Macrophage migration inhibitory factor regulates mitochondrial dynamics and cell growth of human cancer cell lines through CD74-NF-κB signaling

Potential protumor function of CD74 in clear cell renal cell carcinoma

CD74 is a transmembrane protein that functions as a specialized chaperone of HLA class II and CD74 in tumor cells was suggested to be involved in cell proliferation in several kinds of malignant tumors. CD74 is also known to be expressed in macrophages, therefore, we investigated the CD74 expression in clear cell renal cell carcinoma (ccRCC). Immunohistochemistry of CD74 indicated that CD74 was expressed not only in cancer cells but also macrophages. CD74 was detected in surface membrane and cytoplasm of cancer cells in 92 of 94 cases (98%) and of 87 of 94 cases (93%). CD74 was expressed both in cancer cells and TAMs in 86 of 94 cases (91%). In vitro studies using cancer cell lines and monocyte-derived macrophages stimulated by anti-CD74 antibodies showed that CD74 signal accelerated cancer cell proliferation and macrophage activation. However, macrophage activation via CD74 signal did not influence macrophage-mediated cancer cell growth. RNA-sequence of macrophages stimulated by anti-CD74 antibodies indicated that CD74 signal was associated to inflammatory responses in macrophages. In conclusion, we examined the expression and functional significance of CD74 in ccRCC using tissue specimens and cell culture studies. The function of CD74 was suggested to be different in cancer cells and in macrophages, and further studies are necessary to clarify the functional significance of CD74 in ccRCC.

PINK1 insufficiency can be exploited as a specific target for drug combinations inducing mitochondrial pathology-mediated cell death in gastric adenocarcinoma

There exist very limited non-hazardous therapeutic strategies except for surgical resection and lymphadenectomy against gastric cancer (GC) despite being the third leading cause of cancer deaths worldwide. This study proposes an innovative treatment approach against GC using a drug combination strategy that manipulates mitochondrial dynamics in conjunction with the induction of mitochondrial pathology-mediated cell death. Comparative analysis was done with gastric adenocarcinoma and normal cells by qPCR, western blot, microscopic immunocytochemistry, and live cell imaging. In this study, impairment of dynamin-related protein 1 (Drp1)-mediated mitochondrial fission by Mdivi-1 created an imbalance in mitochondrial structural dynamics in indomethacin-treated AGS cells in which mitophagy-regulator protein PINK1 is downregulated. These drug combinations with the individual sub-lethal doses ultimately led to the activation of cell death machinery upregulating pro-apoptotic proteins like Bax, Puma, and Noxa. Interestingly, this combinatorial therapy did not affect normal gastric epithelial cells significantly and also no significant upregulation of death markers was observed. Moreover, the drug combination strategy also retarded cell migration and reduced stemness in GC cells. In summary, this study offers a pioneering specific therapeutic strategy for GC treatment, sparing normal cells providing opportunities for minimal drug-mediated toxicity utilizing mitochondria as a viable and specific target for anti-cancer therapy in gastric cancer.

Calycosin inhibited MIF-mediated inflammatory chemotaxis of macrophages to ameliorate ischemia reperfusion-induced acute kidney injury

BACKGROUND

Inflammatory macrophage infiltration plays a critical role in acute kidney disease induced by ischemia-reperfusion (IRI-AKI). Calycosin is a natural flavone with multiple bioactivities. This study aimed to investigate the therapeutic role of calycosin in IRI-AKI and its underlying mechanism.

METHODS

The renoprotective and anti-inflammatory effects of calycosin were analyzed in C57BL/6 mice with IRI-AKI and lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. RNA-seq was used for mechanism investigation. The molecular target of calycosin was screened by in silico methods and validated by surface plasmon resonance (SPR). Macrophage chemotaxis was analyzed using Transwell and agarose gel spot assays.

RESULTS

Calycosin treatment significantly reduced serum creatinine and urea nitrogen and attenuated tubular destruction in IRI-AKI mice. Additionally, calycosin markedly suppressed NF-κB signaling activation and the expression of inflammatory mediators IL-1β and TNF-α in IRI-AKI kidneys and LPS-stimulated RAW 264.7 cells. Interestingly, RNA-seq revealed calycosin remarkably downregulated chemotaxis-related pathways in RAW 264.7 cells. Among the differentially expressed genes, Ccl2/MCP-1, a critical chemokine mediating macrophage inflammatory chemotaxis, was downregulated in both LPS-stimulated RAW 264.7 cells and IRI-AKI kidneys. Consistently, calycosin treatment attenuated macrophage infiltration in the IRI-AKI kidneys. Importantly, in silico target prediction, molecular docking, and SPR assay demonstrated that calycosin directly binds to macrophage migration inhibitory factor (MIF). Functionally, calycosin abrogated MIF-stimulated NF-κB signaling activation and Ccl2 expression and MIF-mediated chemotaxis in RAW 264.7 cells.

CONCLUSIONS

In summary, calycosin attenuates IRI-AKI by inhibiting MIF-mediated macrophage inflammatory chemotaxis, suggesting it could be a promising therapeutic agent for the treatment of IRI-AKI.

Unraveling the molecular architecture of autoimmune thyroid diseases at spatial resolution

Autoimmune thyroid diseases (AITD) such as Graves' disease (GD) or Hashimoto's thyroiditis (HT) are organ-specific diseases that involve complex interactions between distinct components of thyroid tissue. Here, we use spatial transcriptomics to explore the molecular architecture, heterogeneity and location of different cells present in the thyroid tissue, including thyroid follicular cells (TFCs), stromal cells such as fibroblasts, endothelial cells, and thyroid infiltrating lymphocytes. We identify damaged antigen-presenting TFCs with upregulated CD74 and MIF expression in thyroid samples from AITD patients. Furthermore, we discern two main fibroblast subpopulations in the connective tissue including ADIRF+ myofibroblasts, mainly enriched in GD, and inflammatory fibroblasts, enriched in HT patients. We also demonstrate an increase of fenestrated PLVAP+ vessels in AITD, especially in GD. Our data unveil stromal and thyroid epithelial cell subpopulations that could play a role in the pathogenesis of AITD.

A Comprehensive Pan-Cancer Analysis of Cytochrome C Oxidase Assembly Factor 1 (COA1) Reveals Instrumental Role of Mitochondrial Protein Assembly in Cancer that Modulates Disease Progression and Prognostic Outcome

Cytochrome c oxidase assembly factor 1 (COA1), a mitochondrial respiratory chain complex assembly factor protein of inner mitochondrial membrane (IMM), is involved in translating many mitochondrial components and assembling nuclear-encoded components within mitochondria. Given the lack of extensive research on COA1 in cancer, this study undertakes a comprehensive pan-cancer analysis of COA1, which is overexpressed across various cancer types, shedding light on its multifaceted role in tumorigenesis, prognosis, and tumor microenvironment (TME) modulation. Leveraging bioinformatics tools and public databases, we elucidated its potential as a diagnostic cancer biomarker as well as a target for novel anti-cancer therapeutics. Gene expression analysis using "TIMER2.0", "UALCAN" and "GEPIA2" platforms, supported by protein expression data, revealed a significant correlation between COA1 upregulation and poor prognosis in Kaplan-Meir analysis, underscoring its clinical relevance. Additionally, genetic mutation analysis of COA1 with the help of "cBioPortal" warrants further exploration into its functional significance. Moreover, our investigation of the tumor microenvironment unveiled the interplay of COA1 with fibroblast and T cell infiltration implicating the role of COA1 in the tumor immune microenvironment. Furthermore, COA1-related gene enrichment study in "GeneMANIA" and pathway cross-talk analysis with Gene Ontology (GO) gene sets established comprehensive clarifications about the molecular pathways and protein networks associated with COA1 deregulation. Overall, this study lays a sturdy foundation to support future research endeavors targeting COA1, unraveling the molecular mechanisms underlying COA1 deregulation, and exploring its therapeutic potential in cancer.

Cross-link assisted spatial proteomics to map sub-organelle proteomes and membrane protein topologies

The functions of cellular organelles and sub-compartments depend on their protein content, which can be characterized by spatial proteomics approaches. However, many spatial proteomics methods are limited in their ability to resolve organellar sub-compartments, profile multiple sub-compartments in parallel, and/or characterize membrane-associated proteomes. Here, we develop a cross-link assisted spatial proteomics (CLASP) strategy that addresses these shortcomings. Using human mitochondria as a model system, we show that CLASP can elucidate spatial proteomes of all mitochondrial sub-compartments and provide topological insight into the mitochondrial membrane proteome. Biochemical and imaging-based follow-up studies confirm that CLASP allows discovering mitochondria-associated proteins and revising previous protein sub-compartment localization and membrane topology data. We also validate the CLASP concept in synaptic vesicles, demonstrating its applicability to different sub-cellular compartments. This study extends the scope of cross-linking mass spectrometry beyond protein structure and interaction analysis towards spatial proteomics, and establishes a method for concomitant profiling of sub-organelle and membrane proteomes.

METTL3-Mediated LINC00475 Alternative Splicing Promotes Glioma Progression by Inducing Mitochondrial Fission

Mitochondrial fission promotes glioma progression. The function and regulation mechanisms of lncRNAs in glioma mitochondrial fission are unclear. The expression of LINC00475 and its correlation with clinical parameters in glioma were analyzed using bioinformatics. Then, in vitro and in vivo assays were performed to explore the function of spliced variant LINC00475 (LINC00475-S) in gliomas. To explore the mechanisms, RNA-seq, MeRIP, RIP, pulldown-IP, dCas9-ALKBH5 editing system, LC/MS, and Western blotting were utilized. LINC00475 was confirmed to be overexpressed and with higher frequencies of AS events in gliomas compared to normal brain tissue and was associated with worse prognosis. In vitro and animal tumor formation experiments demonstrated that the effect of LINC00475-S on proliferation, metastasis, autophagy, and mitochondrial fission of glioma cells was significantly stronger than that of LINC00475. Mechanistically, METTL3 induced the generation of LINC00475-S by splicing LINC00475 through m6A modification and subsequently promotes mitochondrial fission in glioma cells by inhibiting the expression of MIF. Pull-down combined LC/MS and RIP assays identified that the m6A recognition protein HNRNPH1 bound to LINC00475 within GYR and GY domains and promoted LINC00475 splicing. METTL3 facilitated HNRNPH1 binding to LINC00475 in an m6A-dependent manner, thereby inducing generation of LINC00475-S. METTL3 facilitated HNRNPH1-mediated AS of LINC00475, which promoted glioma progression by inducing mitochondrial fission. Targeting AS of LINC00475 and m6A editing could serve as a therapeutic strategy against gliomas.

Macrophage migration inhibitory factor reversed senescent phenotype in human chondrocytes in vitro

BACKGROUND

The senescence of chondrocytes, which is closely linked to the development of osteoarthritis (OA), has been found to be influenced by the inflammatory environment of joint cavity. However, there remains a lack of comprehensive understanding regarding the specific mechanisms through which cytokine impacts chondrocytes senescence.

PURPOSE

To investigate the effects of MIF on the chondrocytes senescence and explore the underlying mechanism.

METHODS

Human cytokine array and ELISA were used for the level of MIF in synovium fluid. CCK-8 was used for chondrocytes viability. IF, WB, SA-β-gal staining and flow cytometry were used for the chondrogenic, apoptotic and senescent phenotype of chondrocytes.

RESULTS

The level of MIF was significantly increased in OA patients. MIF significantly reversed the senescent phenotype induced by LPS pretreatment in human chondrocytes. MIF significantly enhanced the expression of Col II, SOX9, and ACAN in LPS pre-treated human chondrocytes. Furthermore, MIF significantly inhibited the apoptosis of LPS-induced senescent chondrocytes.

CONCLUSION

Increased level of MIF in osteoarthritic joint cavity might effectively suppress the senescent phenotype and simultaneously improve the chondrogenic phenotype in chondrocytes, the underlying mechanism was likely to be independent of apoptosis.

The crosstalk between M1 macrophage polarization and energy metabolism disorder contributes to polystyrene nanoplastics-triggered testicular inflammation

Ubiquitous microplastics have become a threat to animal and human health, due to their potential toxicity, persistent nature and consequent bioaccumulation. Supporting evidence elucidates that polystyrene nanoplastics (PS-NPs) can destroy blood-testis barrier integrity, thus causing testicular hypoplasia and impairment of spermatogenesis. Nevertheless, how PS-NPs modulate macrophage polarization-energy metabolism crosstalk has not been fully investigated in testicular tissue. Here, we observed that polystyrene PS-NPs exposure contributes to severe vacuolization in the seminiferous tubules, accompanied by apoptosis of testicular tissue and infiltration of M1 macrophages. Meanwhile, we found that PS-NPs could trigger the M1 polarization phenotype, which activated ROS-macrophage migration inhibitory factor (MIF)/NF-κB signaling that in turn induced apoptosis of GC2 cells in the GC2-macrophage cell coculture model. Simultaneously, we confirmed that PS-NPs exposure increased 3-phospho-D-glycerate, phosphoenolpyruvate and lactate concentrations, accompanied by decreased pyruvate and adenosine triphosphate (ATP) production, likely due to downregulated pyruvate kinase M2 (PKM2) dimer expression. In conclusion, the mechanism of PS-NPs-induced testicular inflammation can be mediated by promoting the infiltration of M1 macrophages, thereby resulting in an ROS burst and subsequent induction of energy metabolism disorders. The current study will provide new insights into PS-NPs-induced male reproductive toxicity and highlight the context-specific roles of testicular macrophages.

Ets1 facilitates EMT/invasion through Drp1-mediated mitochondrial fragmentation in ovarian cancer

Ovarian cancer has sustained as a major cause of cancer-related female mortality owing to its aggressive nature and a dearth of early detection markers. Ets1 oncoprotein, a transcription factor belonging to the Ets family, is a well-established promoter of epithelial to mesenchymal transition (EMT) and a prospective malignancy marker in ovarian cancer. Our study establishes Ets1 as a regulator of mitochondrial fission-fusion dynamics through Drp1 augmentation via direct binding at DNM1L (DRP1) promoter. Ets1 overexpression-mediated Drp1 increment resulted in mitochondrial load reduction and compromised OXPHOS Complex 5 (ATP synthase) expression, facilitating a greater reliance on glycolysis over OXPHOS. Furthermore, our work demonstrates that inhibition of mitochondrial fission through molecular or pharmacological inhibition of Drp1 successfully mitigates Ets1-associated EMT in both in vitro and in vivo syngeneic mice model. Collectively, our data highlight the role of Drp1-mediated mitochondrial fragmentation in driving Ets1-mediated bioenergetic alterations and EMT/invasion in ovarian cancer.

Reanalysis of single-cell data reveals macrophage subsets associated with the immunotherapy response and prognosis of patients with endometrial cancer

Endometrial cancer (EC) is an aggressive gynecological malignancy with an increased incidence rate. The immune landscape crucially affects immunotherapy efficacy and prognosis in EC patients. Here, we characterized the distinct tumor microenvironment signatures of EC tumors by analyzing single-cell RNA sequencing data from Gene Expression Omnibus and bulk RNA sequencing data from The Cancer Genome Atlas, which were compared with normal endometrium. Three macrophage subsets were identified, and two of them showed tissue-specific distribution. One of the macrophage subsets was dominant in macrophages derived from EC and exhibited characteristic behaviors such as promoting tumor growth and metastasis. One of the other macrophage subsets was mainly found in normal endometrium and served functions related to antigen presentation. We also identified a macrophage subset that was found in both EC and normal endometrial tissue. However, the pathway and cellular cross-talk of this subset were completely different based on the respective origin, suggesting a tumor-related differentiation mechanism of macrophages. Additionally, the tumor-enriched macrophage subset was found to predict immunotherapy responses in EC. Notably, we selected six genes from macrophage subset markers that could predict the survival of EC patients, SCL8A1, TXN, ANXA5, CST3, CD74 and NANS, and constructed a prognostic signature. To verify the signature, we identified immunohistochemistry for the tumor samples of 83 EC patients based on the selected genes and further followed up with the survival of the patients. Our results provide strong evidence that the signature can effectively predict the prognosis of EC patients.

Restraint stress promotes monobenzone-induced depigmentation in mice via the activation of glucocorticoid receptor/macrophage migration inhibitory factor signaling pathway

Psychological stress triggers onset and development of vitiligo in humans. However, the mechanism of psychological stress on vitiligo remains unclear. The study aims to investigate whether psychological stress promotes vitiligo and explore the underlying mechanism. A depigmentation mouse model induced by applying a skin-bleaching reagent monobenzone to dorsal skin and an in vitro HaCaT keratinocyte death model induced by monobenzone were employed to explore the effect of restraint stress, which mimics psychological stress, on depigmentation. The results indicated that restraint stress promoted vitiligo-related depigmentation, vacuolisation, spongiosis, CD8+ T lymphocyte infiltration, and loss of melanocytes in the skin. Restraint stress activated cutaneous NLR family containing pyrin domain protein 3 (NLRP3) inflammasome. In addition, restraint stress aggravated anxiety-like behaviors and increased levels of macrophage migration inhibitory factor (MIF) and corticosterone in the circulation, accompanied with decreasing the expression of cutaneous 8-oxoguanine DNA glycosylase (OGG1) in depigmentation mice. In vitro experiments demonstrated that activation of glucocorticoid receptor (GR) by cortisol upregulated NLRP3 expression dependent on MIF, and directly decreased the transcription of OGG1. Blockade of MIF reversed the NLRP3 signal in restraint stress-induced depigmentation mice. In conclusion, restraint stress promotes vitiligo-related depigmentation in mice via the activation of GR/MIF signaling pathway. The findings provide a theoretical basis for prevention and treatments of vitiligo with therapies of targeting GR, MIF, and OGG1.

Pathophysiological involvement of host mitochondria in SARS-CoV-2 infection that causes COVID-19: a comprehensive evidential insight

SARS-CoV-2 is a positive-strand RNA virus that infects humans through the nasopharyngeal and oral route causing COVID-19. Scientists left no stone unturned to explore a targetable key player in COVID-19 pathogenesis against which therapeutic interventions can be initiated. This article has attempted to review, coordinate and accumulate the most recent observations in support of the hypothesis predicting the altered state of mitochondria concerning mitochondrial redox homeostasis, inflammatory regulations, morphology, bioenergetics and antiviral signalling in SARS-CoV-2 infection. Mitochondria is extremely susceptible to physiological as well as pathological stimuli, including viral infections. Recent studies suggest that SARS-CoV-2 pathogeneses alter mitochondrial integrity, in turn mitochondria modulate cellular response against the infection. SARS-CoV-2 M protein inhibited mitochondrial antiviral signalling (MAVS) protein aggregation in turn hinders innate antiviral response. Viral open reading frames (ORFs) also play an instrumental role in altering mitochondrial regulation of immune response. Notably, ORF-9b and ORF-6 impair MAVS activation. In aged persons, the NLRP3 inflammasome is over-activated due to impaired mitochondrial function, increased mitochondrial reactive oxygen species (mtROS), and/or circulating free mitochondrial DNA, resulting in a hyper-response of classically activated macrophages. This article also tries to understand how mitochondrial fission-fusion dynamics is affected by the virus. This review comprehends the overall mitochondrial attribute in pathogenesis as well as prognosis in patients infected with COVID-19 taking into account pertinent in vitro, pre-clinical and clinical data encompassing subjects with a broad range of severity and morbidity. This endeavour may help in exploring novel non-canonical therapeutic strategies to COVID-19 disease and associated complications.

Possible Pathogenesis and Prevention of Long COVID: SARS-CoV-2-Induced Mitochondrial Disorder

Patients who have recovered from coronavirus disease 2019 (COVID-19) infection may experience chronic fatigue when exercising, despite no obvious heart or lung abnormalities. The present lack of effective treatments makes managing long COVID a major challenge. One of the underlying mechanisms of long COVID may be mitochondrial dysfunction. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections can alter the mitochondria responsible for energy production in cells. This alteration leads to mitochondrial dysfunction which, in turn, increases oxidative stress. Ultimately, this results in a loss of mitochondrial integrity and cell death. Moreover, viral proteins can bind to mitochondrial complexes, disrupting mitochondrial function and causing the immune cells to over-react. This over-reaction leads to inflammation and potentially long COVID symptoms. It is important to note that the roles of mitochondrial damage and inflammatory responses caused by SARS-CoV-2 in the development of long COVID are still being elucidated. Targeting mitochondrial function may provide promising new clinical approaches for long-COVID patients; however, further studies are needed to evaluate the safety and efficacy of such approaches.

Generation of miR-15a/16-1 cluster-deficient human induced pluripotent stem cell line (DMBi001-A-2) using CRISPR/Cas9 gene editing

miR-15a/16-1 cluster, composed of MIR15A and MIR16-1 genes located in close proximity on chromosome 13 was described to regulate post-natal cell cycle withdrawal of cardiomyocytes in mice. In humans, on the other hand, the level of miR-15a-5p and miR-16-p was negatively associated with the severity of cardiac hypertrophy. Therefore, to better understand the role of these microRNAs in human cardiomyocytes in regard to their proliferative potential and hypertrophic growth, we generated hiPSC line with complete deletion of miR-15a/16-1 cluster using CRISPR/Cas9 gene editing. Obtained cells demonstrate expression of pluripotency markers, differentiation capacity into all three germ layers and normal karyotype.

Tumor Necrosis Factor α-Dependent Lung Inflammation Promotes the Progression of Lung Adenocarcinoma Originating From Alveolar Type II Cells by Upregulating MIF-CD74

Lung adenocarcinoma is the most common type of lung cancer. We recently reported that inflammation-driven lung adenocarcinoma (IDLA) originates from alveolar type (AT)-II cells, which depend on major histocompatibility complex (MHC) class II to promote the expansion of regulatory T cells. The MHC class II-associated invariant chain (CD74) binds to the macrophage migration inhibitory factor (MIF), which is associated with promoting tumor growth and invasion. However, the role of MIF-CD74 in the progression of lung adenocarcinoma and the underlying mechanisms remain unclear. We aimed to explore the role of MIF-CD74 in the progression of lung adenocarcinoma and elucidate the mechanisms by which tumor necrosis (TNF)-α-mediated inflammation regulates CD74 and MIF expression in IDLA. In human lung adenocarcinoma, CD74 was upregulated on the surface of tumor cells originating from AT-II cells, which correlated positively with lymph node metastasis, tumor origin/nodal involvement/metastasis stage, and TNF-α expression. MIF interaction with CD74 promoted the proliferation and migration of A549 and H1299 cells in vitro. Using a urethane-induced IDLA mouse model, we observed that CD74 was upregulated in tumor cells and macrophages. MIF expression was upregulated in macrophages in IDLA. Blocking TNF-α-dependent inflammation downregulated CD74 expression in tumor cells and CD74 and MIF expression in macrophages in IDLA. Conditioned medium from A549 cells or activated mouse AT-II cells upregulated MIF in macrophages by secreting TNF-α. TNF-α-dependent lung inflammation contributes to the progression of lung adenocarcinoma by upregulating CD74 and MIF expression, and AT-II cells upregulate MIF expression in macrophages by secreting TNF-α. This study provides novel insights into the function of CD74 in the progression of IDLA.

Immunometabolic attributes and mitochondria-associated signaling of Tumor-Associated Macrophages in tumor microenvironment modulate cancer progression

Macrophages are specialized immune cells, which have the capacity to phagocytize and destroy the target cells, including tumor cells. Some macrophages, however on their way to devour the cancer cells undergo a change due to a complex set of signaling pathways. They are induced to change into a polarized state known as M2. The M2 macrophages help in metastasis, tumor suppression, and angiogenesis. The macrophage which gets associated with this TME, are referred to as tumor-associated macrophages (TAMs). TAMS undergo a metabolic reprogramming toward oxidative metabolism for bioenergetic purposes (OXPHOS), fatty acid oxidation (FAO), decreased glycolysis, decreased metabolism via the PPP, and upregulation of arginase 1 (ARG1) which triggers immunosuppressive pro-tumor signaling in the tumor microenvironment (TME) in which mitochondria plays an instrumental role. Reports have suggested that a complex series of interactions and exchange of materials, such as cytokines, metabolic intermediates and sometimes even transfer of mitochondria take place between TAMS and other TME components most importantly cancer cells that reprogram their metabolism to encourage cell growth, division, epithelial to mesenchymal transition, that ultimately play an important role in tumor progression. This review will try to focus on the crosstalk between the TAMs with several other components of TME, what instrumental role mitochondria play in that and also try to explore some of the therapeutic options available in cancer patients.

Hallmarks of Cancer Affected by the MIF Cytokine Family

New diagnostic methods and treatments have significantly decreased the mortality rates of cancer patients, but further improvements are warranted based on the identification of novel tumor-promoting molecules that can serve as therapeutic targets. The macrophage migration inhibitory factor (MIF) family of cytokines, comprising MIF and DDT (also known as MIF2), are overexpressed in almost all cancer types, and their high expressions are related to a worse prognosis for the patients. MIF is involved in 9 of the 10 hallmarks of cancer, and its inhibition by antibodies, nanobodies, or small synthetic molecules has shown promising results. Even though DDT is also proposed to be involved in several of the hallmarks of cancer, the available information about its pro-tumoral role and mechanism of action is more limited. Here, we provide an overview of the involvement of both MIF and DDT in cancer, and we propose that blocking both cytokines is needed to obtain the maximum anti-tumor response.

Usp22 is an intracellular regulator of systemic emergency hematopoiesis

Emergency hematopoiesis is a concerted response aimed toward enhanced protection from infection, involving multiple cell types and developmental stages across the immune system. Despite its importance, the underlying molecular regulation remains poorly understood. The deubiquitinase USP22 regulates the levels of monoubiquitinated histone H2B (H2Bub1), which is associated with activation of interferon responses upon viral infection. Here, we show that in the absence of infection or inflammation, mice lacking Usp22 in all hematopoietic cells display profound systemic emergency hematopoiesis, evident by increased hematopoietic stem cell proliferation, myeloid bias, and extramedullary hematopoiesis. Functionally, loss of Usp22 results in elevated phagocytosis by neutrophilic granulocytes and enhanced innate protection against Listeria monocytogenes infection. At the molecular level, we found this state of emergency hematopoiesis associated with transcriptional signatures of myeloid priming, enhanced mitochondrial respiration, and innate and adaptive immunity and inflammation. Augmented expression of many inflammatory genes was linked to elevated locus-specific H2Bub1 levels. Collectively, these results demonstrate the existence of a tunable epigenetic state that promotes systemic emergency hematopoiesis in a cell-autonomous manner to enhance innate protection, identifying potential paths toward immune enhancement.

Efficacy of Moxa-burning heat stimulating Zusanli (ST36) and Shenshu (BL23) on expressions of macrophage migration inhibitory factor and macrophage apoptosis in rabbits with adjuvant-induced arthritis

OBJECTIVE

To evaluate the effects of moxa-burning heat stimulating acupoints Zusanli (ST36) and Shenshu (BL23) on macrophage migration inhibitory factor (MIF) and its related molecules which can provide scientific experimental basis for the clinical application of moxibustion treatment of rheumatoid arthritis (RA).

METHODS

Thirty rabbits were randomly assigned to control group, RA model (established by injecting Freund's Complete Adjuvant) group (RA group) and RA model with moxibustion group [Moxa group, Zusanli (ST36) and Shenshu (BL23), 5 moxa pillars/day, 6 d × 3]. The expressions of MIF mRNA were evaluated with reverse transcription polymerase chain reaction; the apoptosis rates of macrophages were detected by erminal deoxynucleotidyl transferase-mediated dTUP nick end labeling; the expressions of related signal molecules were detected with immunohistochemical S-P method and the levels of IL-2 were detected with enzyme-linked immunosorbent assay.

RESULTS

The expressions of MIF mRNA, extracellular regulated protein kinases 2, p38 mitogen-activated protein kinase and nuclear factor-κ-gene binding p65 in synovial tissue of RA group were significantly increased when compared with control group, which were lower remarkably in moxa group than those in RA group. The apoptosis rates of macrophages in RA group were significantly down-regulated as compared with the control group, which were up-regulated in moxa group compared with the RA group. The levels of IL-2 in synovial fluid from the RA group were elevated significantly as compared with that from control group, but those of the moxa group were reduced when compared with those from RA group.

CONCLUSIONS

Moxibustion may simultaneously regulate the expressions of MIF and its related signaling pathways molecules, the apoptosis rate of macrophages in synovial tissue, as well as the level of inflammatory factors in synovial fluid. The results suggest that the anti-inflammatory effect of moxibustion on RA may be related to inhibit the expression of MIF in synovial tissue, the molecules of some related signaling pathways and promote the apoptosis of macrophage.

Roles of mitochondrial fusion and fission in breast cancer progression: a systematic review

Background

Mitochondria play critical roles in cellular physiological activity as cellular organelles. Under extracellular stimulation, mitochondria undergo constant fusion and fission to meet different cellular demands. Mitochondrial dynamics, which are involved in mitochondrial fusion and fission, are regulated by specialized proteins and lipids, and their dysregulation causes human diseases, such as cancer. The advanced literature about the crucial role of mitochondrial dynamics in breast cancer is performed.

Methods

All related studies were systematically searched through online databases (PubMed, Web of Science, and EMBASE) using keywords (e.g., breast cancer, mitochondrial, fission, and fusion), and these studies were then screened through the preset inclusion and exclusion criteria.

Results

Eligible studies (n = 19) were evaluated and discussed in the systematic review. These advanced studies established the roles of mitochondrial fission and fusion of breast cancer in the metabolism, proliferation, survival, and metastasis. Importantly, the manipulating of mitochondrial dynamic is significant for the progresses of breast cancer.

Conclusion

Understanding the mechanisms underlying mitochondrial fission and fusion during tumorigenesis is important for improving breast cancer treatments.

TA-MSCs, TA-MSCs-EVs, MIF: their crosstalk in immunosuppressive tumor microenvironment

As an important component of the immunosuppressive tumor microenvironment (TME), it has been established that mesenchymal stem cells (MSCs) promote the progression of tumor cells. MSCs can directly promote the proliferation, migration, and invasion of tumor cells via cytokines and chemokines, as well as promote tumor progression by regulating the functions of anti-tumor immune and immunosuppressive cells. MSCs-derived extracellular vesicles (MSCs-EVs) contain part of the plasma membrane and signaling factors from MSCs; therefore, they display similar effects on tumors in the immunosuppressive TME. The tumor-promoting role of macrophage migration inhibitory factor (MIF) in the immunosuppressive TME has also been revealed. Interestingly, MIF exerts similar effects to those of MSCs in the immunosuppressive TME. In this review, we summarized the main effects and related mechanisms of tumor-associated MSCs (TA-MSCs), TA-MSCs-EVs, and MIF on tumors, and described their relationships. On this basis, we hypothesized that TA-MSCs-EVs, the MIF axis, and TA-MSCs form a positive feedback loop with tumor cells, influencing the occurrence and development of tumors. The functions of these three factors in the TME may undergo dynamic changes with tumor growth and continuously affect tumor development. This provides a new idea for the targeted treatment of tumors with EVs carrying MIF inhibitors.

Deep Insight into the Role of MIF in Spondyloarthritis

PURPOSE OF REVIEW

Pathological roles of macrophage migration inhibitory factor (MIF) have recently been demonstrated in spondyloarthritis (SpA) preclinical models, identifying MIF as a new treatment target for SpA. However, the specific contribution of MIF and therapeutic potential of MIF-targeted therapies to various tissue types affected by SpA are not well delineated.

RECENT FINDINGS

MIF and its cognate receptor CD74 are extensively involved in the pathogenesis of SpA including inflammation in the spine, joint, eyes, skin, and gut. The majority of the current evidence has consistently shown that MIF drives the inflammation in these distinct anatomical sites. In preclinical models, genetic deletion or blockade of MIF reduces the severity of inflammation. Although MIF is generally an upstream cytokine which regulates downstream effector cytokines, MIF also intensifies type 3 immunity by promoting helper T 17 (Th17) plasticity. MIF- or CD74-targeted therapies have also reported to be well tolerated in clinical trials for other diseases. Recent findings suggest that MIF-CD74 axis is a new therapeutic target for SpA to improve various clinical features. Clinical trials for MIF- or CD74-targeted therapies for SpA patients are warranted.

The HBV Specially-Related Long Noncoding RNA HBV-SRL Involved in the Pathogenesis of Hepatocellular Carcinoma

Hepatitis B virus (HBV) is one of the major risk factors for HCC (hepatocellular carcinoma) occurrence with a diverse role in the pathogenesis of HCC. More works need to be performed to elucidate a more thorough understanding of the molecular mechanisms involving in HBV-induced HCC, although some mechanisms such as genome integration have been reported. In the present study, aberrantly expressed lncRNAs were identified between HCC tumor tissues with or without HBV infection. Among these molecules, HBV specially-related long noncoding RNA (HBV-SRL) was further found to correlate with poor prognosis and a shorter overall survival time in HCC patients with HBV infection. Additionally, HBV-SRL was found function as oncogene by upregulating the NF-κB2 expression. These data suggest that HBV infection altered gene expression pattern in liver cells which contributed to HBV-related HCC development, and HBV-SRL may serve as a new molecular marker or potential therapeutic target of HBV-related HCC.

Eugenol inhibits the biological activities of an oral squamous cell carcinoma cell line SCC9 via targeting MIF

BACKGROUND

Oral squamous cell carcinoma (OSCC) is a rampant cancer type in head and neck cancers with a poor prognosis and a high recurrence rate. Eugenol shows anticancer effect in a variety of cancers, but it has been rarely studied in oral squamous cell carcinoma (OSCC).

OBJECTIVE

Therefore, the purpose of this study was to explore the role of Eugenol in OSCC and the underlying mechanism.

METHODS

After different concentrations of Eugenol (0, 200, 400 and 800 μM) treatment, the viability, proliferation, migration and invasion of OSCC cell line SCC9 was measured by CCK-8, colony formation, wound-healing and transwell assays, respectively. TUNEL staining was employed to detect the apoptosis. Western blotting was used to evaluate gene expression at protein level. Molecular docking was used to identify the target of Eugenol.

RESULTS

Eugenol decreased the proliferation, reduced the abilities of invasion and migration along with the expression of matrix metalloproteinases (MMP) 2 and MMP9 in SCC9 cells. On the contrary, the ratio of apoptotic cells was increased by Eugenol. In addition, Eugenol down-regulated B cell lymphoma-2 (Bcl-2) expression, but up-regulated BCL-2 associated X (Bax), cleaved caspase 3 and cleaved poly-ADP ribose polymerase (PARP) expression. Meanwhile, Eugenol exerted its effect on SCC9 cells in a concentration-dependent manner. Eugenol could bind to macrophage migration inhibitory factor (MIF), the expression of which was down-regulated after Eugenol treatment. Besides, overexpression of MIF reversed all the effects of Eugenol on OSCC cells.

CONCLUSION

In summary, Eugenol suppressed the malignant processes of OSCC cells by targeting MIF, which could guide the clinical application of Eugenol in OSCC.

Functional Characterization of the Wheat Macrophage Migration Inhibitory Factor TaMIF1 in Wheat-Stripe Rust (Puccinia striiformis) Interaction

Simple Summary

There have been many breakthroughs in MIF function and mechanism investigation in vertebrates, but it has rarely been studied in plants. Here, we aimed to characterize the function of MIF in wheat and its potential role in Wheat-Stripe rust interaction. We showed that wheat MIF has some similarities with that MIF in vertebrates, such as subcellular localization in both the cytosol and nuclei, as well as significant tautomerase activity, and both can inhibit Bax-induced programmed cell death. In the wheat–Pst interaction, TaMIF1 is upregulated during Pst infection. Silencing TaMIF1 decreased Pst infection of wheat tissues, and the accumulation of ROS was increased in TaMIF1-silenced wheat leaves, which hinted that TaMIF1 mainly modulates the ROS signaling and then alters the subsequent immune responses. The function characterization of TaMIF1 provides significant insight into the role of MIFs across kingdoms and helpful in-depth functional mechanism analysis on these proteins.

Abstract

Macrophage migration inhibitory factor (MIF), named for its role in inhibiting macrophage/monocyte migration, has multiple functions in modulation of inflammation, cell proliferation, angiogenesis, and tumorigenesis in vertebrates. Although homologs of this gene can be found in plants, the function of MIF in plants remains obscure. Here, we characterized TaMIF1 in Triticum aestivum resembling the MIF secreted from Homo sapiens. Transcript analysis revealed that TaMIF1 responded to stripe rust infection of wheat and was upregulated during the infection stage. TaMIF1 was localized to both the cytosol and nuclei in wheat mesophyll protoplast. Additionally, TaMIF1 possessed significant tautomerase activity, indicating conservation of MIFs across kingdoms. Agrobacterium tumefaciens infiltration assay demonstrated that TaMIF1 was capable of suppressing programmed cell death hinting its role in plant immunity. Heterologous expression of TaMIF1 increased fission yeast sensitivity to oxidative stress. Silencing TaMIF1 decreased the susceptibility of wheat to Pst seemingly through increasing reactive oxygen species accumulation. In conclusion, functions of the TaMIF1 were investigated in this study, which provides significant insight into understanding the role of MIFs across kingdoms.

CD74 regulates cellularity and maturation of medullary thymic epithelial cells partially by activating the canonical NF-κB signaling pathway

Thymic epithelial cells (TECs) are indispensable for T cell development, T cell receptor (TCR) repertoire selection, and specific lineage differentiation. Medullary thymic epithelial cells (mTECs), which account for the majority of TECs in adults, are critical for thymocyte selection and self-tolerance. CD74 is a nonpolymorphic transmembrane glycoprotein of major histocompatibility complex class II (MHCII) that is expressed in TECs. However, the exact role of CD74 in regulating the development of mTEC is poorly defined. In this research, we found that loss of CD74 resulted in a significant diminution in the medulla, a selective reduction in the cell number of mature mTECs expressing CD80 molecules, which eventually led to impaired thymic CD4⁺ T cell development. Moreover, RNA-sequence analysis showed that CD74 deficiency obviously downregulated the canonical nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway in mTECs. Our results suggest that CD74 positively controls mTEC cellularity and maturation partially by activating the canonical NF-κB signaling pathway.

Macrophage migration inhibitory factor exerts pro-proliferative and anti-apoptotic effects via CD74 in murine hepatocellular carcinoma

BACKGROUND AND PURPOSE

Macrophage migration inhibitory factor (MIF) is an inflammatory and chemokine-like protein expressed in different inflammatory diseases as well as solid tumours. CD74-as the cognate MIF receptor-was identified as an important target of MIF. We here analysed the role of MIF and CD74 in the progression of hepatocellular carcinoma (HCC) in vitro and in vivo.

EXPERIMENTAL APPROACH

Multilocular HCC was induced using the diethylnitrosamine/carbon tetrachloride (DEN/CCl₄ ) model in hepatocyte-specific Mif knockout (Mif ^Δhep ), Cd74-deficient, and control mice. Tumour burden was compared between the genotypes. MIF, CD74 and Ki67 expression were investigated in tumour and surrounding tissue. In vitro, the effects of the MIF/CD74 axis on the proliferative and apoptotic behaviour of hepatoma cells and respective signalling pathways were assessed after treatment with MIF and anti-CD74 antibodies.

KEY RESULTS

DEN/CCl₄ treatment of Mif ^Δhep mice resulted in reduced tumour burden and diminished proliferation capacity within tumour tissue. In vitro, MIF stimulated proliferation of Hepa 1-6 and HepG2 cells, inhibited therapy-induced cell death and induced ERK activation. The investigated effects could be reversed using a neutralizing anti-CD74 antibody, and Cd74^-/- mice developed fewer tumours associated with decreased proliferation rates.

CONCLUSION AND IMPLICATIONS

We identified a pro-tumorigenic role of MIF during proliferation and therapy-induced apoptosis of HCC cells. These effects were mediated via the MIF cognate receptor CD74. Thus, inhibition of the MIF/CD74 axis could represent a promising target with regard to new pharmacological therapies aimed at HCC.

Mitochondria as the memory of preconditioning

Preconditioning is such a paradigm that a stimulus below the threshold of causing harm makes the brain stronger and resilient to subsequent injury. Preconditioning affords a vigorous tolerance to the brain against neurodegeneration. Numerous efforts have tried to identify the molecular targets involved in preconditioning-induced protective responses and interestingly many of those diverse mechanisms posit mitochondria as a master regulator of preconditioning. Therefore, in this review, we will critically discuss recent and emerging evidence for the involvement of mitochondria within the preconditioning paradigm. We will introduce the crucial targets and signaling cascades by which mitochondria exert preconditioning with a focus on white matter mitochondria and whether and how mechanisms for preconditioning differ in neurons and glial cells. In this aspect, we will evaluate the role of mitochondrial shaping proteins to establish structure-function interdependence for fusion-fission balance, motility, ATP production, Ca⁺², and ROS scavenging. We will also discuss how aging impacts mitochondria and the consequences of mitochondrial aging on preconditioning mechanisms. We will concentrate on the regulation of mitochondrial DNA content and quantification specifically for its value as a biomarker to monitor disease conditions. The identification of these mitochondrial preconditioning mechanisms can be translated to potential pharmacological interventions to increase intrinsic resilience of the brain to injury and to develop novel approaches to neurodegenerative diseases. Moreover, mitochondria dynamics can be used as a memory or biomarker of preconditioning.

Glutamine deficiency promotes stemness and chemoresistance in tumor cells through DRP1-induced mitochondrial fragmentation

Glutamine is essential for maintaining the TCA cycle in cancer cells yet they undergo glutamine starvation in the core of tumors. Cancer stem cells (CSCs), responsible for tumor recurrence are often found in the nutrient limiting cores. Our study uncovers the molecular basis and cellular links between glutamine deprivation and stemness in the cancer cells. We showed that glutamine is dispensable for the survival of ovarian and colon cancer cells while it is required for their proliferation. Glutamine starvation leads to the metabolic reprogramming in tumor cells with enhanced glycolysis and unaltered oxidative phosphorylation. Production of reactive oxygen species (ROS) in glutamine limiting condition induces MAPK-ERK1/2 signaling pathway to phosphorylate dynamin-related protein-1(DRP1) at Ser616. Moreover, p-DRP1 promotes mitochondrial fragmentation and enhances numbers of CD44 and CD117/CD45 positive CSCs. Besides the established features of cancer stem cells, glutamine deprivation induces perinuclear localization of fragmented mitochondria and reduction in proliferation rate which are usually observed in CSCs. Treatment with glutaminase inhibitor (L-DON) mimics the effects of glutamine starvation without altering cell survival in in vitro as well as in in vivo model. Interestingly, the combinatorial treatment of L-DON with DRP1 inhibitor (MDiVi-1) reduces the stem cell population in tumor tissue in mouse model. Collectively our data suggest that glutamine deficiency in the core of tumors can increase the cancer stem cell population and the combination therapy with MDiVi-1 and L-DON is a useful approach to reduce CSCs population in tumor.

MitoQ alleviates LPS-mediated acute lung injury through regulating Nrf2/Drp1 pathway

Lipopolysaccharide (LPS) has been known to cause alveolar epithelial cell (AEC) apoptosis and barrier breakdown that characterize acute lung injury (ALI) and acute respiratory distress syndrome. We aimed to investigate whether mitoquinone (MitoQ), a mitochondria-targeted antioxidant, could alleviate LPS-induced AEC damage in ALI and its underlying mechanisms. In vitro studies in AEC A549 cell line, we noted that LPS could induce dynamin-related protein 1 (Drp1)-mediated mitochondrial fission, AEC apoptosis and barrier breakdown, which could be reversed with MitoQ and mitochondrial division inhibitor 1 treatment. Moreover, the protective role of MitoQ was attenuated with Drp1 overexpression. Nuclear factor E2-related factor 2 (Nrf2) downregulation could block the effect of MitoQ by decreasing the expression of Nrf2 target genes in LPS-treated AEC, such as heme oxygenase-1 (HO-1) and NAD(P)H:quinone oxidoreductase 1 (NQO1). Nrf2 gene knockdown in LPS-treated A549 cells prevented the protective effect of MitoQ from decreasing Drp1-mediated mitochondrial fission, AEC apoptosis and barrier breakdown. The lung protective effect of MitoQ by regulating the Drp1-mediated mitochondrial fission, AEC apoptosis and barrier breakdown was further confirmed in vivo with LPS-induced ALI mouse model. Additionally, the protective effect of MitoQ was inhibited by Nrf2 inhibitor ML385. We therefore conclude that MitoQ exerts ALI-protective effects by preventing Nrf2/Drp1-mediated mitochondrial fission, AEC apoptosis as well as barrier breakdown.

Macrophage migration inhibitory factor facilitates the therapeutic efficacy of mesenchymal stem cells derived exosomes in acute myocardial infarction through upregulating miR-133a-3p

Background

Exosome transplantation is a promising cell-free therapeutic approach for the treatment of ischemic heart disease. The purpose of this study was to explore whether exosomes derived from Macrophage migration inhibitory factor (MIF) engineered umbilical cord MSCs (ucMSCs) exhibit superior cardioprotective effects in a rat model of AMI and reveal the mechanisms underlying it.

Results

Exosomes isolated from ucMSCs (MSC-Exo), MIF engineered ucMSCs (MIF-Exo) and MIF downregulated ucMSCs (siMIF-Exo) were used to investigate cellular protective function in human umbilical vein endothelial cells (HUVECs) and H9C2 cardiomyocytes under hypoxia and serum deprivation (H/SD) and infarcted hearts in rats. Compared with MSC-Exo and siMIF-Exo, MIF-Exo significantly enhanced proliferation, migration, and angiogenesis of HUVECs and inhibited H9C2 cardiomyocyte apoptosis under H/SD in vitro. MIF-Exo also significantly inhibited cardiomyocyte apoptosis, reduced fibrotic area, and improved cardiac function as measured by echocardiography in infarcted rats in vivo. Exosomal miRNAs sequencing and qRT-PCR confirmed miRNA-133a-3p significantly increased in MIF-Exo. The biological effects of HUVECs and H9C2 cardiomyocytes were attenuated with incubation of MIF-Exo and miR-133a-3p inhibitors. These effects were accentuated with incubation of siMIF-Exo and miR-133a-3p mimics that increased the phosphorylation of AKT protein in these cells.

Conclusion

MIF-Exo can provide cardioprotective effects by promoting angiogenesis, inhibiting apoptosis, reducing fibrosis, and preserving heart function in vitro and in vivo. The mechanism in the biological activities of MIF-Exo involves miR-133a-3p and the downstream AKT signaling pathway.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-021-00808-5.

Single-cell transcriptome analysis revealed the heterogeneity and microenvironment of gastrointestinal stromal tumors

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the human gastrointestinal tract. In this study, we performed single-cell RNA sequencing (RNA-seq) on intra- and peri-tumor tissues from GIST patients with the aim of discovering the heterogeneity of tumor cells in GIST and their interactions with other cells. We found four predominating cell types in GIST tumor tissue, including T cells, macrophages, tumor cells, and NK cells. Tumor cells could be clustered into two groups: one was highly proliferating and associated with high risk of metastasis, the other seemed "resting" and associated with low risk. Their clinical relevance and prognostic values were confirmed by RNA-seq of 65 GIST samples. T cells were the largest cell type in our single-cell data. Two groups of CD8⁺ effector memory (EM) cells were in the highest clonal expansion and performed the highest cytotoxicity but were also the most exhausted among all T cells. A group of macrophages were found polarized to possess both M1 and M2 signatures, and increased along with tumor progression. Cell-to-cell interaction analysis revealed that adipose endothelial cells had high interactions with tumor cells to facilitate their progression. Macrophages were at the center of the tumor microenvironment, recruiting immune cells to the tumor site and having most interactions with both tumor and nontumor cells. In conclusion, we obtained an overview of the GIST microenvironment and revealed the heterogeneity of each cell type and their relevance to risk classifications, which provided a novel theoretical basis for learning and curing GISTs.

Overexpression of family with sequence similarity 134, member B (FAM134B) in colon cancers and its tumor suppressive properties in vitro

This study aims to investigate the overexpression-induced properties of tumor suppressor FAM134B (family with sequence similarity 134, member B) in colon cancer, examine the potential gene regulators of FAM134B expression and its impact on mitochondrial function. FAM134B was overexpressed in colon cancer and non-neoplastic colonic epithelial cells. Various cell-based assays including apoptosis, cell cycle, cell proliferation, clonogenic, extracellular flux and wound healing assays were performed. Western blot analysis was used to confirm and identify potential interacting partners of FAM134B in vitro. Immunohistochemistry and qPCR were employed to determine the expressions of MIF and FAM134B, respectively, on 63 patients with colorectal carcinoma. Results showed that FAM134B is involved in the cell cycle and mitochondrial function of colon cancer. Overexpression of FAM134B was coupled with increased expression levels of APC, p53, and MIF. Increased expression of both APC and p53 further validates the potential role of tumor suppressor FAM134B in regulating cancer progression through the WNT/ß-catenin signaling pathway. In approximately 70% of the patients with colorectal cancer, FAM134B downregulation was correlated with MIF protein overexpression while the remaining 30% showed concurrent expression of FAM134B and MIF (P = .045). High expression of MIF coupled with low expression of FAM134B is associated with microsatellite instability status in colorectal carcinomas (P = .049). FAM134B may exert its tumor suppressive function through affecting cell cycle, mitochondrial function via potentially interacting with MIF and p53.

The role of MIF in chronic lung diseases: looking beyond inflammation

Macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine that has been associated with many diseases. Most studies found in literature describe MIF as a proinflammatory cytokine involved in chronic inflammatory conditions, but evidence from last years suggests that many of its key effects are not directly related to inflammation. In fact, MIF is constitutively expressed in most human tissues and in some cases in high levels, which does not reflect the pattern of expression of a classic proinflammatory cytokine. Moreover, MIF is highly expressed during embryonic development and decreases during adulthood, which point toward a more likely role as growth factor. Accordingly, MIF knockout mice develop age-related spontaneous emphysema, suggesting that MIF presence (e.g., in younger individuals and wild-type animals) is part of a healthy lung. In view of this new line of evidence, we aimed to review data on the role of MIF in the pathogenesis of chronic lung diseases.

NF-κB and mitochondria cross paths in cancer: mitochondrial metabolism and beyond

NF-κB plays a pivotal role in oncogenesis. This transcription factor is best known for promoting cancer cell survival and tumour-driving inflammation. However, several lines of evidence support a crucial role for NF-κB in governing energy homeostasis and mediating cancer metabolic reprogramming. Mitochondria are central players in many metabolic processes altered in cancer. Beyond their bioenergetic activity, several facets of mitochondria biology, including mitochondrial dynamics and oxidative stress, promote and sustain malignant transformation. Recent reports revealed an intimate connection between NF-κB pathway and the oncogenic mitochondrial functions. NF-κB can impact mitochondrial respiration and mitochondrial dynamics, and, reciprocally, mitochondria can sense stress signals and convert them into cell biological responses leading to NF-κB activation. In this review we discuss their emerging reciprocal regulation and the significance of this interplay for anticancer therapy.

Macrophage migration inhibitory factor rejuvenates aged human mesenchymal stem cells and improves myocardial repair

The beneficial functions of mesenchymal stem cells (MSCs) decline with age, limiting their therapeutic efficacy for myocardial infarction (MI). Macrophage migration inhibitory factor (MIF) promotes cell proliferation and survival. We investigated whether MIF overexpression could rejuvenate aged MSCs and increase their therapeutic efficacy in MI. Young and aged MSCs were isolated from the bone marrow of young and aged donors. Young MSCs, aged MSCs, and MIF-overexpressing aged MSCs were transplanted into the peri-infarct region in a rat MI model. Aged MSCs exhibited a lower proliferative capacity, lower MIF level, greater cell size, greater senescence-associated-β-galactosidase activity, and weaker paracrine effects than young MSCs. Knocking down MIF in young MSCs induced cellular senescence, whereas overexpressing MIF in aged MSCs reduced cellular senescence. MIF rejuvenated aged MSCs by activating autophagy, an effect largely reversed by the autophagy inhibitor 3-methyladenine. MIF-overexpressing aged MSCs induced angiogenesis and prevented cardiomyocyte apoptosis to a greater extent than aged MSCs, and had improved heart function and cell survival more effectively than aged MSCs four weeks after MI. Thus, MIF rejuvenated aged MSCs by activating autophagy and enhanced their therapeutic efficacy in MI, suggesting a novel MSC-based therapeutic strategy for cardiovascular diseases in the aged population.

LGALS3 is connected to CD74 in a previously unknown protein network that is associated with poor survival in patients with AML

Background

Galectin 3 (LGALS3) gene expression is associated with poor survival in acute myeloid leukemia (AML) but the prognostic impact of LGALS3 protein expression in AML is unknown. LGALS3 supports diverse survival pathways including RAS mediated cascades, protein expression and stability of anti-apoptotic BCL2 family members, and activation of proliferative pathways including those mediated by beta Catenin. CD74 is a positive regulator of CD44 and CXCR4 signaling and this molecule may be critical for AML stem cell function. At present, the role of LGALS3 and CD74 in AML is unclear. In this study, we examine protein expression of LGALS3 and CD74 by reverse phase protein analysis (RPPA) and identify new protein networks associated with these molecules. In addition, we determine prognostic potential of LGALS3, CD74, and their protein networks for clinical correlates in AML patients.

Methods

RPPA was used to determine relative expression of LGALS3, CD74, and 229 other proteins in 231 fresh AML patient samples and 205 samples were from patients who were treated and evaluable for outcome. Pearson correlation analysis was performed to identify proteins associated with LGALS3 and CD74. Progeny clustering was performed to generate protein networks. String analysis was performed to determine protein:protein interactions in networks and to perform gene ontology analysis. Kaplan-Meir method was used to generate survival curves.

Findings

LGALS3 is highest in monocytic AML patients and those with elevated LGALS3 had significantly shorter remission duration compared to patients with lower LGALS3 levels (median 21.9 vs 51.3 weeks, p = 0.016). Pearson correlation of LGALS3 with 230 other proteins identifies a distinct set of 37 proteins positively correlated with LGALS3 expression levels with a high representation of proteins involved in AKT and ERK signaling pathways. Thirty-one proteins were negatively correlated with LGALS3 including an AKT phosphatase. Pearson correlation of proteins associated with CD74 identified 12 proteins negatively correlated with CD74 and 16 proteins that are positively correlated with CD74. CD74 network revealed strong association with CD44 signaling and a high representation of apoptosis regulators. Progeny clustering was used to build protein networks based on LGALS3 and CD74 associated proteins. A strong relationship of the LGALS3 network with the CD74 network was identified. For AML patients with both the LGALS3 and CD74 protein cluster active, median overall survival was only 24.3 weeks, median remission duration was 17.8 weeks, and no patient survived beyond one year.

Interpretation

The findings from this study identify for the first time protein networks associated with LGALS3 and CD74 in AML. Each network features unique pathway characteristics. The data also suggest that the LGALS3 network and the CD74 network each support AML cell survival and the two networks may cooperate in a novel high risk AML population.

Fund

Leukemia Lymphoma Society provided funds to SMK for RPPA study of AML patient population. Texas Leukemia provided funds to PPR and SMK to study CD74 and LGALS3 expression in AML patients using RPPA. No payment was involved in the production of this manuscript.