Mutation analysis and prenatal diagnosis for three families affected by isolated methylmalonic aciduria

Chemerin/ChemR23 axis promotes inflammation of glomerular endothelial cells in diabetic nephropathy

Diabetic nephropathy (DN) is characterized by inflammation of renal tissue. Glomerular endothelial cells (GEnCs) play an important role in inflammation and protein leakage in urine in DN patients. Chemerin and its receptor ChemR23 are inducers of inflammation. The aim of this study was to investigate the function of chemerin/ChemR23 in GEnCs of DN patients. Immunohistochemical staining and qRT‐PCR were used to measure the expression of chemerin, ChemR23 and inflammatory factors in renal tissues of DN patients. Db/db mice were used as animal model. ChemR23 of DN mice was knocked down by injecting LV3‐shRNA into tail vein. Inflammation, physiological and pathological changes in each group was measured. GEnCs were cultured as an in vitro model to study potential signalling pathways. Results showed that expression of chemerin, ChemR23 and inflammatory factors increased in DN patients and mice. LV3‐shRNA alleviated renal damage and inflammation in DN mice. GEnCs stimulated by glucose showed increased chemerin, ChemR23 and inflammatory factors and decreased endothelial marker CD31. Both LV3‐shRNA and SB203580 (p38 MAPK inhibitor) attenuated chemerin‐induced inflammation and injury in GEnCs. Taken together, chemerin/ChemR23 axis played an important role in endothelial injury and inflammation in DN via the p38 MAPK signalling pathway. Suppression of ChemR23 alleviated DN damage.

Microarray analysis reveals long non‑coding RNA SOX2OT as a novel candidate regulator in diabetic nephropathy

Diabetic nephropathy (DN) is a highly complex syndrome involving multiple dysregulated biological processes. Long non-coding RNAs (lncRNAs) are now believed to have an important function in various diseases. However, their roles in DN remain largely unknown. Therefore, the present study was performed in order to investigate the lncRNAs that have a crucial role in DN. db/db mice were used as a DN model while db/m mice served as a control to search for lncRNAs which may have important roles in DN. Microarray and bioinformatics analysis gave an overview of the features of differentially expressed genes. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis demonstrated the typical biological alterations in DN. A co-expression network of lncRNAs and mRNAs revealed the complex interaction pattern in DN conditions. Further data investigation indicated that SOX2-overlapping transcript (SOX2OT), which was significantly downregulated in DN mice, may be the potentially functional lncRNA contributing to the onset of DN. The UCSC database demonstrated that SOX2OT was highly conserved in mice and humans. Additionally further study using cultured human podocytes and mesangial cells confirmed the downregulation of SOX2OT using reverse transcription-quantitative polymerase chain reaction and fluorescence in situ hybridization. However, the cellular location of SOX2OT depended on certain cell types. Taken together, the results of the present study indicated that SOX2OT may act as an important regulator in the pathogenesis of DN by interacting with various mRNAs with critical roles in DN.

Management of adult-onset methylmalonic acidemia with hypotonia and acute respiratory failure: A case report

RATIONALE

Methylmalonic acidemia (MMA) is an autosomal recessive disease of organic acidemia.

PATIENT CONCERNS

We report a 26-year-old male who presented with metabolic acidosis, acute renal failure required hemodialysis and acute respiratory failure required mechanical ventilation support. Progressive hypotonia of muscles made weaning from mechanical ventilator difficult.

DIAGNOSES

High level of serum methylmalonic acid and the mut genotype sequences confirmed the diagnosis of this adult-onset MMA. Two mut genotype sequences were found by analyzing all coding exons and exon-intron junctions. One genotype was well documented (Exon 6 Mutation, c. 1280G>A. p. G427D, heterozygous). The other mut genotype sequence had never been reported elsewhere (Intron 6 Novel, c. 1333-13_c. 1333-8delTTTTTC, heterozygous).

INTERVENTIONS

Diet modification, medication, regular hemodialysis and physical rehabilitation. Weaning strategy adjusted with help of electrical impedance tomography.

OUTCOMES

The muscle power of the patient gradually recovered. Extubation of the patient was successful and he was discharged without oxygen required.

LESSONS

This case gives us the lesson that MMA can be newly diagnosed in adult patient. A new mut genotype sequence was discovered. The use of electrical impedance tomography to select a suitable method for inspiratory muscle training was possible and useful.