Monocytes Release Pro-Cathepsin D to Drive Blood-to-Brain Transcytosis in Diabetes.

BACKGROUND: Microvascular complications are the major outcome of type 2 diabetes progression, and the underlying mechanism remains to be determined. METHODS: High-throughput RNA sequencing was performed using human monocyte samples from controls and diabetes. The transgenic mice expressing human CTSD (cathepsin D) in the monocytes was constructed using CD68 promoter. In vivo 2-photon imaging, behavioral tests, immunofluorescence, transmission electron microscopy, Western blot analysis, vascular leakage assay, and single-cell RNA sequencing were performed to clarify the phenotype and elucidate the molecular mechanism. RESULTS: Monocytes expressed high-level CTSD in patients with type 2 diabetes. The transgenic mice expressing human CTSD in the monocytes showed increased brain microvascular permeability resembling the diabetic microvascular phenotype, accompanied by cognitive deficit. Mechanistically, the monocytes release nonenzymatic pro-CTSD to upregulate caveolin expression in brain endothelium triggering caveolae-mediated transcytosis, without affecting the paracellular route of brain microvasculature. The circulating pro-CTSD activated the caveolae-mediated transcytosis in brain endothelial cells via its binding with low-density LRP1 (lipoprotein receptor-related protein 1). Importantly, genetic ablation of CTSD in the monocytes exhibited a protective effect against the diabetes-enhanced brain microvascular transcytosis and the diabetes-induced cognitive impairment. CONCLUSIONS: These findings uncover the novel role of circulatory pro-CTSD from monocytes in the pathogenesis of cerebral microvascular lesions in diabetes. The circulatory pro-CTSD is a potential target for the intervention of microvascular complications in diabetes.

Ginsenoside Rgl regulates autophagy through AMPK/mTOR signaling pathway and delays brain aging in mice / 中国药理学通报

Aim To investigate the mechanism by which ginsenoside Rgl regulates autophagy anrl delays brain aging in mice through AMPK/mTOR signaling pathway.Methods C57BL/6J male mice were ran¬domly divided into four groups, namely brain aging model group ,control group, Rgl anti-aging group,auto¬phagy activator Rapamycin anti-aging group.After the modeling was completed, the test of each experimental index would be carried out on the next day.Morris wa¬ter maze experiment was used to detect the learning and memory ability of mice.Paraffin sections of the hippocampus were prepared, HE , Nissl and immunohis- tochemical staining were used to observe the morpholo¬gy of hippocampal neurons, the number of neurons and Nissl bodies was counted, and autophagy-related proteins p62 , ATG5 , ULK1 were detected.Brain tissue homogenates were prepared to detect the aetivity of brain tissue acetylcholinesterase ( AChE ).Western blot was userl to detect brain tissue autophagy-related proteins LC3II, P62, beclinl, P-AMPK/AMPK, P- mTOR/mTOR and apoptosis protein P53.Results Water maze test showed that Rgl and Hap significantly improved the learning and memory abilities of brain-ag¬ing mice.HE and Nissl staining showed that Rgl and Rap decreased necrotic cells and increased the number of Nissl bodies in the hippocampus of brain-aging mice.Immunohistochemistry staining showed that Rgl and Rap decreased the expression of neuronal autoph- agv protein P62 in hippocampus and increased the ex-pression of ATG5 and ULK1.Rgl and Rap decreased the activity of AhcE in brain-aging mice.Western blot showed that Rgl and Rap increased autophagy-related proteins LC3II, Beclinl , P-AMPK/AMPK, but de¬creased the expression of P-mTOR/mTOR, P62, P53.Conclusions Ginsenoside Rgl can effectively antago¬nize the aging effect of D-gal on mouse brain.The pos¬sible mechanism is related to the regulation of autoph- agv by Rgl through AMPK/mTOR signaling pathway.

Synthesis and Pharmacological Evaluation of σ2 Receptor Ligands Based on a 3-Alkoxyisoxazole Scaffold: Potential Antitumor Effects against Osteosarcoma.

Since its initial discovery as the basis for nicotinic acetylcholine receptor ligands, the 3-alkoxyisoxazole scaffold has been shown to be a versatile platform for the development of potent σ1 and σ2 receptor ligands. Herein we report a further SAR exploration of the 3-alkoxyisoxazole scaffold with the aim of obtaining potent σ2 receptor ligands. Various substitutions on the benzene ring and at the basic amino regions resulted in a total of 21 compounds that were tested for their binding affinities for the σ2 receptor. In particular, compound 51 [(2S)-1-(4-ammoniobutyl)-2-(((5-((3,4-dichlorophenoxy)methyl)isoxazol-3-yl)oxy)methyl)pyrrolidin-1-ium chloride] was identified as one of the most potent σ2 ligands within the series, with a Ki value of 7.9 nM. It demonstrated potent antiproliferative effects on both osteosarcoma cell lines 143B and MOS-J (IC50 values of 0.89 and 0.71 µM, respectively), relative to siramesine (IC50 values of 1.81 and 2.01 µM). Moreover, compound 51 inhibited clonal formation of osteosarcoma 143B cells at 1 µM, corresponding to half the dose required of siramesine for similar effects. The general cytotoxicity profile of compound 51 was assessed in a number of normal cell lines, including HaCaT, HAF, and LO2 cells. Furthermore, FACS analysis showed that compound 51 likely inhibits osteosarcoma cell growth by disruption of the cell cycle and promotion of apoptosis.

An experimental study of polypropylene combined with flap for trachea reconstruction / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>Canine model established for tracheal defect reconstruction, to investigate the outcome of tracheal reconstruction with combination of polypropylene and flap.</p><p><b>METHODS</b>About 3.5 to 4 centimeter cervical trachea was resected and replaced with artificial trachea made from monofilament knitted polypropylene and surgical flap. Covered stent was implanted postoperatively. Survival period and quality of life were recorded, bronchofibroscopy, X-ray films and HE sections were performed.</p><p><b>RESULTS</b>Six dogs survived well and another two died. The causes of death were respiratory failure in 1 and infection in another. Stenosis of anastomosis in 1 was recorded during survival period. The dogs started drinking and eating on the second postoperative day, no dyspnea was found. The animals were sacrificed at 2, 4, 8 weeks and 6 months after surgery. Soft tissue growth was found in polypropylene net 2 weeks after surgery and more at 4 weeks. The polypropylene net was covered completely with soft tissue at 8 weeks and 6 months postoperatively, the hardness and sustentation degree were enhanced following the growth and fibrosis of soft tissue. The squamous epithelium and columnar epithelium were observed healing well by HE staining method.</p><p><b>CONCLUSIONS</b>One-stage operative artificial trachea made from monofilament knitted polypropylene which has good histocompatibility and surgical flap is the closer artificial trachea to native trachea. It has a promising prospect in clinical use.</p>