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Yunan is a crossed lean meat pig breed in China. Backfat thickness is the gold standard for carcass quality grading. However, over 14 years after breed registration, the backfat of Yunan thickened and the consistency of backfat thickness decreased. Meanwhile, no genetic study has been ever performed on Yunan population. So, in this study we collected all the 120 nucleus individuals of Yunan and recorded six backfat traits of them, carried out population genetic structure analysis, selection signals analysis and genome-wide association study of Yunan pigs with the help of their founder population Duroc and Chinese native Huainan pigs, to determine the genomic loci on backfat of Yunan. Genetic diversity indexes suggested Yunan pigs had no inbreeding risk while population genetic structure showed they had few molecular pedigrees and were stratified. A total of 71 common selection signals affecting growth and fat deposition were detected by F Show less

Membranous Nephropathy (MN) is characterized by the presence of subepithelial deposits. MN has been traditionally classified as primary if it is not associated with other pathologies, or secondary if it is associated with autoimmune diseases, infections or malignancies. The identification of target podocyte antigen was a critical point in the understanding of the disease: firstly in 2009 with M-type phospholipase A2 receptor (PLA2R) and then in 2014 with Thrombospondin Type 1 Domain Containing 7A (THSD7A). In the last years using an innovative approach based on laser microdissection and tandem mass spectrometry (MS/MS) has allowed the identification of new target antigen/protein as EXT1/2, NELL-1, NCAM1, SEMA3B, PCHD7, HTRA1, TGFBR3. Some of these proteins have been found in both primary and secondary MN, blurring the line between the two forms. Further studies are necessary to define and understand the clinical features of different antigen associated diseases. The aim of this review is to take a closer look at the new antigens and to evaluate how their discovery can change MN classification. Show less

Hereditary multiple exostoses (HMEs) syndrome, also known as multiple osteochondromas, represents a rare and severe human skeletal disorder. The disease is characterized by multiple benign cartilage-capped bony outgrowths, termed exostoses or osteochondromas, that locate most commonly in the juxta-epiphyseal portions of long bones. Affected individuals usually complain of persistent pain caused by the pressure on neighboring tissues, disturbance of blood circulation, or rarely by spinal cord compression. However, the most severe complication of this condition is malignant transformation into chondrosarcoma, occurring in up to 3.9% of HMEs patients. The disease results mainly from heterozygous loss-of-function alterations in the Show less

Hereditary multiple exostoses (HME) is a rare skeletal disorder characterized by the formation of multiple benign cartilage-capped tumors, usually in the metaphyseal region of the long bones. Over 70% of HME cases arise from monoallelic mutations in either of the two genes encoding the heparan sulfate (HS) synthesis enzymes, ext1 and ext2. To identify more HME-associated mutations, genomic DNA from members of five independent consanguineous families with HME was sequenced with whole exome sequencing (WES). A novel heterozygous splice site mutation (c.1173+2T>A) in ext2 was detected in all three affected members of family V. Further study showed that the novel mutation caused exon 7 of ext2 mRNA to be skipped during splicing and caused a frameshift after the codon for Arg360, which results in the appearance of new 43 codons, followed by a termination codon. Although the resulting truncated protein was still localized to the Golgi, similar to the full-length EXT2, its HS synthesis activity decreased by 40%. In this study, a novel splice site mutation in ext2 was identified and suggested to be a pathogenic mutation of HME, which may expand the genetic etiology spectrum of HME and may be helpful for clinical genetic counseling and prenatal diagnosis. Show less

Membranous nephropathy (MN) is an autoimmune disease of the kidney glomerulus and one of the leading causes of nephrotic syndrome. The disease exhibits heterogenous outcomes with approximately 30% of cases progressing to end-stage renal disease. The clinical management of MN has steadily advanced owing to the identification of autoantibodies to the phospholipase A2 receptor (PLA2R) in 2009 and thrombospondin domain-containing 7A (THSD7A) in 2014 on the podocyte surface. Approximately 50-80% and 3-5% of primary MN (PMN) cases are associated with either anti-PLA2R or anti-THSD7A antibodies, respectively. The presence of these autoantibodies is used for MN diagnosis; antibody levels correlate with disease severity and possess significant biomarker values in monitoring disease progression and treatment response. Importantly, both autoantibodies are causative to MN. Additionally, evidence is emerging that NELL-1 is associated with 5-10% of PMN cases that are PLA2R- and THSD7A-negative, which moves us one step closer to mapping out the full spectrum of PMN antigens. Recent developments suggest exostosin 1 (EXT1), EXT2, NELL-1, and contactin 1 (CNTN1) are associated with MN. Genetic factors and other mechanisms are in place to regulate these factors and may contribute to MN pathogenesis. This review will discuss recent developments over the past 5 years. Show less

To explore the genetic basis for a pedigree affected with hereditary multiple osteochondroma (HMO). Peripheral blood samples were collected from the proband and members of his pedigree with informed consent. Following extraction of genomic DNA, all coding exons and flanking intronic sequences (-10 bp) of the EXT1 and EXT2 genes were subjected to targeted capture and next generation sequencing (NGS). Suspected variant was verified by Sanger sequencing. A heterozygous nonsense variant (c.1911C>A) was found in exon 10 of the EXT1 gene in the proband and his affected father but not in a healthy sister and normal controls. The variant was classified as a pathogenic based on the guidelines of the American College of Medical Genetics and Genomics (PVS1+PM2+PP1). Bioinformatic analysis predicted that the c.1911C>A variant may be disease-causing via nonsense-mediated mRNA decay and anomalous splicing. The c.1911C>A variant probably underlay the disease in this pedigree. Discovery of this variant enriched the variant spectrum of HMO. Show less

Endothelial glycocalyx loss is integral to increased pulmonary vascular permeability in sepsis-related acute lung injury. Protectin conjugates in tissue regeneration 1 (PCTR1) is a novel macrophage-derived lipid mediator exhibiting potential anti-inflammatory and pro-resolving benefits. PCTR1 was administrated intraperitoneally with 100 ng/mouse after lipopolysaccharide (LPS) challenged. Survival rate and lung function were used to evaluate the protective effects of PCTR1. Lung inflammation response was observed by morphology and inflammatory cytokines level. Endothelial glycocalyx and its related key enzymes were measured by immunofluorescence, ELISA, and Western blot. Afterward, related-pathways inhibitors were used to identify the mechanism of endothelial glycocalyx response to PCTR1 in mice and human umbilical vein endothelial cells (HUVECs) after LPS administration. In vivo, we show that PCTR1 protects mice against lipopolysaccharide (LPS)-induced sepsis, as shown by enhanced the survival and pulmonary function, decreased the inflammatory response in lungs and peripheral levels of inflammatory cytokines such as tumor necrosis factor-α, interleukin-6, and interleukin-1β. Moreover, PCTR1 restored lung vascular glycocalyx and reduced serum heparin sulphate (HS), syndecan-1 (SDC-1), and hyaluronic acid (HA) levels. Furthermore, we found that PCTR1 downregulated heparanase (HPA) expression to inhibit glycocalyx degradation and upregulated exostosin-1 (EXT-1) protein expression to promote glycocalyx reconstitution. Besides, we observed that BAY11-7082 blocked glycocalyx loss induced by LPS in vivo and in vitro, and BOC-2 (ALX antagonist) or EX527 (SIRT1 inhibitor) abolished the restoration of HS in response to PCTR1. PCTR1 protects endothelial glycocalyx via ALX receptor by regulating SIRT1/NF-κB pathway, suggesting PCTR1 may be a significant therapeutic target for sepsis-related acute lung injury. Show less

Exostosin 1 and exostosin 2 (EXT1/EXT2) on glomerular basement membrane (GBM) were recently reported as novel putative antigens in secondary membranous nephropathy with autoimmune disease. However, the clinical significance of glomerular EXT1/EXT2 remains elusive in patients with lupus nephritis (LN). The immunofluorescence staining pattern of glomerular EXT1/EXT2 is also undetermined in membranous LN (MLN) or proliferative LN (PLN). We cross-sectionally analyzed patients with MLN (pure class V, n = 11) and PLN (class III, IV, and mixed class III/IV + V, n = 22) who underwent renal biopsies between 2010 and 2020 at Showa University Hospital. Glomerular EXT1/EXT2 expressions were evaluated by immunofluorescence. T-helper (Th) cell-related serum inflammatory cytokines were measured using enzyme-linked immunosorbent assay. The positivity for both EXT1/EXT2 was higher in patients with MLN than PLN (90.9% vs 63.6%, P = 0.212). MLN showed global and bright granular EXT1/EXT2 expressions along GBM, while PLN showed segmental and moderate expressions on GBM. Additionally, glomerular EXT1/EXT2 positivity was not associated with the degree of proteinuria or renal function in MLN and PLN patients, but the levels of serum anti-dsDNA antibody and circulating immune complexes were lower in patients with EXT1/EXT2-positive MLN than EXT1/EXT2-negative PLN. Moreover, serum complement levels and IL-4/IFN-γ ratios were elevated in EXT1/EXT2-positive MLN than EXT1/EXT2-negative PLN. Collectively, immunofluorescence staining for glomerular EXT1/EXT2 had characteristic patterns between MLN and PLN. Glomerular EXT1/EXT2 expressions tended to be high in Th2-dominant MLN patients without severe hypocomplementemia and elevated autoantibodies. Thus, EXT1/EXT2 might be involved in the unique developmental mechanism of MLN. Show less

Chordoma is a rare bone cancer with an unknown etiology. TBXT is the only chordoma susceptibility gene identified to date; germline single nucleotide variants and copy number variants in TBXT have been associated with chordoma susceptibility in familial and sporadic chordoma. However, the genetic susceptibility of chordoma remains largely unknown. In this study, we investigated rare germline genetic variants in genes involved in TBXT/chordoma-related signaling pathways and other biological processes in chordoma patients from North America and China. We identified variants that were very rare in general population and internal control datasets and showed evidence for pathogenicity in 265 genes in a whole exome sequencing (WES) dataset of 138 chordoma patients of European ancestry and in a whole genome sequencing (WGS) dataset of 80 Chinese patients with skull base chordoma. Rare and likely pathogenic variants were identified in 32 of 138 European ancestry patients (23%), including genes that are part of notochord development, PI3K/AKT/mTOR, Sonic Hedgehog, SWI/SNF complex and mesoderm development pathways. Rare pathogenic variants in COL2A1, EXT1, PDK1, LRP2, TBXT and TSC2, among others, were also observed in Chinese patients. We identified several rare loss-of-function and predicted deleterious missense variants in germline DNA from patients with chordoma, which may influence chordoma predisposition and reflect a complex susceptibility, warranting further investigation in large studies. Show less

Hereditary multiple exostoses (HME), also referred to as multiple osteochondromas, is an autosomal dominant skeletal disease characterized by the development of multiple overgrown benign bony tumors capped by cartilage and is associated with bone deformity, joint limitation, and short stature. Mutations in exostosin glycosyltransferase (EXT)1 and EXT2 genes, which are located on chromosomes 8q24.1 and 11p13, contribute to the pathogenesis of HME. In the present study, a genetic analysis of a four-generation Chinese family with HME was conducted using whole-exome sequencing (WES), followed by validation using Sanger sequencing. A novel heterozygous frameshift mutation in exon 5 of EXT2 (c.944dupT, p.Leu316fs) was identified in all affected individuals but was not detected in any unaffected individuals. This mutation results in a frameshift that introduces a premature termination codon at position 318 (p.Leu316fs) with the ability to produce a truncated EXT2 protein that lacks the last 433 amino acids at its C-terminal to indicate a defective exostosin domain and the absence of the glycosyltransferase family 64 domain, or to lead to the degradation of mRNAs by nonsense-mediated mRNA decay, which is critical for the function of EXT2. Our results indicate that WES is effective in extending the EXT mutational spectra and is advantageous for genetic counseling and the subsequent prenatal diagnosis. Show less

Atomic force microscopy-single-molecule force spectroscopy (AFM-SMFS) is a powerful methodology to probe intermolecular and intramolecular interactions in biological systems because of its operability in physiological conditions, facile and rapid sample preparation, versatile molecular manipulation, and combined functionality with high-resolution imaging. Since a huge number of AFM-SMFS force-distance curves are collected to avoid human bias and errors and to save time, numerous algorithms have been developed to analyze the AFM-SMFS curves. Nevertheless, there is still a need to develop new algorithms for the analysis of AFM-SMFS data since the current algorithms cannot specify an unbinding force to a corresponding/each binding site due to the lack of networking functionality to model the relationship between the unbinding forces. To address this challenge, herein, we develop an unsupervised method, i.e., a network-based automatic clustering algorithm (NASA), to decode the details of specific molecules, e.g., the unbinding force of each binding site, given the input of AFM-SMFS curves. Using the interaction of heparan sulfate (HS)-antithrombin (AT) on different endothelial cell surfaces as a model system, we demonstrate that NASA is able to automatically detect the peak and calculate the unbinding force. More importantly, NASA successfully identifies three unbinding force clusters, which could belong to three different binding sites, for both Ext1 Show less

Next generation sequencing (NGS) has expanded the diagnostic paradigm turning the focus to the growth plate. The aim of the study was to determine the prevalence of variants in genes implicated in skeletal dysplasias in probands with short stature and mild skeletal anomalies. Clinical and radiological data were collected from 108 probands with short stature and mild skeletal anomalies. A customized skeletal dysplasia NGS panel was performed. Variants were classified using ACMG recommendations and Sherloc. Anthropometric measurements and skeletal anomalies were subsequently compared in those with or without an identified genetic defect. Heterozygous variants were identified in 21/108 probands (19.4%). Variants were most frequently identified in ACAN (n = 10) and IHH (n = 7) whilst one variant was detected in COL2A1, CREBBP, EXT1, and PTPN11. Statistically significant differences (P < 0.05) were observed for sitting height/height (SH/H) ratio, SH/H ratio standard deviation score (SDS), and the SH/H ratio SDS >1 in those with an identified variant compared to those without. A molecular defect was elucidated in a fifth of patients. Thus, the prevalence of mild forms of skeletal dysplasias is relatively high in individuals with short stature and mild skeletal anomalies, with variants in ACAN and IHH accounting for 81% of the cases. An elevated SH/H ratio appears to be associated with a greater probability in detecting a variant, but no other clinical or radiological feature has been found determinant to finding a genetic cause. Currently, we cannot perform extensive molecular studies in all short stature individuals so detailed clinical and radiological phenotyping may orientate which are the candidate patients to obtain worthwhile results. In addition, detailed phenotyping of probands and family members will often aid variant classification. Show less

Hypoxia, a strong and selective pressure, has been involved in invasion, metastasis, and angiogenesis of tumor cells. Our study performed the transcriptome profiles of 666 non-small-cell lung cancer (NSCLC) patients. Various bioinformatic approaches were combined to evaluate the immune cell infiltration in the high hypoxia risk patients. In addition, in vitro experiments were performed to assess the effects of tumor-associated neutrophils (TANs) on NSCLC cells proliferation, migration and invasion and to reveal the underlying mechanisms. We divided NSCLC into two groups (Cluster1/2) based on the expression profiles of hypoxia-associated genes. Compared with the Cluster1 subgroup, the Cluster2 had a worse prognosis. Significant enrichment analysis revealed that PI3K/AKT/mTOR signaling pathway and TANs were highly related to hypoxia microenvironment. Eleven hypoxia-related genes (FBP1, NDST2, ADM, LDHA, DDIT4, EXT1, BCAN, IGFBP1, PDGFB, AKAP12, and CDKN3) were scored by LASSO COX regression to yield risk scores, and we revealed a significant difference in overall survival (OS) between the low- and high-risk groups. Mechanistically, CXCL6 in hypoxic cancer cells promoted the migration of TANs in vitro, and in turn promote NSCLC cells proliferation, migration and invasion. In summary, this study revealed a 11-hypoxia gene signature that predicted OS of NSCLC patients, and improved our understanding of the role of TANs in hypoxia microenvironment. Show less

Dysplasia epiphysealis hemimelica (DEH), also known as Trevor's disease, is a rare nonhereditary skeletal disorder affecting one side of the epiphyses or the epiphyses-equivalents. It is often misdiagnosed for traumatic injuries, infections, or other tumors because of the nonspecific clinical features. The diagnosis is mostly based on radiographic involvement of one half of the epiphysis displaying an overgrowth; it is hard to distinguish between DEH and osteochondroma on the gross hystopathological exam. There are few immunohistochemical markers, as well as genetic tests, for EXT1 and EXT2 gene expression that can reveal a more accurate diagnosis. No evidence of malignant changes has been reported and no hereditary transmission or environmental factor has been incriminated as an etiological factor. The natural history of the disease is continuous growth of the lesions until skeletal maturity. Without treatment, the joint might suffer degenerative modification, and the patient can develop early onset osteoarthritis. In the present paper, we report two new cases of DEH of the ankle. The aim of this paper is to consider Trevor's disease when encountering tumoral masses in the epiphyses of pediatric patients and to present our treatment approach and results. Show less

Heparan sulfate (HS) is one of the factors that has been suggested to be associated with angiogenesis and invasion of glioblastoma (GBM), an aggressive and fast-growing brain tumor. However, it remains unclear how HS of endothelial cells is involved in angiogenesis in glioblastoma and its prognosis. Thus, we investigated the effect of endothelial cell HS on GBM development. We generated endothelial cell-specific knockout of The endothelial cell-specific HS reduction in the vascular endothelium of the brain suppressed GBM growth and neovascularization in mice. The online version contains supplementary material available at 10.1007/s12672-021-00444-3. Show less

Hereditary Multiple Exostoses (HME) is a rare autosomal disorder characterized by the presence of multiple exostoses (osteochondromas) caused by a heterozygous loss of function mutation in We performed a randomized cross-over study in 7 male HME patients and 12 healthy controls, matched for age, BMI, blood pressure and renal function. All subjects followed both an 8-day low sodium diet (LSD, <50 mmol/d) and high sodium diet (HSD, >200 mmol/d) in randomized order. After each diet, blood and urine samples were collected. Body fluid compartment measurements were performed by using the distribution curve of iohexol and In HME patients, HSD resulted in significant increase of intracellular fluid volume (ICFV) (1.2 L, HME patients show altered body fluid distribution and osmoregulation after HSD compared to controls. Our results might indicate reduced interstitial sodium accumulation capacity in HME, leading to ICFV increase. Therefore, this study provides additional support that HS is crucial for maintaining constancy of the internal environment. Show less

Heparan sulfate (HS), a highly sulfated linear polysaccharide, is involved in diverse biological functions in various tissues. Although previous studies have suggested a possible contribution of HS to the differentiation of white adipocytes, there has been no direct evidence supporting this. Here, we inhibited the synthesis of HS chains in 3T3-L1 cells using CRISPR-Cas9 technology, resulting in impaired differentiation of adipocytes with attenuated bone morphogenetic protein 4 (BMP4)-fibroblast growth factor 1 (FGF1) signaling pathways. HS reduction resulted in reduced glucose uptake and decreased insulin-dependent intracellular signaling. We then made heterozygous mutant mice for the Ext1 gene, which encodes an enzyme essential for the HS biosynthesis, specifically in the visceral white adipose tissue (Fabp4-Cre Show less

In diabetes mellitus (DM) patients, the morbidity of infectious disease is increased, and these infections can easily progress from local to systemic infection. Sepsis is a characteristic of organ failure related to microcirculation disorders resulting from endothelial cell injury, whose most frequent comorbidity in patients is DM. The aim of the present study was to evaluate the influence of infection on DM-induced microvascular damage on inflammation and pulmonary endothelial structure using an experimental endotoxemia model. Lipopolysaccharide (LPS; 15 mg/kg) was injected intraperitoneally into 10-week-old male C57BLKS/J Iar Show less

Metastatic renal cell carcinoma (mRCC) is the important factor for patient mortality, meanwhile gene mutation constantly changes cancer prognosis in tumor process. Exploring the driver mutation in mRCC process become more and more important. We obtained the 15 paired primary and metastatic mRCC samples and analyzed specific mutation genes in the metastatic foci (SMGs) by next generation sequencing. Moreover, we explored the Correlated networks, Pathway and Gene Ontology (GO) enrichment results, prediction analysis of AS sites and prognosis of survival. We identify EPCAM, TMEM127, EZH2, EXT1, CDKN2A, PRF1, AIP, CDK4, PRKARIA as SMGs and find that CDKN2A mutation sites affect the prognosis of mRCC by altering splicing elements. Based on the differential analysis for SMGs in KIRC, we found that EPCAM, PRF1 and EZH2 were differential expression in both primary tumors with metastasis compared to primary tumors without metastasis or metastatic tissues. By the AS prediction analysis, we suggest that CDKN2A mutation sites play an important role for RCC metastasis by affecting the p16/p14 expression. The SMGs could provide new molecular cues associated with tumor metastasis and have potential clinical implications for cancer prognosis and treatment. Definitive conclusions await further validation and follow up. Show less

Osteoarthritis (OA) represents one major cause of disability worldwide still evading efficient pharmacological or cellular therapies. Severe degeneration of extracellular cartilage matrix precedes the loss of mobility and disabling pain perception in affected joints. Recent studies showed that a reduced heparan sulfate (HS) content protects cartilage from degradation in OA-animal models of joint destabilization but the underlying mechanisms remained unclear. We aimed to clarify whether low HS-content alters the mechano-response of chondrocytes and to uncover pathways relevant for HS-related chondro-protection in response to loading. Tissue-engineered cartilage with HS-deficiency was generated from rib chondrocytes of mice carrying a hypomorphic allele of Show less

Identifying genes or genomic regions influencing carcass-quality traits such as fatness (FTN) is essential to optimize the genetic selection processes in beef cattle. The aim of this study was to identify genomic regions associated with FTN in Nellore cattle as well as to elucidate the metabolic pathways related to the phenotypic expression. Ultrasound-based measurements of FTN were collected in 11 750 animals, with 39 903 animals in the pedigree file. Additionally, 1440 animals were genotyped using the GGP-indicus 35K SNP panel, which contained 33 623 SNPs after quality control. Twenty genes related to FTN were found on 11 chromosomes, explaining 12.96% of the total additive genetic variance. Gene ontology revealed seven genes: NR1L2, PKD2, GSK3β, EXT1, RAD51B, SORCS1 and DPH6, associated with important processes related to FTN. In addition, novel candidate genes (MAATS1, LYPD1, CDK5RAP2, RAD51B, c13H2Oorf96 and TRAPPC11) were detected and could provide further knowledge to uncover genetic regions associated to carcass fatness in beef cattle. Show less

Multiple osteochondromas (MO) is an autosomal dominant hereditary disorder, which typically manifests as skeletal dysplasia, mainly involving long bones and knees, ankles, elbows, wrists, shoulders, and pelvis. Previous studies have demonstrated that mutations in exostosin glycosyl transferase-1 ( Show less

To investigate the origins and stages of vertebrate adaptive radiation, we reconstructed the spatial and temporal histories of adaptive alleles underlying major phenotypic axes of diversification from the genomes of 202 Caribbean pupfishes. On a single Bahamian island, ancient standing variation from disjunct geographic sources was reassembled into new combinations under strong directional selection for adaptation to the novel trophic niches of scale-eating and molluscivory. We found evidence for two longstanding hypotheses of adaptive radiation: hybrid swarm origins and temporal stages of adaptation. Using a combination of population genomics, transcriptomics, and genome-wide association mapping, we demonstrate that this microendemic adaptive radiation of novel trophic specialists on San Salvador Island, Bahamas experienced twice as much adaptive introgression as generalist populations on neighboring islands and that adaptive divergence occurred in stages. First, standing regulatory variation in genes associated with feeding behavior ( Show less

The endoplasmic reticulum (ER) is a central eukaryotic organelle with a tubular network made of hairpin proteins linked by hydrolysis of guanosine triphosphate nucleotides. Among posttranslational modifications initiated at the ER level, glycosylation is the most common reaction. However, our understanding of the impact of glycosylation on the ER structure remains unclear. Here, we show that exostosin-1 (EXT1) glycosyltransferase, an enzyme involved in Show less

Skeletal dysplasia (SD), a heterogeneous disease group with rare incidence and various clinical manifestations, is associated with multiple causative genes. For clinicians, accurate diagnosis of SD is clinically and genetically difficult. The development of next-generation sequencing (NGS) has substantially aided in the genetic diagnosis of SD. In this study, we conducted a targeted NGS of 437 genes - included in the nosology of SD published in 2019 - in 31 patients with a suspected SD. The clinical and genetic diagnoses were confirmed in 16 out of the 31 patients, and the diagnostic yield was 51.9%. In these patients, 18 pathogenic variants were found in 13 genes ( Show less

Membranous nephropathy (MN) results from deposition of antigen-antibody complexes along the glomerular basement membrane (GBM). PLA2R, THSD7A, NELL1, and SEMA3B account for 80%-90% of target antigens in MN. We performed laser microdissection and mass spectrometry (MS/MS) in kidney biopsies from 135 individuals with PLA2R-negative MN, and used immunohistochemistry/immunofluorescence and confocal microscopy to confirm the MS/MS finding, detect additional cases, and localize the novel protein. We also performed MS/MS and immunohistochemistry on 116 controls and used immunofluorescence microscopy to screen biopsy samples from two validation cohorts. Western blot and elution studies were performed to detect antibodies in serum and biopsy tissue. MS/MS studies detected a unique protein, protocadherin 7 (PCDH7), in glomeruli of ten (5.7%) PLA2R-negative MN cases, which also were negative for PLA2R, THSD7A, EXT1/EXT2, NELL1, and SEMA3B. Spectral counts ranged from six to 24 (average 13.2 [SD 6.6]). MS/MS did not detect PCDH7 in controls (which included 28 PLA2R-positive cases). In all ten PCDH7-positive cases, immunohistochemistry showed bright granular staining along the GBM, which was absent in the remaining cases of PLA2R-negative MN and control cases. Four of 69 (5.8%) cases in the validation cohorts (all of which were negative for PLA2R, THSD7A, EXT1, NELL1, and SEMA3B) were PCDH7-positive MN. Kidney biopsy showed minimal complement deposition in 12 of the 14 PCDH7-associated cases. Confocal microscopy showed colocalization of PCDH7 and IgG along the GBM. Western blot analysis using sera from six patients showed antibodies to nonreduced PCDH7. Elution of IgG from frozen tissue of PCDH7-associated MN showed reactivity against PCDH7. MN associated with the protocadherin PCDH7 appears to be a distinct, previously unidentified type of MN. Show less

Solitary osteochondromas are common, benign hyaline cartilage-capped exostoses that primarily arise from the metaphyses of long and flat bones. Diaphyseal aclasis is an autosomal dominant condition resulting from EXT1 or EXT2 gene mutations and is characterized by multifocal osteochondromas. These can result in a wide spectrum of complications, such as skeletal deformity, neurological and vascular complications, adventitial bursa formation, fracture, and rarely malignant transformation to peripheral chondrosarcoma. In this review, we outline in detail the multimodality imaging features of DA and its associated complications. Show less