CRISPR/Cas9 enables the targeting of genes in zygotes; however, efficient approaches to create loxP-flanked (floxed) alleles remain elusive.
Here, we show that the electroporation of Cas9, two gRNAs, ...and long single-stranded DNA (lssDNA) into zygotes, termed CLICK (CRISPR with lssDNA inducing conditional knockout alleles), enables the quick generation of floxed alleles in mice and rats.
The high efficiency of CLICK provides homozygous knock-ins in oocytes carrying tissue-specific Cre, which allows the one-step generation of conditional knockouts in founder (F0) mice.
CRISPR-Cas9 are widely used for gene targeting in mice and rats. The non-homologous end-joining (NHEJ) repair pathway, which is dominant in zygotes, efficiently induces insertion or deletion (indel) ...mutations as gene knockouts at targeted sites, whereas gene knock-ins (KIs) via homology-directed repair (HDR) are difficult to generate. In this study, we used a double-stranded DNA (dsDNA) donor template with Cas9 and two single guide RNAs, one designed to cut the targeted genome sequences and the other to cut both the flanked genomic region and one homology arm of the dsDNA plasmid, which resulted in 20–33% KI efficiency among G0 pups. G0 KI mice carried NHEJ-dependent indel mutations at one targeting site that was designed at the intron region, and HDR-dependent precise KIs of the various donor cassettes spanning from 1 to 5 kbp, such as
EGFP
,
mCherry
,
Cre
, and genes of interest, at the other exon site. These findings indicate that this combinatorial method of NHEJ and HDR mediated by the CRISPR-Cas9 system facilitates the efficient and precise KIs of plasmid DNA cassettes in mice and rats.
Protein quality control in cardiomyocytes is crucial to maintain cellular homeostasis. The accumulation of damaged organelles, such as mitochondria and misfolded proteins in the heart is associated ...with heart failure. During the process to identify novel mitochondria-specific autophagy (mitophagy) receptors, we found FK506-binding protein 8 (FKBP8), also known as FKBP38, shares similar structural characteristics with a yeast mitophagy receptor, autophagy-related 32 protein. However, knockdown of FKBP8 had no effect on mitophagy in HEK293 cells or H9c2 myocytes. Since the role of FKBP8 in the heart has not been fully elucidated, the aim of this study is to determine the functional role of FKBP8 in the heart. Cardiac-specific FKBP8-deficient (Fkbp8−/−) mice were generated. Fkbp8−/− mice showed no cardiac phenotypes under baseline conditions. The Fkbp8−/− and control wild type littermates (Fkbp8+/+) mice were subjected to pressure overload by means of transverse aortic constriction (TAC). Fkbp8−/− mice showed left ventricular dysfunction and chamber dilatation with lung congestion 1week after TAC. The number of apoptotic cardiomyocytes was dramatically elevated in TAC-operated Fkbp8−/− hearts, accompanied with an increase in protein levels of cleaved caspase-12 and endoplasmic reticulum (ER) stress markers. Caspase-12 inhibition resulted in the attenuation of hydrogen peroxide-induced apoptotic cell death in FKBP8 knockdown H9c2 myocytes. Immunocytological and immunoprecipitation analyses indicate that FKBP8 is localized to the ER and mitochondria in the isolated cardiomyocytes, interacting with heat shock protein 90. Furthermore, there was accumulation of misfolded protein aggregates in FKBP8 knockdown H9c2 myocytes and electron dense deposits in perinuclear region in TAC-operated Fkbp8−/− hearts. The data suggest that FKBP8 plays a protective role against hemodynamic stress in the heart mediated via inhibition of the accumulation of misfolded proteins and ER-associated apoptosis.
•This study is the first to identify the in vivo role of FKBP8 in the heart.•Cardiac-specific FKBP8-deficient mice were generated.•FKBP8 plays a cardio-protective role in response to pressure overload.•FKBP8 has anti-apoptotic functions via endoplasmic reticulum-mediated pathway.•FKBP8 prevents the accumulation of misfolded proteins.
Royal jelly is a widely ingested supplement for health, but its effects on humans are not well known. The objective was to evaluate the effects of long-term royal jelly ingestion on humans.
We ...conducted a randomized placebo-controlled, double-blind trial. A total of 61 healthy volunteers aged 42-83 years were enrolled and were randomly divided into a royal jelly group (n = 31) and a control group (n = 30). Three thousand mg of royal jelly (RJ) or a placebo in 100 ml liquid/day were ingested for 6 months. The primary outcomes were changes in anthropometric measurements and biochemical indexes from baseline to 6 months after intervention.
Thirty subjects in the RJ group and 26 in the control group were included in the analysis of endpoints. In an adjusted mean change of the variables from the baseline, significant differences between the two groups could be found in red blood cell counts (+0.16x10⁶/μL for the RJ group vs. -0.01x10⁶/μL for the control group, P = 0.0134), hematocrit (+0.9% vs. -0.8%, P = 0.0251), log (fasting plasma glucose) (+0.01 ± 0.01 log mg/dL vs. +0.05 ± 0.01 log mg/dL, P = 0.0297), log (insulinogenic index) (+0.25 vs. -0.13, P = 0.0319), log dehydroepiandrosterone sulfate (DHEA-S) (+0.08 log μg/dL vs. +0.20 log μg/dL, P = 0.0483), log testosterone (T) (+0.12 ± 0.04 log ng/mL vs. -0.02 ± 0.05 log ng/mL, P = 0.0416), log T/DHEA-S ratio (+0.05 ± 0.05 vs. -0.23 ± 0.59, P = 0.0015), and in one of the SF-36 subscale scores, mental health (MH) (+4 vs. -7, P = 0.0276).
Six-month ingestion of RJ in humans improved erythropoiesis, glucose tolerance and mental health. Acceleration of conversion from DHEA-S to T by RJ may have been observed among these favorable effects.
Subcortical ischemic vascular dementia, one of the major subtypes of vascular dementia, is characterized by lacunar infarcts and white matter lesions caused by chronic cerebral hypoperfusion. In this ...study, we used a mouse model of bilateral common carotid artery stenosis (BCAS) to investigate the role of B-cell translocation gene 2 (BTG2), an antiproliferation gene, in the white matter glial response to chronic cerebral hypoperfusion.
Btg2
mice and littermate wild-type control mice underwent BCAS or sham operation. Behavior phenotypes were assessed by open-field test and Morris water maze test. Brain tissues were analyzed for the degree of white matter lesions and glial changes. To further confirm the effects of Btg2 deletion on proliferation of glial cells in vitro, BrdU incorporation was investigated in mixed glial cells derived from wild-type and Btg2
mice.
Relative to wild-type mice with or without BCAS, BCAS-treated Btg2
mice exhibited elevated spontaneous locomotor activity and poorer spatial learning ability. Although the severities of white matter lesions did not significantly differ between wild-type and Btg2
mice after BCAS, the immunoreactivities of GFAP, a marker of astrocytes, and Mac2, a marker of activated microglia and macrophages, in the white matter of the optic tract were higher in BCAS-treated Btg2
mice than in BCAS-treated wild-type mice. The expression level of Gfap was also significantly elevated in BCAS-treated Btg2
mice. In vitro analysis showed that BrdU incorporation in mixed glial cells in response to inflammatory stimulation associated with cerebral hypoperfusion was higher in Btg2
mice than in wild-type mice.
BTG2 negatively regulates glial cell proliferation in response to cerebral hypoperfusion, resulting in behavioral changes.
Endothelial cell-selective adhesion molecule (ESAM) is a lifelong marker of hematopoietic stem cells (HSCs). Although we previously elucidated the functional importance of ESAM in HSCs in ...stress-induced hematopoiesis in adults, it is unclear how ESAM affects hematopoietic development during fetal life. To address this issue, we analyzed fetuses from conventional or conditional ESAM-knockout mice. Approximately half of ESAM-null fetuses died after mid-gestation due to anemia. RNA sequencing analyses revealed downregulation of adult-type globins and Alas2, a heme biosynthesis enzyme, in ESAM-null fetal livers. These abnormalities were attributed to malfunction of ESAM-null HSCs, which was demonstrated in culture and transplantation experiments. Although crosslinking ESAM directly influenced gene transcription in HSCs, observations in conditional ESAM-knockout fetuses revealed the critical involvement of ESAM expressed in endothelial cells in fetal lethality. Thus, we showed that ESAM had important roles in developing definitive hematopoiesis. Furthermore, we unveiled the importance of endothelial ESAM in this process.
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•ESAM deficiency causes life-threatening anemia in fetuses•ESAM deficiency impairs adult-type hemoglobin synthesis•ESAM deficiency downregulates expression of Alas2 and adult-type globins in HSCs•Endothelial ESAM plays roles in the ontogeny of definitive hematopoiesis
Ueda et al. shed light on the contribution of endothelial cell-selective adhesion molecule (ESAM) to the ontogeny of definitive hematopoiesis. ESAM deficiency caused high mortality in fetuses after mid-gestation. Expression of Alas2 and adult-type globin genes decreased in ESAM-null HSCs, which resulted in the impairment of development of adult-type erythropoiesis. The authors also revealed functional involvement of ESAM-expressing endothelial cells.
Cardiomyocytes proliferate during fetal life but lose their ability to proliferate soon after birth and further increases in cardiac mass are achieved through an increase in cell size or hypertrophy. ...Mammalian target of rapamycin complex 1 (mTORC1) is critical for cell growth and proliferation. Rheb (Ras homologue enriched in brain) is one of the most important upstream regulators of mTORC1. Here, we attempted to clarify the role of Rheb in the heart using cardiac-specific Rheb-deficient mice (Rheb−/−). Rheb−/− mice died from postnatal day 8 to 10. The heart-to-body weight ratio, an index of cardiomyocyte hypertrophy, in Rheb−/− was lower than that in the control (Rheb+/+) at postnatal day 8. The cell surface area of cardiomyocytes isolated from the mouse hearts increased from postnatal days 5 to 8 in Rheb+/+ mice but not in Rheb−/− mice. Ultrastructural analysis indicated that sarcomere maturation was impaired in Rheb−/− hearts during the neonatal period. Rheb−/− hearts exhibited no difference in the phosphorylation level of S6 or 4E-BP1, downstream of mTORC1 at postnatal day 3 but showed attenuation at postnatal day 5 or 8 compared with the control. Polysome analysis revealed that the mRNA translation activity decreased in Rheb−/− hearts at postnatal day 8. Furthermore, ablation of eukaryotic initiation factor 4E-binding protein 1 in Rheb−/− mice improved mRNA translation, cardiac hypertrophic growth, sarcomere maturation, and survival. Thus, Rheb-dependent mTORC1 activation becomes essential for cardiomyocyte hypertrophic growth after early postnatal period.
Background: Rheb (Ras homologue enriched in brain) regulates mammalian target of rapamycin complex 1 (mTORC1).
Results: mTORC1 activity and cardiac hypertrophy are attenuated in Rheb-deficient hearts after the early postnatal period.
Conclusion: Rheb-dependent mTORC1 activation becomes essential for cardiomyocyte hypertrophic growth after the early postnatal period.
Significance: The findings provide insight into the regulatory mechanism of mTORC1 in postnatal heart development.
We have developed and validated a novel scoring system to predict insulin requirement for optimal control of blood glucose during glucocorticoid (GC) treatments, by retrospective analyses of clinical ...parameters before GC treatment.
Three hundred-three adults (the Developing set) undergoing their first treatment of prednisolone (PSL) were divided into two groups, depending on treatment with or without insulin. Independent risk factors for insulin requirement were identified by a stepwise logistic regression analysis after univariate analyses between the two groups. We constructed a point-addition scoring system consisting of several categories and their coefficients in each risk factor derived from another logistic regression analysis. We validated it to two validation sets, A and B.
Male, higher levels of fasting plasma glucose (FPG), HbA1c, and serum creatinine (CRE) and a higher initial dose of PSL were identified as the risk factors. The sensitivity, specificity, and accuracy were 90.0%, 88.1%, and 88.4%; 87.5%, 66.7%, and 70.5%; 83.3%, 76.1%, and 76.6% in the Developing set, Validation set A, and Validation set B, respectively, when the scoring system was applied.
The scoring system is a valid and reliable tool to predict insulin requirements in advance during GC treatment.
Several studies have suggested that both testosterone and dehydroepiandrosterone (DHEA) have weight-reducing and antidiabetic effects, especially in rodent studies; however, the precise mechanism of ...their action remains unclear. Here, we investigated the effect of DHEA on cell growth in adipose tissue. The appearance of senescence-associated β-galactosidase in stromal vascular fraction (SVF) isolated from Otsuka Long-Evans Tokushima fatty rats, an animal model of inherent obese type 2 diabetes, was prevented by DHEA administration. Next, the effects of DHEA and testosterone were compared in vivo and in vitro to evaluate whether these hormones influence cell growth in adipose tissue. Both DHEA and testosterone reduced body weight and epididymal fat weight equivalently when administered for 4 wk. To assess the effect of DHEA and testosterone on cell growth in adipose tissue, 5-bromo-2'-deoxyuridine (BrdU) uptake by SVF was measured. Quantification analysis of BrdU uptake by examining DNA isolated from each SVF revealed that treatment with DHEA and testosterone reduced cell replication. These results indicated that DHEA- and testosterone-induced decreased adiposity was associated with reduced SVF growth. Incubation with DHEA and testosterone equally decreased BrdU uptake by 3T3-L1 preadipocytes. Pretreatment with the androgen receptor (AR) inhibitor flutamide, but not the estrogen receptor inhibitor fulvestrant, abolished these effects. Knockdown of AR with siRNA also inhibited DHEA-induced decreases in BrdU uptake. These results suggest that DHEA-induced growth suppression of preadipocytes is mediated via AR. Therefore, both DHEA and testosterone similarly decrease adipocyte growth possibly via a common mechanism.
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