RMRP accelerates ligamentum flavum hypertrophy by regulating GSDMD-mediated pyroptosis through Gli1 SUMOylation.

Hypertrophy of ligamentum flavum (LF) is a significant contributing factor to lumbar spinal canal stenosis (LSCS). lncRNA plays a vital role in organ fibrosis, but its role in LF fibrosis remains unclear. Our previous findings have demonstrated that Hedgehog-Gli1 signaling is a critical driver leading to LF hypertrophy. Through the RIP experiment, our group found lnc-RMRP was physically associated with Gli1 and exhibited enrichment in Gli1-activated LF cells. Histological studies revealed elevated expression of RMRP in hypertrophic LF. In vitro experiments further confirmed that RMRP promoted Gli1 SUMO modification and nucleus transfer. Mechanistically, RMRP induced GSDMD-mediated pyroptosis, proinflammatory activation, and collagen expression through the Hedgehog pathway. Notably, the mechanical stress-induced hypertrophy of LF in rabbit exhibited analogous pathological changes of LF fibrosis occurred in human and showed enhanced levels of collagen and α-SMA. Knockdown of RMRP resulted in the decreased expression of fibrosis and pyroptosis-related proteins, ultimately ameliorating fibrosis. The above data concluded that RMRP exerts a crucial role in regulating GSDMD-mediated pyroptosis of LF cells via Gli1 SUMOylation, thus indicating that targeting RMRP could serve as a potential and effective therapeutic strategy for LF hypertrophy and fibrosis.

The clinical value of rapidly detecting urinary exosomal lncRNA RMRP in bladder cancer with an RT-RAA-CRISPR/Cas12a method.

BACKGROUND AND AIMS: Bladder cancer (BCa) is a highly aggressive malignancy of the urinary system. Timely detection is imperative for enhancing BCa patient prognosis. MATERIALS AND METHODS: This study introduces a novel approach for detecting long non-coding RNA (lncRNA) Mitochondrial RNA Processing Endoribonuclease (RMRP) in urine exosomes from BCa patients using the reverse transcription recombinase-aided amplification (RT-RAA) and clustered regularly interspaced short palindromic repeats and associated Cas12a proteins (CRISPR/Cas12a) technique. Various statistical methods were used to evaluate its diagnostic value for BCa. RESULTS: The specificity of urine exosomal RMRP detection for BCa diagnosis was enhanced by using RT-RAA combined with CRISPR/Cas12a. The testing process duration was reduced to 30 min, which supports rapid detection. Moreover, this approach allows the identification of target signals in real-time using blue light, facilitating immediate detection. In clinical sample analysis, this methodology exhibited a high level of diagnostic efficacy. This was evidenced by larger area under the curve values with receiver operating characteristic curve analysis compared with using traditional RT-qPCR methods, indicating superior diagnostic accuracy and sensitivity. Furthermore, the combined analysis of RMRP expression in urine exosomes detected by RT-RAA-CRISPR/Cas12a and NMP-22 expression may further enhance diagnostic accuracy. CONCLUSIONS: The RT-RAA-CRISPR/Cas12a technology is a swift, sensitive, and uncomplicated method for nucleic acid detection. Because of its convenient and non-invasive sampling approach, user-friendly operation, and reproducibility, this technology is very promising for automated detection and holds favorable application possibilities within clinical environments.

Analysis of long non-coding RNA RMRP in the diagnosis and prognosis of coronary artery disease.

BACKGROUND: Long non-coding RNAs (lncRNAs) are abundant and closely related to the occurrence and development of human diseases. LncRNAs are known to play a key role in many cardiovascular diseases. The purpose of this study was to investigate the effect of the RNA component of mitochondrial RNA-processing endoribonuclease (RMRP) on the degree of coronary artery lesions and prognosis in patients with coronary artery disease (CAD). METHODS: Patients who underwent coronary angiography (CAG) and dynamical-single photon emission computed tomography (D-SPECT) were selected as study subjects, and the results of CAG were reviewed, and the patients were grouped according to SYNTAX score. Evaluate the factors affecting SYNTAX scores. The follow-up analysis was conducted, and the endpoint events were major adverse cardiovascular events (MACEs). Kaplan-Meier method was used to estimate the survival rate, and multivariate Cox regression was used to analyze the relationship between RMRP and MACEs. RESULTS: The expression level of serum RMRP in patients with CAD was significantly higher than that in healthy people. Multivariate Logistic regression analysis showed that age, low-density lipoprotein cholesterol (LDL-C), RMRP and rest left ventricular ejection fraction (LVEF) were independent factors that affected SYNTAX scores. There were 19 cases of MACEs in the high RMRP group and 9 cases in the low RMRP group, and there was a significant difference in the MACE free survival curve between the two groups. Multivariate Cox regression analysis showed that age, SYNTAX score, rest LVEF and RMRP were risk factors for MACEs. CONCLUSIONS: Serum RMRP is a key factor affecting the degree of coronary artery disease and prognosis in CAD patients.

Mechanism study of lncRNA RMRP regulating esophageal squamous cell carcinoma through miR-580-3p/ATP13A3 axis.

OBJECTIVE: It is well-known that lncRNAs regulate energy metabolism in tumors. This study focused on the action of RMRP on esophageal squamous cell carcinoma (ESCC) cell proliferation, apoptosis, and glycolysis. METHODS: In the resected ESCC tissues and adjacent tissues from patients, RMRP/miR-580-3p/ATP13A3 expressions were evaluated. ESCC cell proliferation rates and apoptotic rates were measured by CCK-8 and flow cytometry, respectively. Apoptosis related markers were examined by Western blot. Moreover, glucose uptake, lactic acid, and ATP were measured by commercial kits, whereas HK2 and PKM2 were evaluated by Western blot to study ESCC cell glycolysis. Finally, the editing program of RMRP/miR-580-3p/ATP13A3 was translated by luciferase reporter assay and RIP analysis. RESULTS: RMRP and ATP13A3 were induced, while miR-580-3p was reduced in their expression in ESCC tissues. Silencing RMRP reduced proliferation, glycolysis, and anti-apoptosis ability of ESCC cells. RMRP sequestered miR-580-3p to target ATP13A3. Silenced ATP13A3 or overexpressed miR-580-3p rescued overexpressed RMRP-mediated promotion of proliferation, glycolysis, and anti-apoptosis of ESCC cells. CONCLUSION: RMRP accelerates ESCC progression through the miR-580-3p/ATP13A3 axis, renewing a reference for lncRNA-based therapies for tumors.

RMRP-related short stature: A report of six additional Japanese individuals with cartilage hair hypoplasia and literature review.

Biallelic pathogenic variants in RMRP, the gene encoding the RNA component of RNase mitochondrial RNA processing enzyme complex, have been reported in individuals with cartilage hair hypoplasia (CHH). CHH is prevalent in Finnish and Amish populations due to a founder pathogenic variant, n.71A > G. Based on the manifestations in the Finnish and Amish individuals, the hallmarks of CHH are prenatal-onset growth failure, metaphyseal dysplasia, hair hypoplasia, immunodeficiency, and other extraskeletal manifestations. Herein, we report six Japanese individuals with CHH from four families. All probands presented with moderate short stature with mild metaphyseal dysplasia or brachydactyly. One of them had hair hypoplasia and the other immunodeficiency. By contrast, the affected siblings of two families showed only mild short stature. We also reviewed all previously reported 13 Japanese individuals. No n.71A > G allele was detected. The proportions of Japanese versus Finnish individuals were 0% versus 70% for birth length < -2.0 SD, 84% versus 100% for metaphyseal dysplasia and 26% versus 88% for hair hypoplasia. Milder manifestations in the Japanese individuals may be related to the difference of genotypes. The mildest form of CHH phenotypes is mild short stature without overt skeletal alteration or extraskeletal manifestation and can be termed "RMRP-related short stature".

Selective Occupation by E2F and RB of Loci Expressed by RNA Polymerase III.

In all cases tested, TFIIIB is responsible for recruiting pol III to its genetic templates. In mammalian cells, RB binds TFIIIB and prevents its interactions with both promoter DNA and pol III, thereby suppressing transcription. As TFIIIB is not recruited to its target genes when bound by RB, the mechanism predicts that pol III-dependent templates will not be occupied by RB; this contrasts with the situation at most genes controlled by RB, where it can be tethered by promoter-bound sequence-specific DNA-binding factors such as E2F. Contrary to this prediction, however, ChIP-seq data reveal the presence of RB in multiple cell types and the related protein p130 at many loci that rely on pol III for their expression, including RMRP, RN7SL, and a variety of tRNA genes. The sets of genes targeted varies according to cell type and growth state. In such cases, recruitment of RB and p130 can be explained by binding of E2F1, E2F4 and/or E2F5. Genes transcribed by pol III had not previously been identified as common targets of E2F family members. The data provide evidence that E2F may allow for the selective regulation of specific non-coding RNAs by RB, in addition to its influence on overall pol III output through its interaction with TFIIIB.

Shorter birth length and decreased T-cell production and function predict severe infections in children with non-severe combined immunodeficiency cartilage-hair hypoplasia.

Background: Cartilage-hair hypoplasia (CHH) is a syndromic inborn error of immunity caused by variants in the RMRP gene. Disease manifestations vary, and their ability to predict outcome is uncertain. The optimal management of infants with CHH who do not fulfill classical severe combined immunodeficiency (SCID) criteria is unknown. Objective: We described longitudinal changes in lymphocyte counts during childhood and explored correlations of early childhood clinical and laboratory features with clinical outcomes on long-term follow-up of CHH patients. Methods: Immunologic laboratory parameters, birth length, the presence of Hirschsprung disease, and severe anemia correlated to the primary end points of respiratory and severe infections. We implemented traditional statistical methods and machine learning techniques. Results: Thirty-two children with CHH were followed up for 2.7 to 22.1 years (median, 8.2 years, in total 331.3 patient-years). None of the patients had classical SCID. Median lymphocyte subclass counts, apart from CD16+/56+ cells, were subnormal throughout childhood, but did not show age-related decline seen in healthy children. Low immunoglobulin levels were uncommon and often transient. Respiratory and/or severe infections developed in 14 children, 8 of whom had low naive T-cell counts, absent T-cell receptor excision circles, and/or partial "leaky" SCID-level lymphopenia. Shorter birth length correlated with lower lymphocyte counts and the occurrence of infections. Of the laboratory parameters, decreased naive T-cell counts and abnormal lymphocyte proliferation responses contributed most to the development of severe infections. In addition, all participants with absent T-cell receptor excision circles developed severe infections. Opportunistic infections occurred only in children with leaky SCID-level lymphopenia. Conclusions: Shorter birth length and a combination of laboratory abnormalities can predict the development of severe infections in children with CHH.

Abnormal expression of long non-coding RNAs RMRP, CTC-487M23.5, and DGCR5 in the peripheral blood of patients with Bipolar disorder.

Long non-coding RNAs (lncRNAs) have been recently considered as one of the regulatory mechanisms of the nervous system. Hence, lncRNAs may be considered diagnostic biomarkers for bipolar disorder (BD). We aimed to investigate the expression of RMRP, CTC-487M23.5, and DGCR5 lncRNAs in bipolar patients. The levels of these three lncRNAs were measured in peripheral blood mononuclear cells (PBMCs) of 50 BD patients and 50 healthy subjects by real-time PCR. Moreover, we performed a ROC curve analysis between the gene expression and some clinical features of BD patients. Significant upregulation of RMRP and CTC-487M23.5 and no significant change in levels of DGCR5 was observed in BD individuals compared with controls. Also, we found upregulation of RMRP and downregulation of CTC-487M23.5 and DGCR5 in females with BD. The areas under the ROC curve (AUC) for RMRP and CTC-487M23.5 lncRNAs were 0.80 and 0.61, respectively. There was no significant correlation between the expression of these three lncRNAs and clinical features in PBMCs of BD patients. These results suggest a role for RMRP and CTC-487M23.5 in the pathogenesis of bipolar disorder. Moreover, the peripheral expression of these two lncRNAs might be beneficial as potential biomarkers for BD.

Exosomal Long Non-Coding Ribonucleic Acid Ribonuclease Component of Mitochondrial Ribonucleic Acid Processing Endoribonuclease Is Defined as a Potential Non-Invasive Diagnostic Biomarker for Bladder Cancer and Facilitates Tumorigenesis via the miR-206/G6PD Axis.

Bladder cancer (BLCA) is one of the cancers that is highly sensitive to specific non-invasive tumor biomarkers that facilitate early diagnosis. Exosome-derived long non-coding RNAs (lncRNAs) hold promise as diagnostic biomarkers for BLCA. In this study, we employed RNA-sequencing to compare the expression patterns of lncRNAs in urine exosomes from three BLCA patients and three healthy individuals. RMRP displayed the most significant differential expression. Elevated RMRP expression levels were observed in urinary and plasma exosomes from BLCA patients compared with those from healthy individuals. RMRP exhibited significant associations with certain BLCA patient clinicopathological features, including tumor stage, poor prognosis, and tumor grade. Combined diagnosis using RMRP in urine and plasma exosomes demonstrated a superior diagnostic performance with receiver operating characteristic curve analysis. RMRP was found to be related to BLCA tumor progression and the cell migration and invasion processes via the miR-206/G6PD axis both in vitro and in vivo. Mechanistically, RMRP serves as an miR-206 sponge, as suggested by dual-luciferase reporter assays and RNA immunoprecipitation. Our study suggests that the combined diagnosis of RMRP in urinary and plasma exosomes can serve as an excellent non-invasive diagnostic biomarker for BLCA patients. Additionally, targeting the RMRP/miR-206/G6PD axis holds promise as a therapeutic strategy for BLCA.

Ropivacaine suppresses the progression of renal cell carcinoma through regulating the lncRNA RMRP/EZH2/CCDC65 axis.

BACKGROUND: Renal cell carcinoma (RCC) is a common malignancy. Local anesthetics were displayed powerful effects against various cancers. This study aims to probe the functions and molecular mechanism of ropivacaine in RCC. METHODS: Different concentrations of ropivacaine were performed to administrate RCC cells including 786-O and Caki-1 cells. Cell viability and cell apoptosis were examined using CCK-8 and flow cytometry, respectively. Cell migration and invasion were determined by transwell assay. RMRP and CCDC65 expression was firstly predicted using TCGA dataset and further validated in RCC cells using qRT-PCR and western blot. The interactions among RMRP, EZH2 and CCDC65 were verified by RNA immunoprecipitation (RIP) and chromatin immunoprecipitation (ChIP) assays. RESULTS: Ropivacaine effectively suppressed RCC cell viability, migration and invasion and enhanced cell apoptosis rate. Aberrantly elevated RMRP expression in RCC tissues was predicted by TCGA database. Interestingly, overexpressed RMRP observed in RCC cells could be also blocked upon the administration of ropivacaine. Likewise, RMRP knockdown further strengthened ropivacaine-mediated tumor suppressive effects on RCC cells. In terms of mechanism, RMRP directly interacted with EZH2, thereby modulating the histone methylation of CCDC65 to silence its expression. Moreover, ropivacaine inhibited tumor growth in mice bearing RCC tumor through regulating RMRP/EZH2/CCDC65 axis. CONCLUSION: In sum up, our work revealed that ropivacaine suppressed capacities of RCC cell viability, migration and invasion through modulating the RMRP/EZH2/CCDC65 axis, which laid the experimental foundation of ropivacaine for clinical application in the future.

Hypoxia-induced m6A demethylase ALKBH5 promotes ovarian cancer tumorigenicity by decreasing methylation of the lncRNA RMRP.

Ovarian cancer is one of the most lethal and drug-resistant gynecological diseases. Among the various post-transcriptional RNA modifications, N6-methyladenosine (m6A) has been implicated in several malignancies, including breast cancer. Recently, the biological significance of long noncoding RNA (lncRNA) methylation has garnered significant attention. The N6-methyladenosine (m6A) demethylase ALKBH5 (Alkylation Repair Homolog Protein 5) has been shown to promote ovarian cancer development by reducing the methylation of the lncRNA RMRP. In this study, we found that a hypoxic microenvironment induces an increase in ALKBH5 expression in ovarian cancer. Both in vitro and in vivo investigations demonstrated that ALKBH5, which is overexpressed in human ovarian cancer, promotes carcinogenesis. Furthermore, using bioinformatics analysis, we predicted interactions between ALKBH5 and lncRNAs, confirming RMRP as a potential binding lncRNA for ALKBH5. ALKBH5 was found to upregulate RMRP expression via demethylation. Knockdown of RMRP in ovarian cancer cell lines led to a decrease in cell growth and migration. Additionally, we demonstrated that the inhibition of ovarian cancer by ALKBH5 knockdown is partially mediated by RMRP suppression. In conclusion, our findings reveal a novel mechanism in which ALKBH5 promotes ovarian cancer by demethylating the lncRNA RMRP, suggesting its potential as a therapeutic target for the disease.

Long noncoding RNA RMRP ameliorates doxorubicin-induced apoptosis by interacting with PFN1 in a P53-Dependent manner.

Doxorubicin (DOX) often causes acute or chronic cardiotoxicity during its application. LncRNA RMRP has been reported to be associated with several biological processes, such as cartilage-hair hypoplasia, but the relationship between RMRP and DOX-induced cardiotoxicity and chronic heart failure remains obscure. To test this hypothesis, GSE124401 and GSE149870 were processed for bioinformatics, and differentially expressed RMRP was then verified in the peripheral blood of 21 patients with heart failure compared with 7 controls. For in vitro validation, we used AC16 and HEK-293T cells. qPCR was used to detect the mRNA expression levels. The degree of apoptosis was detected by Western blot and TUNEL staining. Furthermore, the interaction between RMRP and PFN1 mRNA was verified by dual-luciferase reporter assays. In bioinformatics, RMRP showed significant downregulation, which was verified in clinical samples (p < 0.001) and DOX-treated AC16 models (p < 0.0001). Next, overexpression of RMRP could significantly alleviate DOX-induced apoptosis, and a potential downstream molecule of RMRP, PFN1, was also negatively associated with this change. RESCUE experiments further confirmed that PFN1 could be regulated by RMRP at both the RNA and protein levels, serving as a downstream mediator of RMRP's cardioprotective effects. This interaction was then confirmed to be a direct combination (p < 0.0001). Finally, we found that overexpression of RMRP could inhibit the expression of p53 and its phosphorylation level by suppressing PFN1. In summary, RMRP could exert cardioprotective effects via the PFN1/p53 axis, holding great promise for serving as a therapeutic target and potential biomarker.

TiO2nanotubes promote osteogenic differentiation of human bone marrow stem cells via epigenetic regulation ofRMRP/DLEU2/EZH2 pathway.

TiO2nanotubes (TNTs) significantly promote osteogenic differentiation and bone regeneration of cells. Nevertheless, the biological processes by which they promote osteogenesis are currently poorly understood. Long non-coding RNAs (lncRNAs) are essential for controlling osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). Epigenetic chromatin modification is one of the pathways in which lncRNAs regulate osteogenic differentiation. Here, we reported that TNTs could upregulate lncRNARMRP, and inhibition of lncRNARMRPin human BMSCs (hBMSCs) grown on TNTs could decrease runt-related transcription factor 2 (RUNX2), alkaline phosphatase, osteopontin, and osteocalcin (OCN) expression. Furthermore, we discovered that inhibiting lncRNARMRPelevated the expression of lncRNADLEU2, and lncRNADLEU2knockdown promoted osteogenic differentiation in hBMSCs. RNA immunoprecipitation experiments showed that lncRNADLEU2could interact with EZH2 to induce H3K27 methylation in the promoter regions of RUNX2 and OCN, suppressing gene expression epigenetically. According to these results, lncRNARMRPis upregulated by TNTs to promote osteogenic differentiation throughDLEU2/EZH2-mediated epigenetic modifications.

Expanding the phenotype of anauxetic dysplasia caused by biallelic NEPRO mutations: A case report.

The cartilage hair hypoplasia and anauxetic dysplasia (CHH-AD) spectrum encompasses a group of rare skeletal disorders, with anauxetic dysplasia (ANXD) at the most severe end of the spectrum. Biallelic variants in RMRP, POP1, and NEPRO (C3orf17) have previously been associated with the three currently recognized ANXD types. Generally, all types are characterized by severe short stature, brachydactyly, skin laxity, joint hypermobility and dislocations, and extensive skeletal abnormalities visible on radiological evaluation. Thus far, only five patients with type 3 anauxetic dysplasia (ANXD3) have been reported. Here, we describe one additional ANXD3 patient. We provide a detailed physical and radiological evaluation of this patient, in whom we identified a homozygous variant, c.280C > T, p.(Arg94Cys), in NEPRO. Our patient presented with clinically relevant features not previously described in ANXD3: atlantoaxial subluxation, extensive dental anomalies, and a sagittal suture craniosynostosis resulting in scaphocephaly. We provide an overview of the literature on ANXD3 and discuss our patient's characteristics in the context of previously described patients. This study expands the phenotypic spectrum of ANXD, particularly ANXD3. Greater awareness of the possibility of atlantoaxial subluxation, dental anomalies, and craniosynostosis may lead to more timely diagnosis and treatment.

m6A-mediated upregulation of lncRNA RMRP boosts the progression of bladder cancer via epigenetically suppressing SCARA5.

Aim: This study aimed to elucidate the relationship between SCARA5 and RMRP in bladder cancer and their underlying mechanism. Methods: Biological functions were evaluated using cell-counting kit 8 assay, 5-ethynyl-2'-deoxyuridine incorporation, wound healing and Transwell assays. RNA immunoprecipitation, RNA pull-down and chromatin immunoprecipitation were employed. A xenograft tumor model in nude mice was also conducted. Results & conclusion: RMRP and SCARA5 exhibited an inverse correlation. Downregulation of RMRP significantly suppressed bladder cancer cell proliferation, migration and invasion, which was reversed by SCARA5 overexpression. RMRP recruited DNA methyltransferases to the promoter region of SCARA5, thereby triggering the methylation of the SCARA5 promoter to epigenetically suppress its expression. Our findings elucidate the machinery by which RMRP, stabilized by METTL3, exerts a promoter role in bladder cancer tumorigenesis by triggering SCARA5 methylation.

LncRNA RMRP aggravates LPS-induced HK-2 cell injury and AKI mice kidney injury by upregulating COX2 protein via targeting ELAVL1.

OBJECTIVES: There is emerging evidence that long non-coding RNA component of mitochondrial RNA processing endoribonuclease (lncRNA RMRP) is involved in acute kidney injury (AKI) progression, but the specific mechanism of action still requires further investigation. METHODS: The lipopolysaccharide (LPS)-treated HK-2 cells were transfected with pcDNA-RMRP or si-RMRP, or transfected with pcDNA-ELAV like RNA binding protein 1 (ELAVL1) or si-ELAVL1, and cell viability, apoptosis, inflammatory factor secretion and oxidative stress were detected. The LPS-treated HK-2 cells were transfected with si-RMRP alone or together with pcDNA-ELAVL1, and cell behaviors were examined. The LPS-treated HK-2 cells were transfected with si-ELAVL1 alone or together with pcDNA- cyclooxygenase-2 (COX2), and the cellular changes were observed. The LPS-treated HK-2 cells were transfected with si-RMRP alone or together with pcDNA-ELAVL1, or together with pcDNA-ELAVL1 and si-COX2, and cell behaviors were examined. A mouse model of AKI was constructed using male C57BL/6 mice by the method of cecal ligation and puncture and intraperitoneal injection of LPS to explore the effect of RMRP silencing on renal injury in vivo. RESULTS: RMRP and ELAVL1 was upregulated in LPS-treated HK-2 cells, and RMRP or ELAVL1 overexpression inhibited cell viability and promoted cell apoptosis, inflammatory factor secretion and oxidative stress, and RMRP knockdown showed the opposite effects. ELAVL1 upregulated COX2 protein expression and overexpression of COX2 reversed the promoting effects of RMRP knockdown on cell viability, as well as the inhibitory effects on cell apoptosis, inflammatory factor secretion and oxidative stress. Mechanistic findings suggested that RMRP aggravates LPS induced cell injury by activating prostaglandin E (PGE)/janus kinase-2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway. We observed that knockdown of RMRP expression significantly alleviated renal tissue apoptosis, inflammatory factor secretion, and oxidative stress with AKI mice. CONCLUSIONS: Our findings may provide a new reference for the treatment of AKI.

Natural history and genetic spectrum of the Turkish metaphyseal dysplasia cohort, including rare types caused by biallelic COL10A1, COL2A1, and LBR variants.

BACKGROUND: Metaphyseal chondrodysplasias are a heterogeneous group of diseases characterized by short and bowed long bones and metaphyseal abnormality. The aim of this study is to investigate the genetic etiology and prognostic findings in patients with metaphyseal dysplasia. METHODS: Twenty-four Turkish patients were included in this study and 13 of them were followed for 2-21 years. COL10A1, RMRP sequencing and whole exome sequencing were performed. RESULTS: Results: Seven heterozygous pathogenic variants in COL10A1 were detected in 17 patients with Schmid type metaphyseal chondrodysplasia(MCDS). The phenotype was more severe in patients with heterozygous missense variants (one in signal peptide domain at the N-terminus of the protein, the other, class-1 group mutation at NC1 domain) compared to the patients with truncating variants. Short stature and coxa vara deformity appeared after 3 and 5 years of age, respectively, while large femoral head resolved after the age of 13 years in MCDS group. Interestingly, one patient with severe phenotype also had a biallelic missense variant in NC1 domain of COL10A1. Three patients with biallelic mutations in RMRP had prenatal onset short stature with short limb, and typical findings of cartilage hair hypoplasia (CHH). While immunodeficiency or recurrent infections were not observed, resistant congenital anemia was detected in one. Biallelic mutation in LBR was described in a patient with prenatal onset short stature, short and curved limb and metaphyseal abnormalities. Unlike previously reported patients, this patient had ectodermal findings, similar to CHH. A biallelic COL2A1 mutation was also found in the patient with lower limb deformities and metaphyseal involvement without vertebral and epiphyseal changes. CONCLUSION: Long-term clinical characteristics are presented in a metaphyseal dysplasia cohort, including rare types caused by biallelic COL10A1, COL2A1, and LBR variants. We also point out that the domains where mutations on COL10A1 take place are important in the genotype-phenotype relationship.

Immunologic Heterogeneity in 2 Cartilage-Hair Hypoplasia Patients With a Distinct Clinical Course.

BACKGROUND AND OBJECTIVE: Cartilage-hair hypoplasia (CHH) syndrome is a rare autosomal recessive syndrome associated with skeletal dysplasia, varying degrees of combined immunodeficiency (CID), short stature, hair hypoplasia, macrocytic anemia, increased risk of malignancies, and Hirschsprung disease. To provide clinical and immunological insights obtained from 2 unrelated patients who displayed clinical characteristics of CHH. METHODS: Two patients with suspected CHH syndrome due to skeletal dysplasia and immunodeficiency underwent an immunological and genetic work-up using flow cytometry, next-generation sequencing (NGS) of the immune repertoire, and Sanger sequencing to identify the underlying defects. RESULTS: Patient 1 presented with low birth weight and skeletal dysplasia. Newborn screening was suggestive of T-cell immunodeficiency, as T-cell receptor excision circle levels were undetectable. Both the T-cell receptor (TCR) Vß and TCR-g (TRG) repertoires were restricted, with evidence of clonal expansion. Genetic analysis identified compound heterozygous RMRP variants inherited from both parents. Patient 2 presented with recurrent lung and gastrointestinal infections, skeletal dysplasia, failure to thrive, and hepatomegaly. The polyclonal pattern of the TCRß repertoire was normal, with only slight overexpression of TCR-ßV20 and restricted expression of Vßs. TRG expressed a normal diverse repertoire, similar to that of the healthy control sample. Genetic analysis identified biallelic novel regulatory variants in RMRP. Both parents are carriers of this mutation. CONCLUSION: Our findings demonstrate how the immunological work-up, supported by genetic findings, can dramatically change treatment and future outcome in patients with the same clinical syndrome.

Expression of T cell-related lncRNAs in multiple sclerosis.

Long non-coding RNAs (lncRNAs) have been demonstrated to in the pathophysiology of multiple sclerosis (MS). In order to appraise the role of T cell-related lncRNAs in this disorder, we assessed expressions of NEST, RMRP, TH2-LCR, MAFTRR and FLICR in MS patients and healthy individuals. We detected significant difference in the expression of RMRP and FLICR between cases and controls. There were substantial correlations between expressions of NEST, RMRP, TH2-LCR, MAFTRR and FLICR lncRNAs among patients, but not controls. The strongest correlations were found between RMRP and TH2-LCR, and between MAFTRR and RMRP with correlation coefficients of 0.69 and 0.59, respectively. ROC curve analysis revealed appropriate power of FLICR in differentiating between MS patients and healthy controls (AUC value = 0.84). Expression of NEST lncRNA was positively correlated with disease duration in MS patients, but negatively correlated with age at onset. In brief, we reported dysregulation of two T cell-related lncRNAs in MS patients and proposed FLICR as a putative marker for this disorder.

Prenatal Cases Reflect the Complexity of the COL1A1/2 Associated Osteogenesis Imperfecta.

INTRODUCTION: Osteogenesis imperfecta (OI) is a rare mendelian skeletal dysplasia with autosomal dominant or recessive inheritance pattern, and almost the most common primary osteoporosis in prenatal settings. The diversity of clinical presentation and genetic etiology in prenatal OI cases presents a challenge to counseling yet has seldom been discussed in previous studies. METHODS: Ten cases with suspected fetal OI were enrolled and submitted to a genetic detection using conventional karyotyping, chromosomal microarray analysis (CMA), and whole-exome sequencing (WES). Sanger sequencing was used as the validation method for potential diagnostic variants. In silico analysis of specific missense variants was also performed. RESULTS: The karyotyping and CMA results of these cases were normal, while WES identified OI-associated variants in the COL1A1/2 genes in all ten cases. Six of these variants were novel. Additionally, four cases here exhibited distinctive clinical and/or genetic characteristics, including the situations of intrafamilial phenotypic variability, parental mosaicism, and "dual nosogenesis" (mutations in collagen I and another gene). CONCLUSION: Our study not only expands the spectrum of COL1A1/2-related OI, but also highlights the complexity that occurs in prenatal OI and the importance of clarifying its pathogenic mechanisms.