N-methyl-D-aspartate (NMDA) receptor (NMDAR) is highly compartmentalized in neurons, and its dysfunction has been implicated in various neuropsychiatric and neurodegenerative disorders. Recent failure to exploit NMDAR antagonization as a potential therapeutic target has driven the need to identify molecular mechanisms that regulate NMDAR compartmentalization. Here, we report that the reduction of Kif5b, the heavy chain of kinesin-1, protected neurons against NMDA-induced excitotoxicity and ischemia-provoked neurodegeneration. Direct binding of kinesin-1 to the GluN2B cytoplasmic tails regulated the levels of NMDAR at extrasynaptic sites and the subsequent influx of calcium mediated by extrasynaptic NMDAR by regulating the insertion of NMDARs into neuronal surface. Transient increase of Kif5b restored the surface levels of NMDAR and the decreased neuronal susceptibility to NMDA-induced excitotoxicity. The expression of Kif5b was repressed in cerebral ischemia preconditioning. Our findings reveal that kinesin-1 regulates extrasynaptic NMDAR targeting and signaling, and the reduction of kinesin-1 could be exploited to defer neurodegeneration.

This experiment was conducted to study the effects of different skinning seasons on the fur quality and hair follicle development of Rex rabbits. A total of 80,150-day-old Rex rabbits were slaughtered on 15 July 2022 (summer), 15 October 2022 (autumn), 15 January 2023 (winter), and 15 April 2023 (spring) in Shandong Province (10 males and 10 females in each season). The results show that the skin weight, skin area, skin thickness, and hair follicle density of the Rex rabbits (at 150 days of age) were lower in summer than in winter (p < 0.05). Moreover, the coat length was shorter in summer than in spring, autumn, and winter (p < 0.05). The shoulder fat weight, perirenal fat weight, and perigastric fat weight of the Rex rabbits in winter were higher than those in summer (p < 0.05). Furthermore, the leptin levels in serum were higher in winter than in summer in the Rex rabbits (p < 0.05). In terms of serum biochemistry, the glucose levels were higher in autumn and winter than in spring and summer (p < 0.05). The cholesterol, high-density lipoprotein cholesterol (HDL), and low-density lipoprotein cholesterol (LDL) in summer had higher values than in winter in the Rex rabbits (p < 0.05). In winter, the expression of the Wnt10b, catenin beta 1 (CTNNB1), glycogen synthase kinase 3 beta (GSK3β), insulin like growth factor I (IGF-I), Type I insulin-like growth factor receptor (IGF-IR), and epidermal growth factor (EGF) genes was higher (p < 0.05), and the expression of the dickkopf-1 (DDK1), transforming growth factor beta 1 (TGFβ-1), bone morphogenetic protein 2 (BMP2), and bone morphogenetic protein 4 (BMP4) genes was lower than in summer (p < 0.05). In summer, the heat shock 70 kDa protein (HSP70) expression and CTNNB1 protein phosphorylation levels in skin tissue were higher than in spring, autumn, and winter (p < 0.05). In winter, Wnt10b protein expression was higher (p < 0.05), and GSK-3β protein phosphorylation levels were lower than in spring, autumn, and winter (p < 0.05). These results show that the skinning season can affect the production performance and hair follicle development of Rex rabbits. Compared with other seasons, the quality of skin from rabbits slaughtered in winter is better. Seasons may regulate hair follicle development via the Wnt10b/β-catenin, TGFβ-BMP, IGF1, and EGF signaling pathways in Rex rabbits.

Rabbit astrovirus (RAstV) is a pathogen that causes diarrhea in rabbits, with high infection rate at various stages, which can often cause secondary or mixed infections with other pathogens, bringing great economic losses to the rabbit industry. In this study, 10 samples were collected from cases of rabbits with diarrhea on a rabbit meat farm in the Shandong area of China. The positive sample for astrovirus detected by RT-PCR was inoculated into an RK 13 cell line. A rabbit astrovirus strain named Z317 was successfully isolated, which produced an obvious cytopathic effect 48 h post-inoculation in the RK 13 cell line. The genome structure of this isolate was studied by high-throughput sequencing, showing that the Z317 strain had the highest similarity with the American strain TN/2208/2010, with 92.43% nucleotide homology, belonging to group MRAstV-23. The basic properties of the Z317 capsid (Cap) protein were analyzed, and 10 liner B cell epitopes were screened with the online biosoft Bepipred 2.0 and SVMTriP, including 445–464, 186–205, 655–674, 88–107, 792–811, 45–64, and 257–276 amino acids. This is the first contribution concerning RAstV genomes in China; more studies are needed to understand the diversity and impact of RAstV on rabbit health.

The purpose of this experiment was to study the effects of heat stress on the performance and protein metabolism of skeletal muscle in meat rabbits. A total of 160 New Zealand White rabbits aged 80 days with mean initial body weights of 2359 ± 200 g were randomly divided into a control group and a heat stress group. The experiment duration was 20 days. Heat stress treatment reduced the growth performance and slaughter performance of the rabbits (p < 0.05) and increased muscle yellowness (b*, p < 0.05). In addition, heat stress treatment increased the concentrations of leptin, cholesterol, high-density lipoprotein (HDL) cholesterol, and low-density lipoprotein (LDL) cholesterol in serum (p < 0.05), and decreased the serum total protein and immunoglobulin (IgG, IgM, and IgA) contents of rabbits. Under the criteria fold-change ≥ 1.20 or ≤0.84 and p-value ≤ 0.05, 7 up-regulated proteins and 122 down-regulated proteins were screened. A gene ontology (GO) enrichment analysis of the differentially expressed proteins was performed. The most enriched specific GO terms among the differential proteins were response to stress, extracellular region, and protein binding in the biological process (BP), cellular component (CC), and molecular function (MF) categories, respectively, and the most enriched pathway was the PI3K/Akt signalling pathway. In conclusion, heat stress could reduce the carcass yield of meat rabbits, change the physical characteristics of the skeletal muscle, and influence protein metabolism by changing blood indices, potentially through the PI3K/Akt signalling pathway.

The main purpose of the present research was to evaluate the effect of varying levels of DA inclusion in maternal diet, in the form of powder, on the born-weaning growth performance (days 1–30) and intestinal health of neonatal rabbits. A total of 152 delivered maternal does (3.94 ± 0.05 kg) were allocated into four groups, with thirty-eight replicates of one doe each, and fed with a control diet (CON) supplemented with different levels of powdered DA (85 mg/kg (DA85), 170 mg/kg (DA170), and 340 mg/kg (DA340)) during lactation. The results show that dietary DA increased individual body weight at days 21 and 30 (p = 0.03 and p < 0.01) and showed a linear and quadratic effect on individual body weight and average daily gain (ADG) (p < 0.05), although ADG was not affected by DA. The serum progesterone (P) (p = 0.05) and glutathione peroxidase (GSH-Px) (p = 0.01) concentrations of maternal rabbits were increased in all maternal DA-supplemented groups and showed a linear and quadratic effect (p < 0.05), while a linear effect was observed in estrogen (E-2) (p < 0.05). Interestingly, the concentrations of the serum insulin-like growth factor-1 (IGF-I) (p < 0.01) and immunoglobulin (IgA and IgG) (p < 0.01 and p = 0.01) in neonatal rabbits were increased in all dietary DA groups, and both showed a linear and quadratic effect (p < 0.05). In addition, the serum interleukin (IL-1β) (p = 0.03) and catalase (CAT) (p = 0.04) concentrations were affected by DA supplements, but linear and quadratic effects were only observed in the catalase (CAT) of neonatal rabbits (p < 0.05). Importantly, the duodenal and jejunal villus heights (p < 0.04 and p = 0.01) and the ratio of villus height to crypt depth (p = 0.02 and p = 0.01) in neonatal rabbits were elevated in all DA-supplemented treatments, while a linear and quadratic effect was observed in jejunum, but a quadratic effect was observed in duodenum (p < 0.05). The ileal villus height (p < 0.01) was also elevated in all DA-supplemented treatments exhibiting both linear and quadratic effects (p < 0.05). Moreover, the expression levels of occludin (p = 0.04), zonula occludens-1 (ZO-1) (p < 0.01), IGF-1 (p = 0.03), and solute carrier family 5 member 9 (SCL5A9) (p < 0.01) in jejunum were markedly elevated in the DA175 and 340 mg/kg DA-supplemented groups and were showing linear and quadratic effects (p < 0.05). Finally, inflammation-related gene expression levels such as NF-κB, TLR4, and MYD88 in jejunal (p = 0.01, p = 0.04, and p < 0.01) and ileal (p = 0.04, p = 0.04, and p = 0.03) epithelium were decreased in the DA170 and DA340 groups (p < 0.05), while linear and quadratic effects were observed for TLR4 in jejunum and for NF-κB and TLR4 MYD88 in ileum (p < 0.05). In summary, as a functional additive, maternal DA supplementation with 170 and 340 mg/kg DA during lactation can promote the growth of neonatal rabbits, which is related to improved antioxidative capacity and immunity, as well as improved intestinal health in neonatal rabbits.