR) were done for the detection of markers for M1 and M2 macrophages. Our results showed that bubbles formed after decompression and repeated hyperbaric exposures significantly reduced the total lung volume and functional residual volume. Moreover, repetitive diving dramatically increased proinflammatory factors and increased the markers of both M1 and M2 macrophages. HCH inhalation improved lung function to a certain extent, and significantly reduced the pro-inflammatory factors. These effects were related to the reduction of M1 macrophages as well as the increase in M2 macrophages. This study indicates that repetitive diving damages lung function and activates lung macrophages, resulting in lung inflammation. HCH inhalation after each diving may be a promising strategy for the prevention of DILI.

On the Role of Paraoxonase-1 and Chemokine Ligand 2 (C-C motif) in Metabolic Alterations Linked to Inflammation and Disease. A 2021 Update

Infectious and many non-infectious diseases share common molecular mechanisms. Among them, oxidative stress and the subsequent inflammatory reaction are of particular note. Metabolic disorders induced by external agents, be they bacterial or viral pathogens, excessive calorie intake, poor-quality nutrients, or environmental factors produce an imbalance between the production of free radicals and endogenous antioxidant systems; the consequence being the oxidation of lipids, proteins, and nucleic acids. Oxidation and inflammation are closely related, and whether oxidative stress and inflammation represent the causes or consequences of cellular pathology, both produce metabolic alterations that influence the pathogenesis of the disease. In this review, we highlight two key molecules in the regulation of these processes: Paraoxonase-1 (PON1) and chemokine (C-C motif) ligand 2 (CCL2). PON1 is an enzyme bound to high-density lipoproteins. It breaks down lipid peroxides in lipoproteins and cells, participates in the protection conferred by HDL against different infectious agents, and is considered part of the innate immune system. With PON1 deficiency, CCL2 production increases, inducing migration and infiltration of immune cells in target tissues and disturbing normal metabolic function. This disruption involves pathways controlling cellular homeostasis as well as metabolically-driven chronic inflammatory states. Hence, an understanding of these relationships would help improve treatments and, as well, identify new therapeutic targets.

Prospective Observational Study of Bisphosphonate-Related Osteonecrosis of the Jaw in Multiple Myeloma: Microbiota Profiling and Cytokine Expression

PURPOSE

Define incidence and risk factors of osteonecrosis of the jaw (ONJ) and explore oral microbial signatures and host immune response as reflected by cytokine changes in saliva and serum in multiple myeloma (MM) patients on bisphosphate (BP) therapy.

PATIENTS AND METHODS

A single center observational prospective study of MM patients (n = 110) on >2 years of BP, none had ONJ at enrollment. Patients were followed every 3 months for 18 months with clinical/dental examination and serial measurements of inflammatory cytokines, bone turnover markers, and angiogenic growth factors. Oral microbiota was characterized by sequencing of 16S rRNA gene from saliva.

RESULTS

Over the study period 14 patients (13%) developed BRONJ, at a median of 5.7 years (95% CI: 1.9-12.0) from MM diagnosis. Chronic periodontal disease was the main clinically observed risk factor. Oral microbial profiling revealed lower bacterial richness/diversity in BRONJ. Streptococcus intermedius, S. mutans, and S. perioris were abundant in controls; S. sonstellatus and S anginosus were prevalent in BRONJ. In the saliva, at baseline patients who developed BRONJ had higher levels of MIP-1β; TNF-α and IL-6 compared to those without BRONJ, cytokine profile consistent with M-1 macrophage activation. In the serum, patients with BRONJ have significantly lower levels of TGF beta and VEGF over the study period.

CONCLUSION

Periodontal disease associated with low microbial diversity and predominance of invasive species with a proinflammatory cytokine profile leading to tissue damage and alteration of immunity seems to be the main culprit in pathogenesis of BRONJ.

Anti-inflammatory and M2 macrophage polarization-promoting effect of mesenchymal stem cell-derived exosomes

Mesenchymal stem cells (MSCs) are multipotent cells beneficial in regenerative medicine and tissue repair. The therapeutic potential of MSCs for inflammatory diseases and conditions is partly due to secreted exosomes. Exosomes are one group of extracellular vesicles with 50-150 nm in diameter. They can carry numerous molecules and introduce them to the recipient cells to produce various biological effects. Macrophages are classified into M1 and M2 subtypes based on their activation states. M1 macrophages release pro-inflammatory factors like tumor necrosis factoralfa (TNF-α), interleukin1alfa (IL-1α), interleukin1beta (IL-1β), interleukin6 (IL-6), C-X-C motif chemokine ligand 9 (CXCL9), and C-X-C motif chemokine ligand 10 (CXCL10), while M2 macrophages secrete anti-inflammatory mediators including interleukin10 (IL-10), transforming growth factor beta (TGF-β), C-C motif chemokine ligand 1 (CCL1), C-C motif chemokine ligand 17 (CCL17), C-C motif chemokine ligand 18 (CCL18), and C-C motif chemokine ligand 22 (CCL22). This review summarizes the effect of MSC-derived exosomes in the polarization of M2 macrophages, which their anti-inflammatory and immunomodulatory properties are potentially effective in inflammation diseases and conditions such as central nervous system (CNS) diseases, autoimmune diseases, inflammatory bowel disease, cardiomyopathy, graftversushost disease, kidney, liver, lung, and skin injuries.

Macrophages Derived From Human Induced Pluripotent Stem Cells: The Diversity of Protocols, Future Prospects, and Outstanding Questions

Macrophages (Mφ) derived from induced pluripotent stem cells (iMphs) represent a novel and promising model for studying human Mφ function and differentiation and developing new therapeutic strategies based on or oriented at Mφs. iMphs have several advantages over the traditionally used human Mφ models, such as immortalized cell lines and monocyte-derived Mφs. The advantages include the possibility of obtaining genetically identical and editable cells in a potentially scalable way. Various applications of iMphs are being developed, and their number is rapidly growing. However, the protocols of iMph differentiation that are currently used vary substantially, which may lead to differences in iMph differentiation trajectories and properties. Standardization of the protocols and identification of minimum required conditions that would allow obtaining iMphs in a large-scale, inexpensive, and clinically suitable mode are needed for future iMph applications. As a first step in this direction, the current review discusses the fundamental basis for the generation of human iMphs, performs a detailed analysis of the generalities and the differences between iMph differentiation protocols currently employed, and discusses the prospects of iMph applications.

Tumor Necrosis Factor-α Blockade Corrects Monocyte/Macrophage Imbalance in Primary Immune Thrombocytopenia

Primary immune thrombocytopenia (ITP) is an acquired autoimmune bleeding disorder. Monocytes and macrophages are the major cells involved in autoantibody-mediated platelet clearance in ITP. In the present study, we found increased percentages of peripheral blood proinflammatory CD16+ monocytes and elevated frequencies of splenic tumor necrosis factor-α (TNF-α)-expressing macrophages in ITP patients compared with healthy controls. Concurrently, we observed elevated TNF-α secretion in plasma as well as higher TNF-α mRNA expression in total peripheral blood mononuclear cells and CD14+ monocytes of ITP patients. Of note, in vitro TNF-α blockade with neutralizing antibody remarkably reduced polarization to M1 macrophages by inhibiting the nuclear factor kappa B (NF-κB) signaling pathway. Moreover, TNF-α blockade dampened macrophage phagocytosis and T cell stimulatory capacity. Finally, in passive and active murine models of ITP, anti-TNF-α therapy reduced the number of nonclassical monocytes and M1 macrophages, ameliorated the retention of platelets in spleen and liver, and increased the platelet count of ITP mice. Taken together, TNF-α blockade decreased the number and function of proinflammatory subsets of monocytes and macrophages by inhibiting the NF-κB signaling pathway, leading to remarkable attenuation of antibody-mediated platelet destruction. Thus, TNF-α blockade may be a promising therapeutic strategy for the management of ITP.

Intersection between macrophages and periodontal pathogens in periodontitis

Periodontitis is a chronic infectious disease characterized by loss of periodontal attachment and resorption of alveolar bone. Dysregulated oral microbial community is the initial factor of periodontitis and causes excessive infiltration of immune cells in periodontal tissues. Macrophage, as an important part of the innate immune system, interacts continually with oral pathogens. Macrophages can recognize and phagocytize pathogens and apoptotic neutrophils and produce the specialized pro-resolving mediators (SPMs) playing an important role in maintaining the homeostasis of tissue microenvironment. However, macrophages may also induce abnormal immune responses with the overstimulation from pathogens, leading to the destruction of periodontal tissues and alveolar bone. Looking for targeted drugs that can regulate the activities of oral pathogens and the functions of macrophages provides a new idea for periodontitis treatment. This review summarizes the interaction between macrophages and periodontal pathogens in periodontitis, focusing on the pro-inflammation and anti-inflammation phenotypes of macrophages, and briefly concludes potential new methods of periodontitis therapy targeted at oral pathogens and macrophages.

Rebalancing the Oral Microbiota as an Efficient Tool in Endocrine, Metabolic and Immune Disorders

The current treatment and prevention procedures of oral disorders follow a very targeted approach considering mouth and its structures as a system that is completely independent, than the rest of the body. The main therapeutic approach is to keep the levels of oral bacteria and hygiene in an acceptable range compatible with oral-mouth health, completely separated from systemic microbial homeostasis (eubiosis vs dysbiosis). This can negatively impact the diagnosis of a more complex systemic disease and its progression. Dysbiosis occurs as a consequence of imbalance in oral and gut microbiota which leads to cardiovascular diseases, diabetes mellitus, rheumatoid arthritis, and Alzheimer's disease, as reported in current literature. Likewise, there is a need to highlight and develop a novel philosophical approach in the treatments for oral diseases that will necessarily involve nonconventional approaches.

MicroRNAs in Metastasis and the Tumour Microenvironment

Metastasis is the process whereby cancer cells migrate from the primary tumour site to colonise the surrounding or distant tissue or organ. Metastasis is the primary cause of cancer-related mortality and approximately half of all cancer patients present at diagnosis with some form of metastasis. Consequently, there is a clear need to better understand metastasis in order to develop new tools to combat this process. MicroRNAs (miRNAs) regulate gene expression and play an important role in cancer development and progression including in the metastatic process. Particularly important are the roles that miRNAs play in the interaction between tumour cells and non-tumoral cells of the tumour microenvironment (TME), a process mediated largely by circulating miRNAs contained primarily in extracellular vesicles (EVs). In this review, we outline the accumulating evidence for the importance of miRNAs in the communication between tumour cells and the cells of the TME in the context of the pre-metastatic and metastatic niche.

Withania somnifera (L.) Dunal: Opportunity for Clinical Repurposing in COVID-19 Management

As the COVID-19 pandemic is progressing, the therapeutic gaps in conventional management have highlighted the need for the integration of traditional knowledge systems with modern medicine. Ayurvedic medicines, especially Ashwagandha (Withania somnifera (L.) Dunal, WS), may be beneficial in the management of COVID-19. WS is a widely prescribed Ayurvedic botanical known as an immunomodulatory, antiviral, anti-inflammatory, and adaptogenic agent. The chemical profile and pharmacological activities of WS have been extensively reported. Several clinical studies have reported its safety for use in humans. This review presents a research synthesis of in silico, in vitro, in vivo, and clinical studies on Withania somnifera (L.) Dunal (WS) and discusses its potential for prophylaxis and management of COVID-19. We have collated the data from studies on WS that focused on viral infections (HIV, HSV, H1N1 influenza, etc.) and noncommunicable diseases (hypertension, diabetes, cancer, etc.). The experimental literature indicates that WS has the potential for 1) maintaining immune homeostasis, 2) regulating inflammation, 3) suppressing pro-inflammatory cytokines, 4) organ protection (nervous system, heart, lung, liver, and kidney), and 5) anti-stress, antihypertensive, and antidiabetic activities. Using these trends, the review presents a triangulation of Ayurveda wisdom, pharmacological properties, and COVID-19 pathophysiology ranging from viral entry to end-stage acute respiratory distress syndrome (ARDS). The review proposes WS as a potential therapeutic adjuvant for various stages of COVID-19 management. WS may also have beneficial effects on comorbidities associated with the COVID-19. However, systematic studies are needed to realize the potential of WS for improving clinical outcome of patients with COVID-19.

Pathological and Immunohistochemical Characteristics of Granuloma and Lymphatics in Cheilitis Granulomatosa

ABSTRACT

Cheilitis granulomatosa (CG) is an idiopathic, rare, and chronic granulomatous disorder involving the lips. We characterized the pathological and immunohistopathological findings of these granulomas and their relationship with the lymphatic vessels. Pathologically confirmed cases of primary CG from 2001 to 2016 were collected. Cases of inflammatory cheilitis without the presence of granuloma were included in the control group. Demographic data, clinical presentation, response to therapy, and pathological differences were compared. Periodic acid-Schiff and acid-fast stains excluded patients having infections. CD68, CD163, and D2-40 stains demonstrated features of granuloma, macrophage polarization, and the relationship between granuloma and lymphatic vessels. Thirteen patients diagnosed with CG were enrolled. Thirteen people were enrolled in the control group. The granulomas were either mononuclear or sarcoidal. They were predominantly positive for CD68 but negative for CD163. Perilymphatic granulomas were found in all patients. Intralymphatic histiocytosis and lymphatic dilatation were more commonly observed in patients diagnosed with CG than those in controls (54% vs. 15%, P = 0.03 and 92% vs. 23%, P < 0.01). TH1 immune response due to CD68+ M1 macrophages results in CG. Perilymphatic aggregation of macrophages and intralymphatic histiocytosis were important pathological clues for diagnosis.

CD163+ macrophages suppress T cell response by producing TGF-β in pediatric colorectal polyps

The local immune response plays an important role in the pathogenesis of colorectal carcinoma. Patients with colorectal polyps are at increased risk of colorectal cancer. However, the immunoregulation of early-stage colorectal polyps remain unknown. In the study, 202 biopsy samples from 80 pediatric patients with colorectal polyps and from 42 normal controls were collected. We found that the number of CD4⁺, CD8⁺T cells and CD19⁺B cells were reduced, whereas CD68⁺macrophages (Mϕ) were increased in colorectal polyps compared to the distal normal tissue from the same patients and the tissue from healthy donors. The frequency of Mϕwas negatively correlated with the number of CD4⁺ and CD8⁺T cells but not CD19⁺B cells in colorectal polyps. We further identified that CD163 was highly expressed on Mϕϕ from colorectal polyps compared to those from normal controls. Furthermore, real-time PCR revealed that TGF-β, but not IL-10 and IL-4, was increased in colorectal polyps. Immunofluorescence and flow cytometry showed that TGF-β was predominantly produced by CD163⁺Mϕ. In vitro experiments demonstrated that the supernatant from cultured polyps induced CD163 expression and TGF-β production in blood-derived Mϕ. A co-culture experiment revealed that purified Mϕ from colorectal polyps suppressed T cell proliferation. Based on these results, we hypothesized that abundant CD163⁺Mϕ may promote the progression of colorectal polyps by inhibiting the local T cell response through TGF-β production.

Imaging of Inflammation in Spinal Cord Injury: Novel Insights on the Usage of PFC-Based Contrast Agents

Labeling of macrophages with perfluorocarbon (PFC)-based compounds allows the visualization of inflammatory processes by ¹⁹F-magnetic resonance imaging (¹⁹F-MRI), due to the absence of endogenous background. Even if PFC-labeling of monocytes/macrophages has been largely investigated and used, information is lacking about the impact of these agents over the polarization towards one of their cell subsets and on the best way to image them. In the present work, a PFC-based nanoemulsion was developed to monitor the course of inflammation in a model of spinal cord injury (SCI), a pathology in which the understanding of immunological events is of utmost importance to select the optimal therapeutic strategies. The effects of PFC over macrophage polarization were studied in vitro, on cultured macrophages, and in vivo, in a mouse SCI model, by testing and comparing various cell tracking protocols, including single and multiple administrations, the use of MRI or Point Resolved Spectroscopy (PRESS), and application of pre-saturation of Kupffer cells. The blood half-life of nanoemulsion was also investigated by ¹⁹F Magnetic Resonance Spectroscopy (MRS). In vitro and in vivo results indicate the occurrence of a switch towards the M2 (anti-inflammatory) phenotype, suggesting a possible theranostic function of these nanoparticles. The comparative work presented here allows the reader to select the most appropriate protocol according to the research objectives (quantitative data acquisition, visual monitoring of macrophage recruitment, theranostic purpose, rapid MRI acquisition, etc.). Finally, the method developed here to determine the blood half-life of the PFC nanoemulsion can be extended to other fluorinated compounds.

Locoregional Treatment of Metastatic Pancreatic Cancer Utilizing Resection, Ablation and Embolization: A Systematic Review

Simple Summary

Metastatic pancreatic ductal adenocarcinoma (mPDAC) has a dismal prognosis. In selected patients with limited metastatic disease, locoregional therapy, in addition to systemic chemotherapy, may improve survival. This systematic review sought to examine current evidence on the value of additional locoregional treatment, including resection, ablation and embolization, in patients with hepatic or pulmonary mPDAC. The results, although liable to substantial bias, demonstrated superior survival from metastatic diagnosis or treatment in a subset of patients after radical-intent local primary and metastatic treatment (hepatic mPDAC 7.8–19 months; pulmonary mPDAC 22.8–47 months) compared to chemotherapy or best supportive care (hepatic mPDAC 4.3–7.6 months; pulmonary mPDAC 11.8 months). However, as a consequence of the bias, definitive conclusions regarding the seemingly beneficial effect of locoregional treatment cannot be endorsed. Randomized controlled trials with strictly selected oligometastatic PDAC patients are required to deduce final recommendations on this notion.

Abstract

The prognosis of metastatic pancreatic ductal adenocarcinoma (mPDAC) remains universally poor, requiring new and innovative treatment approaches. In a subset of oligometastatic PDAC patients, locoregional therapy, in addition to systemic chemotherapy, may improve survival. The aim of this systematic review was to explore and evaluate the current evidence on locoregional treatments for mPDAC. A systematic literature search was conducted on locoregional techniques, including resection, ablation and embolization, for mPDAC with a focus on hepatic and pulmonary metastases. A total of 59 studies were identified, including 63,453 patients. Although subject to significant bias, radical-intent local therapy for both the primary and metastatic sites was associated with a superior median overall survival from metastatic diagnosis or treatment (hepatic mPDAC 7.8–19 months; pulmonary mPDAC 22.8–47 months) compared to control groups receiving chemotherapy or best supportive care (hepatic mPDAC 4.3–7.6 months; pulmonary mPDAC 11.8 months). To recruit patients that may benefit from these local treatments, selection appears essential. Most significant is the upfront possibility of local radical pancreatic and metastatic treatment. In addition, a patient’s response to neoadjuvant systemic chemotherapy, performance status, metastatic disease load and, to a lesser degree, histological differentiation grade and tumor marker CA19-9 serum levels, are powerful prognostic factors that help identify eligible subjects. Although the exact additive value of locoregional treatments for mPDAC patients cannot be distillated from the results, locoregional primary pancreatic and metastatic treatment seems beneficial for a highly selected group of oligometastatic PDAC patients. For definite recommendations, well-designed prospective randomized controlled trials with strict in- and exclusion criteria are needed to validate these results.

The role of irreversible electroporation in promoting M1 macrophage polarization via regulating the HMGB1-RAGE-MAPK axis in pancreatic cancer

Irreversible electroporation (IRE) is an effective method for treating pancreatic ductal adenocarcinoma (PDAC). It remains unclear whether IRE can induce a specific immune response by stimulating macrophages. Here, the associated markers of macrophages were analyzed after exposure to tumor culture supernatant (TSN) of tumor cells treated with electroporation. Subcutaneous and orthotopic PDAC models were also used to evaluate the effect of macrophage polarization induced by IRE. Aside from its direct killing effect, IRE could induce the immunogenic cell death of tumor cells by increasing the synthesis and secretion of damage associated molecular patterns. Moreover, IRE could increase the release of HMGB1, which activates the MAPK-p38 pathway and leads to the increased expression of M1 markers in macrophages, through binding to the receptor of the advanced glycation end-product (RAGE) receptor. M1 polarization was inhibited by the inhibitors of HMGB1 release, the RAGE receptor, and the MAPK-p38 signaling pathway, but it was activated by rHMGB1 or the stimulator of MAPK-p38. In addition, the promotion of M1 macrophage polarization was enhanced by the positive-feedback release or expression of HMGB1 and RAGE through the MAPK-ERK pathway in macrophages. The promotion of M1 macrophage polarization induced by IRE provided a specific rationale for the combination of IRE and immune therapy in treating PDAC.

Macrophage Polarization in Cardiac Tissue Repair Following Myocardial Infarction

Cardiovascular disease is the leading cause of mortality and morbidity around the globe, creating a substantial socio-economic burden as a result. Myocardial infarction is a significant contributor to the detrimental impact of cardiovascular disease. The death of cardiomyocytes following myocardial infarction causes an immune response which leads to further destruction of tissue, and subsequently, results in the formation of non-contractile scar tissue. Macrophages have been recognized as important regulators and participants of inflammation and fibrosis following myocardial infarction. Macrophages are generally classified into two distinct groups, namely, classically activated, or M1 macrophages, and alternatively activated, or M2 macrophages. The phenotypic profile of cardiac macrophages, however, is much more diverse and should not be reduced to these two subsets. In this review, we describe the phenotypes and functions of macrophages which are present in the healthy, as well as the infarcted heart, and analyze them with respect to M1 and M2 polarization states. Furthermore, we discuss therapeutic strategies which utilize macrophage polarization towards an anti-inflammatory or reparative phenotype for the treatment of myocardial infarction.

The Role of Mitochondria in Immune-Cell-Mediated Tissue Regeneration and Ageing

During tissue injury events, the innate immune system responds immediately to alarms sent from the injured cells, and the adaptive immune system subsequently joins in the inflammatory reaction. The control mechanism of each immune reaction relies on the orchestration of different types of T cells and the activators, antigen-presenting cells, co-stimulatory molecules, and cytokines. Mitochondria are an intracellular signaling organelle and energy plant, which supply the energy requirement of the immune system and maintain the system activation with the production of reactive oxygen species (ROS). Extracellular mitochondria can elicit regenerative effects or serve as an activator of the immune cells to eliminate the damaged cells. Recent clarification of the cytosolic escape of mitochondrial DNA triggering innate immunity underscores the pivotal role of mitochondria in inflammation-related diseases. Human mesenchymal stem cells could transfer mitochondria through nanotubular structures to defective mitochondrial DNA cells. In recent years, mitochondrial therapy has shown promise in treating heart ischemic events, Parkinson's disease, and fulminating hepatitis. Taken together, these results emphasize the emerging role of mitochondria in immune-cell-mediated tissue regeneration and ageing.

Downregulation of Macrophage-Specific Act-1 Intensifies Periodontitis and Alveolar Bone Loss Possibly via TNF/NF-κB Signaling

Periodontitis is a chronic inflammatory oral disease that affects almost half of the adult population. NF-κB activator 1 (Act1) is mainly expressed in immune cells, including macrophages, and modulates immune cells' function to regulate inflammation in inflammatory diseases. Macrophages play a vital role in the pathophysiology of periodontitis. However, the effect of macrophage-specific Act1 on periodontitis has not been investigated yet. This study aims to unravel the role of macrophage-specific Act1 on the pathophysiology of periodontitis. The expression of Act1 in healthy and periodontitis periodontal tissue was confirmed by immunohistochemistry. Macrophage-specific Act1 expression downregulated (anti-Act1) mice were developed by inserting anti-Act1 antisense oligonucleotides after the CD68 promoter of C57BL/6 mice. Ligature-induced periodontitis (LIP) was induced in anti-Act1 mice and wildtype mice. Micro-CT, histology, and TRAP staining analyzed the periodontal tissue status, alveolar bone loss, and osteoclast numbers. Immunohistochemistry, RT-qPCR, and ELISA analyzed the inflammatory cells infiltration, expression of inflammatory cytokines, and M1/M2 macrophage polarization. mRNA sequencing of in vitro bacterial lipopolysaccharide (LPS)-treated peritoneal macrophages analyzed the differentially expressed genes in anti-Act1 mice during inflammation. Anti-Act1 mice showed aggravated periodontitis and alveolar bone loss compared to wildtype. Periodontitis-affected periodontal tissue (PAPT) of anti-Act1 mice showed a higher degree of macrophage infiltration, and M1 macrophage polarization compared to wildtype. Levels of pro-inflammatory cytokines (IL-1β, IL-6, and TNFα), and macrophage activity-related factors (CCL2, CCL3, and CCL4) were robustly high in PAPT of anti-Act1 mice compared to wildtype. mRNA sequencing and KEGG analysis showed activated TNF/NF-κB signaling in LPS-treated macrophages from anti-Act1 mice. In vitro studies on LPS-treated peritoneal macrophages from anti-act1 mice showed a higher degree of cell migration and expression of inflammatory cytokines, macrophage activity-related factors, M1 macrophage-related factors, and TNF/NF-κB signaling related P-p65 protein. In conclusion, downregulation of macrophage-specific Act1 aggravated periodontitis, alveolar bone loss, macrophage infiltration, inflammation, and M1 macrophage polarization. Furthermore, LPS-treated macrophages from anti-Act1 mice activated TNF/NF-κB signaling. These results indicate the distinct role of macrophage-specific Act1 on the pathophysiology of periodontitis possibly via TNF/NF-κB signaling.

Macrophages in dermatology: pathogenic roles and targeted therapeutics

The field of macrophage biology is rapidly growing. Recent studies have shifted focus from classic wound healing roles to newly identified roles in dermatologic pathology. These studies have identified pathogenic roles of macrophages in relatively common conditions, such as psoriasis, skin cancer, and cutaneous T-cell lymphoma. Selective depletion of these cells or their associated cytokines leads to improved clinical outcome. Herein, we review recent animal and human studies that have elucidated novel pathogenic roles of macrophages in conditions frequently encountered by dermatologists and discuss clinically relevant macrophage-targeted therapies.

Sophoridine Inhibits the Tumour Growth of Non-Small Lung Cancer by Inducing Macrophages M1 Polarisation via MAPK-Mediated Inflammatory Pathway

Lung cancer is one of the most common and lethal neoplasms for which very few efficacious treatments are currently available. M1-like polarised tumour-associated macrophages (TAMs) are key mediators to modulate the tumour microenvironment, which play a key role in inhibiting cancer cell growth. Sophoridine, a naturally occurring alkaloid, exerts multiple pharmacological activities including anti-tumour and anti-inflammatory activities, but it has not been characterised as a regulator of tumour microenvironment towards NSCLC. Herein, the regulatory effects of sophoridine on the polarisation of THP-1 cells into TAMs and the anti-tumour effects of sophoridine-stimulated M1 polarised macrophages towards lung cancer cells were carefully investigated both in vitro and in vivo. The results showed that sophoridine could significantly promote M1 polarisation of RAW264.7 and THP-1-derived macrophages, leading to increased expression of pro-inflammatory cytokines and the M1 surface markers CD86 via activating MAPKs signaling pathway. Further investigations showed that sophoridine-stimulated RAW264.7 and THP-1-derived M1 macrophages effectively induced cell apoptosis as well as inhibited the cell colony formation and cell proliferation in both H460 and Lewis lung cancer cells. In Lewis-bearing mice model, sophoridine (15 or 25 mg/kg) significantly inhibited the tumour growth and up-regulated the expression of CD86/F4/80 in tumour tissues. Collectively, the findings clearly demonstrate that sophoridine promoted M1-like polarisation in vitro and in vivo, suggesting that sophoridine held a great therapeutic potential for treating lung cancer.

The role of CD68+ and CD163+ macrophages in immunopathogenesis of oral lichen planus and oral lichenoid lesions

Macrophages are phagocytic cells with essential participation in immunological events of the oral cavity. However, the role of these cells in oral lichen planus (OLP) and oral lichenoid lesions (OLL) remains unclear. The present study aimed to evaluate the density of macrophages in OLP and OLL, and to compare it with that of oral inflammatory fibrous hyperplasia (OIFH) (control group). 14 cases of OLP, 14 cases of OLL and 14 cases of OIFH were selected for immunohistochemical analysis of CD68⁺ (M1) and CD163⁺ (M2) macrophage expression. CD68⁺ and CD163⁺ macrophages densities were measured in the intraepithelial and subepithelial areas. The statistical tests used were multivariate analysis of variance, as well as a correlation and linear regression. OLP has more CD68+ macrophages when comparing with OLL (p = 0.001) and OIFH (p = 0.045). There is a very strong relationship between the macrophages types (p < 0.0001) in OLP and OLL. The linear regression showed that to OLL development (p < 0.0001/R^2' = 0.9584), the presence of different types of macrophages are more essential than to OLP (p < 0.0001/R^2' = 0.8983). However, in the OLP these dependencies are also largely. CD68⁺ macrophages may be associated with immunopathogenesis of OLP, indicating a pro-inflammatory activity and regulatory role in the type of T-cell response. Besides, CD68⁺ macrophages can cooperate in the diagnosis of OLP. These results are essential to future studies that seek a therapeutic target for OLP and OLL.

Cyclin A2 maintains colon homeostasis and is a prognostic factor in colorectal cancer

To clarify the function of cyclin A2 in colon homeostasis and colorectal cancer (CRC), we generated mice deficient for cyclin A2 in colonic epithelial cells (CECs). Colons of these mice displayed architectural changes in the mucosa and signs of inflammation, as well as increased proliferation of CECs associated with the appearance of low- and high-grade dysplasias. The main initial events triggering those alterations in cyclin A2-deficient CECs appeared to be abnormal mitoses and DNA damage. Cyclin A2 deletion in CECs promoted the development of dysplasia and adenocarcinomas in a murine colitis-associated cancer model. We next explored the status of cyclin A2 expression in clinical CRC samples at the mRNA and protein levels and found higher expression in tumors of patients with stage 1 or 2 CRC compared with those of patients with stage 3 or 4 CRC. A meta-analysis of 11 transcriptome data sets comprising 2239 primary CRC tumors revealed different expression levels of CCNA2 (the mRNA coding for cyclin A2) among the CRC tumor subtypes, with the highest expression detected in consensus molecular subtype 1 (CMS1) and the lowest in CMS4 tumors. Moreover, we found high expression of CCNA2 to be a new, independent prognosis factor for CRC tumors.

Interleukin 12p40 Deficiency Promotes Abdominal Aortic Aneurysm by Activating CCN2/MMP2 Pathways

Background Development of abdominal aortic aneurysm (AAA) is associated with proinflammatory cytokines including interleukin-12 (IL12). Deficiency of interleukin 12p40 (IL12p40) increases localized fibrotic events by promoting TGFβ2 (transforming growth factor β)-dependent anti-inflammatory response. Here, we determined whether IL12p40 deficiency in apolipoprotein E-/- mice attenuates the development of AAA by antagonizing proinflammatory response. Methods and Results Double knockout (DKO) mice were generated by crossbreeding IL12p40-/- mice with apolipoprotein E-/- mice (n=12). Aneurysmal studies were performed using angiotensin II (1 µg/kg/min; subcutaneous). Surprisingly, DKO mice did not prevent the development of AAA with angiotensin II infusion. Immunohistological analysis, however, showed distinct pathological features between apolipoprotein E-/- and DKO mice. Polymerase chain reaction (7 day) and cytokine arrays (28 day) of the aortic tissues from DKO mice showed significantly increased expression of cytokines related to anti-inflammatory response (interleukin 5 and interleukin 13), synthetic vascular smooth muscle cell phenotype (Activin receptor-like kinase-1 (ALK-1), artemin, and betacellulin) and T helper 17-associated response (4-1BB, interleukin-17e (Il17e) and Cd40 ligand (Cd-40L)). Indeed, DKO mice exhibited increased expression of the fibro-proteolytic pathway in the medial layer of aortae induced by cellular communication network factor 2 (CCN2) and Cd3+IL17+ cells compared with apolipoprotein E-/- mice. Laser capture microdissection showed predominant expression of CCN2/TGFβ2 in the medial layer of human AAA. Finally, Ccn2 haploinsufficiency in the mice showed decreased AAA incidence in response to elastase infusion, associated with decreased matrix metalloproteinase-2 expression. Conclusions Our study reveals novel roles for IL12p40 deficiency in inducing fibro-proteolytic activities in the aneurysmal mouse model. Mechanistically, these effects of IL12p40 deficiency are mediated by CCN2/matrix metalloproteinase-2 crosstalk in the medial layer of aneurysmal aortae.

Inflammation/bioenergetics-associated neurodegenerative pathologies and concomitant diseases: a role of mitochondria targeted catalase and xanthophylls

Various inflammatory stimuli are able to modify or even "re-program" the mitochondrial metabolism that results in generation of reactive oxygen species. In noncommunicable chronic diseases such as atherosclerosis and other cardiovascular pathologies, type 2 diabetes and metabolic syndrome, these modifications become systemic and are characterized by chronic inflammation and, in particular, "neuroinflammation" in the central nervous system. The processes associated with chronic inflammation are frequently grouped into "vicious circles" which are able to stimulate each other constantly amplifying the pathological events. These circles are evidently observed in Alzheimer's disease, atherosclerosis, type 2 diabetes, metabolic syndrome and, possibly, other associated pathologies. Furthermore, chronic inflammation in peripheral tissues is frequently concomitant to Alzheimer's disease. This is supposedly associated with some common genetic polymorphisms, for example, Apolipoprotein-E ε4 allele carriers with Alzheimer's disease can also develop atherosclerosis. Notably, in the transgenic mice expressing the recombinant mitochondria targeted catalase, that removes hydrogen peroxide from mitochondria, demonstrates the significant pathology amelioration and health improvements. In addition, the beneficial effects of some natural products from the xanthophyll family, astaxanthin and fucoxanthin, which are able to target the reactive oxygen species at cellular or mitochondrial membranes, have been demonstrated in both animal and human studies. We propose that the normalization of mitochondrial functions could play a key role in the treatment of neurodegenerative disorders and other noncommunicable diseases associated with chronic inflammation in ageing. Furthermore, some prospective drugs based on mitochondria targeted catalase or xanthophylls could be used as an effective treatment of these pathologies, especially at early stages of their development.

Selective killing of human M1 macrophages by Smac mimetics alone and M2 macrophages by Smac mimetics and caspase inhibition

The inflammatory and anti-inflammatory Mϕs have been implicated in many diseases including rheumatoid arthritis, multiple sclerosis, and leprosy. Recent studies suggest targeting Mϕ function and activation may represent a potential target to treat these diseases. Herein, we investigated the effect of second mitochondria-derived activator of caspases (SMAC) mimetics (SMs), the inhibitors of apoptosis (IAPs) proteins, on the killing of human pro- and anti-inflammatory Mϕ subsets. We have shown previously that human monocytes are highly susceptible whereas differentiated Mϕs (M0) are highly resistant to the cytocidal abilities of SMs. To determine whether human Mϕ subsets are resistant to the cytotoxic effects of SMs, we show that M1 Mϕs are highly susceptible to SM-induced cell death whereas M2a, M2b, and M2c differentiated subsets are resistant, with M2c being the most resistant. SM-induced cell death in M1 Mϕs was mediated by apoptosis as well as necroptosis, activated both extrinsic and intrinsic pathways of apoptosis, and was attributed to the IFN-γ-mediated differentiation. In contrast, M2c and M0 Mϕs experienced cell death through necroptosis following simultaneous blockage of the IAPs and the caspase pathways. Overall, the results suggest that survival of human Mϕs is critically linked to the activation of the IAPs pathways. Moreover, agents blocking the cellular IAP1/2 and/or caspases can be exploited therapeutically to address inflammation-related diseases.