The human MIF polymorphism CATT7 enhances pro-inflammatory macrophage polarization in a clinically relevant model of allergic airway inflammation

High level expression of the pro-inflammatory cytokine macrophage migration inhibitory factor (MIF) has been associated with severe asthma. The role of MIF and its functional promotor polymorphism in innate immune training is currently unknown. Using novel humanized CATT7 MIF mice, this study is the first to investigate the effect of MIF on bone marrow-derived macrophage (BMDM) memory after house dust mite (HDM) challenge. CATT7 BMDMs demonstrated a significant primed increase in M1 markers following HDM and LPS stimulation, compared to naive mice. This M1 signature was found to be MIF-dependent, as administration of a small molecule MIF inhibitor, SCD-19, blocked the induction of this pro-inflammatory M1-like phenotype in BMDMs from CATT7 mice challenged with HDM. Training naive BMDMs in vitro with HDM for 24 h followed by a rest period and subsequent stimulation with LPS led to significantly increased production of the pro-inflammatory cytokine TNFα in BMDMs from CATT7 mice but not WT mice. Addition of the pan methyltransferase inhibitor MTA before HDM training significantly abrogated this effect in BMDMs from CATT7 mice, suggesting that HDM-induced training is associated with epigenetic remodelling. These findings suggest that trained immunity induced by HDM is under genetic control, playing an important role in asthma patients with the high MIF genotypes (CATT6/7/8).

Macrophage migration inhibitory factor (MIF) predicts survival in patients with clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is one of the most common subtypes of renal cancer, with 30% of patients presenting with systemic disease at diagnosis. This aggressiveness is a consequence of the activation of epithelial-mesenchymal transition (EMT) caused by many different inducers or regulators, signaling cascades, epigenetic regulation, and the tumor environment. Alterations in EMT-related genes and transcription factors are associated with poor prognosis in ccRCC. EMT-related factors suppress E-cadherin expression and are associated with tumor progression, local invasion, and metastasis. The aim of this study was to investigate the expression levels and prognostic significance of macrophage migration inhibitory factor (MIF), β-catenin, and E-cadherin in ccRCC patients. We examined these proteins immunohistochemically in tumor areas and adjacent normal tissues resected from patients with ccRCC. Analysis of the cancer genome atlas (TCGA) cohort was performed to verify our results. Kaplan-Meier analysis showed that median overall survival (OS) was significantly shorter in patients with tumors exhibiting high MIFn and MIFm-c levels compared to those with low MIFn and MIFm-c levels (p = 0.03 and p = 0.007, respectively). In the TCGA cohort, there was a significant correlation between MIF expression and OS (p < 0.0001). In conclusion, this study provides further evidence for the biological and prognostic value of MIF in the context of EMT as a potential early prognostic marker for advanced-stage ccRCC.

The Tautomerase Activity of Tumor Exosomal MIF Promotes Pancreatic Cancer Progression by Modulating MDSC Differentiation

Pancreatic cancer is a deadly disease that is largely resistant to immunotherapy, in part because of the accumulation of immunosuppressive cells in the tumor microenvironment (TME). Much evidence suggests that tumor-derived exosomes (TDE) contribute to the immunosuppressive activity mediated by myeloid-derived suppressor cells (MDSC) within the pancreatic cancer TME. However, the underlying mechanisms remain elusive. Herein, we report that macrophage migration inhibitory factor (MIF) in TDEs has a key role in inducing MDSC formation in pancreatic cancer. We identified MIF in both human and murine pancreatic cancer-derived exosomes. Upon specific shRNA-mediated knockdown of MIF, the ability of pancreatic cancer-derived exosomes to promote MDSC differentiation was abrogated. This phenotype was rescued by reexpression of the wild-type form of MIF rather than a tautomerase-null mutant or a thiol-protein oxidoreductase-null mutant, indicating that both MIF enzyme activity sites play a role in exosome-induced MDSC formation in pancreatic cancer. RNA sequencing data indicated that MIF tautomerase regulated the expression of genes required for MDSC differentiation, recruitment, and activation. We therefore developed a MIF tautomerase inhibitor, IPG1576. The inhibitor effectively inhibited exosome-induced MDSC differentiation in vitro and reduced tumor growth in an orthotopic pancreatic cancer model, which was associated with decreased numbers of MDSCs and increased infiltration of CD8+ T cells in the TME. Collectively, our findings highlight a pivotal role for MIF in exosome-induced MDSC differentiation in pancreatic cancer and underscore the potential of MIF tautomerase inhibitors to reverse the immunosuppressive pancreatic cancer microenvironment, thereby augmenting anticancer immune responses.

Association of MIF-173G/C, IL-4 VNTR, and IL-1RA VNTR variants with FMF-related amyloidosis in a Turkish cohort

The most important complication of familial Mediterranean fever (FMF) is secondary amyloidosis. The aim of this study is to investigate the risk of developing FMF-related amyloidosis with macrophage migration inhibitory factor (MIF), interleukin 4 (IL-4), and IL-1 receptor antagonist (IL-1RA) variants. This study included 62 FMF patients with amyloidosis, 110 FMF patients without amyloidosis, and 120 controls. The clinical information of the patient groups was compared. MIF-173G/C, IL-4 variant number tandem repeat (VNTR), and IL-1RA VNTR variants were analyzed for all participants. The use of colchicine, pleurisy, and appendectomy was more common in FMF patients with amyloidosis than in FMF patients without amyloidosis. MIF-173G/C C/C genotype and C allele were higher in both patient groups compared to controls. IL-1RA VNTR A1/A2 and A1/A4 genotypes and A1-A4 alleles were more common in both patient groups than controls. The IL-4 VNTR P1 allele was more common in FMF patients with amyloidosis compared to controls. The MIF-173G/C allele and the IL-1RA VNTR A1-A4 allele are associated with FMF in the Turkish population but not with amyloidosis risk in FMF patients. The IL-4 VNTR P1 allele is more common in FMF patients with amyloidosis than in healthy individuals.

Phosphorylation of MIF by PIP4K2a is necessary for cilia biogenesis

Primary cilia are microtubule-based organelles that play important roles in development and tissue homeostasis. Macrophage migration inhibitory factor (MIF) has long been recognized as a secreted cytokine in the pathogenesis of various human diseases, including cancer and autosomal dominant polycystic kidney disease (ADPKD). Unlike other cytokines, unique functional characteristics of intracellular MIF have emerged. In this study, we show that MIF is localized and formed a ring like structure at the proximal end of centrioles, where it regulates cilia biogenesis through affecting 1) the recruitment of TTBK2 to basal body and the removal of CP110 from mother centriole, 2) the accumulation of CEP290 at centriolar satellites, and 3) the trafficking of intraflagellar transport (IFT) related proteins. We also show that MIF functions as a novel transcriptional factor to regulate the expression of genes related to ciliogenesis via binding on the promotors of those genes. MIF also binds chromatin and regulates transcription of genes involved in diverse homeostatic signaling pathways. We identify phosphatidylinositol-5-phosphate 4-kinase type 2 alpha (PIP4K2a) as an upstream regulator of MIF, which interacts with and phosphorylates MIF at S91 to increase its interaction with 14-3-3ζ, resulting in its nuclear translocation and transcription regulation. This study suggests that MIF is a key player in cilia biogenesis and a novel transcriptional regulator in homeostasis, which forward our understanding of how MIF is able to carry out several nonoverlapping functions.

Plant MDL proteins synergize with the cytokine MIF at CXCR2 and CXCR4 receptors in human cells

Mammalian macrophage migration inhibitory factor (MIF) and its paralog, D-dopachrome tautomerase, are multifunctional inflammatory cytokines. Plants have orthologous MIF and D-dopachrome tautomerase-like (MDL) proteins that mimic some of the effects of MIF on immune cells in vitro. We explored the structural and functional similarities between the three Arabidopsis thaliana MDLs and MIF. X-ray crystallography of the MDLs revealed high structural similarity between MDL and MIF homotrimers and suggested a potential explanation for the lack of tautomerase activity in the MDLs. MDL1 and MDL2 interacted with each other and with MIF in vitro, in yeast, and in plant leaves and formed hetero-oligomeric complexes with MIF in vitro. The MDLs stimulated signaling through the MIF receptors CXCR2 or CXCR4 and enhanced the responses to MIF in a yeast reporter system, in human neutrophils, and in human lung epithelial cells. Pharmacological inhibitors that disrupted MIF activity or prevented the formation of MIF-MDL hetero-oligomers blocked the observed synergism. These findings demonstrate that MDLs can enhance cellular responses to MIF, which may have functional implications in tissues exposed to MDLs from the diet or environment.

Haplotypes of [-794(CATT)5-8 /-173G>C] MIF gene polymorphisms and its soluble levels in cutaneous squamous cell carcinoma in western Mexican population

BACKGROUND

Some cytokines are strongly implicated in the development of squamous cell carcinoma (SCC) such as the Macrophage migration inhibitory factor (MIF). The haplotype -794 (CATT)5-8 /-173G>C in MIF gene polymorphisms has been associated with some types of cancer. The aim of this study is to establish the possible association between the presence of this haplotype in the MIF gene and its subsequent soluble levels with the susceptibility of SCC in western Mexican population.

METHODS

This study included 175 SCC patients and 175 age-sex-matched individuals as a reference group (RG) from western Mexico. Genomic DNA was extracted from peripheral blood leukocytes. Polymorphisms were genotyped by endpoint PCR and PCR-RFLP, and the determination of MIF serum levels was measured by ELISA. Clinical characteristics were evaluated by a group of dermatologists.

RESULTS

Analysis of [-794(CATT)5-8 /-173G>C] MIF gene polymorphisms showed that the 5C (OR = 2.7, p = 0.02) and the 7G (OR = 3.39, p < 0.01) haplotypes are associated with susceptibility in SCC. MIF soluble levels in SCC patients showed a median of 13.93 ng/mL, whereas the reference group showed 6.000 ng/mL.

CONCLUSIONS

Our findings suggest that 5C and 7G [-794(CATT)5-8 /-173G>C] MIF gene haplotypes are associated with susceptibility to SCC and that SCC patients present increased soluble levels of MIF.

Macrophages, MIFs, and MSCs: Defining an MOA in murine experimental asthma

The mechanistically defined attributes of primed MSCs as here described not only provide a novel use case of MIF activated MSCs that can address the potency shortcomings of generic culture-adapted MSCs for acute lung injury but also provide some intriguing "Rosetta Stone" insights on plausible in vivo physiology of MSCs with host innate effectors such as macrophages in response to inflammation.

Jasmonate biosynthesis enzyme allene oxide cyclase 2 mediates cold tolerance and pathogen resistance

Allene oxide cyclase (AOC) is a key enzyme in the biosynthesis of jasmonic acid (JA), which is involved in plant growth and development as well as adaptation to environmental stresses. We identified the cold- and pathogen-responsive AOC2 gene from Medicago sativa subsp. falcata (MfAOC2) and its homolog MtAOC2 from Medicago truncatula. Heterologous expression of MfAOC2 in M. truncatula enhanced cold tolerance and resistance to the fungal pathogen Rhizoctonia solani, with greater accumulation of JA and higher transcript levels of JA downstream genes than in wild-type plants. In contrast, mutation of MtAOC2 reduced cold tolerance and pathogen resistance, with less accumulation of JA and lower transcript levels of JA downstream genes in the aoc2 mutant than in wild-type plants. The aoc2 phenotype and low levels of cold-responsive C-repeat-binding factor (CBF) transcripts could be rescued by expressing MfAOC2 in aoc2 plants or exogenous application of methyl jasmonate. Compared with wild-type plants, higher levels of CBF transcripts were observed in lines expressing MfAOC2 but lower levels of CBF transcripts were observed in the aoc2 mutant under cold conditions; superoxide dismutase, catalase, and ascorbate-peroxidase activities as well as proline concentrations were higher in MfAOC2-expressing lines but lower in the aoc2 mutant. These results suggest that expression of MfAOC2 or MtAOC2 promotes biosynthesis of JA, which positively regulates expression of CBF genes and antioxidant defense under cold conditions and expression of JA downstream genes after pathogen infection, leading to greater cold tolerance and pathogen resistance.

Investigation of MIF gene promoter variations and their haplotypes in the Alzheimer disease in Turkish population

In Alzheimer's disease, which is characterized by amyloid plaques and neurofibrillary tangles in the brain tissue, many components such as acute phase proteins, cytokines, and proteases contribute to the progression of the disease or are part of the pathological process. The macrophage migration inhibitory factor (MIF) gene encodes a cytokine, which is secreted by lymphocytes, and has a role in the pathogenesis of autoimmune/inflammatory diseases such as rheumatoid arthritis. The purpose of this study to investigate the association between Alzheimer disease and MIF gene promoter polymorphisms. The 205 patients with Alzheimer disease (AD) and 130 age-sex matched healthy individuals were investigated in terms of MIF -173 G/C and MIF -794 CATT polymorphisms. The genotyping of MIF -173 G/C was determined using the RT-PCR method. MIF-794 CATT polymorphism was analyzed using PCR and DNA Sequencing. In terms of binary genotypes and haplotypes, the 5/5-GC (p = 0.004), 6/7-GG (p = 0.02) and, 6/6-GG (p = 0.026) binary genotypes, and 5-C (p = 0.003), 7-G (p = 0.026) and 6-G (p = 0.025) haplotypes were differed significantly between the patients and the controls. This is the first study investigating the relationship between AD and MIF in terms of different genotypes, haplotypes and, alleles. The fact that the binary genotype and allele distributions are significantly different between the patient and control group, suggests that this MIF variants may play a role in the pathogenesis of AD.

The MIF promoter SNP rs755622 is associated with immune activation in glioblastoma

Intratumoral heterogeneity is a defining hallmark of glioblastoma, driving drug resistance and ultimately recurrence. Many somatic drivers of microenvironmental change have been shown to affect this heterogeneity and, ultimately, the treatment response. However, little is known about how germline mutations affect the tumoral microenvironment. Here, we find that the single-nucleotide polymorphism (SNP) rs755622 in the promoter of the cytokine macrophage migration inhibitory factor (MIF) is associated with increased leukocyte infiltration in glioblastoma. Furthermore, we identified an association between rs755622 and lactotransferrin expression, which could also be used as a biomarker for immune-infiltrated tumors. These findings demonstrate that a germline SNP in the promoter region of MIF may affect the immune microenvironment and further reveal a link between lactotransferrin and immune activation.

Association of ACE ID, MTHFR C677T, and MIF-173GC variants with the clinical course of COVID-19 patients

The course of coronavirus disease-2019 (COVID-19) differs from person to person. The relationship between the genetic variations of the host and the course of COVID-19 has been a matter of interest. In this study, we investigated whether Angiotensin-Converting Enzyme (ACE) ID, Methylenetetrahydrofolate Reductase (MTHFR) C677T, and Macrophage Migration Inhibitory Factor (MIF)-173GC variants are risk factors for the clinical course of COVID-19 disease in Turkish patients. One hundred COVID-19 patients were included in the study. The diagnosis of COVID-19 was made using Reverse Transcription Polymerase Chain Reaction (RT-PCR) and Chest Computed Tomography (CT). The patients were evaluated in 3 groups: intensive care, service, and outpatient treatment. ACE ID, MTHFR C677T, and MIF-173GC variants were genotyped by PCR-Restriction Fragment Length Polymorphism (RFLP) methods. When the genotype distribution between the groups was examined, it was found that the frequency of the ACE DD genotype and the D allele was higher in the intensive care group compared to the hospitalized and outpatient groups. MTHFR C677T CT genotype T allele and MIF-173GC, CC genotype C allele were more prevalent in the intensive care group compared to other groups. Patients with PCR-positive results had a higher MTHFR C677T C/C genotype and C allele. In CT-positive patients, the MTHFR C677T CT genotype and the MIF-173GC, G allele were more common. It is predicted that genetic predisposition may contribute to COVID-19 morbidity and mortality. Our results show that ACE ID, MTHFR C677T, and MIF-173GC variants affect the course of COVID-19 disease in the Turkish population.

MIF is a common genetic determinant of COVID-19 symptomatic infection and severity

BACKGROUND

Genetic predisposition to coronavirus disease 2019 (COVID-19) may contribute to its morbidity and mortality. Because cytokines play an important role in multiple phases of infection, we examined whether commonly occurring, functional polymorphisms in macrophage migration inhibitory factor (MIF) are associated with COVID-19 infection or disease severity.

AIM

To determine associations of common functional polymorphisms in MIF with symptomatic COVID-19 or its severity.

METHODS

This retrospective case-control study utilized 1171 patients with COVID-19 from three tertiary medical centers in the USA, Hungary and Spain, together with a group of 637 pre-pandemic, healthy control subjects. Functional MIF promoter alleles (-794 CATT5-8,rs5844572), serum MIF and soluble MIF receptor levels, and available clinical characteristics were measured and correlated with COVID-19 diagnosis and hospitalization. Experimental mice genetically engineered to express human high- or low-expression MIF alleles were studied for response to coronavirus infection.

RESULTS

In patients with COVID-19, there was a lower frequency of the high-expression MIF CATT7 allele when compared to healthy controls [11% vs. 19%, odds ratio (OR) 0.54 [0.41-0.72], P < 0.0001]. Among inpatients with COVID-19 (n = 805), there was a higher frequency of the MIF CATT7 allele compared to outpatients (n = 187) (12% vs. 5%, OR 2.87 [1.42-5.78], P = 0.002). Inpatients presented with higher serum MIF levels when compared to outpatients or uninfected healthy controls (87 ng/ml vs. 35 ng/ml vs. 29 ng/ml, P < 0.001, respectively). Among inpatients, circulating MIF concentrations correlated with admission ferritin (r = 0.19, P = 0.01) and maximum CRP (r = 0.16, P = 0.03) levels. Mice with a human high-expression MIF allele showed more severe disease than those with a low-expression MIF allele.

CONCLUSIONS

In this multinational retrospective study of 1171 subjects with COVID-19, the commonly occurring -794 CATT7MIF allele is associated with reduced susceptibility to symptomatic SARS-CoV-2 infection but increased disease progression as assessed by hospitalization. These findings affirm the importance of the high-expression CATT7MIF allele, which occurs in 19% of the population, in different stages of COVID-19 infection.

hUC-MSCs exosomal miR-451 alleviated acute lung injury by modulating macrophage M2 polarization via regulating MIF-PI3K-AKT signaling pathway

In the previous study, we have proved that exosomal miR-451 from human umbilical cord mesenchymal stem cells (hUC-MSCs) attenuated burn-induced acute lung injury (ALI). However, the mechanism of exosomal miR-451 in ALI remains unclear. Therefore, this study aimed to study the molecular mechanism of hUC-MSCs-derived exosomal miR-451 on ALI by regulating macrophage polarization. Exosomes were isolated and identified by transmission electron microscope (TEM) and nanoparticle tracking analysis (NTA). The expression of miR-451, macrophage migration inhibitory factor (MIF) and PI3K/AKT signaling pathway proteins were detected by qRT-PCR and western blot. Flow cytometry was used to detect the CD80 and CD206 positive cells. Severe burn rat model was established and HE was used to detect the inflammatory cell infiltration and inflammatory injury. Dual luciferase reporter system was used to detect the regulation of miR-451 to MIF. The contents of cytokines were detected by ELISA. The results showed that hUC-MSCs exosomes promoted macrophage M1 to M2 polarization. Furthermore, hUC-MSCs-derived exosomal miR-451 alleviated ALI development and promoted macrophage M1 to M2 polarization. Moreover, MIF was a direct target of miR-451. Downregulation of MIF regulated by miR-451 alleviated ALI development promoted macrophage M1 to M2 polarization. In addition, we found that MIF and hUC-MSCs-derived exosomal miR-451 participated in ALI by regulating PI3K/AKT signaling pathway. In conclusion, we indicated that hUC-MSCs-derived exosomal miR-451 alleviated ALI by modulating macrophage M2 polarization via regulating MIF-PI3K-AKT signaling pathway, which provided great scientific significance and clinical application value for the treatment of burn-induced ALI.

Enhancement of TRP Gene Expression and UV Absorption by Bioconverted Chestnut Inner Shell Extracts Using Lactiplantibacillus plantarum

In this work, the suppression of tyrosinase-related genes, including an improvement in UV absorption effects of bioconverted CS extracts (BCS), was investigated to improve the skin-whitening effect. Total polyphenols and total flavonoids, which are bioactive components, increased 2.6- and 5.4-times in bioconversion using Lactiplantibacillus plantarum SM4, respectively, as compared to ultrasound-assisted extracts (UCS). The effect of BCS on radical scavenging activity, UV-A absorption, and tyrosinase activity inhibition, contributing to skin-whitening, were 1.3-, 1.2-, and 1.2-times higher than those of UCS, respectively. The main component identified in high-performance liquid chromatography (HPLC) was gallic acid in both UCS and BCS, which increased by 2.9-times following bioconversion. The gene expression of tyrosinase-related proteins, including TRP-1 and TRP-2 genes, was studied to confirm the suppression of melanin synthesis by BCS in order to identify the skin-whitening mechanism, and BCS decreased both genes’ expression by 1.7- and 1.6-times, demonstrating that BCS effectively suppressed melanin synthesis. These findings imply that the chestnut inner shell can be employed as a cosmetic material by simultaneously inhibiting melanogenesis and enhancing UV-A absorption through bioconversion using L. plantarum SM4.

"Near Cure" treatment of severe acute EAE in MIF-1-deficient female and male mice with a bifunctional MHCII-derived molecular construct

Our previous studies demonstrated increased serum levels of macrophage migration inhibitory factor (MIF-1) and its homologue, MIF-2, in males during MS progression; and that genetically high-MIF-expressing male subjects with relapsing multiple sclerosis (MS) had a significantly greater risk of conversion to progressive MS than lower-MIF-expressing males and females. However, female MS subjects with severe disease expressed higher levels of CD74, the common MIF-1/MIF-2 receptor, on blood cells. In the murine model of MS, experimental autoimmune encephalomyelitis (EAE), both male and female mice lacking MIF-1 and/or MIF-2 were clinically improved during development of moderately severe disease, thus implicating both homologs as co-pathogenic contributors. The current study using MIF-deficient mice with severe acute EAE revealed a highly significant reduction of EAE scores in MIF-1-deficient females, in contrast to only minor and delayed reduction of clinical signs in MIF-1-deficient males. However, clinical EAE scores and factor expression were strongly suppressed in males and further reduced in females after treatment of WT and MIF-1-, MIF-2- and MIF-1/2-DUAL-deficient female and male mice with a MHCII DRα1-MOG-35-55 molecular construct that competitively inhibits MIF-1 & MIF-2 signaling through CD74 as well as T cell activation. These results suggest sex-dependent differences in which the absence of the MIF-1 and/or MIF-2 genotypes may permit stronger compensatory CD74-dependent EAE-inducing responses in males than in females. However, EAE severity in both sexes could still be reduced nearly to background (a "near cure") with DRα1-MOG-35-55 blockade of compensatory MIF and CD74-dependent factors known to attract peripheral inflammatory cells into the spinal cord tissue.

MIF confers survival advantage to pancreatic CAFs by suppressing interferon pathway-induced p53-dependent apoptosis

The presence of activated pancreatic stellate cells (PSCs) in the pancreatic ductal adenocarcinoma (PDAC) microenvironment plays a significant role in cancer progression. Macrophage migration inhibitory factor (MIF) is overexpressed in PDAC tissues and expressed by both cancer and stromal cells. The pathophysiological role of MIF in PDAC-associated fibroblasts or PSCs is yet to be elucidated. Here we report that the PSCs of mouse or cancer-associated fibroblast cells (CAFs) of human expresses MIF and its receptors, whose expression gets upregulated upon LPS or TNF-α stimulation. In vitro functional experiments showed that MIF significantly conferred a survival advantage to CAFs/PSCs upon growth factor deprivation. Genetic or pharmacological inhibition of MIF also corroborated these findings. Further, co-injection of mouse pancreatic cancer cells with PSCs isolated from Mif-/- or Mif+/+ mice confirmed the pro-survival effect of MIF in PSCs and also demonstrated the pro-tumorigenic role of MIF expressed by CAFs in vivo. Differential gene expression analysis and in vitro mechanistic studies indicated that MIF expressed by activated CAFs/PSCs confers a survival advantage to these cells by suppression of interferon pathway induced p53 dependent apoptosis.

MIF rs755622 and IL6 rs1800795 Are Implied in Genetic Susceptibility to End-Stage Renal Disease (ESRD)

Chronic kidney disease (CKD) is characterized by an increased risk of kidney failure and end-stage renal disease (ESRD). Aging and comorbidities as cardiovascular diseases, metabolic disorders, infectious diseases, or tumors, might increase the risk of dialysis. In addition, genetic susceptibility factors might modulate kidney damage evolution. We have analyzed, in a group of ESRD patients and matched controls, a set of SNPs of genes (Klotho rs577912, rs564481, rs9536314; FGF23 rs7955866; IGF1 rs35767; TNFA rs1800629; IL6 rs1800795; MIF rs755622, rs1007888) chosen in relation to their possible involvement with renal disease and concomitant pathologies. Analysis of the raw data did indicate that IL6 rs180795 and MIF rs755622 SNPs might be markers of genetic susceptibility to ESRD. In particular, the C positive genotypes of MIF rs755622, (dominant model) seem to be an independent risk factor for ESDR patients (data adjusted for age, gender, and associated pathologies). Stratifying results according to age MIF rs755622 C positive genotype frequencies are increased in both the two age classes considered (<59 and ≥59-year-old subjects). Analyses of data according to gender allowed us to observe that ESRD women shoved a significantly reduced frequency of genotypes bearing IL6 rs180795 C allele. In addition, MIF rs755622 might interact with diabetes or hypercholesterolemia in increasing susceptibility to ESRD. In conclusion, our data indicate that some polymorphisms involved in the regulation of both renal function and inflammatory response can influence the evolution of chronic kidney disease and suggest that the modulation of the activities of these and other genes should also be considered as therapeutic targets on to intervene with innovative therapies.

Protein Biochemistry and Molecular Modeling of the Intra-Melanosomal Domain of Human Recombinant Tyrp2 Protein and OCA8-Related Mutant Variants

Tyrosinase-related protein 2 (Tyrp2) is involved in the melanogenesis pathway, catalyzing the tautomerization of dopachrome to 5,6-dihydroxyindole-2-carboxylic acid (DHICA). Recently, a new type of albinism was discovered with disease-causing mutations in the TYRP2 gene. Here, for the first time, we characterized the intra-melanosomal protein domain of Tyrp2 (residues 1-474) and missense variants C40S and C61W, which mimic the alterations found in genetic studies. Recombinant proteins were produced in the Trichoplusia Ni (Ti. Ni) larvae, purified by a combination of immobilized metal affinity (IMAC) and gel-filtration (GF) chromatography, and biochemically characterized. The mutants showed the protein expression in the lysates such as the wild type; however, undetectable protein yield after two steps of purification exhibited their misfolding and instability. In addition, the misfolding effect of the mutations was confirmed computationally using homology modeling and molecular docking. Together, experiments in vitro and computer simulations indicated the critical role of the Cys-rich domain in the Tyrp2 protein stability. The results are consistent with molecular modeling, global computational mutagenesis, and clinical data, proving the significance of genetic alterations in cysteine residues, which could cause oculocutaneous albinism type 8.

Drosophila yellow-h encodes dopaminechrome tautomerase: A new enzyme in the eumelanin biosynthetic pathway

Melanin is a widely distributed phenolic pigment that is biosynthesized from tyrosine and its hydroxylated product, dopa, in all animals. However, recent studies reveal a significant deviation from this paradigm, as insects appear to use dopamine rather than dopa as the major precursor of melanin. This observation calls for a reconsideration of the insect melanogenic pathway. While phenoloxidases and laccases can oxidize dopamine for dopaminechrome production, the fate of dopaminechrome remains undetermined. Dopachrome decarboxylase/tautomerase, encoded by yellow-f/f2 of Drosophila melanogaster, can convert dopaminechrome into 5,6-dihydroxyindole, but the same enzyme from other organisms does not act on dopaminechrome, suggesting the existence of a specific dopaminechrome tautomerase (DPT). We now report the identification of this novel enzyme that biosynthesizes 5,6-dihydroxyindole from dopaminechrome in Drosophila. Dopaminechrome tautomerase acted on both dopaminechrome and N-methyl dopaminechrome but not on dopachrome or other aminochromes tested. Our biochemical and molecular studies reveal that this enzyme is encoded by the yellow-h gene, a member of the yellow gene family, and advance our understanding of the physiological functions of this gene family. Identification and characterization of DPT clarifies the precursor for melanin biosynthetic pathways and proves the existence of an independent melanogenic pathway in insects that utilizes dopamine as the primary precursor.

Macrophage migration inhibitory factor gene polymorphisms (SNP -173 G>C and STR-794 CATT5-8) confer risk of plaque psoriasis: A case-control study

BACKGROUND

Macrophage inhibitory factor (MIF) is a pro-inflammatory cytokine secreted by several cells, including those in the immune system and the skin. The MIF gene contains the SNP -173 G> C and STR -794 CATT5-8 polymorphisms in the promoter region capable of affecting its activity. Our objective was to investigate the MIF polymorphisms as a risk factor for plaque psoriasis (PP) in the Mexican population.

METHODS

We genotyped both MIF polymorphism (rs5844572 and rs755622) in 224 PP patients with a clinical and histopathological diagnosis and 232 control subjects (CS) by the PCR-RFLP method. MIF serum levels were determined by an ELISA kit.

RESULTS

We found significant differences in the genotypic and allelic frequencies for the MIF -173 G>C polymorphism; carriers of the GC genotype (OR 1.51, 95% CI 1.026-2.228, p = 0.03) and the C allele (OR 1.34, 95% CI 1.005-1.807, p = 0.04) had higher odds to present with PP. Moreover, the 6C haplotype was associated with PP risk (OR 2.10, 95% CI 1.22-3.69, p < 0.01). Also, the -173 CC genotype was associated with high MIF serum levels (p < 0.05).

CONCLUSIONS

The -173 GC genotype and the 6C haplotype of the MIF polymorphisms are associated with susceptibility to PP in the Mexican population.

LncRNA MEG3 inhibits the proliferation of neural stem cells after ischemic stroke via the miR-493-5P/MIF axis

OBJECTIVE

The proliferation of neural stem cells (NSCs1), or lack thereof, can have profound effects on brain tissue remodeling for ischemic stroke (IS2). In this study, we aimed to reveal the influence of the lncRNA MEG3/miR-493-5p/MIF axis on NSC proliferation after IS.

METHODS

We established an oxygen glucose-deprivation/reoxygenation (OGD/R3) in vitro model of IS in NSCs. We evaluated NSC isolation efficiency and proliferation by NESTIN, SOX2, and PCNA immunofluorescence staining. MEG3 and miR-493-5P levels were assessed by quantitative real-time polymerase chain reaction (qRT-PCR4). Changes in MIF protein expression levels were analyzed using Western blotting. We then evaluated the role of MEG3 and miR-493-5p by transfection of si-MEG3, a miR-493-5p mimic, or miR-493-5p inhibitor. NSC proliferation was quantified using Cell Counting Kit-8 analysis.

RESULTS

NESTIN and SOX2 were co-expressed in endogenous NSCs. Following OGD/R, MEG3 and miR-493-5P were significantly upregulated in NSCs, while MIF levels decreased and proliferation was inhibited. Knockdown of MEG3 inhibited miR-493-5p and rescued expression of MIF and PCNA, restoring cellular proliferation levels. In NSCs transfected with a miR-493-5p mimic or inhibitor, MIF levels were down- or upregulated, respectively. Consistently, transfection of a miR-493-5p mimic reduced NSC proliferation, while transfection with a miR-493-5p inhibitor or si-MEG3 rescued the inhibitory effect of OGD/R on NSC proliferation. After co-transfection of si-MEG3 and a miR-493-5p mimic of OGD/R-induced NSCs, levels of PCNA, an indicator of cellular proliferation, were significantly reduced. Conclusion MEG3 inhibits NSC proliferation of after IS via positive regulation of miR-493-5p and potential subsequent downregulation of MIF.

A structurally preserved allosteric site in the MIF superfamily affects enzymatic activity and CD74 activation in D-dopachrome tautomerase

The macrophage migration inhibitory factor (MIF) family of cytokines contains multiple ligand-binding sites and mediates immunomodulatory processes through an undefined mechanism(s). Previously, we reported a dynamic relay connecting the MIF catalytic site to an allosteric site at its solvent channel. Despite structural and functional similarity, the MIF homolog D-dopachrome tautomerase (also called MIF-2) has low sequence identity (35%), prompting the question of whether this dynamic regulatory network is conserved. Here, we establish the structural basis of an allosteric site in MIF-2, showing with solution NMR that dynamic communication is preserved in MIF-2 despite differences in the primary sequence. X-ray crystallography and NMR detail the structural consequences of perturbing residues in this pathway, which include conformational changes surrounding the allosteric site, despite global preservation of the MIF-2 fold. Molecular simulations reveal MIF-2 to contain a comparable hydrogen bond network to that of MIF, which was previously hypothesized to influence catalytic activity by modulating the strength of allosteric coupling. Disruption of the allosteric relay by mutagenesis also attenuates MIF-2 enzymatic activity in vitro and the activation of the cluster of differentiation 74 receptor in vivo, highlighting a conserved point of control for nonoverlapping functions in the MIF superfamily.

Alternative activation of macrophages by prostacyclin synthase ameliorates alcohol induced liver injury

Alcoholic liver disease (ALD) is a major cause of chronic liver disease worldwide. Macrophages exhibit different functional states and are classified as classically activated (M1) and alternatively activated (M2) macrophages. However, the mechanisms that govern M1/M2 polarization in chronic ALD remain to be elucidated. Prostacyclin (PGI2) synthase (PTGIS) is an enzyme of the prostaglandin pathway which catalyzes the conversion of Prostaglandin H2 (PGH2) to PGI2. PTGIS has anti-inflammatory properties. However, the function of PTGIS in ALD has not yet been determined. In this study, we demonstrated that PTGIS was downregulated in ALD and forced PTGIS expression in vivo using recombinant adeno-associated viral vector-packed PTGIS overexpression plasmid, which alleviated the inflammatory response and suppressed the macrophage M1 phenotype in mice. Loss- and gain-of function-experiments demonstrated that forced PTGIS expression inhibited the macrophage switch to the M1 phenotype and promoted M2 polarization. Furthermore, we identified the genes regulated by PTGIS through RNA-sequencing (RNA-seq) analysis. Gene ontology and KEGG pathway analyses showed that PTGIS regulates many genes involved in the immune response and is enriched in the Janus kinase/signal transducers and activators of transcription (JAK/STAT) signal transduction pathway, which plays an important role in regulating macrophage polarization. The proteins interacting with JAKs were predicted using the STRING database. The overlap between the RNA-seq and the STRING database was interleukin-6; this indicated that it was involved in macrophage polarization regulated by JAK/STAT signaling. We further explored the microRNAs that could regulate the expression of PTGIS through TargetScan. The results of luciferase assay illustrated that the expression of PTGIS was regulated by miR-140-3p.1. These results imply that PTGIS plays a pivotal role in ALD, partly by influencing macrophage polarization.

Herbivore-induced and constitutive volatiles are controlled by different oxylipin-dependent mechanisms in rice

Despite the importance of volatile organic compounds (VOCs) for plants, control mechanisms for their basal and stress-induced biosynthesis and release remain unclear. We sampled and characterized headspace and internal leaf volatile pools in rice (Oryza sativa), after a simulated herbivory treatment, which triggers an endogenous jasmonate burst. Certain volatiles, such as linalool, were strongly upregulated by simulated herbivory stress. In contrast, other volatiles, such as β-caryophyllene, were constitutively emitted and fluctuated according to time of day. Transcripts of the linalool synthase gene transiently increased 1-3 h after exposure of rice to simulated herbivory, whereas transcripts of caryophyllene synthase peaked independently at dawn. Unexpectedly, although emission and accumulation patterns of rice inducible and constitutive VOCs were substantially different, both groups of volatiles were compromised in jasmonate-deficient hebiba mutants, which lack the allene oxide cyclase (AOC) gene. This suggests that rice employs at least two distinct oxylipin-dependent mechanisms downstream of AOC to control production of constitutive and herbivore-induced volatiles. Levels of the JA precursor, 12-oxo-phytodienoic acid (OPDA), were correlated with constitutive volatile levels suggesting that OPDA or its derivatives could be involved in control of volatile emission in rice.

Jasmonic Acid Plays a Pivotal Role in Pollen Development and Fertility Regulation in Different Types of P(T)GMS Rice Lines

Two-line hybrid rice systems represent a new technical approach to utilizing the advantages of rice hybrids. However, the mechanism underlying the male sterile-line fertility transition in rice remains unclear. Peiai 64S (PA64S) is a photoperiod- and thermo-sensitive genic male sterile (PTGMS) line in which male sterility manifests at an average temperature above 23.5 °C under long-day (LD) conditions. Nongken 58S (NK58S) is a LD-sensitive genic male sterile (PGMS) rice that is sterile under LD conditions (above 13.75 h-day). In contrast, D52S is a short-day (SD)-PGMS line that manifests male sterility under SD conditions (below 13.5 h-day). In this study, we obtained fertile and sterile plants from all three lines and performed transcriptome analyses on the anthers of the plants. Gene ontology (GO) analysis suggested that the differentially expressed genes identified were significantly enriched in common terms involved in the response to jasmonic acid (JA) and in JA biosynthesis. On the basis of the biochemical and molecular validation of dynamic, tissue-specific changes in JA, indole-3-acetic acid (IAA) levels, gibberellin (GA) levels, and JA biosynthetic enzyme activities and expression, we proposed that JA could play a pivotal role in viable pollen production through its initial upregulation, constant fluctuation and leaf-spikelet signaling under certain fertility-inducing conditions. Furthermore, we also sprayed methyl jasmonate (MEJA) and salicylhydroxamic acid (SHAM) on the plants, thereby achieving fertility reversal in the PGMS lines NK58S and D52S, with 12.91–63.53% pollen fertility changes. Through qPCR and enzyme activity analyses, we identified two key enzymes—allene oxide synthase (AOS) and allene oxide cyclase (AOC)—that were produced and upregulated by 20–500-fold in PGMS in response to spraying; the activities of these enzymes reversed pollen fertility by influencing the JA biosynthetic pathway. These results provide a new understanding of hormone interactions and networks in male-sterile rice based on the role of JA that will help us to better understand the potential regulatory mechanisms of fertility development in rice in the future.

Biallelic mutations in L-dopachrome tautomerase (DCT) cause infantile nystagmus and oculocutaneous albinism

Infantile nystagmus syndrome (INS) denominates early-onset, involuntary oscillatory eye movements with different etiologies. Nystagmus is also one of the symptoms in oculocutaneus albinism (OCA), a heterogeneous disease mainly caused by defects in melanin synthesis or melanosome biogenesis. Dopachrome tautomerase (DCT, also called TYRP2) together with tyrosinase (TYR) and tyrosin-related protein 1 (TYRP1) is one of the key enzymes in melanin synthesis. Although DCT´s role in pigmentation has been proven in different species, until now only mutations in TYR and TYRP1 have been found in patients with OCA. Detailed ophthalmological and orthoptic investigations identified a consanguineous family with two individuals with isolated infantile nystagmus and one family member with subtle signs of albinism. By whole-exome sequencing and segregation analysis, we identified the missense mutation c.176G > T (p.Gly59Val) in DCT in a homozygous state in all three affected family members. We show that this mutation results in incomplete protein maturation and targeting in vitro compatible with a partial or total loss of function. Subsequent screening of a cohort of patients with OCA (n = 85) and INS (n = 25) revealed two heterozygous truncating mutations, namely c.876C > A (p.Tyr292*) and c.1407G > A (p.Trp469*), in an independent patient with OCA. Taken together, our data suggest that mutations in DCT can cause a phenotypic spectrum ranging from isolated infantile nystagmus to oculocutaneous albinism.

Deletion of Alox15 improves kidney dysfunction and inhibits fibrosis by increased PGD2 in the kidney

BACKGROUND

Lipid-metabolizing enzymes and their metabolites affect inflammation and fibrosis, but their roles in chronic kidney disease (CKD) have not been completely understood.

METHODS

To clarify their role in CKD, we measured the mRNA levels of major lipid-metabolizing enzymes in 5/6 nephrectomized (Nx) kidneys of C57BL/6 J mice. Mediator lipidomics was performed to reveal lipid profiles of CKD kidneys.

RESULTS

In 5/6 Nx kidneys, both mRNA and protein levels of Alox15 were higher when compared with those in sham kidneys. With respect to in situ hybridization, the mRNA level of Alox15 was higher in renal tubules of 5/6 Nx kidneys. To examine the role of Alox15 in CKD pathogenesis, we performed 5/6 Nx on Alox15-/- mice. Alox15-/- CKD mice exhibited better renal functions than wild-type mice. Interstitial fibrosis was also inhibited in Alox15-/- CKD mice. Mediator lipidomics revealed that Alox15-/- CKD mouse kidneys had significantly higher levels of PGD2 than the control. To investigate the effects of PGD2 on renal fibrosis, we administered PGD2 to TGF-β1-stimulated NRK-52E cells and HK-2 cells, which lead to a dose-dependent suppression of type I collagen and αSMA in both cell lines.

CONCLUSION

Increased PGD2 in Alox15-/- CKD mouse kidneys could inhibit fibrosis, thereby resulting in CKD improvement. Thus, Alox15 inhibition and PGD2 administration may be novel therapeutic targets for CKD.

IL-8, MSPa, MIF, FGF-9, ANG-2 and AgRP collection were identified for the diagnosis of colorectal cancer based on the support vector machine model

Colorectal cancer (CRC) is one of the most common cancer, and the early detection of CRC is essential to improve the survival rate of patients. To identify diagnostic markers for colorectal cancer (CRC) by screening differentially expressed proteins (DEPs) in CRC. The DEPs were initially obtained from 12 CRC samples and 12 healthy control samples, and verification analysis was performed in another 34 CRC samples and 34 normal controls. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment with DEPs was analyzed by the R package clusterProfiler (Version 3.2.11), and the DEP-associated protein-protein interaction (PPI) network was created from the STRING database. Additionally, Support Vector Machine (SVM) model prediction and survival analyses were conducted on the key DEPs. Preliminary screening and functional analysis showed that the DEPs mainly overrepresented in pathways such as cytokine-cytokine receptor interaction, chemokine signaling pathway, Rap1, Ras, and MAPK signaling pathways. The key DEPs, including AgRP, ANG-2, Dtk, EOT3, FGF-4, FGF-9, HCC-4, IL-16, IL-8, MIF, MSPa, TECK, TPO, TRAIL R3, and VEGF-D, were used to construct a custom chip. The drug-gene interaction network suggested that TPO was a key drug target. ROC curve showed the SVM diagnostic model with the DEPs IL-8, MSPa, MIF, FGF-9, ANG-2, and AgRP had better diagnostic performance with an AUC of 0.933. Survival analysis showed the expression of FGF9, TPO, TRAIL R3, Dtk, TECK and FGF4 were associated with prognosis. This study revealed the important serum proteins in the pathogenesis of CRC, which might serve as useful and noninvasive predictors for the diagnosis of CRC.

Coordinated action of microsomal prostaglandin E synthase-1 and prostacyclin synthase on contact hypersensitivity

Microsomal prostaglandin (PG) E synthase-1 (mPGES-1) and prostacyclin (PGI2) synthase (PGIS) are PG terminal synthases that work downstream of cyclooxygenase and synthesize PGE2 and PGI2, respectively. Although the involvement of PG receptors in acquired cutaneous immune responses was recently shown, the roles of these PG terminal synthases remain unclear. To identify the pathophysiological roles of mPGES-1 and PGIS in cutaneous immune systems, we applied contact hypersensitivity (CHS) to mPGES-1 and PGIS knockout (KO) mice as a model of acquired immune responses. Mice were treated with 1-fluoro-2,4-dinitrobenzene (DNFB) and evaluated for ear thickness and histopathological features. The results showed that the severity of ear swelling in both gene-deficient mice was much lower than that in wild-type (WT) mice. Histological examination of DNFB-treated ears showed that inflammatory cell infiltration and edema in the dermis were also less apparent in both genotypic mice. LC-MS analysis further showed that the increment in PGE2 levels in DNFB-treated ear tissue was reduced in mPGES-1 KO mice, and that 6-keto PGF1α (a stable metabolite of PGI2) was not detected in PGIS KO mice. Furthermore, we made bone marrow (BM) chimera and found that transplantation of WT mouse-derived BM cells restored the impaired CHS response in mPGES-1 KO mice but did not restore the response in PGIS KO mice. These results indicated that mPGES-1 in BM-derived cells and PGIS in non-BM-derived cells might play critical roles in DNFB-induced CHS. mPGES-1-derived PGE2 and PGIS-derived PGI2 might coordinately promote acquired cutaneous immune responses.

Integrase-Defective Lentiviral Vector Is an Efficient Vaccine Platform for Cancer Immunotherapy

Integrase-defective lentiviral vectors (IDLVs) have been used as a safe and efficient delivery system in several immunization protocols in murine and non-human primate preclinical models as well as in recent clinical trials. In this work, we validated in preclinical murine models our vaccine platform based on IDLVs as delivery system for cancer immunotherapy. To evaluate the anti-tumor activity of our vaccine strategy we generated IDLV delivering ovalbumin (OVA) as a non-self-model antigen and TRP2 as a self-tumor associated antigen (TAA) of melanoma. Results demonstrated the ability of IDLVs to eradicate and/or controlling tumor growth after a single immunization in preventive and therapeutic approaches, using lymphoma and melanoma expressing OVA. Importantly, LV-TRP2 but not IDLV-TRP2 was able to break tolerance efficiently and prevent tumor growth of B16F10 melanoma cells. In order to improve the IDLV efficacy, the human homologue of murine TRP2 was used, showing the ability to break tolerance and control the tumor growth. These results validate the use of IDLV for cancer therapy.

Hsp90-stabilized MIF supports tumor progression via macrophage recruitment and angiogenesis in colorectal cancer

Macrophage migration inhibitory factor (MIF) is an upstream regulator of innate immunity, but its expression is increased in some cancers via stabilization with HSP90-associated chaperones. Here, we show that MIF stabilization is tumor-specific in an acute colitis-associated colorectal cancer (CRC) mouse model, leading to tumor-specific functions and selective therapeutic vulnerabilities. Therefore, we demonstrate that a Mif deletion reduced CRC tumor growth. Further, we define a dual role for MIF in CRC tumor progression. Mif deletion protects mice from inflammation-associated tumor initiation, confirming the action of MIF on host inflammatory pathways; however, macrophage recruitment, neoangiogenesis, and proliferative responses are reduced in Mif-deficient tumors once the tumors are established. Thus, during neoplastic transformation, the function of MIF switches from a proinflammatory cytokine to an angiogenesis promoting factor within our experimental model. Mechanistically, Mif-containing tumor cells regulate angiogenic gene expression via a MIF/CD74/MAPK axis in vitro. Clinical correlation studies of CRC patients show the shortest overall survival for patients with high MIF levels in combination with CD74 expression. Pharmacological inhibition of HSP90 to reduce MIF levels decreased tumor growth in vivo, and selectively reduced the growth of organoids derived from murine and human tumors without affecting organoids derived from healthy epithelial cells. Therefore, novel, clinically relevant Hsp90 inhibitors provide therapeutic selectivity by interfering with tumorigenic MIF in tumor epithelial cells but not in normal cells. Furthermore, Mif-depleted colonic tumor organoids showed growth defects compared to wild-type organoids and were less susceptible toward HSP90 inhibitor treatment. Our data support that tumor-specific stabilization of MIF promotes CRC progression and allows MIF to become a potential and selective therapeutic target in CRC.

Investigating MIF in Mouse Models of Severe Corticosteroid-Resistant Neutrophilic Asthma

Experimental mouse models of asthma are widely used to investigate the underlying mechanisms of this complex and heterogeneous disease. Using mouse models of ovalbumin-induced asthma, previous investigators have established a crucial role for MIF in the development of type 2-mediated eosinophilic asthma. Surprisingly, however, the role of MIF in other phenotypes of asthma has received little attention. MIF is an important mediator of neutrophilic inflammation, and also acts to antagonize the actions of corticosteroids. Thus, MIF may play a role in the development of severe forms of asthma in which airway neutrophilia and corticosteroid insensitivity are major features. In this chapter, we provide an experimental protocol that may be used to investigate the role of MIF in a mouse model of severe corticosteroid-resistant neutrophilic asthma.

ScAOC1, an allene oxide cyclase gene, confers defense response to biotic and abiotic stresses in sugarcane

KEY MESSAGE

An allene oxide cyclase gene which is involved in defense against biotic and abiotic stresses was cloned and characterized in sugarcane. Allene oxide cyclase (AOC), a key enzyme in jasmonate acid (JA) biosynthesis, affects the stereoisomerism and biological activity of JA molecules, and plays an important role in plant stress resistance. In this study, four SsAOC alleles (SsAOC1-SsAOC4), which shared similar gene structure and were located on Chr1A, Chr1B, Chr1C, and Chr1D, respectively, were mined from sugarcane wild species Saccharum spontaneum, and a homologous gene ScAOC1 (GenBank Accession Number: MK674849) was cloned from sugarcane hybrid variety Yacheng05-179 inoculated with Sporisorium scitamineum for 48 h. ScAOC1 and SsAOC1-SsAOC4 were alkaline, unstable, hydrophilic, and non-secretory proteins, which possess the same set of conserved motifs and were clustered into one group in the phylogenetic analysis. ScAOC1 was expressed in all sugarcane tissues, but with different levels. After infection by S. scitamineum, the transcripts of ScAOC1 were increased significantly both in the smut-susceptible (ROC22) and resistant (Yacheng05-179) varieties, but its transcripts were more accumulated and lasted for a longer period in the smut-resistant variety than in the smut-susceptible one. ScAOC1 was down-regulated under MeJA and NaCl treatments, but up-regulated under SA, ABA, PEG, and cold stresses. Transiently overexpressing ScAOC1 gene into Nicotiana benthamiana leaves regulated the responses of N. benthamiana to two pathogens Ralstonia solanacearum and Fusarium solani var. coeruleum. Furthermore, prokaryotic expression analysis showed overexpression of ScAOC1 in Escherichia coli BL21 could enhance its tolerance to NaCl, mannitol, and cold stimuli. These results indicated that ScAOC1 may play an active role in response to biotic and abiotic stresses in sugarcane.

Macrophage migration inhibitory factor is regulated by HIF-1α and cAMP and promotes renal cyst cell proliferation in a macrophage-independent manner

Progressive cyst growth leads to decline of renal function in polycystic kidney disease. Macrophage migration inhibitory factor (MIF) was found to be upregulated in cyst-lining cells in a mouse model of polycystic kidney disease and to promote cyst growth. In addition, MIF can be secreted by tubular cells and may contribute to cyst growth in an autocrine manner. However, the underlying mechanisms leading to induction of MIF in cyst-lining cells remained elusive. Here, we demonstrate that hypoxia-inducible transcription factor (HIF) 1α upregulates MIF in cyst-lining cells in a tubule-specific PKD1 knockout mouse. Pharmacological stabilization of HIF-1α resulted in significant increase of MIF in cyst epithelial cells whereas tubule-specific knockout of HIF-1α prevented MIF upregulation. Identical regulation could be found for ABCA1, which has been shown to act as a transport protein for MIF. Furthermore, we show that MIF and ABCA1 are direct target genes of HIF-1α in human primary tubular cells. Next to HIF-1α and hypoxia, we found MIF being additionally regulated by cAMP which is a strong promotor of cyst growth. In line with these findings, HIF-1α- and cAMP-dependent in vitro cyst growth could be decreased by the MIF-inhibitor ISO-1 which resulted in reduced cyst cell proliferation. In conclusion, HIF-1α and cAMP regulate MIF in primary tubular cells and cyst-lining epithelial cells, and MIF promotes cyst growth in the absence of macrophages. In line with these findings, the MIF inhibitor ISO-1 attenuates HIF-1α- and cAMP-dependent in vitro cyst enlargement. KEY MESSAGES: • MIF is upregulated in cyst-lining cells in a polycystic kidney disease mouse model. • MIF upregulation is mediated by hypoxia-inducible transcription factor (HIF) 1α. • ABCA1, transport protein for MIF, is also regulated by HIF-1α in vitro and in vivo. • MIF is additionally regulated by cAMP, a strong promotor of cyst growth. • MIF-inhibitor ISO-1 reduces HIF-1α- and cAMP-dependent cyst growth.

Tuft Cells Inhibit Pancreatic Tumorigenesis in Mice by Producing Prostaglandin D2

BACKGROUND & AIMS

Development of pancreatic ductal adenocarcinoma (PDA) involves acinar to ductal metaplasia and genesis of tuft cells. It has been a challenge to study these rare cells because of the lack of animal models. We investigated the role of tuft cells in pancreatic tumorigenesis.

METHODS

We performed studies with LSL-KrasG12D/+;Ptf1aCre/+ mice (KC; develop pancreatic tumors), KC mice crossed with mice with pancreatic disruption of Pou2f3 (KPouC mice; do not develop tuft cells), or mice with pancreatic disruption of the hematopoietic prostaglandin D synthase gene (Hpgds, KHC mice) and wild-type mice. Mice were allowed to age or were given caerulein to induce pancreatitis; pancreata were collected and analyzed by histology, immunohistochemistry, RNA sequencing, ultrastructural microscopy, and metabolic profiling. We performed laser-capture dissection and RNA-sequencing analysis of pancreatic tissues from 26 patients with pancreatic intraepithelial neoplasia (PanIN), 19 patients with intraductal papillary mucinous neoplasms (IPMNs), and 197 patients with PDA.

RESULTS

Pancreata from KC mice had increased formation of tuft cells and higher levels of prostaglandin D2 than wild-type mice. Pancreas-specific deletion of POU2F3 in KC mice (KPouC mice) resulted in a loss of tuft cells and accelerated tumorigenesis. KPouC mice had increased fibrosis and activation of immune cells after administration of caerulein. Pancreata from KPouC and KHC mice had significantly lower levels of prostaglandin D2, compared with KC mice, and significantly increased numbers of PanINs and PDAs. KPouC and KHC mice had increased pancreatic injury after administration of caerulein, significantly less normal tissue, more extracellular matrix deposition, and higher PanIN grade than KC mice. Human PanIN and intraductal papillary mucinous neoplasm had gene expression signatures associated with tuft cells and increased expression of Hpgds messenger RNA compared with PDA.

CONCLUSIONS

In mice with KRAS-induced pancreatic tumorigenesis, loss of tuft cells accelerates tumorigenesis and increases the severity of caerulein-induced pancreatic injury, via decreased production of prostaglandin D2. These data are consistent with the hypothesis that tuft cells are a metaplasia-induced tumor attenuating cell type.

Mechanistic definition of the cardiovascular mPGES-1/COX-2/ADMA axis

AIMS

Cardiovascular side effects caused by non-steroidal anti-inflammatory drugs (NSAIDs), which all inhibit cyclooxygenase (COX)-2, have prevented development of new drugs that target prostaglandins to treat inflammation and cancer. Microsomal prostaglandin E synthase-1 (mPGES-1) inhibitors have efficacy in the NSAID arena but their cardiovascular safety is not known. Our previous work identified asymmetric dimethylarginine (ADMA), an inhibitor of endothelial nitric oxide synthase, as a potential biomarker of cardiovascular toxicity associated with blockade of COX-2. Here, we have used pharmacological tools and genetically modified mice to delineate mPGES-1 and COX-2 in the regulation of ADMA.

METHODS AND RESULTS

Inhibition of COX-2 but not mPGES-1 deletion resulted in increased plasma ADMA levels. mPGES-1 deletion but not COX-2 inhibition resulted in increased plasma prostacyclin levels. These differences were explained by distinct compartmentalization of COX-2 and mPGES-1 in the kidney. Data from prostanoid synthase/receptor knockout mice showed that the COX-2/ADMA axis is controlled by prostacyclin receptors (IP and PPARβ/δ) and the inhibitory PGE2 receptor EP4, but not other PGE2 receptors.

CONCLUSION

These data demonstrate that inhibition of mPGES-1 spares the renal COX-2/ADMA pathway and define mechanistically how COX-2 regulates ADMA.

Diethylcarbamazine activates TRP channels including TRP-2 in filaria, Brugia malayi

Diethylcarbamazine is an important classic drug used for prevention and treatment of lymphatic filariasis and loiasis, diseases caused by filarial nematodes. Despite many studies, its site of action has not been established. Until now, the consensus has been that diethylcarbamazine works by activating host immune systems, not by a direct action on the parasites. Here we show that low concentrations of diethylcarbamazine have direct and rapid (<30 s) temporary spastic paralyzing effects on the parasites that lasts around 4 h, which is produced by diethylcarbamazine opening TRP channels in muscle of Brugia malayi involving TRP-2 (TRPC-like channel subunits). GON-2 and CED-11, TRPM-like channel subunits, also contributed to diethylcarbamazine responses. Opening of these TRP channels produces contraction and subsequent activation of calcium-dependent SLO-1K channels. Recovery from the temporary paralysis is consistent with inactivation of TRP channels. Our observations elucidate mechanisms for the rapid onset and short-lasting therapeutic actions of diethylcarbamazine.

Characterization of PtAOS1 Promoter and Three Novel Interacting Proteins Responding to Drought in Poncirus trifoliata

Jasmonic acid (JA) plays a crucial role in various biological processes including development, signal transduction and stress response. Allene oxide synthase (AOS) catalyzing (13S)-hydroperoxyoctadecatrienoic acid (13-HPOT) to an unstable allene oxide is involved in the first step of JA biosynthesis. Here, we isolated the PtAOS1 gene and its promoter from trifoliate orange (Poncirus trifoliata). PtAOS1 contains a putative chloroplast targeting sequence in N-terminal and shows relative to pistachio (Pistacia vera) AOS. A number of stress-, light- and hormone-related cis-elements were found in the PtAOS1 promoter which may be responsible for the up-regulation of PtAOS1 under drought and JA treatments. Transient expression in tobacco (Nicotiana benthamiana) demonstrated that the P_-532 (-532 to +1) fragment conferring drive activity was a core region in the PtAOS1 promoter. Using yeast one-hybrid, three novel proteins, PtDUF886, PtDUF1685 and PtRAP2.4, binding to P_-532 were identified. The dual luciferase assay in tobacco illustrated that all three transcription factors could enhance PtAOS1 promoter activity. Genes PtDUF1685 and PtRAP2.4 shared an expression pattern which was induced significantly by drought stress. These findings should be available evidence for trifoliate orange responding to drought through JA modulation.

Macrophage migration inhibitory factor -173 G>C single nucleotide polymorphism and its association with active pulmonary tuberculosis

PURPOSE

The establishment of candidate genes associated with susceptibility to TB is a challenge especially due to divergent frequencies among different populations. The objective of this study was to evaluate the association between macrophage migration inhibitory factor (MIF) -173 G>C single nucleotide polymorphism (SNP) and susceptibility to pulmonary TB in a population of southern Brazil.

METHODS

Case-control study. Patients > 18 years old, diagnosed with pulmonary TB were included. The control group consisted of blood donors and household contacts, not relatives, healthy and > 18 years old. MIF -173 G>C SNPs were genotyped using real-time PCR using a TaqMan SNP Genotyping assay.

RESULTS

174 patients and 166 controls were included. There were no statistically significant differences between cases and controls regarding genotype prevalence (p>0.05). Comparing patients with normal genotype (GG) with those with at least one C allele, there was also no statistically significant difference (p = 0.135). Also, there was no statistically significant difference comparing the homozygous for the mutation (CC) with the other patients (GG and CG) (p = 0.864).

CONCLUSIONS

We did not find association between MIF -173 G>C polymorphism and susceptibility to pulmonary TB.

The Role of MIF-173G/C Gene Polymorphism in the Susceptibility of Autoimmune Diseases

Some certain genetic polymorphisms have been considered to implicate in the pathogenesis and progression of autoimmune diseases and may predispose to an early stage of general autoimmune susceptibility. Recent studies have been conducted to investigate the association between macrophage migration inhibitory factor- (MIF-) 173G/C gene polymorphism and autoimmune diseases; however, the results were not exactly identical. In the present study, a systematic review and meta-analysis of case-control studies was performed to estimate the relationship. A comprehensive search of PubMed, Ebsco, EMbase, WanFang databases and CNKI was done. Odds ratio (ORs) and corresponding 95% confidence intervals (CIs) were combined to pool the effect size. The publication bias was examined by Begg's funnel plots and Egger's test. RevMan 5.3 and STATA 12.0 software were used for statistical processing. 23 papers were included, and the results revealed that MIF-173G/C was significantly associated with an increased risk of autoimmune diseases in five genetic models (recessive genetic model: OR = 1.95, 95% CI: 1.52-2.50; dominant genetic model: OR = 1.35, 95% CI: 1.24-1.46; allele model: OR = 1.32, 95% CI: 1.23-1.41; homozygote model: OR = 1.92, 95% CI: 1.57-2.35; heterozygote model: OR = 4.92, 95% CI: 4.03-6.02), whether in Asia, Europe, or North America. Furthermore, subgroup analysis showed an increasing risk in rheumatoid arthritis (RA), ulcerative colitis (UC), Crohn's disease (CD), atopic dermatitis (AD), Henoch-Schonlein purpura (HSP), and Henoch-Schonlein purpura nephritis (HSPN), but it was not related to the susceptibility of autoimmune hepatitis (AIH). Therefore, it could be considered that MIF-173G/C polymorphism could increase the susceptibility of autoimmune diseases, while there may be the discrepancy of disease entity.

Comparative Proteomic Analysis of Wild-Type Physcomitrella Patens and an OPDA-Deficient Physcomitrella Patens Mutant with Disrupted PpAOS1 and PpAOS2 Genes after Wounding

Wounding is a serious environmental stress in plants. Oxylipins such as jasmonic acid play an important role in defense against wounding. Mechanisms to adapt to wounding have been investigated in vascular plants; however, those mechanisms in nonvascular plants remain elusive. To examine the response to wounding in Physcomitrella patens, a model moss, a proteomic analysis of wounded P. patens was conducted. Proteomic analysis showed that wounding increased the abundance of proteins related to protein synthesis, amino acid metabolism, protein folding, photosystem, glycolysis, and energy synthesis. 12-Oxo-phytodienoic acid (OPDA) was induced by wounding and inhibited growth. Therefore, OPDA is considered a signaling molecule in this plant. Proteomic analysis of a P. patens mutant in which the PpAOS1 and PpAOS2 genes, which are involved in OPDA biosynthesis, are disrupted showed accumulation of proteins involved in protein synthesis in response to wounding in a similar way to the wild-type plant. In contrast, the fold-changes of the proteins in the wild-type plant were significantly different from those in the aos mutant. This study suggests that PpAOS gene expression enhances photosynthesis and effective energy utilization in response to wounding in P. patens.

Differentially Expressed Genes in Matched Normal, Cancer, and Lymph Node Metastases Predict Clinical Outcomes in Patients With Breast Cancer

Genome-wide screening of transcriptional changes among normal, cancer, and nodal metastases provides insights into the molecular basis of breast cancer (BC) progression and metastasis. To identify transcriptional changes and differentially expressed genes (DEGs) in the metastatic progression of BC and to determine the prognostic role of these DEGs in clinical outcome, we compared transcriptome profiling in matched normal, cancer, and lymph node metastatic tissues of 7 patients with estrogen receptor-positive, HER2-negative BC by using massive parallel RNA sequencing. The global profiles of gene expression in cancer and nodal metastases were highly correlated (r=0.962, P<0.001). In 6 (85.8%) patients, cancer and corresponding nodal metastases from the same patient clustered together. We identified 1522 and 664 DEGs between normal and cancer and between cancer and nodal metastases, respectively. The DEGs in normal versus cancer and cancer versus nodal metastases were significantly clustered in 1 and 8 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, respectively. The chemokine signaling pathway was the most significant pathway in the cancer-to-nodal metastasis transition (false discovery rate=2.15E-13). The expression of 2 dysregulated RAC2 and PTGDS genes was confirmed by quantitative real-time polymerase chain reaction and immunohistochemistry. Interestingly, the lower RAC2 and PTGDS expression were associated with significantly worse disease-free survival in patients with BC. Our results show a high concordance of gene expression in BC and their nodal metastases, and identify DEGs associated with the metastatic progression of BC. The DEGs identified in this study represent novel biomarkers for predicting the prognosis of patients with BC.

Reversing UVB-induced photoaging with Hibiscus sabdariffa calyx aqueous extract

BACKGROUND

Hibiscus sabdariffa is commonly used in daily life and its extract is applied widely in food and cosmetics. However, it has not been evaluated for its anti-aging effects.

RESULTS

Hibiscus sabdariffa calyx aqueous extract (HSCAE) has shown potential collagenase activity suppression effects, together with tyrosinase activity inhibition, and anti-oxidation as a free radical scavenger. The current investigation demonstrated that HSCAE was not cytotoxic in skin fibroblasts, and it significantly decreased ultraviolet B (UVB)-induced reactive oxygen species (ROS) on a flow cytometry assay. Moreover, HSCAE reduced matrix metalloproteinase (MMP) expression, increased tissue inhibition of metalloproteinase (TIMP)-1 level, and enhanced collagen content by inhibiting collagenase activity. It also blocked mRNA and protein expressions of melanin production pathway key factors, including the microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related protein-1 (TRP-1), and dopachrome tautomerase-2 (TRP-2).

CONCLUSION

These results demonstrated, for the first time, the potential of HSCAE as a natural antioxidant with the ability to maintain collagen production and to decrease melanin syntheses under UVB radiation, for anti-aging effects. © 2019 Society of Chemical Industry.

Knockdown of macrophage migration inhibitory factor (MIF), a novel target to protect neurons from parthanatos induced by simulated post-spinal cord injury oxidative stress

Parthanatos is a form of regulated cell death (RCD) that is closely linked to DNA damage, which is a common consequence of oxidative stress due to central nervous trauma, such as spinal cord injury (SCI). The mechanism by which apoptosis-inducing factor (AIF) mediates DNA strand breaks in parthanatos was not clear until the discovery of the nuclease function of MIF. A previous study suggested that observed results may not be reliable if the oxidative stress induced in cells observed under experimental pathological conditions does not accurately replicate the specific pathologies being studied. According to an earlier direct measurement of extracellular oxidative stress in a rat SCI model, post-SCI oxidative stress was approximately the same as exposure to 150 μM H₂O₂. However, this concentration has been reported as sublethal oxidative stress in other cell types related to senescence, apoptosis, and parthanatos. Using sublethal H₂O₂ concentrations to induce oxidative stress is equivocal. Also, different cell types have diverse tolerances and responses to oxidative stress, and, therefore, exposure to H₂O₂. To avoid these limitations, the present study explored the mechanism of neuronal death under this simulated post-SCI oxidative stress and determined the effects of MIF knockdown in parthanatos associated with SCI. Immunofluorescence and flow cytometry were used to reveal typical characteristics of parthanatos that were blocked by PARP-1 inhibitors but not caspase inhibitors. In addition to classic features like PARP-1 and caspase-3 cleavage that were absent, we determined that parthanatos instead of apoptosis played a major role in the cell death caused by oxidative stress following SCI. Flow cytometry analysis of cells transfected by adenovirus with MIF-shRNA then exposed to H₂O₂ showed a significant decrease in cell death for MIF knockdown cells, even after AIF nuclear translocation. The comet assay also displayed significantly fewer DNA strand breaks after MIF knockdown. This is the first study has verified that MIF knockdown enables to protect neurons from parthanatos under a simulated in vivo oxidative stress following SCI. It suggests that MIF knockdown is a promising therapy to rescue neurons suffering from oxidative stress-induced SCI pathology.

Catalysis by allene oxide synthases (CYP74A and CYP74C): Alterations by the Phe/Leu mutation at the SRS-1 region

The CYP74 family of cytochromes P450 includes four fatty acid hydroperoxide metabolizing enzymes: allene oxide synthase (AOS), hydroperoxide lyase (HPL), divinyl ether synthase, and epoxyalcohol synthase (EAS). All P450s have six substrate recognition sites (SRSs) in their structures. Some CYP74 mutations in SRSs leading to their interconversions including substitutions in "F/L toggle" (SRS-1 region) were reported before. For further elucidation of the role of this site in CYP74 catalysis, the effect of Phe/Leu mutation on the specificity of selected AOSs was studied in the present work. Mutant forms of ZmAOS1 (CYP74A19, Zea mays), LeAOS3 (CYP74C3, Lycopersicon esculentum), and PpAOS2 (CYP74A8, Physcomitrella patens) acquired partial EAS activity. Mutant forms of ZmAOS1 and PpAOS2 possessed additional HPL activities. The results validate the significance of the "F/L toggle" as a catalytic determinant of CYP74s, as well as the importance of the conserved Phe at this site for the AOS catalysis.

CRISPR/Cas9-Mediated Gene Editing of the Jasmonate Biosynthesis OsAOC Gene in Rice

The function of Jasmonate (JA) is well documented in different plant physiological processes as well as in the interactions with their environment. Mutants impaired in JA production and/or signaling are useful materials to study the function of this phytohormone. Genes involved in the JA biosynthesis pathway in rice have been described, but few mutants deficient in JA production and signaling have been identified. Moreover, these mutants are mostly generated through random mutagenesis approaches, such as irradiation, EMS treatment, or T-DNA insertion, and potentially harbor undesired mutations that could affect other biological processes. The CRISPR/Cas9 system is a precise and efficient genome editing tool that creates DNA modification at specific loci and limit undesired mutations.In this chapter, we describe a procedure to generate new JA-deficient mutant using CRISPR/Cas9 system in rice. The Allene Oxide Cyclase (OsAOC) gene is targeted since it is a single copy gene in the JA biosynthesis pathway in rice. The widely used variety Oryza sativa japonica Kitaake has been chosen due to its short life cycle and its ease of genetic transformation. This protocol describes the selection of the 20-nt target sequence, construction of the binary vector, and strategy for selecting the T-DNA-free mutant.

Tautomerase Activity-Lacking of the Macrophage Migration Inhibitory Factor Alleviates the Inflammation and Insulin Tolerance in High Fat Diet-Induced Obese Mice

Macrophage migration inhibitory factor (MIF) has multiple intrinsic enzymatic activities of the dopachrome/phenylpyruvate tautomerase and thiol protein oxidoreductase, and plays an important role in the development of obesity as a pro-inflammatory cytokine. However, which enzymatic activity of MIF is responsible for regulating in obesity are still unknown. In the present study, we investigated the roles of the tautomerase of MIF in high fat diet (HFD)-induced obesity using MIF tautomerase activity-lacking (MIF^P1G/P1G) mice. Our results showed that the serum MIF and the expression of MIF in adipose tissue were increased in HFD-treated mice compared with normal diet fed mice. The bodyweights were significantly reduced in MIF^P1G/P1G mice compared with WT mice fed with HFD. The sizes of adipocytes were smaller in MIF^P1G/P1G mice compared with WT mice fed with HFD using haematoxylin and eosin (H&E) staining. In addition, the MIF^P1G/P1G mice reduced the macrophage infiltration, seen as the decreases of the expression of inflammatory factors such as F4/80, IL-1β, TNFα, MCP1, and IL-6. The glucose tolerance tests (GTT) and insulin tolerance tests (ITT) assays showed that the glucose tolerance and insulin resistance were markedly improved, and the expressions of IRS and PPARγ were upregulated in adipose tissue from MIF^P1G/P1G mice fed with HFD. Furthermore, we observed that the expressions of Bax, a pro-apoptotic protein, and the cleaved caspase 3-positive cells in white tissues were decreased and the ratio of Bcl2/Bax was increased in MIF^P1G/P1G mice compared with WT mice. Taken together, our results demonstrated that the tautomerase activity-lacking of MIF significantly alleviated the HFD-induced obesity and adipose tissue inflammation, and improved insulin resistance in MIF^P1G/P1G mice.

Primary hypertrophic osteoarthropathy related gastrointestinal complication has distinctive clinical and pathological characteristics: two cases report and review of the literature

BACKGROUND

Primary hypertrophic osteoarthropathy (PHO) is a rare disease related to HPGD and SLCO2A1 gene mutation. Gastrointestinal involvement of PHO is even rarer with unknown pathogenesis. Clinical features of GI complication in PHO mimics other auto-immune based bowel entities, such as inflammatory bowel diseases and cryptogenic multifocal ulcerous stenosing enteritis (CMUSE). We aimed to analyze the clinical, genetic, radiological and pathological features of Chinese patients with PHO and determine the difference between PHO patients presenting with and without GI involvement.

METHODS

We reported two PHO cases with gastrointestinal involvement and reviewed all the studies of PHO in Chinese population published from January 1, 2000, to April 30, 2018. Clinical and genetic presentations of PHO in Chinese patients were analyzed. We compared the characteristics of those patients with gastrointestinal involvement against those without.

RESULTS

The two patients were both males with complete-form PHO for more than 10 years. GI related symptoms included diarrhea, chronic gastrointestinal hemorrhage, incomplete intestinal obstruction, anemia, and edema, which were unresponsive to etoricoxib treatment. Radiological examinations revealed segmental intestinal stenosis and thickened intestinal wall. Endoscopic findings included multiple ulcers and mucosal inflammation. Both patients had mutations of SLCO2A1 according to sequence analysis. The surgical pathology revealed chronic inflammation involving the intestinal mucosa and submucosa, similar to histological changes in CMUSE. According to the systemic review of 158 Chinese patients with PHO, 17.2% had gastrointestinal involvement, including peptic ulcer, gastric polyps, hypertrophic gastritis, and segmental intestinal stenosis. Patients with gastrointestinal involvement were more likely to have anemia (40.0% vs. 4.5%, P < 0.001), hypoalbuminemia (16.7% vs. 0.9%, P = 0.003), and myelofibrosis (19.0% vs. 0.9%, P = 0.002) than those without. Most patients with gastrointestinal complication had SLCO2A1 mutation (86.7%, 13 /15).

CONCLUSIONS

Digestive tract involvement is uncommon in patients with PHO and often presents with anemia, and hypoalbuminemia resulted from intestinal inflammation. The intestinal pathologic characteristics are distinct from Crohn's disease but similar to CMUSE. Mutations in SLCO2A1 might be the pathogenic cause of GI involvement of PHO. NSAIDs may not be effective for PHO patients with gastrointestinal complications.