Search

Pathogenic variants in the v-maf avian musculoaponeurotic fibrosarcoma oncogene homologue (MAF) encoding a transcription factor (from a unique subclass of basic leucine zipper transcription factors) are associated with isolated congenital cataracts (CCs) and Aymé-Gripp syndrome (AYGRPS). We collected detailed disease histories from, and performed comprehensive ophthalmic and systemic examinations in 269 patients with CCs; we then performed whole-exome sequencing. Pathogenicity assessments were evaluated using multiple predictive tools. The clinical validities of the reported gene-disease relationships for MAF genes (MAF-CCs and MAF-AYGRPS) were assessed using the ClinGen gene curation framework. We identified two novel (c.173CA, p.Thr58Asn and c.947TC, p. Leu316Pro) variants and one known (c.173CT, p.Thr58Ile) MAF missense variant in three patients. We described novel phenotypes including cleft palate, macular hypoplasia, and retinal neovascularization in the peripheral avascular area and analyzed the genotype-phenotype correlations. We demonstrated associations of variants in the MAF C-terminal DNA-binding domain with CCs and associations of variants in the N-terminal transactivation domain of MAF with AYGRPS. We thus expand the genotypic and phenotypic spectrum of the MAF gene. The ClinGen gene curation framework results suggested that variants in different domains of MAF are associated with different diseases.

The genetic locus containing the WWOX and MAF genes was implicated as a clinical Alzheimer's disease (AD) risk locus in two recent large meta-analytic genome wide association studies (GWAS). In a prior GWAS, we identified a variant in WWOX as a suggestive risk allele for hippocampal sclerosis (HS). We hypothesized that the WWOX/MAF locus may be preferentially associated with non-plaque- and non-tau-related neuropathological changes (NC). Data from research participants with GWAS and autopsy measures from the National Alzheimer's Coordinating Center (NACC) and the Religious Orders Study and the Rush Memory and Aging Project (ROSMAP) were meta-analyzed. Notably, no variants in the locus were significantly associated with ADNC. However, several WWOX/MAF variants had significant adjusted associations with limbic-predominant age-related TDP-43 encephalopathy NC (LATE-NC), HS, and brain arteriolosclerosis. These associations remained largely unchanged after adjustment for ADNC (operationalized with standard semiquantitative staging), suggesting that these associations are independent of ADNC. Thus, WWOX genetic variants associated with clinical AD-type dementia phenotype were associated pathologically with LATE-NC related brain changes, not ADNC.

The fate of neurons in the developing brain is largely determined by the combination of transcription factors they express. In particular, stem cells must follow different transcriptional cascades during differentiation in order to generate neurons with different neurotransmitter properties, such as glutamatergic and GABAergic neurons. In the mouse cerebral cortex, it has been shown that large Maf family proteins, MafA, MafB and c-Maf, regulate the development of specific types of GABAergic interneurons but are not expressed in glutamatergic neurons. In this study, we examined the expression of large Maf family proteins in the developing mouse olfactory bulb by immunohistochemistry and found that the cell populations expressing MafA and MafB are almost identical, and most of them express Tbr2. Since Tbr2 is expressed in glutamatergic neurons in the olfactory bulb, we further examined the expression of glutamatergic and GABAergic neuronal markers in MafA and MafB positive cells. The results showed that in the olfactory bulb, MafA and MafB are expressed exclusively in glutamatergic neurons, but not in GABAergic neurons. We also found that few cells express c-Maf in the olfactory bulb. These results indicate that, unlike the cerebral cortex, MafA and/or MafB may regulate the development of glutamatergic neurons in the developing olfactory bulb. This study advances our knowledge about the development of glutamatergic neurons in the olfactory bub, and also provides insight into the mechanism by which the cortex and olfactory bulb, although both generated from the telencephalon, generate projection and interneurons with different properties.

The primary function of the small intestine (SI) is to absorb nutrients to maintain whole-body energy homeostasis. Enterocytes are the major epithelial cell type facilitating nutrient sensing and uptake. However, the molecular regulators governing enterocytes have remained undefined. Here, we identify c-Maf as an enterocyte-specific transcription factor within the SI epithelium. c-Maf expression was determined by opposing Noggin/BMP signals and overlapped with the zonated enrichment of nutrient transporters in the mid-villus region. Functionally, enterocytes required c-Maf to appropriately differentiate along the villus axis. Specifically, gene programs controlling carbohydrate and protein absorption were c-Maf–dependent. Consequently, epithelial cell–specific c-Maf deletion resulted in impaired enterocyte maturation and nutrient uptake, including defects in the adaptation to different nutrient availability. Concomitantly, intraepithelial lymphocytes were less abundant, while commensal epithelial cell–attaching SFB overgrew in a c-Maf–deficient environment, highlighting the close interdependence between the intestinal epithelium, immune system, and microbiota. Collectively, our data identified c-Maf as a key regulator of SI enterocyte differentiation and function, essential for nutrient, immune, and microbial homeostasis.

There are fundamental differences in how neonatal and adult intestines absorb nutrients. In adults, macromolecules are broken down into simpler molecular components in the lumen of the small intestine, then absorbed. In contrast, neonates are thought to rely on internalization of whole macromolecules and subsequent degradation in the lysosome. Here, we identify the Maf family transcription factors MAFB and c-MAF as markers of terminally differentiated intestinal enterocytes throughout life. The expression of these factors is regulated by HNF4α and HNF4γ, master regulators of enterocyte cell fate. Loss of Maf factors results in a neonatal-specific failure to thrive and loss of macromolecular nutrient uptake. RNA-Seq and CUT&RUN analyses defined an endo-lysosomal program as being downstream of these transcription factors. We demonstrate major transcriptional changes in metabolic pathways, including fatty acid oxidation and increases in peroxisome number, in response to loss of Maf proteins. Finally, we show that loss of BLIMP1, a repressor of adult enterocyte genes, shows highly overlapping changes in gene expression and similar defects in macromolecular uptake. This work defines transcriptional regulators that are necessary for nutrient uptake in neonatal enterocytes.

Testis differentiation is initiated when Sry in pre-Sertoli cells directs the gonad toward a male-specific fate. Sertoli cells are essential for testis development, but cell types within the interstitial compartment, such as immune and endothelial cells, are also critical for organ formation. Our previous work implicated macrophages in fetal testis morphogenesis, but little is known about genes underlying immune cell development during organogenesis. Here we examine the role of the immune-associated genes Mafb and Maf in mouse fetal gonad development, and we demonstrate that deletion of these genes leads to aberrant hematopoiesis manifested by supernumerary gonadal monocytes. Mafb;Maf double knockout embryos underwent initial gonadal sex determination normally, but exhibited testicular hypervascularization, testis cord formation defects, Leydig cell deficit, and a reduced number of germ cells. In general, Mafb and Maf alone were dispensable for gonad development; however, when both genes were deleted, we observed significant defects in testicular morphogenesis, indicating that Mafb and Maf work redundantly during testis differentiation. These results demonstrate previously unappreciated roles for Mafb and Maf in immune and vascular development and highlight the importance of interstitial cells in gonadal differentiation.Summary statementDeletion of Mafb and Maf genes leads to supernumerary monocytes in fetal mouse gonads, resulting in vascular, morphogenetic, and differentiation defects during testicular organogenesis.

The oncogenic transcription factor c-Maf has been proposed as an ideal therapeutic target for multiple myeloma (MM), but how to achieve it is still elusive. In the present study, we found the Otub1/c-Maf axis could be a potential target. Otub1, an OTU family deubiquitinase, was found to interact with c-Maf by mass spectrometry. Otub1 abrogates c-Maf K48-linked polyubiquitination, thus preventing its degradation and enhancing its transcriptional activity. Specifically, this deubiquitinating activity depends on its Lys71 and the N terminus but is independent of UBE2O, a known E2 of c-Maf. Otub1 promotes MM cell survival and MM tumor growth. In contrast, silence of Otub1 leads to c-Maf degradation and c-Maf-expressing MM cell apoptosis. Therefore, the Otub1/c-Maf axis could be a therapeutic target of MM. In order to explore this concept, we performed a c-Maf recognition element–driven luciferase-based screen against US Food and Drug Administration–approved drugs and natural products, from which the generic cardiac glycoside lanatoside C (LanC) is found to prevent c-Maf deubiquitination and induces its degradation by disrupting the interaction of Otub1 and c-Maf. Consequently, LanC inhibits c-Maf transcriptional activity, induces c-Maf-expressing MM cell apoptosis, and suppresses MM growth and prolongs overall survival of model mice, but without apparent toxicity. Therefore, the present study identifies Otub1 as a novel deubiquitinase of c-Maf and establishes that the Otub1/c-Maf axis is a potential therapeutic target for MM.

Multiple myeloma (MM) is an aggressive plasma cell neoplasm characterized by genomic heterogeneity. Superenhancers (SEs) are defined as large clusters of enhancers in close genomic proximity, which regulate genes for maintaining cellular identity and promote oncogenic transcription to which cancer cells highly addicted. Here, we analyzed cis-regulatory elements in MM samples with H3K27ac ChIP-seq, to identify novel SE-associated genes involved in the myeloma pathogenesis. SEs and their associated genes in cancerous tissue were compared with the control samples, and we found SE analysis alone uncovered cell-lineage-specific transcription factors and well-known oncogenes ST3GAL6 and ADM. Using a transcriptional CDK7 inhibitor, THZ1, coupled with H3K27ac ChlP-seq, we identified MAGI2 as a novel SE-associated gene of myeloma cells. Elevated MAGI2 was related to myelomagenesis with gradual increased expression from MGUS, SMM to newly diagnosed and relapsed MM. High prevalence of MAGI2 was also associated with poor survival of MM patients. Importantly, inhibition of the SE activity associated with MAGI2 decreased MAGI2 expression, inhibited cell growth and induced cell apoptosis. Mechanistically, we revealed that the oncogenic transcription factor, MAF, directly bound to the SE region and activated gene transcription. In summary, the discoveries of these acquired SEs-associated genes and the novel mechanism by which they are regulated provide new insights into MM biology and MAGI2-MAF-SE regulatory circuit offer potential novel targets for disease treatment.

Cellular metabolism has been proposed to govern distinct γδ T cell effector functions, but the underlying molecular mechanisms remain unclear. We show that interleukin-17 (IL-17)–producing γδ T (γδT17) and interferon-γ (IFN-γ)–producing γδ T (γδT1) cells have differential metabolic requirements and that the rate-limiting enzyme isocitrate dehydrogenase 2 (IDH2) acts as a metabolic checkpoint for their effector functions. Intriguingly, the transcription factor c-Maf regulates γδT17 effector function through direct regulation of IDH2 promoter activity. Moreover, mTORC2 affects the expression of c-Maf and IDH2 and subsequent IL-17 production in γδ T cells. Deletion of c-Maf in γδ T cells reduces metastatic lung cancer development, suggesting c-Maf as a potential target for cancer immune therapy. We show that c-Maf also controls IL-17 production in human γδ T cells from peripheral blood and in oral cancers. These results demonstrate a critical role of the transcription factor c-Maf in regulating γδT17 effector function through IDH2-mediated metabolic reprogramming.

Group-2 innate lymphoid cells (ILC2s), which are involved in type 2 inflammatory diseases such as allergy, can exhibit immunological memory, but the basis of this ILC2 "trained immunity" has remained unclear. Here, we found that stimulation with IL-33/IL-25 or exposure to the allergen papain induces the expression of the transcription factor c-Maf in mouse ILC2s. Chronic papain exposure results in high production of IL-5 and IL-13 cytokines and lung eosinophil recruitment, effects that are blocked by c-Maf deletion in ILCs. Transcriptomic analysis revealed that knockdown of c-Maf in ILC2s suppresses expression of type 2 cytokine genes, as well as of genes linked to a memory-like phenotype. Consistently, c-Maf was found highly expressed in human adult ILC2s but absent in cord blood and required for cytokine production in isolated human ILC2s. Furthermore, c-Maf-deficient mouse or human ILC2s failed to exhibit strengthened (“trained”) responses upon repeated challenge. Thus, the expression of c-Maf is indispensable for optimal type 2 cytokine production and proper memory-like responses in group-2 innate lymphoid cells.

The present study investigated a pathogenic mutation and its mechanism on membranous cataract in a congenital membranous cataract family. An autosomal dominant four-generation Chinese congenital membranous cataract family was recruited and whole-exome sequencing was performed to screen for sequence variants. Candidate variants were validated using polymerase chain reaction and Sanger sequencing. Wild-type and mutant low-density lipoprotein receptor–related protein 5–like (LRP5L) plasmids were constructed and transfected into human lens epithelial cells (HLE B-3) and human anterior lens capsules. The cell lysates, nuclear and cytoplasmic proteins, and basement membrane components of HLE B-3 cells were harvested. LRP5L and laminin γ1 were knocked down in HLE B-3 cells using specific small-interfering RNA. The protein expression levels of LRP5L, laminin γ1, and c-MAF were detected using immunoblotting and immunofluorescence. We identified a novel suspected pathogenic mutation in LRP5L (c.107C > G, p.P36R) in the congenital membranous cataract family. This mutation was absent in 300 normal controls and 300 age-related cataract patients. Bioinformatics analysis with PolyPhen-2 and SIFT suggested that LRP5L-P36R was pathogenic. LRP5L upregulated laminin γ1 expression in the cytoplasmic proteins of HLE B-3 cells and human anterior lens capsules, and LRP5L-P36R inhibited the effects of LRP5L. LRP5L upregulated c-MAF expression in the nucleus and cytoplasm of HLE B-3 cells, and LRP5L-P36R inhibited c-MAF expression via inhibition of laminin γ1. Our study identified a novel gene, LRP5L, associated with congenital membranous cataract, and its mutant LRP5L-P36R contributed to membranous cataract development via inhibition of laminin γ1 and c-MAF.

Background Multiple Myeloma (MM) is a hematological malignancy with genomic heterogeneity and poor survival outcome. Apart from the central role of genetic lesions, epigenetic anomalies have been identified as drivers in the development of the disease. Methods Alterations in the DNA methylome were mapped in 52 newly diagnosed MM (NDMM) patients of six molecular subgroups and matched with loci-specific chromatin marks to define their impact on gene expression. Differential DNA methylation analysis was performed using DMAP with a ≥10% increase (hypermethylation) or decrease (hypomethylation) in NDMM subgroups, compared to control samples, considered significant for all the subsequent analyses with p Results We identified differentially methylated regions (DMRs) within the etiological cytogenetic subgroups of myeloma, compared to control plasma cells. Using gene expression data we identified genes that are dysregulated and correlate with DNA methylation levels, indicating a role for DNA methylation in their transcriptional control. We demonstrated that 70% of DMRs in the MM epigenome were hypomethylated and overlapped with repressive H3K27me3. In contrast, differentially expressed genes containing hypermethylated DMRs within the gene body or hypomethylated DMRs at the promoters overlapped with H3K4me1, H3K4me3, or H3K36me3 marks. Additionally, enrichment of BRD4 or MED1 at the H3K27ac enriched DMRs functioned as super-enhancers (SE), controlling the overexpression of genes or gene-cassettes. Conclusions Therefore, this study presents the underlying epigenetic regulatory networks of gene expression dysregulation in NDMM patients and identifies potential targets for future therapies.

Lacaziosis is a cutaneous chronic mycosis caused by Lacazia loboi. Macrophages are important cells in the host immune response in fungal infections. The macrophage population exhibits strong plasticity that varies according to the stimuli in the microenvironment of lesions M1 profile promotes a Th1 pattern of cytokines and a microbicidal function and M2 is related to Th2 cytokines and immunomodulatory response. We investigated the population of M1 and M2 polarized macrophages in human cutaneous lesions. A total of 27 biopsies from human lesions were submitted to an immunohistochemistry protocol using antibodies to detect M1 and M2 macrophages (Arginase-1, CD163, iNOS, RBP-J and cMAF). We could observe high number of cells expressing Arginase1, CD163 and c-MAF that correspond to elements of the M2 profile of macrophage, over iNOS and RBP-J (elements of the M1 profile). The results suggest a predominant phenotype of M2 macrophages, which have an immunomodulatory role and probably contributing to chronicity of Lacaziosis. Electronic supplementary material The online version of this article (10.1007/s11046-020-00450-z) contains supplementary material, which is available to authorized users.

The Maf proteins, including c-Maf, MafA, and MafB, are critical transcription factors in myelomagenesis. Previous studies demonstrated that Maf proteins are processed by the ubiquitin-proteasome pathway, but the mechanisms remain elusive. This study applied MS to identify MafB ubiquitination-associated proteins and found that the ubiquitin-specific protease USP7 was present in the MafB interactome. Moreover, USP7 also interacted with c-Maf and MafA and blocked their polyubiquitination and degradation. Consistently, knockdown of USP7 resulted in Maf protein degradation along with increased polyubiquitination levels. The action of USP7 thus promoted Maf transcriptional activity as evidenced by luciferase assays and by the up-regulation of the expression of Maf-modulated genes. Furthermore, USP7 was up-regulated in myeloma cells, and it was negatively associated with the survival of myeloma patients. USP7 promoted myeloma cell survival, and when it was inhibited by its specific inhibitor P5091, myeloma cell lines underwent apoptosis. These results therefore demonstrated that USP7 is a deubiquitinase of Maf proteins and promotes MM cell survival in association with Maf stability. Given the significance of USP7 and Maf proteins in myeloma genesis, targeting the USP7/Maf axle is a potential strategy to the precision therapy of MM.

Regulatory B cells (Bregs) have been highlighted in very different pathology settings including autoimmune diseases, allergy, graft rejection, and cancer. Improving tools for the characterization of Bregs has become the main objective especially in humans. Transitional, mature B cells and plasma cells can differentiate into IL-10 producing Bregs in both mice and humans, suggesting that Bregs are not derived from unique precursors but may arise from different competent progenitors at unrestricted development stages. Moreover, in addition to IL-10 production, regulatory B cells used a broad range of suppressing mechanisms to modulate the immune response. Although Bregs have been consistently described in the literature, only a few reports described the molecular aspects that control the acquisition of the regulatory function. In this manuscript, we detailed the latest reports describing the control of IL-10, TGFβ, and GZMB production in different Breg subsets at the molecular level. We focused on the understanding of the role of the transcription factors STAT3 and c-MAF in controlling IL-10 production in murine and human B cells and how these factors may represent an important crossroad of several key drivers of the Breg response. Finally, we provided original data supporting the evidence that MAF is expressed in human IL-10- producing plasmablast and could be inducedin vitrofollowing different stimulation cocktails. At steady state, we reported that MAF is expressed in specific human B-cell tonsillar subsets including the IgD+CD27+unswitched population, germinal center cells and plasmablast.

Macrophages are an essential part of tissue development and physiology. Perivascular macrophages have been described in tissues and appear to play a role in development and disease processes, although it remains unclear what the key features of these cells are. Here, we identify a subpopulation of perivascular macrophages in several organs, characterized by their dependence on the transcription factor c-MAF and displaying nonconventional macrophage markers including LYVE1, folate receptor 2, and CD38. Conditional deletion of c-MAF in macrophage lineages caused ablation of perivascular macrophages in the brain and altered muscularis macrophages program in the intestine. In the white adipose tissue (WAT), c-MAF–deficient perivascular macrophages displayed an altered gene expression profile, which was linked to an increased vascular branching. Upon feeding high-fat diet (HFD), mice with c-MAF–deficient macrophages showed improved metabolic parameters compared with wild-type mice, including less weight gain, greater glucose tolerance, and reduced inflammatory cell profile in WAT. These results define c-MAF as a central regulator of the perivascular macrophage transcriptional program in vivo and reveal an important role for this tissue-resident macrophage population in the regulation of metabolic syndrome.

Multiple myeloma is a genetically heterogeneous cancer of the bone marrow plasma cells (PC). Distinct myeloma transcriptome profiles are primarily driven by myeloma initiating events (MIE) and converge into a mutually exclusive overexpression of the CCND1 and CCND2 oncogenes. Here, with reference to their normal counterparts, we find that myeloma PC enhanced chromatin accessibility combined with paired transcriptome profiling can classify MIE-defined genetic subgroups. Across and within different MM genetic subgroups, we ascribe regulation of genes and pathways critical for myeloma biology to unique or shared, developmentally activated or de novo formed candidate enhancers. Such enhancers co-opt recruitment of existing transcription factors, which although not transcriptionally deregulated per se, organise aberrant gene regulatory networks that help identify myeloma cell dependencies with prognostic impact. Finally, we identify and validate the critical super-enhancer that regulates ectopic expression of CCND2 in a subset of patients with MM and in chronic lymphocytic leukemia., Despite extensive genetic heterogeneity, nearly half of all multiple myeloma (MM) cases are driven by cyclin D2 (CCND2) over-expression. Here the authors dissect the chromatin landscape of MM to provide insights into the transcriptional regulatory landscape driving MM and divergent transcriptomes corresponding to different MM genetic subtypes.

Topoisomerase (TOP) inhibitors were commonly used as chemotherapeutic agents in the treatment of cancers. In our present study, we found that etoposide (ETO), a topoisomerase 2 (TOP2) inhibitor, upregulated the production of Interleukin 10 (IL-10) in lipopolysaccharide (LPS)-stimulated macrophages. Besides, other TOP2 inhibitors including doxorubicin hydrochloride (DOX) and teniposide (TEN) were also able to augment IL-10 production. Meanwhile, the expression levels of pro-inflammatory factors, for example IL-6 and TNF-α, were also decreased accordingly by the treatment of the TOP2 inhibitors. Of note, ETO facilitated IL-10 secretion, which might be regulated by transcription factor Maf via PI3K/AKT pathway, as pharmaceutic blockage of kinase PI3K or AKT attenuated ETO-induced Maf and IL-10 expression. Further, in LPS-induced mice sepsis model, the enhanced generation of IL-10 was observed in ETO-treated mice, whereas pro-inflammatory cytokines were decreased, which significantly reduced the mortality of mice from LPS-induced lethal cytokine storm. Taken together, these results indicated that ETO may exhibit an anti-inflammatory role by upregulating the alteration of transcription factor Maf and promoting subsequential IL-10 secretion via PI3K/Akt pathway in LPS-induced macrophages. Therefore, ETO may serve as a potential anti-inflammatory agent and employed to severe pro-inflammatory diseases including COVID-19.

MAF is a transcription factor that may act either as a tumor suppressor or as an oncogene, depending on cell type. We have shown previously that the overexpressed miR-1290 influences MAF protein levels in LSCC (laryngeal squamous cell carcinoma) cell lines. In this study, we shed further light on the interaction between miR-1290 and MAF, as well as on cellular MAF protein localization in LSCC. We confirmed the direct interaction between miR-1290 and MAF 3′UTR by a dual-luciferase reporter assay. In addition, we used immunohistochemistry staining to analyze MAF protein distribution and observed loss of MAF nuclear expression in 58% LSCC samples, of which 10% showed complete absence of MAF, compared to nuclear and cytoplasmatic expression in 100% normal mucosa. Using TCGA data, bisulfite pyrosequencing and CNV analysis, we excluded the possibility that loss-of-function mutations, promoter region DNA methylation or CNV are responsible for MAF loss in LSCC. Finally, we identified genes involved in the regulation of apoptosis harboring the MAF binding motif in their promoter region by applied FIMO and DAVID GO analysis. Our results highlight the role of miR-1290 in suppressing MAF expression in LSCC. Furthermore, MAF loss or mislocalization in FFPE LSCC tumor samples might suggest that MAF acts as a LSCC tumor suppressor by regulating apoptosis.

Immunosuppressive Interleukin (IL)-10 production by pro-inflammatory CD4

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the CNS. CD8We performed a cohort, case-control study for phenotyping analysis of PD-1In the disease remission state, PD-1This study uncovered a favorable role of PD-1

We have recently demonstrated that the function of T follicular helper (Tfh) cells from lymph nodes (LN) of HIV-infected individuals is impaired. We found that these cells were unable to provide proper help to germinal center (GC)-B cells, as observed by altered and inefficient anti-HIV antibody response and premature death of memory B cells. The underlying molecular mechanisms of this dysfunction remain poorly defined. Herein, we have used a unique transcriptional approach to identify these molecular defects. We consequently determined the transcriptional profiles of LN GC-Tfh cells following their interactions with LN GC-B cells from HIV-infected and HIV-uninfected individuals, rather than analyzing resting ex-vivo GC-Tfh cells. We observed that proliferating GC-Tfh cells from HIV-infected subjects were transcriptionally different than their HIV-uninfected counterparts, and displayed a significant downregulation of immune- and GC-Tfh-associated pathways and genes. Our results strongly demonstrated that MAF (coding for the transcription factor c-Maf) and its upstream signaling pathway mediators (IL6R and STAT3) were significantly downregulated in HIV-infected subjects, which could contribute to the impaired GC-Tfh and GC-B cell functions reported during infection. We further showed that c-Maf function was associated with the adenosine pathway and that the signaling upstream c-Maf could be partially restored by adenosine deaminase -1 (ADA-1) supplementation. Overall, we identified a novel mechanism that contributes to GC-Tfh cell impairment during HIV infection. Understanding how GC-Tfh cell function is altered in HIV is crucial and could provide critical information about the mechanisms leading to the development and maintenance of effective anti-HIV antibodies., Author summary Human immunodeficiency virus (HIV) remains a worldwide burden despite available treatments. The virus induces dysregulations in major immune cells and organs including lymph nodes. Germinal center T follicular helper (GC-Tfh) cells are immune cells which induce specific anti-HIV antibodies by helping GC-B cells. In chronic HIV, the interaction between these two cell types is defective, leading to modified and inefficient anti-HIV antibody responses. In this study, we examined the underlying mechanisms of this dysfunction. We observed that proliferating GC-Tfh cells from HIV-infected individuals, displayed distinctive gene expression than those from -uninfected subjects, following GC-B cell interaction. Furthermore, GC-Tfh cells from HIV patients showed a reduction in important immune-related pathway and gene expression. A number of essential GC-Tfh cell genes, such as MAF and its associated genes (IL6R and STAT3), were particularly attenuated in HIV, contributing to the impaired cells function. Moreover, we found an association between MAF function and the key enzyme adenosine deaminase-1 (ADA-1), where supplementation with ADA-1 partially restored the dysfunctional signaling in GC-Tfh cells during chronic infection. Understanding how GC-Tfh cells are altered in HIV is critical to elucidate the mechanisms leading to effective anti-HIV antibodies.

Aymé-Gripp syndrome (AYGRPS) is a recognizable condition caused by a restricted spectrum of dominantly acting missense mutations affecting the transcription factor MAF. Major clinical features of AYGRPS include congenital cataracts, sensorineural hearing loss, intellectual disability, and a distinctive flat facial appearance. Skeletal abnormalities have also been observed in affected individuals, even though these features have not been assessed systematically. Expanding the series with four additional patients, here we provide a more accurate delineation of the molecular aspects and clinical phenotype, particularly focusing on the skeletal features characterizing this disorder. Apart from previously reported malar flattening and joint limitations, we document that carpal/tarsal and long bone defects, and hip dysplasia occur in affected subjects more frequently than formerly appreciated.

The large Maf transcription factors are expressed in immune cells including macrophages and lymphocytes. To investigate the distribution of Maf expression in human organs, immunostaining for Maf was performed using sections of several human organs. High Maf expression was seen in the nucleus of macrophages in the gastrointestinal tract and lymph node sinus macrophages (LySMs). Then, we assessed whether Maf expression in LySMs was correlated with CD169 expression and the clinical prognosis in patients with esophageal cancer. Maf expression was associated with CD169 expression, but Maf expression in LySMs was not associated with the clinical course in patients with esophageal cancer. We determined which cytokines stimulate Maf expression using cultured macrophages. Immunocytochemistry showed that Maf expression was significantly elevated by interferon-γ. These results are the first report of Maf expression in human samples. Maf expression may be a marker for the macrophage population in humans.

BACKGROUND/AIM Serum-derived macrophage activating factor, serum-MAF, is known to increase the phagocytic activity of macrophages by enhancing the engulfment efficiency. To elucidate the mechanisms underlying phagocytic activation, morphological changes were observed and analyzed. MATERIALS AND METHODS Morphological changes in macrophages were observed and quantitatively analyzed using scanning electron microscope (SEM) and confocal microscope. RESULTS SEM and confocal microscopy images revealed frill-like structures and active actin accumulations, respectively, in serum-MAF treated macrophages. Actin accumulation was induced within 5 min following serum-MAF treatment. CONCLUSION Serum-MAF induced a rapid rearrangement of cytoskeletal actin and enhanced phagocytic activity. Findings of the current study may contribute to the development of techniques that facilitate activation of the human immune system, which in turn may be beneficial for cancer immunotherapy.

c-Maf is a critical oncogenic transcription factor that contributes to myelomagenesis. Our previous studies demonstrated that the deubiquitinase USP5 stabilizes c-Maf and promotes myeloma cell proliferation and survival; therefore, the USP5/c-Maf axis could be a potential target for myeloma therapy. As a concept of principle, the present study established a USP5/c-Maf-based luciferase system that was used to screen an FDA-approved drug library. It was found that mebendazole, a typical anthelmintic drug, preferentially induced apoptosis in c-Maf-expressing myeloma cells. Moreover, oral administration of mebendazole delayed the growth of human myeloma xenografts in nude mice but did not show overt toxicity. Further studies showed that the selective antimyeloma activity of mebendazole was associated with the inhibition of the USP5/c-Maf axis. Mebendazole downregulated USP5 expression and disrupted the interaction between USP5 and c-Maf, thus leading to increased levels of c-Maf ubiquitination and subsequent c-Maf degradation. Mebendazole inhibited c-Maf transcriptional activity, as confirmed by both luciferase assays and expression measurements of c-Maf downstream genes. In summary, this study identified mebendazole as a USP5/c-Maf inhibitor that could be developed as a novel antimyeloma agent.

Mielke et al. show that TCF-1 limits IL-17–producing CD8+ T (Tc17) cell development from double-positive thymocytes through the sequential suppression of MAF and RORγt, while cementing conventional CD8+ T cell fate., Interleukin (IL)-17–producing CD8+ T (Tc17) cells have emerged as key players in host-microbiota interactions, infection, and cancer. The factors that drive their development, in contrast to interferon (IFN)-γ–producing effector CD8+ T cells, are not clear. Here we demonstrate that the transcription factor TCF-1 (Tcf7) regulates CD8+ T cell fate decisions in double-positive (DP) thymocytes through the sequential suppression of MAF and RORγt, in parallel with TCF-1–driven modulation of chromatin state. Ablation of TCF-1 resulted in enhanced Tc17 cell development and exposed a gene set signature to drive tissue repair and lipid metabolism, which was distinct from other CD8+ T cell subsets. IL-17–producing CD8+ T cells isolated from healthy humans were also distinct from CD8+IL-17− T cells and enriched in pathways driven by MAF and RORγt. Overall, our study reveals how TCF-1 exerts central control of T cell differentiation in the thymus by normally repressing Tc17 differentiation and promoting an effector fate outcome.

The transcription factor v-maf avain musculoaponeurotic fibrosarcoma oncogene homolog (MAF) plays an important role in lens development. It contains a unique extended homology region (EHR) in the DNA binding domain. MAF mutations are associated with phenotypically distinct forms of congenital cataract and show different effects on the transactivation of target genes. Mutations in the MAF EHR region were rarely reported and their corresponding phenotype and impact on target genes' transactivation were not evaluated. A three- generation Chinese family with congenital cataract was recruited. The patients in the family present non-syndromic congenital nuclear and lamellar opacities. A novel MAF mutation (c.812 T > A, p.Val271Glu) was identified by targeted next-generation sequencing. The mutation is in highly conserved EHR region of MAF and co-segregates with the cataract in the family. It is predicted to be pathogenic by multiple algorithms and is absent in a control population. Dual luciferase activity assay shows the mutation significantly impair the transcriptional activity of four crystallin genes (CRYAA, CRYBA4, CRYBA1, and CRYGA) and two non-crystallin genes (HMOX1 and KDELR2). Herein, we report a novel missense mutation in the MAF EHR region of the DNA binding domain in a family with congenital cataract. The mutation is associated with non-syndromic bilateral nuclear cataract and impacts the transactivation of cataract associated genes involved in lens structure and stress response.

The activation of Nuclear Factor, Erythroid 2 Like 2 - Kelch Like ECH Associated Protein 1 (NRF2-KEAP1) signaling pathway plays a critical dual role by either protecting or promoting the carcinogenesis process. However, its activation or nuclear translocation during hepatocellular carcinoma (HCC) progression has not been addressed yet. This study characterizes the subcellular localization of both NRF2 and KEAP1 during diethylnitrosamine-induced hepatocarcinogenesis in the rat. NRF2-KEAP1 pathway was continuously activated along with the increased expression of its target genes, namely Nqo1, Hmox1, Gclc, and Ptgr1. Similarly, the nuclear translocation of NRF2, MAF, and KEAP1 increased in HCC cells from weeks 12 to 22 during HCC progression. Likewise, colocalization of NRF2 with KEAP1 was higher in the cell nuclei of HCC neoplastic nodules than in surrounding cells. Moreover, immunofluorescence analyses revealed that the interaction of KEAP1 with filamentous Actin was disrupted in HCC cells. This disruption may be contributing to the release and nuclear translocation of NRF2 since the cortical actin cytoskeleton serves as anchoring of KEAP1. In conclusion, this evidence indicates that NRF2 is progressively activated and promotes the progression of experimental HCC.

γδ T cells with distinct properties develop in the embryonic and adult thymus and have been identified as critical players in a broad range of infections, antitumor surveillance, autoimmune diseases, and tissue homeostasis. Despite their potential value for immunotherapy, differentiation of γδ T cells in the thymus is incompletely understood. Here, we establish a high‐resolution map of γδ T‐cell differentiation from the fetal and adult thymus using single‐cell RNA sequencing. We reveal novel sub‐types of immature and mature γδ T cells and identify an unpolarized thymic population which is expanded in the blood and lymph nodes. Our detailed comparative analysis reveals remarkable similarities between the gene networks active during fetal and adult γδ T‐cell differentiation. By performing a combined single‐cell analysis of Sox13, Maf, and Rorc knockout mice, we demonstrate sequential activation of these factors during IL‐17‐producing γδ T‐cell (γδT17) differentiation. These findings substantially expand our understanding of γδ T‐cell ontogeny in fetal and adult life. Our experimental and computational strategy provides a blueprint for comparing immune cell differentiation across developmental stages., A comprehensive transcription map of γδ T‐cell development at single‐cell resolution reveals novel subtypes, as well as similarities in gene regulatory programs during fetal and adult γδ T‐cell differentiation.

Key Points Malat1 is suppressed during Th1 and Th2 differentiation. Malat1 loss suppresses IL-10 and Maf expression in effector Th cells. Malat1−/− mice mount enhanced immune responses in leishmaniasis and malaria models., Despite extensive mapping of long noncoding RNAs in immune cells, their function in vivo remains poorly understood. In this study, we identify over 100 long noncoding RNAs that are differentially expressed within 24 h of Th1 cell activation. Among those, we show that suppression of Malat1 is a hallmark of CD4+ T cell activation, but its complete deletion results in more potent immune responses to infection. This is because Malat1−/− Th1 and Th2 cells express lower levels of the immunosuppressive cytokine IL-10. In vivo, the reduced CD4+ T cell IL-10 expression in Malat1−/−mice underpins enhanced immunity and pathogen clearance in experimental visceral leishmaniasis (Leishmania donovani) but more severe disease in a model of malaria (Plasmodium chabaudi chabaudi AS). Mechanistically, Malat1 regulates IL-10 through enhancing expression of Maf, a key transcriptional regulator of IL-10. Maf expression correlates with Malat1 in single Ag-specific Th cells from P. chabaudi chabaudi AS–infected mice and is downregulated in Malat1−/− Th1 and Th2 cells. The Malat1 RNA is responsible for these effects, as antisense oligonucleotide-mediated inhibition of Malat1 also suppresses Maf and IL-10 levels. Our results reveal that through promoting expression of the Maf/IL-10 axis in effector Th cells, Malat1 is a nonredundant regulator of mammalian immunity.

Group 2 innate lymphoid cells (ILC2s) and Th2 type immune response are critically involved in the pathogenesis of allergic rhinitis (AR), and this pathological process is influenced by microRNAs-mediated post-transcriptional regulation. The present study investigated the adaptation and function of miR-155 in AR patients and mouse model. We found that significantly increased miR-155 expression (1.63 ± 0.12 vs. 0.92 ± 0.11 in human, and 1.68 ± 0.15 vs. 1.06 ± 0.06 in mice) and ILC2s activity in nasal mucosa and serum in AR patients and mice. Administration of miR-155 antagomir significantly reduced the activity of ILC2s in nasal mucosa, suppressed the production of Th2 cytokines in serum and nasal mucosa, and alleviated the airway inflammation and allergic symptoms in AR mice, while miR-155 agomir increased ILC2s activity and production of Th2 cytokines and induced airway inflammation and allergic symptoms in control mice. Meanwhile, the expression of transcriptional factor c-Maf (0.57 ± 0.05 vs. 0.37 ± 0.04) in nasal mucosa in AR mice, which was significantly recovered by miR-155 antagomir (0.56 ± 0.04). Treatment with miR-155 agomir decreased c-Maf expression in nasal mucosa in control mice. This synchronized with the similar pattern in the current observations that miR-155 regulated Th2 cytokine (IL-4, IL-5, IL-9 and IL-13) production, airway inflammation and allergic symptoms in AR mice. Together, upregulation miR-155 suppressed the expression of transcriptional factor c-Maf and was critically involved in the ILC2s activation, which contributed to the airway inflammation and allergic symptoms in AR.

​Maf (c-Maf) and Mafb transcription factors (TFs) have compensatory roles in repressing somatostatin (SST+) interneuron (IN) production in medial ganglionic eminence (MGE) secondary progenitors in mice. Maf and Mafb conditional deletion (cDKO) decreases the survival of MGE-derived cortical interneurons (CINs) and changes their physiological properties. Herein, we show that (1) Mef2c and Snap25 are positively regulated by Maf and Mafb to drive IN morphological maturation; (2) Maf and Mafb promote Mef2c expression which specifies parvalbumin (PV+) INs; (3) Elmo1, Igfbp4 and Mef2c are candidate markers of immature PV+ hippocampal INs (HIN). Furthermore, Maf/Mafb neonatal cDKOs have decreased CINs and increased HINs, that express Pnoc, an HIN specific marker. Our findings not only elucidate key gene targets of Maf and Mafb that control IN development, but also identify for the first time TFs that differentially regulate CIN vs. HIN production.

Macrophages have been linked to tumor initiation, progression, metastasis, and treatment resistance. However, the transcriptional regulation of macrophages driving the protumor function remains elusive. Here, we demonstrate that the transcription factor c-Maf is a critical controller for immunosuppressive macrophage polarization and function in cancer. c-Maf controls many M2-related genes and has direct binding sites within a conserved noncoding sequence of the Csf-1r gene and promotes M2-like macrophage-mediated T cell suppression and tumor progression. c-Maf also serves as a metabolic checkpoint regulating the TCA cycle and UDP-GlcNAc biosynthesis, thus promoting M2-like macrophage polarization and activation. Additionally, c-Maf is highly expressed in tumor-associated macrophages (TAMs) and regulates TAM immunosuppressive function. Deletion of c-Maf specifically in myeloid cells results in reduced tumor burden with enhanced antitumor T cell immunity. Inhibition of c-Maf partly overcomes resistance to anti-PD-1 therapy in a subcutaneous LLC tumor model. Similarly, c-Maf is expressed in human M2 and tumor-infiltrating macrophages/monocytes as well as circulating monocytes of human non-small cell lung carcinoma (NSCLC) patients and critically regulates their immunosuppressive activity. The natural compound β-glucan downregulates c-Maf expression on macrophages, leading to enhanced antitumor immunity in mice. These findings establish a paradigm for immunosuppressive macrophage polarization and transcriptional regulation by c-Maf and suggest that c-Maf is a potential target for effective tumor immunotherapy.

IL-10 is critical for Foxp3(+) regulatory T cell (Tregs)–mediated immune suppression, but how to efficiently upregulate IL-10 production in Tregs remains unclear. In this article, we show that human IL-10(+) FOXP3(+)–induced regulatory T cell (iTreg) generation can be dramatically promoted by inhibiting GSK3 activity. IL-10(+) FOXP3(+) iTregs induced by GSK3 inhibition exhibit classical features of immune-suppressive T cells. We further demonstrate that IL-10(+) iTregs exhibit enhanced suppressive function in both IL-10–dependent and –independent manners. The enhanced suppressive function of IL-10(+) Tregs is not due to a single factor such as IL-10, although IL-10 may mediate this enhanced suppressive function to some extent. Mechanistically, the increased transcriptional activity of IL-10 promoter and the enhanced expression of C-Maf and BLIMP1 coordinately facilitate IL-10 expression in human iTregs under GSK3 inhibition. Our study provides a new strategy to generate human immune-suppressive IL-10(+) FOXP3(+) Tregs for immunotherapies.

The signal regulated transcription factors (SRTFs) control the ultimate transcriptional output of signaling pathways. Here, we examined a family of FGF-induced SRTFs – Etv1, Etv 4, and Etv 5 – in murine lens development. Contrary to FGF receptor mutants that displayed loss of ERK signaling and defective cell differentiation, Etv deficiency augmented ERK phosphorylation without disrupting the normal lens fiber gene expression. Instead, the transitional zone for lens differentiation was shifted anteriorly as a result of reduced Jag1-Notch signaling. We also showed that Etv proteins suppresses mTOR activity by promoting Tsc2 expression, which is necessary for the nuclei clearance in mature lens. These results revealed the functional divergence between Etv and FGF in lens development, demonstrating that these SRTFs can operate outside the confine of their upstream signaling., eLife digest Many cells contain proteins known as signal-induced transcription factors, which are poised to receive messages from the environment and then react by activating genes required for the cell to respond appropriately. It is commonly thought that these transcription factors faithfully follow the instructions they receive from the external signal: for instance, if the message was to encourage the cell to grow, the transcription factors would switch on growth-related genes. As the eyes of mice and other mammals develop, a signal known as FGF is required for certain cells to specialize into lens fiber cells: these long, thin, transparent cells form the bulk of the lens, the structure that allows focused vision. Previous studies suggest that FGF activates three transcription factors known as Etv1, Etv4 and Etv5, but their precise roles in the development of the lens has remained unclear. Here, Garg, Hannan, Wang et al. confirm that FGF signaling does indeed activate all three proteins. However, mutant mice that lacked Etv1, Etv4 and Etv5 still created lens fiber cells, suggesting that the transcription factors are largely unnecessary for lens fiber cells formation. Instead, the Etv proteins participated in a cascade of molecular events involving a protein called Notch; as a result, if the transcription factors were absent, the lens fiber cells formed prematurely. In addition, deactivating Etv1, Etv4 and Etv5 also promoted the activity of a protein which interfered with the removal of internal cell compartments, a process required for lens fiber cells to mature properly. These findings reveal that the roles of Etv1, Etv4 and Etv5 deviate from and even oppose FGF signaling in the lenses of mice. Transcription factors control the ultimate fate of a cell, and there is therefore increased interest in targeting them for therapy. The work by Garg, Hannan, Wang et al. reveals an unexpected complexity in how these proteins respond to upstream signals, highlighting the importance of further dissecting these relationships.

The transcription factor c-MAF is a member of the large MAF family, members of which possess transactivation and bZIP domains. c-MAF plays an important role in lens formation, T-lymphocyte differentiation, hypertrophic chondrocyte differentiation, and kidney development in mouse embryos. However, because homozygous deletion of c-Maf in C57BL/6J mice causes embryonic lethality, the functions of c-MAF in adult mice remain largely uninvestigated. To address this issue, we generated c-Maf floxed (c-Maffl/fl) C57BL/6J mice and established tamoxifen-inducible c-Maf knockout mice (c-Maffl/fl; CAG-Cre-ERTM mice, c-MafΔTAM). After tamoxifen injection, adult c-MafΔTAM mice showed successful deletion of c-Maf protein and developed severe cataracts; cataracts are also seen in human patients who have mutations in the c-MAF DNA binding domain. Furthermore, adult c-MafΔTAM mice exhibited abnormal lens structure and impaired differentiation of lens fiber cells. In summary, we established c-Maffl/fl and c-MafΔTAM C57BL/6J mice, which can be useful animal models for the investigation of c-MAF function in various developmental stages and can also be used as a disease model for cataracts.

As a deubiqutinase Otub1 stabilizes and promotes the oncogenic activity of the transcription factor c-Maf in multiple myeloma (MM), a malignancy of plasma cells. In the screen for bioactive inhibitors of the Otub1/c-Maf axis for MM treatment, nanchangmycin (Nam), a polyketide antibiotic, was identified to suppress c-Maf activity in the presence of Otub1. By suppressing Otub1, Nam induces c-Maf polyubiquitination and subsequent degradation in proteasomes but does not alter its mRNA level. Consistently, Nam downregulates the expression of CCND2, ARK5, and ITGB7, the downstream genes regulated by c-Maf, and promotes MM cell apoptosis as evidenced by PARP and Caspase-3 cleavage, as well as Annexin V staining. In line with the hypothesis, overexpression of Otub1 partly rescues Nam-induced MM cell apoptosis, and interestingly, when Otub1 is knocked down, Nam-decreased MM cell survival is also partly ablated, suggesting Otub1 is essential for Nam anti-MM activity. Nam also displays potent anti-MM activity synergistically with Doxorubicin or lenalidomide. In the in vivo assays, Nam almost completely suppresses the growth of MM xenografts in nude mice at low dosages but it shows no toxicity. Given its safety and efficacy, Nam has a potential for MM treatment by targeting the Otub1/c-Maf axis.