Macrophage expressed tartrate-resistant acid phosphatase 5 promotes pulmonary fibrosis progression.

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disorder involving scarring of pulmonary tissue and a subsequent decrease in respiratory capacity, ultimately resulting in death. Tartrate resistant acid phosphatase 5 (ACP5) plays a role in IPF but the exact mechanisms are yet to be elucidated. In this study, we have utilized various perturbations of the bleomycin mouse model of IPF including genetic knockout, RANKL inhibition, and macrophage adoptive transfer to further understand ACP5's role in pulmonary fibrosis. Genetic ablation of Acp5 decreased immune cell recruitment to the lungs and reduced the levels of hydroxyproline (reflecting extracellular matrix-production) as well as histological damage. Additionally, gene expression profiling of murine lung tissue revealed downregulation of genes including Ccl13, Mmp13, and Il-1α that encodes proteins specifically related to immune cell recruitment and macrophage/fibroblast interactions. Furthermore, antibody-based neutralization of RANKL, an important inducer of Acp5 expression, reduced immune cell recruitment but did not decrease fibrotic lung development. Adoptive transfer of Acp5-/- bone marrow-derived monocyte (BMDM) macrophages 7 or 14 days after bleomycin administration resulted in reductions of cytokine production and decreased levels of lung damage, compared to adoptive transfer of WT control macrophages. Taken together, the data presented in this study suggest that macrophage derived ACP5 plays an important role in development of pulmonary fibrosis and could present a tractable target for therapeutic intervention in IPF.

Inhibition of tartrate-resistant acid phosphatase 5 can prevent cardiac fibrosis after myocardial infarction.

BACKGROUND: Myocardial infarction (MI) leads to enhanced activity of cardiac fibroblasts (CFs) and abnormal deposition of extracellular matrix proteins, resulting in cardiac fibrosis. Tartrate-resistant acid phosphatase 5 (ACP5) has been shown to promote cell proliferation and phenotypic transition. However, it remains unclear whether ACP5 is involved in the development of cardiac fibrosis after MI. The present study aimed to investigate the role of ACP5 in post-MI fibrosis and its potential underlying mechanisms. METHODS: Clinical blood samples were collected to detect ACP5 concentration. Myocardial fibrosis was induced by ligation of the left anterior descending coronary artery. The ACP5 inhibitor, AubipyOMe, was administered by intraperitoneal injection. Cardiac function and morphological changes were observed on Day 28 after injury. Cardiac CFs from neonatal mice were extracted to elucidate the underlying mechanism in vitro. The expression of ACP5 was silenced by small interfering RNA (siRNA) and overexpressed by adeno-associated viruses to evaluate its effect on CF activation. RESULTS: The expression of ACP5 was increased in patients with MI, mice with MI, and mice with Ang II-induced fibrosis in vitro. AubipyOMe inhibited cardiac fibrosis and improved cardiac function in mice after MI. ACP5 inhibition reduced cell proliferation, migration, and phenotypic changes in CFs in vitro, while adenovirus-mediated ACP5 overexpression had the opposite effect. Mechanistically, the classical profibrotic pathway of glycogen synthase kinase-3ß (GSK3ß)/ß-catenin was changed with ACP5 modulation, which indicated that ACP5 had a positive regulatory effect. Furthermore, the inhibitory effect of ACP5 deficiency on the GSK3ß/ß-catenin pathway was counteracted by an ERK activator, which indicated that ACP5 regulated GSK3ß activity through ERK-mediated phosphorylation, thereby affecting ß-catenin degradation. CONCLUSION: ACP5 may influence the proliferation, migration, and phenotypic transition of CFs, leading to the development of myocardial fibrosis after MI through modulating the ERK/GSK3ß/ß-catenin signaling pathway.

Spondyloenchondrodysplasia in five new patients: identification of three novel ACP5 variants with variable neurological presentations.

Spondyloenchondrodysplasia (SPENCD) is an immune-osseous disorder caused by biallelic variants in ACP5 gene and is less commonly associated with neurological abnormalities such as global developmental delay, spasticity and seizures. Herein, we describe five new patients from four unrelated Egyptian families with complex clinical presentations including predominant neurological presentations masking the skeletal and immunological manifestations. All our patients had spasticity with variable associations of motor and mental delay or epilepsy. All except for one patient had bilateral calcification in the basal ganglia. One patient had an associated growth hormone deficiency with fair response to growth hormone therapy (GH) where the height improved from -3.0 SD before GH therapy to -2.35 SD at presentation. Patients had different forms of immune dysregulation. All patients except for one had either cellular immunodeficiency (3 patients) or combined immunodeficiency (1 patient). Whole exome sequencing was performed and revealed four ACP5 variants: c.629C > T (p.Ser210Phe), c.526C > T (p.Arg176Ter), c.742dupC (p.Gln248ProfsTer3) and c.775G > A (p.Gly259Arg). Of them, three variants were not described before. Our study reinforces the striking phenotypic variability associated with SPENCD and expands the mutational spectrum of this rare disorder. Further, it documents the positive response to growth hormone therapy in the studied patient.

Prognostic Significance of ACP5 in Human Gastric Cancer.

INTRODUCTION: Tartrate-resistant acid phosphatase (ACP5) plays crucial roles in multiple pathological processes, including the genesis and progression of malignant tumors. We performed this study with the purpose of determining whether ACP5 is a crucial biomarker significantly related to prognoses of gastric cancer (GC) patients. METHODS: The expression level of ACP5 level was assessed among 170 GC specimens using immunohistochemistry. The associations between ACP5 expression and clinicopathological variables were evaluated. Univariate and multivariate Cox regression analyses were performed to confirm independent prognostic factors for GC patients. RESULTS: It was revealed that ACP5 expression level in GC tissue was significantly associated with depth of invasion (p = 0.029) and TNM stage (p = 0.036). ACP5 was demonstrated by multivariate Cox regression analysis to be an independent prognostic factor for overall survival (OS) (p = 0.001) and recurrence-free survival (RFS) (p = 0.011) of GC patients. CONCLUSIONS: The expression of ACP5 in GC tissue was significantly higher than that in normal tissues, and its overexpression was associated with a poorer prognosis, suggesting its potential roles in preventing and treating GC.

A Novel Sandwich ELISA for Tartrate-Resistant Acid Phosphatase 5a and 5b Protein Reveals that Both Isoforms are Secreted by Differentiating Osteoclasts and Correlate to the Type I Collagen Degradation Marker CTX-I In Vivo and In Vitro.

Tartrate-resistant acid phosphatase type 5 (TRAP) exists as two isoforms, 5a and 5b. 5b is a marker of osteoclast number and 5a of chronic inflammation; however, its association with bone resorption is unknown. In this study, a double-TRAP 5a/5b sandwich ELISA measuring 5a and 5b protein in the same sample was developed. TRAP 5a and 5b protein levels were evaluated as osteoclast differentiation/activity markers in serum and in culture, and their correlation to the resorption marker CTX-I was examined. Serum TRAP 5a and 5b concentrations in healthy men were 4.4 ± 0.6 ng/ml and 1.3 ± 0.2 ng/ml, respectively, and they correlated moderately to each other suggesting that their secretion is coupled under healthy conditions. A correlation was also observed between serum TRAP 5a and 5b with CTX-I, suggesting that both TRAP isoforms associate with osteoclast number. During osteoclast differentiation on plastic/bone, predominantly 5b increased in media/lysate from M-CSF/RANKL-stimulated CD14+ PBMCs. However, substantial levels of 5a were detected at later stages suggesting that both isoforms are secreted from differentiating OCs. More TRAP 5b was released on bone indicating a connection to osteoclast resorptive activity, and a peak in TRAP 5b/5a-ratio coincided with rapid CTX-I release. At the end of the culture period of M-CSF + RANKL-stimulated CD14+ PBMCs, there was a correlation between the secretion of TRAP 5a and 5b proteins with CTX-I. The correlation of not only 5b but also 5a with collagen degradation, both in serum and osteoclast cultures indicates that a considerable proportion of the TRAP 5a originates from osteoclasts and may reflect a hitherto undisclosed regulatory mechanism during bone resorption and bone remodeling.

Monogenic lupus due to spondyloenchondrodysplasia with spastic paraparesis and intracranial calcification: case-based review.

Spondyloenchondrodysplasia (SPENCD) is a rare skeletal dysplasia characterized with platyspondyly and metaphyseal lesions of the long bones mimicking enchondromatosis, resulting in short stature. SPENCD often coexists with neurologic disorders and immune dysregulation. Spasticity, developmental delay and intracranial calcification are main neurologic abnormalities. Large spectrum of immunologic abnormalities may be seen in SPENCD, including immune deficiencies and autoimmune disorders with autoimmune thrombocytopenia and systemic lupus erythematosus as the most common phenotypes. SPENCD is caused by loss of tartrate-resistant acid phosphatase (TRAP) activity, due to homozygous mutations in ACP5, playing a role in non-nucleic acid-related stimulation/regulation of the type I interferon pathway. We present two siblings, 13-year-old girl and 25-year-old boy with SPENCD, from consanguineous parents. Both patients had short stature, platyspondyly, metaphyseal changes, spastic paraparesis, mild intellectual disability, and juvenile-onset SLE. The age at disease-onset was 2 years for girl and 19 years for boy. Both had skin and mucosa involvement. The age at diagnosis of SLE was 4 years for girl, and 19 years for boy. The clinical diagnosis of SPENCD was confirmed by sequencing of ACP5 gene, which revealed a homozygous c.155A > C (p.K52T), a variant reported before as pathogenic. Juvenile-onset SLE accounts for about 15-20% of all SLE cases. But, the onset of SLE before 5-years of age and also monogenic SLE are rare. Our case report and the literature review show the importance of multisystemic evaluation in the diagnosis of SPENCD and to remind the necessity of investigating the monogenic etiology in early-onset and familial SLE cases.

Intensive weight gain therapy in patients with anorexia nervosa results in improved serum tartrate-resistant acid phosphatase (TRAP) 5a and 5b isoform protein levels.

AIM: Tartrate-resistant acid phosphatase (TRAP) exists as isoforms 5a and 5b. TRAP 5a is a biomarker of chronic inflammation and influences adipose tissue and 5b associates with bone metabolism/pathologies. The aim was to investigate the association of serum TRAP 5a/5b isoforms with fat and bone markers and anthropometric parameters in patients with anorexia nervosa (AN) during weight gain therapy. METHODS: Twenty-five Swedish female AN patients, age 16-24 years, were treated for 12 weeks with a high-energy diet with six meals daily. Serum TRAP 5a/5b, markers of fat/glucose metabolism, markers of bone resorption and formation were measured. Parameters of bone and body composition were assessed by dual-energy X-ray absorptiometry and peripheral quantitative computed tomography. RESULTS: BMI increased from median 15.4 kg/m2 to 19.0 kg/m2, p < 0.0001. TRAP 5a and 5a/5b ratio increased but TRAP 5b decreased during the study. TRAP Δ5a and Δ5b correlated with Δinsulin and Δadiponectin, respectively. TRAP 5b correlated with trabecular density at start but not at week 12. At 12 weeks, TRAP 5b correlated with CTX, and Δ decrease in TRAP 5b correlated to Δ increase in bone-specific alkaline phosphatase. CONCLUSIONS: This clinical interventional study resulted in increased BMI in patients with AN. The decreased TRAP 5b protein levels confirm a role for TRAP 5b as a marker of bone resorption, whereas increased TRAP 5a seemed to derive from systemic changes in bone as well as metabolic changes. The combined detection of TRAP 5a and TRAP 5b in serum could be an indicator of improved bone metabolism. LEVEL OF EVIDENCE: Level III, prospective interventional cohort study.

Tartrate-resistant acid phosphatase (TRAP/ACP5) promotes metastasis-related properties via TGFß2/TßR and CD44 in MDA-MB-231 breast cancer cells.

BACKGROUND: Tartrate-resistant acid phosphatase (TRAP/ACP5), a metalloenzyme that is characteristic for its expression in activated osteoclasts and in macrophages, has recently gained considerable focus as a driver of metastasis and was associated with clinically relevant parameters of cancer progression and cancer aggressiveness. METHODS: MDA-MB-231 breast cancer cells with different TRAP expression levels (overexpression and knockdown) were generated and characterized for protein expression and activity levels. Functional cell experiments, such as proliferation, migration and invasion assays were performed as well as global phosphoproteomic and proteomic analysis was conducted to connect molecular perturbations to the phenotypic changes. RESULTS: We identified an association between metastasis-related properties of TRAP-overexpressing MDA-MB-231 breast cancer cells and a TRAP-dependent regulation of Transforming growth factor (TGFß) pathway proteins and Cluster of differentiation 44 (CD44). Overexpression of TRAP increased anchorage-independent and anchorage-dependent cell growth and proliferation, induced a more elongated cellular morphology and promoted cell migration and invasion. Migration was increased in the presence of the extracellular matrix (ECM) proteins osteopontin and fibronectin and the basement membrane proteins collagen IV and laminin I. TRAP-induced properties were reverted upon shRNA-mediated knockdown of TRAP or treatment with the small molecule TRAP inhibitor 5-PNA. Global phosphoproteomics and proteomics analyses identified possible substrates of TRAP phosphatase activity or signaling intermediates and outlined a TRAP-dependent regulation of proteins involved in cell adhesion and ECM organization. Upregulation of TGFß isoform 2 (TGFß2), TGFß receptor type 1 (TßR1) and Mothers against decapentaplegic homolog 2 (SMAD2), as well as increased intracellular phosphorylation of CD44 were identified upon TRAP perturbation. Functional antibody-mediated blocking and chemical inhibition demonstrated that TRAP-dependent migration and proliferation is regulated via TGFß2/TßR, whereas proliferation beyond basal levels is regulated through CD44. CONCLUSION: Altogether, TRAP promotes metastasis-related cell properties in MDA-MB-231 breast cancer cells via TGFß2/TßR and CD44, thereby identifying a potential signaling mechanism associated to TRAP action in breast cancer cells.

The adipokine tartrate-resistant acid phosphatase 5a in serum correlates to adipose tissue expansion in obesity.

PURPOSE: Tartrate-resistant acid phosphatase (TRAP) exists as two isoforms, 5a and 5b. TRAP 5a is elevated in adipose tissue of obese women, interacts with pre-adipocytes and is linked to insulin-sensitive hyperplastic obesity when overexpressed in mice. The aim of this study was to investigate the relation between serum TRAP 5a, adiposity indices and metabolic syndrome risk markers in lean and obese women, using a newly developed TRAP 5a-specific ELISA. MATERIALS AND METHODS: A TRAP 5a sandwich ELISA was optimized using TRAP 5a-specific monoclonal antibodies and tested in sera of healthy males. TRAP 5a levels were quantitated in sera from healthy males and lean and obese women. RESULTS: Serum TRAP 5a protein levels were lower in obese women in comparison with lean. In obese, but not in lean women, serum TRAP 5a correlated positively to % fat mass, BMI, waist- and hip circumference, waist-to-hip ratio and PAI, while no correlations to serum leptin, HOMA, glucose, insulin, FFA, HDL, TG, APO-A1 and APO-B were observed. CONCLUSIONS: TRAP 5a serum levels correlated positively to anthropometric obesity parameters but not to metabolic syndrome risk factors, indicating that serum TRAP 5a is associated with pathological adipose tissue expansion.

Spondyloenchondrodysplasia Due to Mutations in ACP5: A Comprehensive Survey.

PURPOSE: Spondyloenchondrodysplasia is a rare immuno-osseous dysplasia caused by biallelic mutations in ACP5. We aimed to provide a survey of the skeletal, neurological and immune manifestations of this disease in a cohort of molecularly confirmed cases. METHODS: We compiled clinical, genetic and serological data from a total of 26 patients from 18 pedigrees, all with biallelic ACP5 mutations. RESULTS: We observed a variability in skeletal, neurological and immune phenotypes, which was sometimes marked even between affected siblings. In total, 22 of 26 patients manifested autoimmune disease, most frequently autoimmune thrombocytopenia and systemic lupus erythematosus. Four patients were considered to demonstrate no clinical autoimmune disease, although two were positive for autoantibodies. In the majority of patients tested we detected upregulated expression of interferon-stimulated genes (ISGs), in keeping with the autoimmune phenotype and the likely immune-regulatory function of the deficient protein tartrate resistant acid phosphatase (TRAP). Two mutation positive patients did not demonstrate an upregulation of ISGs, including one patient with significant autoimmune disease controlled by immunosuppressive therapy. CONCLUSIONS: Our data expand the known phenotype of SPENCD. We propose that the OMIM differentiation between spondyloenchondrodysplasia and spondyloenchondrodysplasia with immune dysregulation is no longer appropriate, since the molecular evidence that we provide suggests that these phenotypes represent a continuum of the same disorder. In addition, the absence of an interferon signature following immunomodulatory treatments in a patient with significant autoimmune disease may indicate a therapeutic response important for the immune manifestations of spondyloenchondrodysplasia.

Three cases of spondyloenchondrodysplasia (SPENCD) with systemic lupus erythematosus: a case series and review of the literature.

Spondyloenchondrodysplasia (SPENCD) is a rare autosomal recessive skeletal dysplasia caused by recessive mutations in the ACP5 gene, and it is characterized by the persistence of chondroid tissue islands within the bone. The clinical spectrum of SPENCD includes neurological involvement and immune dysfunction, such as systemic lupus erythematosus (SLE). To date, there are only 12 reported cases of SPENCD associated with SLE in the literature; however, detailed clinical follow-up data is absent for this comorbidity. This report presents clinical and laboratory data of three patients diagnosed with SPENCD-associated SLE. All three patients had short stature, arthralgia/arthritis, lupus nephritis, hypocomplementemia, and positive autoantibodies, including anti-nuclear and anti-dsDNA antibodies. Two patients exhibited class IV and one patient exhibited class V lupus nephritis. The early recognition of SPENCD is imperative, and this condition should be considered in patients with SLE, particularly in individuals with short stature and skeletal abnormalities. The cases presented here demonstrate that timely diagnosis and follow-up are key factors for the successful management of these conditions.

The small chemical enzyme inhibitor 5-phenylnicotinic acid/CD13 inhibits cell migration and invasion of tartrate-resistant acid phosphatase/ACP5-overexpressing MDA-MB-231 breast cancer cells.

Tartrate-resistant acid phosphatase (TRAP/ACP5/uteroferrin/purple acid phosphatase/PP5) has received considerable attention as a newly discovered proinvasion metastasis driver associated with different malignancies. This renders TRAP an interesting target for novel anti-cancer therapy approaches. TRAP exists as two isoforms, 5a and 5b, where the 5a isoform represents an enzymatically less active monomeric precursor to the more enzymatically active 5b isoform generated by proteolytic excision of a repressive loop domain. Recently, three novel lead compounds were identified by fragment-based screening and demonstrated to be efficient TRAP enzyme inhibitors in vitro. We conclude that one of the three compounds i.e. 5-phenylnicotinic acid (CD13) was efficient as a TRAP inhibitor with Kic values in the low micromolar range towards the TRAP 5b isoform, but was not able to inhibit the TRAP 5a isoform. Structure-based docking revealed similar interactions of CD13 with the active site in both TRAP isoforms. In stably TRAP-overexpressing MDA-MB-231 breast cancer cells, CD13 inhibited intracellular TRAP activity and showed no cytotoxicity at 200 µM. Furthermore, CD13 selectively blocked the TRAP 5b isoform compared to the TRAP 5a in cultured cells, indicating the usefulness of CD13 for assessing the different biological functions of the two TRAP isoforms 5a and 5b in cell systems. Moreover, inhibition of cell migration and invasion of stably TRAP-overexpressing MDA-MB-231 by CD13 was observed. These data establish a proof of principle that a small chemical inhibitor of the TRAP enzyme can block TRAP-dependent functions in cancer cells.

Spondyloenchondrodysplasia with immune dysregulation related to ACP5. A report of 4 cases. / Espondiloencondrodisplasia con desregulación inmune relacionada a ACP5. Reporte de cuatro casos.

Spondyloenchondrodysplasia with immune dysregulation related to ACP5 (SPENCDI, OMIM number 607944) is an uncommon immune-skeletal dysplasia with heterogeneous manifestations and variable severity. It is characterized by spondylar and metaphyseal lesions, immune dysfunction, and neurological involvement. Here we report the clinical, radiological and genetic aspects of 4 girls with SPENCDI treated at a children's hospital. They all had skeletal manifestations and 3 developed severe immune disease. In 3 patients, the likely pathogenic variant c.791T>A; p.Met264Lys (homozygous mutation) was observed, while 1 patient had variants c.791T>A; p.Met264Lys and c.632T>C; p.lle211Thr (variant of uncertain significance with pathogenic prediction based on bioinformatics algorithms) caused by a compound heterozygous mutation in ACP5. The repeated presence of variant c.791T>A suggests the possibility of a common ancestor in our population. The recognition and diagnosis of this disorder is important to achieve a timely approach, which should be multidisciplinary and aimed at preventing possible complications.

La espondiloencondrodisplasia con desregulación inmune relacionada a ACP5 (SPENCDI #607944, por la sigla de spondyloenchondrodysplasia with immune dysregulation y el número que le corresponde en OMIM, Online Mendelian Inheritance in Man) es una displasia inmuno-ósea poco frecuente con manifestaciones heterogéneas y gravedad variable. Presenta lesiones espondilometafisarias, disfunción inmune y compromiso neurológico. Se reportan aspectos clínicos, radiológicos y genéticos de cuatro niñas con SPENCDI en un hospital pediátrico. Todas presentaron manifestaciones esqueléticas y tres de ellas enfermedad inmunológica grave. Se encontró en tres pacientes la variante probablemente patogénica c.791T>A; p.Met264Lys en homocigosis, y en una paciente las variantes c.791T>A; p.Met264Lys y c.632T>C; p.lle211Thr (variante de significado incierto con predicción patogénica según algoritmos bioinformáticos) en heterocigosis compuesta en ACP5. La presencia de la variante repetida c.791T>A sugiere la posibilidad de un ancestro en común en nuestra población. El reconocimiento y diagnóstico de esta entidad es importante para lograr un oportuno abordaje, que deberá ser multidisciplinario, orientado hacia la prevención de posibles complicaciones.

Studies on the in vitro mechanism and in vivo therapeutic effect of the antimicrobial peptide ACP5 against Trichophyton mentagrophytes.

Trichophyton mentagrophytes is a zoophilic dermatophyte that can cause dermatophytosis in humans and animals. Antimicrobial peptides (AMPs) are considered as a promising agent to overcome the drug-resistance of T. mentagrophytes. Our findings suggest that cationic antimicrobial peptide (ACP5) not only possesses stronger activity against T. mentagrophytes than fluconazole, but also shows lower toxicity to L929 mouse fibroblast cells than terbinafine. Notably, its resistance development rate after resistance induction was lower than terbinafine. The present study aimed to evaluate the fungicidal mechanism of ACP5 in vitro and its potential to treat dermatophyte infections in vivo. ACP5 at 1 ×MIC completely inhibited T. mentagrophytes spore germination in vitro. ACP5 severely disrupts the mycelial morphology, leading to mycelial rupture. Mechanistically, ACP5 induces excessive ROS production, damaging the integrity of the cell membrane and decreasing the mitochondrial membrane potential, causing irreversible damage in T. mentagrophytes. Furthermore, 1% ACP5 showed similar efficacy to the commercially available drug 1% terbinafine in a guinea pig dermatophytosis model, and the complete eradication of T. mentagrophytes from the skin by ACP5 was verified by tissue section observation. These results indicate that ACP5 is a promising candidate for the development of new agent to combat dermatophyte resistance.

Tartrate-resistant acid phosphatase (TRAP/ACP5) promotes bone length, regulates cortical and trabecular bone mass, and maintains growth plate architecture and width in a sex- and site-specific manner in mice.

Tartrate-resistant acid phosphatase (TRAP) serum levels reflect osteoclast number, bone remodeling activity, and fracture risk. Deletion or loss of function of TRAP results in short stature in mice and man. Yet, the impact and mechanisms of TRAP for the site- and sex-specific development of bone and cartilage is not well understood. Here, we use a global TRAP knockout (TRAPKO) and wildtype littermate control (WT) mice of both sexes to investigate TRAP as a possible sex- and site-specific regulator of bone and growth plate development. TRAPKO mice of both sexes weighed less and had shorter tibial length than their WT, features that were more accentuated in male than female TRAPKO mice. These changes were not associated with a general reduction in growth as not all organs displayed a proportionally lower mass, and serum IGF-1 was unchanged. Using µCT and site-specificity analysis of the cortical bone revealed wider proximal tibia, a higher trabecular thickness, and lower trabecular separation in male TRAPKO compared to WT mice, an effect not seen in female mice. Histomorphometric analysis revealed that the growth plate height as well as height of terminal hypertrophic chondrocytes were markedly increased, and the number of columns was decreased in TRAPKO mice of both sexes. These effects were more accentuated in female mice. Proliferation and differentiation of bone marrow derived macrophages into osteoclasts, as well as C-terminal cross links were normal in TRAPKO mice of both sexes. Collectively, our results show that TRAP regulates bone and cartilage development in a sex-and site-specific manner in mice.

Association of ACP5 with the tumor immune microenvironment and its role in cell proliferation and metastasis in pancreatic cancer.

BACKGROUND: Tartrate-resistant acid phosphatase (ACP5) has been implicated in the progression of most malignant tumors, but its role in pancreatic cancer (PC) remained unclear. Thus, this study aimed to elucidate the role and function of ACP5 in PC progression. METHODS: The expression of ACP5 in PC samples was assessed via R programming, TNM plot, and Gene Expression Profiling Interactive Analysis (GEPIA). Western blotting and immunohistochemistry (IHC) were performed to detect ACP5 expression in cells and tissues. The correlation between ACP5 and methylation was analyzed using the University of ALabama at Birmingham Cancer data analysis Portal (UALCAN) and cBio Cancer Genomics Portal (cBioPortal). The Database for Annotation, Visualization and Integrated Discovery (DAVID) and Gene Set Enrichment Analysis (GSEA) were used for the enrichment of ACP5 in PC. Subsequently, Cell Counting Kit-8 (CCK8), clonogenic, and wound healing assays were used to investigate the role of ACP5 in PC. Finally, Tumor Immune Estimation Resource (TIMER) and R programming was utilized in evaluating the association between ACP5 and immune cell infiltration in PC. RESULTS: The analyses confirmed that ACP5 was highly expressed in PC samples. According to UALCAN and cBioPortal analysis, ACP5 expression, and methylation levels were negatively correlated in PC. The enrichment analysis also revealed that ACP5 was enriched in the proliferation and migration pathways. Meanwhile, ACP5 knockout reduced PC cell proliferation and migration and impaired the cells' independent viability. This gene also positively correlated with immune cell infiltration in PC, particularly regulatory T cells (Tregs). CONCLUSION: ACP5 is crucial for proliferation, migration, and immune cell infiltration in PC. Therefore, ACP5 may be a valuable target for future PC treatment.

Case report: Refractory Evans syndrome in two patients with spondyloenchondrodysplasia with immune dysregulation treated successfully with JAK1/JAK2 inhibition.

Biallelic mutations in the ACP5 gene cause spondyloenchondrodysplasia with immune dysregulation (SPENCDI). SPENCDI is characterized by the phenotypic triad of skeletal dysplasia, innate and adaptive immune dysfunction, and variable neurologic findings ranging from asymptomatic brain calcifications to severe developmental delay with spasticity. Immune dysregulation in SPENCDI is often refractory to standard immunosuppressive treatments. Here, we present the cases of two patients with SPENCDI and recalcitrant autoimmune cytopenias who demonstrated a favorable clinical response to targeted JAK inhibition over a period of more than 3 years. One of the patients exhibited steadily rising IgG levels and a bone marrow biopsy revealed smoldering multiple myeloma. A review of the literature uncovered that approximately half of the SPENCDI patients reported to date exhibited increased IgG levels. Screening for multiple myeloma in SPENCDI patients with rising IgG levels should therefore be considered.

Novel Mutations in ACP5 and SAMHD1 in a Patient With Pediatric Systemic Lupus Erythematosus.

Background: The study of genetic predisposition to pediatric systemic lupus erythematosus (pSLE) has brought new insights into the pathophysiology of SLE, as it is hypothesized that genetic predisposition is greater in children. Furthermore, identifying genetic variants and linking disrupted genes to abnormal immune pathways and clinical manifestations can be beneficial for both diagnosis and treatment. Here, we identified genetic alterations in a patient with childhood-onset SLE and analyzed the immunological mechanisms behind them to support future diagnosis, prognosis, and treatment. Methods: Whole exome sequencing (WES) was adopted for genetic analysis of a patient with childhood-onset SLE. Gene mutations were confirmed by Sanger sequencing. Clinical data of this patient were collected and summarized. Ingenuity Pathway Analysis was used to provide interacting genes of the perturbed genes. Online Enrichr tool and Cytoscape software were used to analysis the related pathways of these genes. Results: We present a case of a 2-year-old girl who was diagnosed with idiopathic thrombocytopenic purpura (ITP) and SLE. The patient was characterized by cutaneous bleeding spots on both lower extremities, thrombocytopenia, decreased serum complements levels, increased urinary red blood cells, and positive ANA and dsDNA. The patient was treated with methylprednisolone and mycophenolate, but clinical remission could not be achieved. The genomic analysis identified three novel mutations in this pSLE patient, a double-stranded missense mutation in ACP5 (c.1152G>T and c.420G>A) and a single-stranded mutation in SAMHD1 (c.1423G>A). Bioinformatic analysis showed that these two genes and their interacting genes are enriched in the regulation of multiple immune pathways associated with SLE, including cytokine signaling and immune cell activation or function. Analysis of the synergistic regulation of these two genes suggests that abnormalities in the type I interferon pathway caused by genetic variants may contribute to the pathogenesis of SLE. Conclusion: The combined complexity of polymorphisms in the coding regions of ACP5 and SAMHD1 influences the susceptibility to SLE. Alterations in these genes may lead to abnormalities in the type I interferon pathway. Our study extends the spectrum of mutations in the ACP5 and SAMHD1 genes. The identification of these mutations could aid in the diagnosis of SLE with genetic counseling and suggest potential precise treatments for specific pathways.

Tartrate resistant acid phosphatase 5 (TRAP5) mediates immune cell recruitment in a murine model of pulmonary bacterial infection.

Introduction: During airway infection, upregulation of proinflammatory cytokines and subsequent immune cell recruitment is essential to mitigate bacterial infection. Conversely, during prolonged and non-resolving airway inflammation, neutrophils contribute to tissue damage and remodeling. This occurs during diseases including cystic fibrosis (CF) and COPD where bacterial pathogens, not least Pseudomonas aeruginosa, contribute to disease progression through long-lasting infections. Tartrate-resistant acid phosphatase (TRAP) 5 is a metalloenzyme expressed by alveolar macrophages and one of its target substrates is the phosphoglycoprotein osteopontin (OPN). Methods: We used a knockout mouse strain (Trap5-/-) and BALB/c-Tg (Rela-luc)31Xen mice paired with siRNA administration or functional protein add-back to elucidate the role of Trap5 during bacterial infection. In a series of experiments, Trap5-/- and wild-type control mice received intratracheal administration of P.aerugniosa (Xen41) or LPS, with mice monitored using intravital imaging (IVIS). In addition, multiplex cytokine immunoassays, flow cytometry, multispectral analyses, histological staining were performed. Results: In this study, we found that Trap5-/- mice had impaired clearance of P. aeruginosa airway infection and reduced recruitment of immune cells (i.e. neutrophils and inflammatory macrophages). Trap5 knockdown using siRNA resulted in a decreased activation of the proinflammatory transcription factor NF-κB in reporter mice and a subsequent decrease of proinflammatory gene expression. Add-back experiments of enzymatically active TRAP5 to Trap5-/- mice restored immune cell recruitment and bacterial killing. In human CF lung tissue, TRAP5 of alveolar macrophages was detected in proximity to OPN to a higher degree than in normal lung tissue, indicating possible interactions. Discussion: Taken together, the findings of this study suggest a key role for TRAP5 in modulating airway inflammation. This could have bearing in diseases such as CF and COPD where excessive neutrophilic inflammation could be targeted by pharmacological inhibitors of TRAP5.

Androgen receptor (AR) decreases HCC cells migration and invasion via miR-325/ACP5 signaling.

Hepatocellular carcinoma (HCC) is the most 5th commonly diagnosed and 2nd most lethal tumor in the world. The obvious gender advantage of HCC indicates that androgen receptor (AR) may play an important role in the tumor occurrence, develop and metastasis of HCC. Here we found that decreased AR could alter miR-325 to increase ACP5 expression in HCC cells, to increase HCC cells migration and invasion capacities. Mechanism dissection revealed that AR could regulate miR-325 expression through transcriptional regulation and miR-325 might directly target the 3'UTR of ACP5-mRNA to suppress its translation. The in vivo orthotopic xenografts mouse model with oemiR-325 also validated in vitro data. Together, these findings suggest that AR may decrease HCC progression through miR-325/ACP5 signaling and targeting the AR/miR-325/ACP5 signaling may help in the development of the novel therapies to better suppress the HCC progression.