OBJECTIVES: To investigate the causal relationship between gut microbiota and kidney stones. METHODS: Mendelian randomization analysis was conducted based on data from the MiBioGen consortium gut microbiota GWAS (exposure factors) and the IEU Open GWAS kidney stone dataset ukb-b-8297 (outcome variables) using the inverse variance weighted, MR-Egger regression, weighted median, weighted mode, and simple mode methods. Heterogeneity, pleiotropy, and leave-one-out sensitivity analyses were also performed. In the animal experiment, 12 male SD rats were randomized into control group with saline treatment and kidney stone model group treated with 1% ethylene glycol and 2% ammonium chloride for 28 consecutive days. Urine, blood, and intestinal samples of the rats were collected for testing the changes in renal function and intestinal barrier-related indicators, and kidney and colon pathologies were examined with histological staining and immunohistochemistry. The changes in diversity and abundance of gut microbiota were analyzed using 16S rRNA gene sequencing. RESULTS: Mendelian randomization analysis showed that decreased abundances of Lachnospiraceae NK4A136 group (OR=0.9974, 95% CI: 0.9948-0.9999, P=0.0393) and Gordonibacter (OR=0.9987, 95% CI: 0.9974-0.9999, P=0.0403) were associated with an increased risk of kidney stones without significant heterogeneity or horizontal pleiotropy, and sensitivity analyses suggested robustness of the results. The rat models of kidney stones exhibited significant renal function impairment and calcium oxalate crystal deposition, accompanied by decreased expressions of intestinal barrier-related proteins with lowered intestinal α- and β-diversity indices. Intestinal Gordonibacter abundance was significantly reduced in the rat models while the Lachnospiraceae NK4A136 group did not differ significantly between the control and model groups. CONCLUSIONS Decreased Gordonibacter abundance in gut microbiota is associated with an increased risk of kidney stones. The protective role of the Lachnospiraceae NK4A136 group against kidney stones as suggested by Mendelian randomization analysis fails to be supported by the experimental evidence and awaits further investigation.
Animals ; Kidney Calculi/microbiology* ; Gastrointestinal Microbiome ; Mendelian Randomization Analysis ; Rats, Sprague-Dawley ; Rats ; Male ; Disease Models, Animal ; Intestines/microbiology* ; RNA, Ribosomal, 16S/genetics*

BACKGROUND: This study aimed to explore the effect of a nanomaterial-based miR-320a inhibitor sustained release system in trauma-induced osteonecrosis of the femoral head (TIONFH). METHODS: The miR-320a inhibitor-loaded polyethylene glycol (PEG)- Poly(lactic-co-glycolic acid) (PLGA)- Poly-L-lysine (PLL) nanoparticles were constructed using the double emulsion method. The TIONFH rabbit model was established to observe the effects of miR-320a inhibitor nanoparticles in vivo. Hematoxylin–eosin staining and microcomputed tomography scanning were used for bone morphology analysis. Bone marrow mesenchymal stem cells (BMSCs), derived from TIONFH rabbits, were used for in vitro experiments. Cell viability was determined using the MTT assay. RESULTS: High expression of miR-320a inhibited the osteogenic differentiation capacity of BMSCs in vitro by inhibiting the expression of the osteoblastic differentiation markers ALP and RUNX2. MiR-320a inhibitor-loaded PEG-PLGA-PLL nanoparticles were constructed with a mean loading efficiency of 1.414 ± 0.160%, and a mean encapsulation efficiency of 93.45 ± 1.24%, which released 50% of the loaded miR-320a inhibitor at day 12 and 80% on day 18. Then, inhibitor release entered the plateau. After treatment with the miR-320a inhibitor nanoparticle, the empty lacunae were decreased in the femoral head tissue of TIONFH rabbits, and the osteoblast surface/bone surface (Ob.S/BS), osteoblast number/bone perimeter (Ob.N/B.Pm), bone volume fraction, and bone mineral density increased. Additionally, the expression of osteogenic markers RUNX2 and ALP was significantly elevated in the TIONFH rabbit model. CONCLUSION The miR-320a inhibitor-loaded PEG-PLGA-PLL nanoparticle sustained drug release system significantly contributed to bone regeneration in the TIONFH rabbit model, which might be a promising strategy for the treatment of TIONFH.

This paper proposed a new design on multi-layer flexible microelectrode arrays (MEA) of epiretinal prosthesis, as well as a set of automatic testing system to evaluate and analyze the MEA. Experiment results showed that the MEA was satisfying on both flexibility and impedance and the multi-layer design didn't introduce significant differences.
Microarray Analysis ; Microelectrodes ; Prostheses and Implants ; Prosthesis Design ; Prosthesis Implantation ; instrumentation ; Retina

This review paper presents the current research progress, challenges and future development on microelectrode array of retinal prosthesis, including epi-retinal and sub-retinal implants.
Microelectrodes ; Prosthesis Design ; Visual Prosthesis