Hnrnpk protects against osteoarthritis through targeting WWC1 mRNA and inhibiting Hippo signaling pathway

Osteoarthritis (OA) is an age-related or post-traumatic degenerative whole joint disease characterized by the rupture of articular cartilage homeostasis, the regulatory mechanisms of which remain elusive. This study identifies the essential role of heterogeneous nuclear ribonucleoprotein K (hnRNPK) in maintaining articular cartilage homeostasis. Hnrnpk expression is markedly downregulated in human and mice OA cartilage. The deletion of Hnrnpk effectively accelerates the development of post-traumatic and age-dependent OA in mice. Mechanistically, the KH1 and KH2 domain of Hnrnpk bind and degrade the mRNA of WWC1. Hnrnpk deletion increases WWC1 expression, which in turn leads to the activation of Hippo signaling and ultimately aggravates OA. In particular, intra-articular injection of LPA and adeno-associated virus serotype 5 expressing WWC1 RNA interference ameliorates cartilage degeneration induced by Hnrnpk deletion, and intra-articular injection of adeno-associated virus serotype 5 expressing Hnrnpk protects against OA. Collectively, this study reveals the critical roles of Hnrnpk in inhibiting OA development through WWC1-dependent downregulation of Hippo signaling in chondrocytes and defines a potential target for the prevention and treatment of OA.

Effect of CDH1 and CDH2 genes polymorphisms in oral squamous cell carcinoma susceptibility in a sample of Iranian population: A case-control study

Background and Aims

Oral squamous cell carcinoma (OSCC) is a global malignant epithelial neoplasm affecting the oral cavity. Cadherins, as an adhesion molecule, are involved in cell-cell interaction. We aim to study the effect of two cadherin polymorphisms on OSCC risk in southeast of Iran.

Methods

In this case-control study, 94 individuals (47 OSCC cases and 47 controls), that referred to the Department of Oral Pathology, Faculty of Dentistry, Zahedan University of Medical Sciences, Iran were included. Cadherin single nucleotide polymorphisms CDH1 (rs16260) and CDH2 (rs11564299) were genotyped by the tetra-Amplification Refractory Mutation System-PCR technique.

Results

N-cadherin genotyping showed that the AA, AG, and AG + GG were presented 78.7%, 17%, 21.3% versus 66%, 29.7%, 34% in the cases and the control group, respectively. AG genotype was more common in control than case (OR = 0.47, 95% CI: 0.17-1.29, p = 0.14). G allele was more prevalent in control (19.1%) than the case group (12.8%) (OR = 0.61, 95% CI: 0.27-1.36, p = 0.23). In E-cadherin, AC, AA, and AC + AA genotypes frequency were 17%, 12.8%, and 29.8% in case versus 8.5%, 8.5%, and 17% in the control group. Allele A was more common in the case than the control group (OR = 1.84, 95% CI: 0.84-4.03, p = 0.12). Also, AA and CC, the codominant genotypes were common in CDH2 and CDH1 respectively in all histopathological grades, and no statically significant association was observed between OSCC different histopathological grades and cadherin genotypes (p = 0.39 in N-cadherin, p = 0.74 in E-cadherin).

Conclusion

Our results showed a lack of association between CDH1 and CDH2 gene polymorphisms with OSCC risk in a population of Southeastern of Iran.

ETS1 loss in mice impairs cardiac outflow tract septation via a cell migration defect autonomous to the neural crest

Ets1 deletion in some mouse strains causes septal defects and has been implicated in human congenital heart defects in Jacobsen syndrome, in which one copy of the Ets1 gene is missing. Here, we demonstrate that loss of Ets1 in mice results in a decrease in neural crest (NC) cells migrating into the proximal outflow tract cushions during early heart development, with subsequent malalignment of the cushions relative to the muscular ventricular septum, resembling double outlet right ventricle (DORV) defects in humans. Consistent with this, we find that cultured cardiac NC cells from Ets1 mutant mice or derived from iPS cells from Jacobsen patients exhibit decreased migration speed and impaired cell-to-cell interactions. Together, our studies demonstrate a critical role for ETS1 for cell migration in cardiac NC cells that are required for proper formation of the proximal outflow tracts. These data provide further insights into the molecular and cellular basis for development of the outflow tracts, and how perturbation of NC cells can lead to DORV.

Significance of m6A regulatory factor in gene expression and immune function of osteoarthritis

One of the most prevalent posttranscriptional modifications of eukaryotic mRNA is the RNA N6-methyladenosine (m⁶A) regulator, which plays a significant role in various illnesses. The involvement of m⁶A regulators in osteoarthritis (OA) is not fully known. By comparing nonosteoarthritic and osteoarthritic patients, 26 important m⁶A regulators were identified from the gene expression omnibus GSE48556 dataset. Seven candidate m⁶A regulators (IGFBP3, WTAP, IGFBP1, HNRNPC, RBM15B, YTHDC1, and METTL3) were screened using a random forest model to assess the likelihood of OA. A column line graph model founded on seven m⁶A modulator candidates was created. According to decision curve analysis, patients might profit from the column line graph model. Based on chosen relevant m⁶A modifiers, a consensus clustering approach was utilized to categorize OA into two m⁶A categories (group A and group B). To measure the m⁶A pattern, a principal component analysis technique was created to generate the m⁶A score for every sample. Cluster A patients exhibited more excellent m⁶A scores than cluster B patients. Furthermore, we discovered that patients with lower and higher m⁶A scores had varied immunological responses using the m⁶A type. At last, m⁶A regulators contribute significantly to the progression of OA. Our research on m⁶A patterns might help to guide further OA immunotherapeutic techniques.

Integrins, cadherins and channels in cartilage mechanotransduction: perspectives for future regeneration strategies

Articular cartilage consists of hyaline cartilage, is a major constituent of the human musculoskeletal system and has critical functions in frictionless joint movement and articular homoeostasis. Osteoarthritis (OA) is an inflammatory disease of articular cartilage, which promotes joint degeneration. Although it affects millions of people, there are no satisfying therapies that address this disease at the molecular level. Therefore, tissue regeneration approaches aim at modifying chondrocyte biology to mitigate the consequences of OA. This requires appropriate biochemical and biophysical stimulation of cells. Regarding the latter, mechanotransduction of chondrocytes and their precursor cells has become increasingly important over the last few decades. Mechanotransduction is the transformation of external biophysical stimuli into intracellular biochemical signals, involving sensor molecules at the cell surface and intracellular signalling molecules, so-called mechano-sensors and -transducers. These signalling events determine cell behaviour. Mechanotransducing ion channels and gap junctions additionally govern chondrocyte physiology. It is of great scientific and medical interest to induce a specific cell behaviour by controlling these mechanotransduction pathways and to translate this knowledge into regenerative clinical therapies. This review therefore focuses on the mechanotransduction properties of integrins, cadherins and ion channels in cartilaginous tissues to provide perspectives for cartilage regeneration.

CDH2 gene rs11564299 polymorphism is a risk factor for knee osteoarthritis in a Chinese population: a case-control study

Background

Cadherin-2 (CDH2) gene polymorphisms were reported to be associated with the induction and development of knee osteoarthritis (OA).

Methods

This case–control study was designed to explore the association between CDH2 gene rs11564299 polymorphism and the risk of knee OA in Chinese subjects. The polymorphism was genotyped by polymerase chain reaction and Sanger sequencing.

Results

G allele or GG genotype of CDH2 gene rs11564299 polymorphism was related to increased risk for knee OA in the Chinese Han population. Additionally, subgroup analyses indicated that the female, smoker, drinker, and BMI ≥ 25 kg/m² groups showed increased risk for knee OA. Additionally, this polymorphism was associated with CRP and Kellgren–Lawrence grade.

Conclusion

In summary, this current study reveals that CDH2 gene rs11564299 polymorphism is a risk factor for knee OA development in this Chinese population. The genotypes distribution differed significantly among OA patients and healthy controls and may be a useful tool in the evaluation of OA susceptibility in Chinese Han population.

Identification of a single-nucleotide polymorphism within CDH2 gene associated with bone morbidity in childhood acute lymphoblastic leukemia survivors

Aim: To identify genetic markers associated with late treatment-related skeletal morbidity in survivors of childhood acute lymphoblastic leukemia (ALL). Patients & methods: To this end, we measured the association between reduction in bone mineral density or vertebral fractures prevalence and variants from 1039 genes derived through whole exome sequencing in 242 childhood ALL survivors. Top-ranking variants were confirmed through genotyping, and further explored with stratified analyses and multivariable models. Results: The minor allele of rs1944294 in CDH2 gene was associated with bone geometrical parameter, trabecular cross-sectional area (p = 0.001). The association was modulated by radiation therapy (p = 0.001) and post-treatment time (p = 0.0002). Conclusion: The variant in CDH2 gene is a potential novel risk factor of bone morbidity in survivors of childhood ALL.

Single-nucleotide polymorphisms of the adherent junction component cadherin gene are associated with leukoaraiosis

BACKGROUND

Leukoaraiosis (LA) is one of the manifestations of cerebral small vessel disease. Blood-brain barrier (BBB) disruption plays a key role in LA. Cadherin is a component of adherent junctions (AJ), which play a crucial role in cell-cell adhesion, cell-cell recognition and homeostasis in BBB development. We hypothesized that alterations in cadherin genes might be a potential cause of BBB abnormalities that result in LA.

METHODS

A total of 339 LA individuals (LA-PVWM, 183; LA-DWM 156) were enrolled, who underwent brain magnetic resonance imaging with obtainable vascular risk factors. Genotyping of cadherin single-nucleotide polymorphisms (SNPs) (rs5030625, rs1801026, and rs16260) was performed by real-time polymerase chain reaction with LightSNiP reagents (coupled primer and probe) and FastStart DNAMaster HybProbe (Roche Diagnostic, GmBH, Mannheim, Germany) on a LightCycler 2.0 instrument.

RESULTS

Two SNPs, rs1801026 and rs16260, were significantly different between the control and LA groups. The combinatorial effects of the three SNPs were also significant. The haplotypes G-T-C and GA-T-A increased the development of LA-PVWM (OR = 1.76 and OR = 40.7, respectively). The haplotypes G-T-A and GA-T-A increased the development of LA-DWM (OR = 2.56 and OR = 10.48, respectively), but G-C-C decreased the development of LA-DWM (OR = 17.57).

CONCLUSION

This study provides evidence for genetic polymorphisms of the AJ component cadherin gene and the association of its haplotypes with LA.

Analysis of the association between CDH2 gene polymorphism and osteoarthritis risk

OBJECTIVE

to define the cadherin 2 (CDH2) gene polymorphism in Chinese osteoarthritis and control populations and to explore the correlation between CDH2 gene polymorphism and the risk of osteoarthritis.

METHOD

a total of 476 patients with osteoarthritis were collected and 380 control subjects were included in the study. Clinical data such as gender, age and functional score were collected. The blood and tissue samples were collected and genotyped by PCR. Data analysis was performed using SPSS 19.0, Hapioview 4.2 and SNPstats softwares.

RESULTS

the association of rs11083271 and osteoarthritis was initially validated in this study population (P = 0.016, OR = 1.43 (1.07- 1.93)]. The risk of OA was significantly higher in heterozygous T/C than in homozygous T/T and C/C in rs11083271. By adjusting the age, according to gender stratification analysis, the heterozygous T/C genotype in rs11083271 significantly increased the risk of OA incidence in males [p = 0.011, 3.40 (1.55-7.43)]. The remaining rs sites were not significantly associated with OA. Notably, the association of rs11564299 with OA, regardless of genotyping, gene frequency and RNA expression levels in the study population, was not confirmed.

CONCLUSION

in this study, we have analyzed the association between CDH2 gene polymorphism and OA in Chinese population. We found that rs11083271 heterozygous T/C genotype significantly increases the risk of OA and the severity of the disease. By contrast, the rs11564299 locus and OA have no significant correlation in the Chinese population. The role of rs11083271 in the regulation of CDH2 expression levels and the mechanisms by which it impacts OA remain to be further studied.

Egr-1 increases angiogenesis in cartilage via binding Netrin-1 receptor DCC promoter

Background

Osteoarthritis (OA) is a joint disease characterized by degradation of cartilage. The etiology of OA is still unclear. Vascular endothelial growth factor (VEGF) plays a key role of angiogenesis in the pathogenesis of OA and contributes to the angiogenesis of NT-1/DCC. Whether or not NT-1/DCC and VEGF interact in regulating angiogenesis of OA cartilage is not known.

Methods

Histological studies for CD34, VEGF, and safranin-O staining were performed to determine angiogenesis and cartilage tissue injury. ELISA indicated the level of pro-inflammation cytokines. Immunoblotting, immunoprecipitation, and electrophoretic mobility shift assay (EMSA) were performed to assay the expression and function of NT-1/DCC-VEGF signaling pathway.

Results

Our data indicated that VEGF expression was increased in cartilage tissue from OA rats, while the chondrocytes were disorganized, and cartilage degeneration was increasing in OA rats. The inflammation factors in articular cavity fluid were higher in the OA rats than in the sham. The protein expression of NT-1, DCC, and VEGF were increased in osteoarthritic cartilage. DCC was involved in the positive regulation of osteoarthritic angiogenesis by VEGF. Egr-1 expression was higher in OA rats than in sham rats. Egr-1 is a regulator of DCC promoter activity, and the binding is higher in OA rats than in sham rats.

Conclusion

Our present study provides a mechanism by which Egr-1 induced angiogenesis via NT-1/DCC-VEGF pathway.

Osteoarthritis year in review 2014: genetics and genomics

Recent developments in genetics/genomics of osteoarthritis (OA) are discussed to improve our understanding of OA pathophysiology. The discovery of a novel variant near the NCOA3 (nuclear receptor coactivator 3) gene associated with hip OA and the regulation of GDF5 gene by four transcription factors via the OA susceptibility locus rs143383 are among important findings in OA genetics. Several microarray-based gene expression studies were published for different tissues of the joint. In OA synovium elevation of collagens and cross-linking enzymes (COL1A1, COL5A1, PLOD2, LOX and TIMP1) responsive to TGF-β was found as well as differential expression pattern between different areas of the osteoarthritic synovial membrane. In OA peripheral blood the role of apoptotic genes was highlighted, while whole genome expression profiling in OA subchondral bone and cartilage revealed common genes in cartilage and bone to be involved in OA development. In epigenetics, several microRNAs (miRNAs) were found to regulate genes' expression in chondrocytes, among which miR-125, miR-127b miR-21, miR-148a and their use as potential drug targets was highlighted. Future studies must focus on the integration of genetics, genomics and epigenetics for the identification of signaling pathways and regulatory networks responsible for OA development.

Association between interleukin 8 -251 A/T and +781 C/T polymorphisms and osteoarthritis risk

PURPOSE

Interleukin 8 (IL-8), as a member of the CXC chemokine family, has a regulatory role in joint inflammation and cartilage degradation, and contribute to the pathophysiology of osteoarthritis. The aim of the current study was to examine the influence of the IL-8 gene polymorphisms at positions -251 (rs4073) and +781 (rs2227306) on the risk of osteoarthritis.

METHODS

This hospital-based case-control study comprised 150 patients with osteoarthritis and 150 age- and gender-matched controls. IL-8 251 A/T and +781 C/T polymorphisms were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).

RESULTS

Patients with osteoarthritis had a significantly higher frequency of IL-8 -251 TT genotype [odds ratio (OR)=2.16, 95% confidence interval (CI)=1.09, 4.26; P=0.03], IL-8 -251 T allele (OR=1.41, 95% CI=1.02, 1.94; P=0.04), IL-8 +781 TT genotype (OR=2.79, 95% CI=1.10, 7.08; P=0.03) and IL-8 +781 T allele (OR=1.48, 95% CI=1.02, 2.14; P=0.04) than controls. But the findings are less emphatic by the Bonferroni correction. When stratifying by body mass index, type, articular involvement, and Kellgren-Lawrence grade, no significant differences were found in any groups.

CONCLUSIONS

For the first time, the current data suggested that the TT genotype and T allele of the IL-8 gene polymorphisms at positions -251 and +781 might confer a high risk of osteoarthritis. In the future, additional well-designed large studies were required for the validation of our results.