A novel small deletion of LMX1B in a large Chinese family with nail-patella syndrome

A multi-cohort genome-wide association study in African ancestry individuals reveals risk loci for primary open-angle glaucoma

Primary open-angle glaucoma (POAG), the leading cause of irreversible blindness worldwide, disproportionately affects individuals of African ancestry. We conducted a genome-wide association study (GWAS) for POAG in 11,275 individuals of African ancestry (6,003 cases; 5,272 controls). We detected 46 risk loci associated with POAG at genome-wide significance. Replication and post-GWAS analyses, including functionally informed fine-mapping, multiple trait co-localization, and in silico validation, implicated two previously undescribed variants (rs1666698 mapping to DBF4P2; rs34957764 mapping to ROCK1P1) and one previously associated variant (rs11824032 mapping to ARHGEF12) as likely causal. For individuals of African ancestry, a polygenic risk score (PRS) for POAG from our mega-analysis (African ancestry individuals) outperformed a PRS from summary statistics of a much larger GWAS derived from European ancestry individuals. This study quantifies the genetic architecture similarities and differences between African and non-African ancestry populations for this blinding disease.

Knockdown of LMX1B Suppressed Cell Apoptosis and Inflammatory Response in IL-1β-Induced Human Osteoarthritis Chondrocytes through NF-κB and NLRP3 Signal Pathway

Osteoarthritis (OA), a chronic degenerative joint disease, always occurred in the aging population. There is evidence suggests that chondrocytes' survival, inflammation, and apoptosis play critical roles in OA pathogenesis. LMX1B has been shown to be involved in antiosteogenic function in early patterning of the calvaria. However, the role and mechanism of LMX1B in OA is not unknown. The present study observed that LMX1B was highly expressed in OA patients compared with normal patients. Besides, we found that IL-1β increased LMX1B mRNA and protein expression in SW1353 and C28/I2 chondrocytes. LMX1B knockdown increased IL-1β-induced cell viability and proliferation and suppressed cell apoptosis and inflammation response, including IFN-γ, TNF-α, IL-6, prostaglandin E2 (PGE2), and NO both in SW1353 and C28/I2. Furthermore, LMX1B silence inhibited MMP-3 and MMP-13 expression both in SW1353 and C28/I2 cells. Also, the activation of the NF-κB and NLRP3 signaling pathway was suppressed in LMX1B silence cells by decreasing the p-p65 and NLRP3 protein expressions. Additionally, inhibition of NF-κB by PDTC suppressed NLRP3 expression. Moreover, NLRP3 overexpression reversed the effects of LMX1B silence on chondrocytes' survival, proliferation, apoptosis, and inflammation. Finally, we confirmed that LMX1B depletion had protective effects in OA rats in vivo.

Case Report: Corneal Leucoma as a Novel Clinical Presentation of Nail-Patella Syndrome in a 5-Year-Old Girl

Nail-patella syndrome (NPS) is a rare autosomal-dominant disorder characterized by the classic tetrad of absent or hypoplastic finger and toe nails, absent or hypoplastic patella, skeletal deformities involving the elbow joints, and iliac horns. This disease is caused by heterozygous pathogenic variations in the LMX1B gene, which encodes the LIM homeodomain transcription factor protein (LMX1B). We report a case of corneal leucoma and dysplasia prior to overt steroid-resistant nephrotic syndrome (SRNS) in a patient with NPS. At presentation, the parents of a 5-year-old female patient reported their daughter had corneal leucoma, psychomotor delay and speech defect. We also noted the presence of bilateral edema of the lower extremities, hypertension, nail dystrophy, and the bilateral absence of patella. She developed steroid-resistant nephrotic syndrome. Lowe oculocerebrorenal syndrome and NPS were the conditions considered in differential diagnosis. Trio-based whole genome sequencing indicated a heterozygous de novo likely pathogenic variation in the LMX1B gene (c.805A>C [p.Asn269His]). Patients with NPS often develop nail, ocular, or orthopedic symptoms prior to nephrotic syndrome. Corneal leucoma may be a novel clinical presentation of NPS.

LMX1B involved in the radioresistance, proliferation and migration of esophageal cancer cells

OBJECTIVES

Esophageal cancer (EC) is one of the most difficult malignancies to cure. The radioresistance remains a major obstacle for effective treatment of EC.

METHODS

Esophageal cancer radioresistant cell lines were screened by the cumulative dose of radiation assays. qRT-PCR and Western blotting assays were used to detect the expression of LMXIB in EC. The survival fraction experiments were performed to test the effects of LMXIB in the radioresistance of EC. Following, the ionizing radiation and clonogenic, cell proliferation, wound healing and Flow cytometry apoptosis assays were used to characterize the properties of these cell lines.

RESULTS

We found that the LMX1B gene, encoding a LIM-homeodomain transcription factor, is expressed in a higher level in the radio-resistant EC cell lines. The following radiation assays revealed that LMX1B promotes the radioresistance of EC cells. Moreover, LMX1B plays roles in the proliferation, cell migration and apoptosis of EC cells.

CONCLUSION

All these results indicated that LMX1B is a key regulator involved in the radioresistance of EC, which might be used as a biomarker to guide the clinical therapy of EC.