Effects of self-assembled type II collagen fibrils on the morphology and growth of pre-chondrogenic ATDC5 cells.

Objective: Although type II collagen could have marked potential for developing cartilage tissue engineering (CTE) scaffolds, its erratic supply and viscous nature have limited these studies, and there are no studies on the use of marine-derived type II collagen fibrils for CTE scaffold materials. In this study, we aimed to generate a fibril-based, thin-layered scaffold from marine-derived type II collagen and investigate its chondrogenic potential. Methods: Time-lapse observations revealed the cell adhesion process. The Cell Counting Kit-8 (CCK-8) assay, light microscopy, and scanning electron microscopy were performed to detect proliferation and filopodium morphology. Alcian blue staining was used to show the deposition of extracellular secretions, and qRT-PCR was performed to reveal the expression levels of chondrogenesis-related genes. Results: The cell adhesion speed was similar in both fibril-coated and control molecule-coated groups, but the cellular morphology, proliferation, and chondrogenesis activity differed. On fibrils, more elongated finer filopodia showed inter-cell communications, whereas the slower proliferation suggested an altered cell cycle. Extracellular secretions occurred before day 14 and continued until day 28 on fibrils, and on fibrils, the expression of the chondrogenesis-related genes Sox9 (p â€‹< â€‹0.001), Col10a1 (p â€‹< â€‹0.001), Acan (p â€‹< â€‹0.001), and Col2a1 (p â€‹= â€‹0.0049) was significantly upregulated on day 21. Conclusion: Marine-derived type II collagen was, for the first time, fabricated into a fibril state. It showed rapid cellular affinity and induced chondrogenesis with extracellular secretions. We presented a new model for studying chondrogenesis in vitro and a potential alternative material for cell-laden CTE research.

MicroRNA-23b prevents aortic aneurysm formation by inhibiting smooth muscle cell phenotypic switching via FoxO4 suppression.

AIMS: Phenotypic switching of vascular smooth muscle cells (VSMCs) is essential for the formation of abdominal aortic aneurysms (AAAs). MicroRNA-23b (miR-23b) has recently been shown to play a vital role in maintaining the VSMC contractile phenotype; however, little is known about the role of miR-23b in the formation of AAAs. Here, we investigated whether miR-23b prevents AAA formation by inhibiting VSMC phenotypic switching. MATERIALS AND METHODS: We administered angiotensin II (Ang II, 1000 ng/kg/min) or vehicle to 10-12-week-old male apolipoprotein E knockout (ApoE-/-) or C57BL/6J mice via subcutaneous osmotic minipumps for 4 weeks. KEY FINDINGS: The expression of miR-23b was significantly reduced in the aorta during the early onset of AAA in angiotensin II-treated ApoE-/- mice and in human AAA samples. In vitro experiments showed that the suppression of SMC contractile marker gene expression induced by Ang II was accelerated by miR-23b inhibitors but inhibited by mimics. In vivo studies revealed that miR-23b deficiency in Ang II-treated C57BL/6J mice aggravated the formation of AAAs in these mice compared with control mice; the opposite results were observed in miR-23b-overexpressing mice. Mechanistically, miR-23b knockdown significantly increased the expression of the transcription factor forkhead box O4 (FoxO4) during VSMC phenotypic switching induced by Ang II. In addition, a luciferase reporter assay showed that FoxO4 is a target of miR-23b in VSMCs. SIGNIFICANCE: Our study revealed a pivotal role for miR-23b in protecting against aortic aneurysm formation by maintaining the VSMC contractile phenotype.

Clinical comparative analysis of various duodenal diseases in different age groups.

BACKGROUND/AIMS: This study aimed to investigate the differences and relevance of various common duodenal diseases in different parts in the aspects of age, gender, helicobacter pylori (H. pylori) infection, application of nonsteroidal anti-inflammatory drugs (NSAIDs), smoking, or alcohol consumption. MATERIALS AND METHODS: The medical records of various duodenal diseases were collected and tested for difference using the χ2 test or the Fisher exact probability method. RESULTS: 1) The proportions of duodenal ulcer (DU), inflammation, and duodenal bulb diseases in the adult group (A) (47.98%, 36.70%, and 66.63%) were higher than those in the elderly group (E) (41.38%, 29.83%, and 56.82%), but the proportions of duodenal diverticulum (DD) and tumor diseases in the descending and ascending segments (2.95%, 1.43%, 9.14%, and 0.14%) were lower than those in group E (13.73%, 3.69%, 19.41%, and 0.76%) (p<0.001). 2) The positive rate of H. pylori (63.64%) in the duodenal bulb diseases was higher than that in the bulb-descending segment (53.75%), but the application rate of NSAIDs (16.44%) in the duodenal bulb-descending diseases was lower than that in the descending segment (24.81%) (p<0.001). CONCLUSION: 1) DU, inflammation, and duodenal bulb diseases are common in adults, but DD and tumor diseases in the descending and ascending segments are more common in the elderly. 2) Compared with the duodenal bulb-descending diseases, the application of NSAIDs has greater impact on the diseases in the descending segment, and the rate of H. pylori infection is higher in duodenal bulb diseases.

Highly efficient synthesis of N-substituted isoindolinones and phthalazinones using Pt nanowires as catalysts.

A series of N-substituted isoindolinones have been successfully synthesized through the reductive C-N coupling and intramolecular amidation of 2-carboxybenzaldehyde and amines. This one-pot synthesis gives excellent yields using ultrathin Pt nanowires as catalysts under 1 bar of hydrogen. These unsupported catalysts can also be used for the synthesis of phthalazinones in high yield when hydrazine or phenyl hydrazine is used instead of amines.

A highly active nano-palladium catalyst for the preparation of aromatic azos under mild conditions.

A worm-like Pd nanocatalyst has been prepared and used in the preparation of azo compounds from nitroaromatics under mild reaction conditions. This highly dispersible nano-Pd catalyst shows high activity toward the synthesis of both symmetric aromatic azo compounds and a range of asymmetric aromatic azo compounds.

Catalytic epoxidation of stilbene with FePt@Cu nanowires and molecular oxygen.

A novel FePt@Cu nanowire catalyst was prepared by the reduction of Cu(acac)(2) on the surface of FePt nanowires, in oleylamine (OAm). This nanowire catalyst efficiently epoxidised stilbene in the presence of molecular oxygen, and the conversion and selectivity were maintained with repeated use of the catalyst, compared with recycled catalyst.