The present study was aimed to investigate whether Gasdermin D (GSDMD)-mediated pyroptosis participated in lipopolysaccharide (LPS)-induced sepsis-associated acute kidney injury (AKI), and to explore the role of caspase-1 and caspase-11 pyroptosis pathways in this process. The mice were divided into four groups: wild type (WT), WT-LPS, GSDMD knockout (KO) and KO-LPS. The sepsis-associated AKI was induced by intraperitoneal injection of LPS (40 mg/kg). Blood samples were taken to determine the concentration of creatinine and urea nitrogen. The pathological changes of renal tissue were observed via HE staining. Western blot was used to investigate the expression of pyroptosis-associated proteins. The results showed that the concentrations of serum creatinine and urea nitrogen in the WT-LPS group were significantly increased, compared with those in the WT group (P < 0.01); whereas serum creatinine and urea nitrogen in the KO-LPS group were significantly decreased, compared with those in the WT-LPS group (P < 0.01). HE staining results showed that LPS-induced renal tubular dilatation was mitigated in GSDMD KO mice. Western blot results showed that LPS up-regulated the protein expression levels of interleukin-1β (IL-1β), GSDMD and GSDMD-N in WT mice. GSDMD KO significantly down-regulated the protein levels of IL-1β, caspase-11, pro-caspase-1, caspase-1(p22) induced by LPS. These results suggest that GSDMD-mediated pyroptosis is involved in LPS-induced sepsis-associated AKI. Caspase-1 and caspase-11 may be involved in GSDMD cleavage.
Animals ; Mice ; Acute Kidney Injury ; Caspase 1 ; Caspases/metabolism* ; Creatinine ; Lipopolysaccharides ; Mice, Knockout ; Nitrogen ; Sepsis ; Urea ; Gasdermins/metabolism*

OBJECTIVE: To investigate the changes and roles of reactive oxygen species (ROS) and nuclear factor erythroid 2-related factor 2 (Nrf2) related antioxidases during erythroid development. METHODS: Flow cytometry was used to detect the sensibility of peripheral red blood cells of wild-type mice to a strong oxidant hydrogen peroxide (H₂O₂). Erythroid cells from different developmental stages in bone marrow (BM) were obtained using fluorescence-activated cell sorter and the ROS levels were detected by flow cytometry. RT-qPCR was used to detect the changes of expression levels of Nrf2 and related antioxidases in erythroid cells from different developmental stages in BM. The ROS levels of the peripheral blood and BM nucleated erythrocytes in Nrf2 knockout mice were further examined. The expression level of Nrf2 in erythroid precursors isolated from 14.5 d embryonic liver of wild-type mice during differentiation and culture in vitro was detected. RESULTS: In the peripheral blood of wild-type mice, the ROS level of reticulocytes and mature erythrocytes treated with H₂O₂ increased about 4 times and 7 times, respectively (P<0.01). In BM erythrocytes, the ROS level gradually decreased as the cells matured (r=0.85), while the expression level of Nrf2 and its related anti-oxidative genes increased (r=0.99). The ROS levels in peripheral blood erythrocytes and BM nucleated erythrocytes of Nrf2 knockout mice were significantly increased compared with wild-type mice (P<0.01). The expression of Nrf2 increased during the early erythroid development after embryonic liver cell sorting (P<0.01). CONCLUSION The expression levels of Nrf2 and its related factors vary during erythropoiesis. Nrf2 at physiological level plays an important antioxidant role during the erythroid development.
Animals ; Mice ; Hydrogen Peroxide ; Mice, Knockout ; NF-E2-Related Factor 2/metabolism* ; Oxidative Stress ; Reactive Oxygen Species/metabolism*

Brain size abnormality is correlated with an increased frequency of autism spectrum disorder (ASD) in offspring. Genetic analysis indicates that heterozygous mutations of the WD repeat domain 62 (WDR62) are associated with ASD. However, biological evidence is still lacking. Our study showed that Wdr62 knockout (KO) led to reduced brain size with impaired learning and memory, as well as ASD-like behaviors in mice. Interestingly, Wdr62 Nex-cKO mice (depletion of WDR62 in differentiated neurons) had a largely normal brain size but with aberrant social interactions and repetitive behaviors. WDR62 regulated dendritic spinogenesis and excitatory synaptic transmission in cortical pyramidal neurons. Finally, we revealed that retinoic acid gavages significantly alleviated ASD-like behaviors in mice with WDR62 haploinsufficiency, probably by complementing the expression of ASD and synapse-related genes. Our findings provide a new perspective on the relationship between the microcephaly gene WDR62 and ASD etiology that will benefit clinical diagnosis and intervention of ASD.
Mice ; Animals ; Microcephaly/genetics* ; Autistic Disorder/metabolism* ; Autism Spectrum Disorder/metabolism* ; Nerve Tissue Proteins/metabolism* ; Brain/metabolism* ; Mice, Knockout ; Cell Cycle Proteins/metabolism*

Our previous study has shown that p66^Shc plays an important role in the process of myocardial regeneration in newborn mice, and p66^Shc deficiency leads to weakened myocardial regeneration in newborn mice. This study aims to explore the role of p66^Shc protein in myocardial injury repair after myocardial infarction in adult mice, in order to provide a new target for the treatment of myocardial injury after myocardial infarction. Mouse myocardial infarction models of adult wild-type (WT) and p66^Shc knockout (KO) were constructed by anterior descending branch ligation. The survival rate and heart-to-body weight ratio of two models were compared and analyzed. Masson's staining was used to identify scar area of injured myocardial tissue, and myocyte area was determined by wheat germ agglutinin (WGA) staining. TUNEL staining was used to detect the cardiomyocyte apoptosis. The protein expression of brain natriuretic peptide (BNP), a common marker of myocardial hypertrophy, was detected by Western blotting. The results showed that there was no significant difference in survival rate, myocardial scar area, myocyte apoptosis, and heart weight to body weight ratio between the WT and p66^ShcKO mice after myocardial infarction surgery. Whereas the protein expression level of BNP in the p66^ShcKO mice was significantly down-regulated compared with that in the WT mice. These results suggest that, unlike in neonatal mice, the deletion of p66^Shc has no significant effect on myocardial injury repair after myocardial infarction in adult mice.
Animals ; Mice ; Body Weight ; Cicatrix/metabolism* ; Mice, Knockout ; Myocardial Infarction/genetics* ; Oxidative Stress ; Shc Signaling Adaptor Proteins/metabolism* ; Src Homology 2 Domain-Containing, Transforming Protein 1/metabolism*

Many people affected by fragile X syndrome (FXS) and autism spectrum disorders have sensory processing deficits, such as hypersensitivity to auditory, tactile, and visual stimuli. Like FXS in humans, loss of Fmr1 in rodents also cause sensory, behavioral, and cognitive deficits. However, the neural mechanisms underlying sensory impairment, especially vision impairment, remain unclear. It remains elusive whether the visual processing deficits originate from corrupted inputs, impaired perception in the primary sensory cortex, or altered integration in the higher cortex, and there is no effective treatment. In this study, we used a genetic knockout mouse model (Fmr1^KO), in vivo imaging, and behavioral measurements to show that the loss of Fmr1 impaired signal processing in the primary visual cortex (V1). Specifically, Fmr1^KO mice showed enhanced responses to low-intensity stimuli but normal responses to high-intensity stimuli. This abnormality was accompanied by enhancements in local network connectivity in V1 microcircuits and increased dendritic complexity of V1 neurons. These effects were ameliorated by the acute application of GABA_A receptor activators, which enhanced the activity of inhibitory neurons, or by reintroducing Fmr1 gene expression in knockout V1 neurons in both juvenile and young-adult mice. Overall, V1 plays an important role in the visual abnormalities of Fmr1^KO mice and it could be possible to rescue the sensory disturbances in developed FXS and autism patients.
Animals ; Disease Models, Animal ; Fragile X Mental Retardation Protein/metabolism* ; Fragile X Syndrome/metabolism* ; Humans ; Mice ; Mice, Knockout ; Neurons/metabolism*

In mammals, the piezoelectric protein, Prestin, endows the outer hair cells (OHCs) with electromotility (eM), which confers the capacity to change cellular length in response to alterations in membrane potential. Together with basilar membrane resonance and possible stereociliary motility, Prestin-based OHC eM lays the foundation for enhancing cochlear sensitivity and frequency selectivity. However, it remains debatable whether Prestin contributes to ultrahigh-frequency hearing due to the intrinsic nature of the cell's low-pass features. The low-pass property of mouse OHC eM is based on the finding that eM magnitude dissipates within the frequency bandwidth of human speech. In this study, we examined the role of Prestin in sensing broad-range frequencies (4-80 kHz) in mice that use ultrasonic hearing and vocalization (to >100 kHz) for social communication. The audiometric measurements in mice showed that ablation of Prestin did not abolish hearing at frequencies >40 kHz. Acoustic associative behavior tests confirmed that Prestin-knockout mice can learn ultrahigh-frequency sound-coupled tasks, similar to control mice. Ex vivo cochlear Ca²⁺ imaging experiments demonstrated that without Prestin, the OHCs still exhibit ultrahigh-frequency transduction, which in contrast, can be abolished by a universal cation channel blocker, Gadolinium. In vivo salicylate treatment disrupts hearing at frequencies <40 kHz but not ultrahigh-frequency hearing. By pharmacogenetic manipulation, we showed that specific ablation of the OHCs largely abolished hearing at frequencies >40 kHz. These findings demonstrate that cochlear OHCs are the target cells that support ultrahigh-frequency transduction, which does not require Prestin.
Animals ; Cochlea/metabolism* ; Hair Cells, Auditory, Outer/metabolism* ; Hearing ; Humans ; Mammals/metabolism* ; Mice ; Mice, Knockout ; Molecular Motor Proteins/metabolism*

Gene expression analyses suggest that more than 1000-2000 genes are expressed predominantly in mouse and human testes. Although functional analyses of hundreds of these genes have been performed, there are still many testis-enriched genes whose functions remain unexplored. Analyzing gene function using knockout (KO) mice is a powerful tool to discern if the gene of interest is essential for sperm formation, function, and male fertility in vivo. In this study, we generated KO mice for 12 testis-enriched genes, 1700057G04Rik, 4921539E11Rik, 4930558C23Rik, Cby2, Ldhal6b, Rasef, Slc25a2, Slc25a41, Smim8, Smim9, Tmem210, and Tomm20l, using the clustered regularly interspaced short palindromic repeats /CRISPR-associated protein 9 (CRISPR/Cas9) system. We designed two gRNAs for each gene to excise almost all the protein-coding regions to ensure that the deletions in these genes result in a null mutation. Mating tests of KO mice reveal that these 12 genes are not essential for male fertility, at least when individually ablated, and not together with other potentially compensatory paralogous genes. Our results could prevent other laboratories from expending duplicative effort generating KO mice, for which no apparent phenotype exists.
Animals ; CRISPR-Cas Systems/genetics* ; Fertility/genetics* ; Gene Editing ; Humans ; Male ; Mice ; Mice, Knockout ; Testis/metabolism*

As an important enzyme for gluconeogenesis, mitochondrial phosphoenolpyruvate carboxykinase (PCK2) has further complex functions beyond regulation of glucose metabolism. Here, we report that conditional knockout of Pck2 in osteoblasts results in a pathological phenotype manifested as craniofacial malformation, long bone loss, and marrow adipocyte accumulation. Ablation of Pck2 alters the metabolic pathways of developing bone, particularly fatty acid metabolism. However, metformin treatment can mitigate skeletal dysplasia of embryonic and postnatal heterozygous knockout mice, at least partly via the AMPK signaling pathway. Collectively, these data illustrate that PCK2 is pivotal for bone development and metabolic homeostasis, and suggest that regulation of metformin-mediated signaling could provide a novel and practical strategy for treating metabolic skeletal dysfunction.
Mice ; Animals ; Metformin/pharmacology* ; Phosphoenolpyruvate Carboxykinase (ATP)/metabolism* ; Gluconeogenesis/genetics* ; Mice, Knockout

Very long chain polyunsaturated fatty acids (VLC-PUFAs) are unique fatty acids in tissues of mammals such as retina and testis, and the key enzyme of its biosynthesis is very long chain fatty acid elongase 4 (Elovl4). Development of an animal model of tissue-specific knockout of Elovl4 gene is conducive to the in-depth study of the biological function of VLC-PUFAs. Therefore, we constructed Stra8-Cre mice and Elovl4 floxed mice based on Cre/loxP system, and obtained the (Elovl4[flox/+], Stra8-Cre) heterozygous knockout mice by hybridization. Subsequently, female mice were selected to cross with male mice with homozygous Elovl4[flox/flox] to gain homozygous mice (Elovl4[flox/flox], Stra8-Cre) through genotype identification and screening. RT-PCR, qRT-PCR, Western blotting, immunohistochemistry and immunofluorescence techniques were used to detect the knock-out efficiency of Elovl4 in testis. The expression of Elovl4 in testis of both heterozygous and homozygous knockout mice were significantly down-regulated at mRNA and protein levels, but were not affected in other tissues. In summary, we constructed a mouse model with specific knockout of Elovl4 gene in testis, which provides a reliable animal model for studying the effect of VLC-PUFAs on the reproductive function of male mice and the underpinning molecular mechanisms.
Animals ; Disease Models, Animal ; Eye Proteins/metabolism* ; Female ; Gene Knockout Techniques ; Integrases ; Male ; Mammals/metabolism* ; Membrane Proteins/metabolism* ; Mice ; Mice, Knockout ; Testis/metabolism*

Myostatin (Mstn) is known as growth/differentiation factor-8 (GDF-8). Knockout or knockdown of Mstn gene promotes muscle development and reduces fat content. Here we prepared Mstn knockdown mice by RNA interference, then the morphology of the skeletal muscle, the content of triglyceride (TG), the content and composition of fatty acids in the skeletal muscle were detected. The expression of Mstn reduced in muscle of Mstn knockdown mice compared to the controls. The cross sectional areas of the skeletal muscle myofibers were significantly larger while the content of TG was less than that of the controls, and the ratios of n-3/n-6 and unsat/sat in the knockdown mice increased significantly. Subsequently, we detected the expression of genes associated with fatty acid metabolism. The expression of the genes associated with lipolysis and fatty acid transportation were up-regulated, while the genes associated with fatty acid synthesis were down-regulated. Of these genes, the up-regulation of a gene associated with β oxidation, Cpt1b, was up-regulated remarkably. We further detected the enzyme activity of CPT1 in skeletal muscle and obtained the same results with gene expression. Moreover, chromatin immunoprecipitation assay was performed and we found that SMAD3, a transcription factor downstream of Mstn, directly binds to the promoter of Cpt1b gene. These results showed that knockdown of Mstn up-regulated the expression of Cpt1b through the binding of SMAD3 to the promoter of Cpt1b, then promoted the β oxidation metabolism of intramuscular fatty acids.
Animals ; Carnitine O-Palmitoyltransferase/metabolism* ; Fatty Acids ; Lipid Metabolism ; Mice ; Mice, Knockout ; Muscle, Skeletal/metabolism* ; Myostatin/metabolism* ; Oxidation-Reduction ; Up-Regulation