The Interplay of NEAT1 and miR-339-5p Influences on Mesangial Gene Expression and Function in Various Diabetic-Associated Injury Models.

Mesangial cells (MCs), substantial cells for architecture and function of the glomerular tuft, take a key role in progression of diabetic kidney disease (DKD). Despite long standing researches and the need for novel therapies, the underlying regulatory mechanisms in MCs are elusive. This applies in particular to long non-coding RNAs (lncRNA) but also microRNAs (miRNAs). In this study, we investigated the expression of nuclear paraspeckle assembly transcript 1 (NEAT1), a highly conserved lncRNA, in several diabetes in-vitro models using human MCs. These cells were treated with high glucose, TGFß, TNAα, thapsigargin, or tunicamycin. We analyzed the implication of NEAT1 silencing on mesangial cell migration, proliferation, and cell size as well as on mRNA and miRNA expression. Here, the miRNA hsa-miR-339-5p was not only identified as a potential interaction partner for NEAT1 but also for several coding genes. Furthermore, overexpression of hsa-miR-339-5p leads to a MC phenotype comparable to a NEAT1 knockdown. In-silico analyses also underline a relevant role of NEAT1 and hsa-miR-339-5p in mesangial physiology, especially in the context of DKD.

Glomerular expression pattern of long non-coding RNAs in the type 2 diabetes mellitus BTBR mouse model.

The prevalence of type 2 diabetes mellitus (T2DM) and by association diabetic nephropathy (DN) will continuously increase in the next decades. Nevertheless, the underlying molecular mechanisms are largely unknown and studies on the role of new actors like long non-coding RNAs (lncRNAs) barely exist. In the present study, the inherently insulin-resistant mouse strain "black and tan, brachyuric" (BTBR) served as T2DM model. While wild-type mice do not exhibit pathological changes, leptin-deficient diabetic animals develop a severe T2DM accompanied by a DN, which closely resembles the human phenotype. We analyzed the glomerular expression of lncRNAs from wild-type and diabetic BTBR mice (four, eight, 16, and 24 weeks) applying the "GeneChip Mouse Whole Transcriptome 1.0 ST" array. This microarray covered more lncRNA gene loci than any other array before. Over the observed time, our data revealed differential expression patterns of 1746 lncRNAs, which markedly differed from mRNAs. We identified protein-coding and non-coding genes, that were not only co-located but also co-expressed, indicating a potentially cis-acting function of these lncRNAs. In vitro-experiments strongly suggested a cell-specific expression of these lncRNA-mRNA-pairs. Additionally, protein-coding genes, being associated with significantly regulated lncRNAs, were enriched in various biological processes and pathways, that were strongly linked to diabetes.

Structural and mechanical evaluations of a topology optimized titanium interbody fusion cage fabricated by selective laser melting process.

A topology optimized lumbar interbody fusion cage was made of Ti-Al6-V4 alloy by the rapid prototyping process of selective laser melting (SLM) to reproduce designed microstructure features. Radiographic characterizations and the mechanical properties were investigated to determine how the structural characteristics of the fabricated cage were reproduced from design characteristics using micro-computed tomography scanning. The mechanical modulus of the designed cage was also measured to compare with tantalum, a widely used porous metal. The designed microstructures can be clearly seen in the micrographs of the micro-CT and scanning electron microscopy examinations, showing the SLM process can reproduce intricate microscopic features from the original designs. No imaging artifacts from micro-CT were found. The average compressive modulus of the tested caged was 2.97+/-0.90 GPa, which is comparable with the reported porous tantalum modulus of 3 GPa and falls between that of cortical bone (15 GPa) and trabecular bone (0.1-0.5 GPa). The new porous Ti-6Al-4V optimal-structure cage fabricated by SLM process gave consistent mechanical properties without artifactual distortion in the imaging modalities and thus it can be a promising alternative as a porous implant for spine fusion.

Structural, mechanical and in vitro characterization of individually structured Ti-6Al-4V produced by direct laser forming.

Direct laser forming (DLF) is a rapid prototyping technique which enables prompt modelling of metal parts with high bulk density on the base of individual three-dimensional data, including computer tomography models of anatomical structures. In our project, we tested DLF-produced material on the basis of the titanium alloy Ti-6Al-4V for its applicability as hard tissue biomaterial. To this end, we investigated mechanical and structural properties of DLF-Ti-6Al-4V. While the tensile and yield strengths of untreated DLF alloy ranged beyond 1000 MPa, a breaking elongation of 6.5+/-0.6% was determined for this material. After an additional post-DLF annealing treatment, this parameter was increased two-fold to 13.0+/-0.6%, while tensile and yield strengths were reduced by approx. 8%. A Young's modulus of 118.000+/-2.300 MPa was determined for post-DLF annealed Ti-6Al-4V. All data gained from tensile testing of post-DLF annealed Ti-6Al-4V matched American Society of Testing and Materials (ASTM) specifications for the usage of this alloy as medical material. Rotating bending tests revealed that the fatigue profile of post-DLF annealed Ti-6Al-4V was comparable to casted/hot isostatic pressed alloy. We characterized the structure of non-finished DLF-Ti-6Al-4V by scanning electron microscopy and observed a surface-associated layer of particles, which was removable by sandblasting as a finishing step. We manufactured porous specimens with nominal pore diameters of 500, 700 and 1000 microm. The diameters were reduced by the used DLF processing by approx. 300 microm. In an in vitro investigation, we cultured human osteoblasts on non-porous and porous blasted DLF-Ti-6Al-4V specimens to study morphology, vitality, proliferation and differentiation of the cells. The cells spreaded and proliferated on DLF-Ti-6Al-4V over a culture time of 14 days. On porous specimens, osteoblasts grew along the rims of the pores and formed circle-shaped structures, as visualized by live/dead staining as well as scanning electron microscopy. Overall, the DLF-Ti-6Al-4V approach proved to be efficient and could be further advanced in the field of hard tissue biomaterials.