Impact of Nicosulfuron on Sperm Quality: Insights into Testicular Cell Apoptosis and NF-κB Signaling Pathway in Mice Testes.

BACKGROUND: Nicosulfuron, a widely used herbicide in crops, has raised concerns due to its escalating presence as an environmental pollutant, particularly in soil and water. The potential adverse effects of nicosulfuron on animals, including reproductive toxicity, have garnered attention. OBJECTIVE: The study aimed to evaluate the reproductive toxicity of nicosulfuron in male mice. METHODS: Male mice were orally administrated with three different concentration gradients (350, 700, and 1400 mg/kg) of nicosulfuron for 35 days. The investigation delved into sperm quality, testicular structures, and expression of cleaved caspase-3 and NF-κB p65 of the testes. RESULTS: The finding unveiled a correlation between nicosulfuron exposure and detrimental effects on sperm quality and alteration of testicular structure. Notably, parameters, such as sperm survival rate (SUR) and sperm motility (MOT), exhibited a decline in relation to increasing nicosulfuron dosages. Moreover, in the mice subjected to higher doses of nicosulfuron, elevated expression of cleaved caspase-3 and NF-κB p65 was observed in the testes. Interestingly, we also observed an increase of NF-κB p65 expression in the mice exposed to the nicosulfuron. CONCLUSION: Our research revealed that exposure to nicosulfuron resulted in compromised sperm quality and alterations in testicular structure. The correlation between nicosulfuron and apoptosis, especially via the NF-κB pathway, provided significant insights into the mechanisms underpinning these detrimental effects. These findings significantly enhance our comprehension of the potential hazards associated with nicosulfuron exposure and its impacts on the reproductive health of animals.

SETDB2 interacts with BUBR1 to induce accurate chromosome segregation independently of its histone methyltransferase activity.

SETDB2 is a H3K9 histone methyltransferase required for accurate chromosome segregation. Its H3K9 histone methyltransferase activity was reported to be associated with chromosomes during metaphase. Here, we confirm that SETDB2 is required for mitosis and accurate chromosome segregation. However, these functions are independent of its histone methyltransferase activity. Further analysis showed that SETDB2 can interact with BUBR1, and is required for CDC20 binding to BUBR1 and APC/C complex and CYCLIN B1 degradation. The ability of SETDB2 to regulate the binding of CDC20 to BUBR1 or APC/C complex, and stabilization of CYCLIN B1 are also independent of its histone methyltransferase activity. These results suggest that SETDB2 interacts with BUBR1 to promote binding of CDC20 to BUBR1 and APC3, then degrades CYCLIN B1 to ensure accurate chromosome segregation and mitosis, independently of its histone methyltransferase activity.

MMP10 alleviates non-alcoholic steatohepatitis by regulating macrophage M2 polarization.

BACKGROUND: Non-alcoholic steatohepatitis (NASH), the most severe form of non-alcoholic fatty liver disease (NAFLD), is currently untreatable with a clinically validated treatment. Matrix Metallopeptidase 10 (MMP10) is a common host-response-gene involved in the immune response. However, it remains unknown whether and how MMP10 influences NASH development by modulating macrophage function. METHODS: In vitro, MMP10 overexpression (MMP10-OE), MMP10 knockout (MMP10-KO), proliferator-activated receptor γ (PPARγ)-OE, and control plasmids were transfected into primary Kupffer cells, which were then cultured with or without Interleukin (IL)-4 stimulation. MMP10-OE mice and MMP10-KO mice were fed a normal chow diet (NCD) or a high-fat diet (HFD) for 30 weeks to study the role of MMP10 in NASH model. Hepa1-6 cells were cultured with or without free fatty acid (FFA) treatment for 24 h. RESULTS: MMP10 is downregulated in NASH, and M1/M2 indicators are significantly imbalanced. MMP10 is triggered in response to M2 macrophages polarization. MMP10 overexpression diminishes hepatic steatosis and inflammation in HFD-induced NASH. Mechanistically, PPARγ can bind to the MMP10 promoter and then up-regulates MMP10 expression, which is engaged when IL-4 stimulates M2 macrophage polarization. The downstream STAT3 signaling pathway is further activated to induce M2 polarization, which results in a decreased expression of the pro-inflammatory IL-1ß and tumor necrosis factor (TNF)-a and an increased expression of the anti-inflammatory IL-10, ultimately alleviating NASH progression. CONCLUSIONS: We demonstrate that IL-4 effectively promotes MMP10 expression via PPARγ, and MMP10 overexpression modulates macrophage polarization, hepatic steatosis, and fibrosis, offering prospective targets for NASH treatment.

Association of tumor necrosis factor-α-308G/A polymorphism with the risk of obstructive sleep apnea: A meta-analysis of 14 case-control studies.

Although numerous studies have suggested the association between TNF-α-308G/A polymorphism and susceptibility to obstructive sleep apnea (OSA), the results remained controversial and ambiguous. We performed the present meta-analysis to derive a more precise estimation.The PubMed, Embase, Cochrane library, Web of Science, China National Knowledge Infrastructure, Wanfang databases, and Weipu databases (until January 8, 2022) were accessed to retrieve relevant articles. Pooled odds ratios (ORs) with 95% confidence interval (95% CI) were calculated using the STATA statistical software.Totally, fourteen studies involving 2595 cases and 2579 controls were enrolled in this meta-analysis. Pooled results demonstrated significant association between TNF-α-308G/A polymorphism and OSA risk for the overall population(allele model:OR = 1.87 [1.47, 2.38] (n = 14), dominant model: OR = 1.88[1.48, 2.39] (n = 14), recessive model:OR = 2.83 [2.00, 4.00] (n = 11), homozygous model:OR = 3.30 [2.32, 4.68] (n = 11), and heterozygous model:OR = 1.67 [1.36, 2.06] (n = 14); P<0.001, respectively).Subgroup analysis showed that in both Caucasians and Asians, the A allele conferred increased risk to OSA compared to the G allele (Caucasians: OR = 1.40[1.03, 1.90] (n = 5), P = 0.033, Asians: OR = 2.30 [1.62, 3.26] (n = 9), P< 0.001). In subgroup analysis restricted to hospital-based individuals, significant association between TNF-α-308G/A polymorphism and OSA risk was identified under each genetic model. Whereas, in population-based individuals, increased risk of OSA were only found in homozygous model (OR = 2.19[1.23, 3.90] (n = 3), P = 0.008) and recessive model (OR = 1.77 [1.00, 3.13] (n = 3), P = 0.048). There was a substantial between-study heterogeneity (I2 = 69.10%) across studies which was explained by source of control participants (P = 0.036) by meta-regression. The results of leave-one-out meta-analysis and publication bias suggested the reliability and stability of our results.This meta-analysis suggested that TNF-α-308A allele may be a risk factor for the development of OSA. However, large scale,multi-center and well-designed case-control studies are needed in the future.

Neutrophil extracellular traps mediate TLR9/Merlin axis to resist ferroptosis and promote triple negative breast cancer progression.

Neutrophil and neutrophil extracellular traps (NETs) were reported to be associated with tumor development, but the exact role and concrete mechanisms are still poorly understood, especially in triple negative breast cancer (TNBC). In this study, our results exhibited that NETs formation in TNBC tissues was higher than that in non-TNBC tissues, and NETs formation was distinctly correlated with tumor size, ki67 level and lymph node metastasis in TNBC patients. Subsequent in vivo experiments demonstrated that NETs inhibition could suppress TNBC tumor growth and lung metastasis. Further in vitro experiments uncovered that oncogenic function of NETs on TNBC cells were possibly dependent on TLR9 expression. We also found that neutrophils from peripheral blood of TNBC patients with postoperative fever were prone to form NETs and could enhance the proliferation and invasion of TNBC cells. Mechanistically, we revealed that NETs could interact with TLR9 to decrease Merlin phosphorylation which contributed to TNBC cell ferroptosis resistance. Our work provides a novel insight into the mechanism of NETs promoting TNBC progression and blocking the key modulator of NETs might be a promising therapeutic strategy in TNBC.

HRG inhibits liver cancer lung metastasis by suppressing neutrophil extracellular trap formation.

BACKGROUND: Distant metastasis is a sign of poor prognosis for cancer patients. Extrahepatic liver cancer metastases commonly spread to the lung. Remodelling of the metastatic microenvironment is essential for tumour metastasis. Neutrophil-associated metastatic microenvironment contributes to the early metastatic colonisation of cancer cells in the lung. METHOD: The lung metastasis models were constructed via treated cancer cells by tail vein injection into mice. And samples of lung were harvested at the indicated time to analyze tumor growth and immune cells in the microenvironment. Tumors and lung metastasis specimens were obtained via surgical operations for research purposes. Neutrophils were obtained from peripheral blood of patients with liver cancer or healthy donors (HD). RESULTS: Hepatocellular carcinoma cells reduce the secretion of histidine-rich glycoprotein (HRG), regulate the recruitment and activation of neutrophils in the metastatic microenvironment and promote the production of neutrophil extracellular traps (NETs), thereby promoting liver cancer lung metastasis. HRG binds to FCγR1 on the neutrophil membrane while inhibiting PI3K and NF-κB activation, thereby reducing IL-8 secretion to reduce neutrophil recruitment. Meanwhile, HRG inhibited IL8-MAPK and NF-κB pathway activation and ROS production, resulting in reduced NETs formation. CONCLUSIONS: Our study reveals that liver cancer regulates neutrophil recruitment and NETs formation in the metastatic microenvironment by reducing HRG secretion, thereby promoting tumour lung metastasis. The results of this study will contribute to the development of possible strategies for treating metastases.

Obesity induces male mice infertility via oxidative stress, apoptosis, and glycolysis.

In brief: The current declining trend in male fertility parallels the increasing prevalence of obesity worldwide. This paper revealed that the poor in vitro fertilization rates and decreased sperm motility in obese mice due to excessive oxidative stress enhanced apoptosis and impaired glucose metabolism in the testes. Abstract: Obesity is an urgent public health problem in recent decades, linked to reduced reproductive potential, and negatively affects the success of assisted reproduction technology. The aim of this study is to investigate the mechanisms underlying impaired male fertility caused by obesity. Male C57BL/6 mice fed a high-fat diet for 20 weeks served as mouse models with moderate (20% < body fat rate (BFR) < 30%) and severe obesity (BFR > 30%). Our results showed poor in vitro fertilization rates and decreased sperm motility in obese mice. Abnormal testicular structures were identified in male mice with moderate and severe obesity. The expression level of malondialdehyde increased with obesity severity. This finding indicates that oxidative stress plays a role in male infertility caused by obesity, which was further confirmed by the decreased expression of nuclear factor erythroid 2-related factor 2, superoxide dismutase, and glutathione peroxidases. Our study also found that the expression of cleaved caspase-3 and B-cell lymphoma-2 showed an obesity severity-dependent manner indicating that apoptosis is highly correlated with male infertility caused by obesity. Moreover, the expression of glycolysis-related proteins, including glucose transporter 8, lactate dehydrogenase A, monocarboxylate transporter 2 (MCT2), and MCT4, decreased significantly in the testes of obese male mice, suggesting energy supply for spermatogenesis is impaired by obesity. Taken together, our findings provide evidence that obesity impairs male fertility through oxidative stress, apoptosis, and blockage of energy supply in the testes and suggest that male obesity influences fertility through complex and multiple mechanisms.

Generation of genetically modified rat models via the CRISPR/Cas9 technology.

The RNA-guided CRISPR/Cas9 genomic editing system consists of a single guide RNA (sgRNA) and a Cas9 nuclease. The two components form a complex in cells and target the genomic loci complementary to the sgRNA. The Cas9 nuclease cleaves the target site creating a double stranded DNA break (DSB). In mammalian cells, DSBs are often repaired via error prone non-homologous end joining (NHEJ) or via homology directed repair (HDR) with the presence of donor DNA templates. Micro-injection of the CRISPR/Cas9 system into the rat embryos enables generation of genetically modified rat models. Here, we describe a detailed protocol for creating gene knockout or knockin rat models via the CRISPR/Cas9 technology.

Stable Transgenic Mouse Strain with Enhanced Photoactivatable Cre Recombinase for Spatiotemporal Genome Manipulation.

Optogenetic genome engineering is a powerful technology for high-resolution spatiotemporal genetic manipulation, especially for in vivo studies. It is difficult to generate stable transgenic animals carrying a tightly regulated optogenetic system, as its long-term expression induces high background activity. Here, the generation of an enhanced photoactivatable Cre recombinase (ePA-Cre) transgenic mouse strain with stringent light responsiveness and high recombination efficiency is reported. Through serial optimization, ePA-Cre is developed to generate a transgenic mouse line that exhibits 175-fold induction upon illumination. Efficient light-dependent recombination is detected in embryos and various adult tissues of ePA-Cre mice crossed with the Ai14 tdTomato reporter. Importantly, no significant background Cre activity is detected in the tested tissues except the skin. Moreover, efficient light-inducible cell ablation is achieved in ePA-Cre mice crossed with Rosa26-LSL-DTA mice. In conclusion, ePA-Cre mice offer a tightly inducible, highly efficient, and spatiotemporal-specific genome engineering tool for multiple applications.

Macrophage Notch1 inhibits TAK1 function and RIPK3-mediated hepatocyte necroptosis through activation of ß-catenin signaling in liver ischemia and reperfusion injury.

BACKGROUND: Notch signaling is highly conserved and critically involved in cell differentiation, immunity, and survival. Activation of the Notch pathway modulates immune cell functions during the inflammatory response. However, it remains unknown whether and how the macrophage Notch1 may control the innate immune signaling TAK1, and RIPK3-mediated hepatocyte necroptosis in liver ischemia and reperfusion injury (IRI). This study investigated the molecular mechanisms of macrophage Notch1 in modulating TAK1-mediated innate immune responses and RIPK3 functions in liver IRI. METHODS: Myeloid-specific Notch1 knockout (Notch1M-KO) and floxed Notch1 (Notch1FL/FL) mice (n = 6/group) were subjected to 90 min partial liver warm ischemia followed by 6 h of reperfusion. In a parallel in vitro study, bone marrow-derived macrophages (BMMs) were isolated from these conditional knockout mice and transfected with CRISPR/Cas9-mediated ß-catenin knockout (KO) vector followed by LPS (100 ng/ml) stimulation. RESULTS: IR stress-induced Notch1 activation evidenced by increased nuclear Notch intracellular domain (NICD) expression in liver macrophages. Myeloid Notch1 deficiency exacerbated IR-induced liver damage, with increased serum ALT levels, macrophage/neutrophil accumulation, and proinflammatory cytokines/chemokines production compared to the Notch1FL/FL controls. Unlike in the Notch1FL/FL controls, Notch1M-KO enhanced TRAF6, TAK1, NF-κB, RIPK3, and MLKL but reduced ß-catenin activation in ischemic livers. However, adoptive transfer of lentivirus ß-catenin-modified macrophages markedly improved liver function with reduced TRAF6, p-TAK1, RIPK3 and p-MLKL in IR-challenged livers. Moreover, disruption of RIPK3 in Notch1M-KO mice with an in vivo mannose-mediated RIPK3 siRNA delivery system diminished IR-triggered hepatocyte death. In vitro studies showed that macrophage NICD and ß-catenin co-localized in the nucleus, whereby ß-catenin interacted with NICD in response to LPS stimulation. Disruption of ß-catenin with a CRISPR/Cas9-mediated ß-catenin KO in Notch1FL/FL macrophage augmented TRAF6 activation leading to enhanced TAK1 function. While CRISPR/Cas9-mediated TRAF6 KO in Notch1M-KO macrophage inhibited RIPK3-mediated hepatocyte necroptosis after co-culture with primary hepatocytes. CONCLUSIONS: Macrophage Notch1 controls TAK1-mediated innate immune responses and RIPK3-mediated hepatocyte necroptosis through activation of ß-catenin. ß-catenin is required for the macrophage Notch1-mediated immune regulation in liver IRI. Our findings demonstrate that the macrophage Notch1-ß-catenin axis is a crucial regulatory mechanism in IR-triggered liver inflammation and provide novel therapeutic potential in organ IRI and transplant recipients. Video abstract.

Disulfiram inhibits liver fibrosis in rats by suppressing hepatic stellate cell activation and viability.

BACKGROUND: Liver fibrosis is a wound-healing response to chronic injury, featuring with excess accumulation of extracellular matrix secreted by the activated hepatic stellate cells (HSC). Disulfiram (DSF), also known as Antabuse, has been used for the treatment of alcohol addiction and substance abuse. Recently, overwhelming studies had revealed anti-cancer effects of DSF in multiple cancers, including liver cancer. But the actual effects of DSF on liver fibrosis and liver function remain unknown. METHODS: In this study, we evaluated the effects of low-dose DSF in CCl4- and Bile Duct Ligation (BDL)-induced hepatic fibrosis rat models. Cell proliferation was detected by using the Cell-Light™ EdU Apollo®567 Cell Tracking Kit. Cell apoptosis was analyzed using a TdT-mediated dUTP nick end labeling (TUNEL) kit, viability was measured with Cell Counting Kit-8(CCK8). Relative mRNA expression of pro-fibrogenic was assessed using quantitative RT-PCR. The degree of liver fibrosis, activated HSCs, were separately evaluated through Sirius Red-staining, immunohistochemistry and immunofluorescence. Serum alanine aminotransferase (ALT) and asparagine aminotransferase (AST) activities were detected with ALT and AST detecting kits using an automated analyzer. RESULTS: Liver fibrosis was distinctly attenuated while liver functions were moderately ameliorated in the DSF-treated group. Activation and proliferation of primary rat HSCs isolated from rat livers were significantly suppressed by low-dose DSF. DSF also inhibited the viability of in vitro cultured rat or human HSC cells dose-dependently but had no repressive role on human immortalized hepatocyte THLE-2 cells. Interestingly, upon DSF treatment, the viability of LX-2 cells co-cultured with THLE-2 was significantly inhibited, while that of THLE-2 co-cultured with LX-2 was increased. Further study indicated that HSCs apoptosis was increased in DSF/CCl4-treated liver samples. These data indicated that DSF has potent anti-fibrosis effects and protective effects toward hepatocytes and could possibly be repurposed as an anti-fibrosis drug in the clinic. CONCLUSIONS: DSF attenuated ECM remodeling through suppressing the transformation of quiet HSCs into proliferative, fibrogenic myofibroblasts in hepatic fibrosis rat models. DSF provides a novel approach for the treatment of liver fibrosis.

Long-term correction of hemophilia B through CRISPR/Cas9 induced homology-independent targeted integration.

CRISPR/Cas9-mediated site-specific insertion of exogenous genes holds potential for clinical applications. However, it is still infeasible because homologous recombination (HR) is inefficient, especially for non-dividing cells. To overcome the challenge, we report that a homology-independent targeted integration (HITI) strategy is used for permanent integration of high-specificity-activity Factor IX variant (F9 Padua, R338L) at the albumin (Alb) locus in a novel hemophilia B (HB) rat model. The knock-in efficiency reaches 3.66%, as determined by droplet digital PCR (ddPCR). The clotting time is reduced to a normal level four weeks after treatment, and the circulating factor IX (FIX) level is gradually increased up to 52% of the normal level over nine months even after partial hepatectomy, demonstrating the amelioration of hemophilia. Through primer-extension-mediated sequencing (PEM-seq), no significant off-target effect is detected. This study not only provides a novel model for HB but also identifies a promising therapeutic approach for rare inherited diseases.

New insights into the reverse of chromium-induced reprotoxicity of pregnant mice by melatonin.

Hexavalent chromium Cr(VI) is a well-known environmental toxic metal that causes reprotoxicity in pregnant females. There are currently no appropriate interventions or treatments for Cr(VI) exposure during pregnancy. Herein, the protective effect of melatonin (MLT) against Cr(VI)-induced reprotoxicity is investigated by administrating MLT to pregnant mice exposed to Cr(VI). The results indicate that MLT effectively alleviates Cr(VI)-induced adverse pregnancy outcomes, restoring the decreased fetal weight and increased fetal resorption and malformation caused by Cr(VI) exposure to normal levels. MLT reduces the negative effects of Cr(VI) on follicular atresia and the development of primordial follicle in the maternal ovarian, thereby mitigating the decline in the reserve of primordial follicles. MLT alleviates Cr(VI)-induced oxidative stress, hence reducing the excessive accumulation of malondialdehyde in the maternal ovary. MLT inhibits Cr(VI)-induced apoptosis of ovarian granulosa cells and the expression of cleaved caspase-3 in the ovary. MLT reduces the increase in serum follicle-stimulating hormone caused by Cr(VI) exposure, while elevating anti-Mullerian hormone levels. We demonstrate that MLT reverses Cr(VI)-induced reprotoxicity in pregnant mice, opening up a new avenue for treating reproductive defects caused by environmental stress.

Polyphenol Oxidase as a Promising Alternative Therapeutic Agent for Cancer Therapy.

Cancers have always been the most difficult to fight, the treatment of cancer is still not considered. Thus, exploring new anticancer drugs is still imminent. Traditional Chinese medicine has played an important role in the treatment of cancer. Polyphenol oxidase (PPO) extracted from Edible mushroom has many related reports on its characteristics, but its role in cancer treatment is still unclear. This study aims to investigate the effects of PPO extracted from Edible mushroom on the proliferation, migration, invasion, and apoptosis of cancer cells in vitro and explore the therapeutic effects of PPO on tumors in vivo. A cell counting kit-8 (CCK8) assay was used to detect the effect of PPO on the proliferation of cancer cells. The effect of PPO on cancer cell migration ability was detected by scratch test. The effect of PPO on the invasion ability of cancer cells was detected by a transwell assay. The effect of PPO on the apoptosis of cancer cells was detected by flow cytometry. Female BALB/c mice (18-25 g, 6-8 weeks) were used for in vivo experiments. The experiments were divided into control group, model group, low-dose group (25 mg/kg), and high-dose group (50 mg/kg). In vitro, PPO extracted from Edible mushroom significantly inhibited the proliferation, migration, and invasion capability of breast cancer cell 4T1, lung cancer cell A549, and prostate cancer cell C4-2, and significantly promoted the apoptosis of 4T1, A549, and C4-2. In vivo experiments showed PPO inhibitory effect on tumor growth. Collectively, the edible fungus extract PPO could play an effective role in treating various cancers, and it may potentially be a promising agent for treating cancers.

Reconstructing the Climatic-Oceanic Environment and Exploring the Enrichment Mechanism of Organic Matter in the Black Shale across the Late Ordovician-Early Silurian Transition on the Upper Yangtze Platform Using Geochemical Proxies.

Black shale deposited in the transitional period from the Late Ordovician to Early Silurian is the most important source rock and shale gas reservoir in the Yangtze region of South China. However, the source of these sediments is still controversial. In this paper, the changes in total organic carbon (TOC), total sulfur (TS), organic carbon isotopes (δ13Corg), biomarkers, trace elements, and rare earth elements in the Ordovician-Silurian boundary strata of the XK-1 well in northern Guizhou Province, South China, have been systematically studied. The paleoenvironmental and paleoclimatic conditions of the Late Ordovician to Early Silurian and their relationship with organic matter enrichment in the Upper Yangtze Platform have been reconstructed. The distribution of biomarkers reflects that the Late Ordovician-Early Silurian shale was deposited in the marine environment and was highly contributed by marine plankton/algae and microorganisms. Paleoclimatic proxies (Sr/Cu, δ13Corg) show that the global climate system experienced significant changes from a warm-humid climate to a brief period of cold-dry climate and then back to a warm-humid climate during the Ordovician-Silurian transition. This warm and humid climate condition helps to improve the biological productivity within the photic zone of the water column during deposition. In addition, the low oxygen (reduction) conditions during the deposition of the Late Ordovician-Early Silurian deposits are characterized by low Pr/Ph values (0.39-0.79) and relatively high elemental ratios of V/Ni (1.40-5.77) and V/(V + Ni) (0.58-0.85). This paleoredox condition contributes to the preservation of organic matter during deposition of the Late Ordovician-Early Silurian deposits. Therefore, it is demonstrated that the climate and ocean fluctuated greatly during the Late Ordovician-Early Silurian transition period, and this fluctuation provided necessary control factors for marine anoxia, primary productivity, and subsequent organic-rich black shale deposition in the Upper Yangtze region during the Late Ordovician and Early Silurian intervals.

Dual base editor catalyzes both cytosine and adenine base conversions in human cells.

Although base editors are useful tools for precise genome editing, current base editors can only convert either adenines or cytosines. We developed a dual adenine and cytosine base editor (A&C-BEmax) by fusing both deaminases with a Cas9 nickase to achieve C-to-T and A-to-G conversions at the same target site. Compared to single base editors, A&C-BEmax's activity on adenines is slightly reduced, whereas activity on cytosines is higher and RNA off-target activity is substantially decreased.

Amelioration of an Inherited Metabolic Liver Disease through Creation of a De Novo Start Codon by Cytidine Base Editing.

Base editing technology efficiently generates nucleotide conversions without inducing excessive double-strand breaks (DSBs), which makes it a promising approach for genetic disease therapy. In this study, we generated a novel hereditary tyrosinemia type 1 (HT1) mouse model, which contains a start codon mutation in the fumarylacetoacetate hydrolase (Fah) gene by using an adenine base editor (ABE7.10). To investigate the feasibility of base editing for recombinant adeno-associated virus (rAAV)-mediated gene therapy, an intein-split cytosine base editor (BE4max) was developed. BE4max efficiently induced C-to-T conversion and restored the start codon to ameliorate HT1 in mice, but an undesired bystander mutation abolished the effect of on-target editing. To solve this problem, an upstream sequence was targeted to generate a de novo in-frame start codon to initiate the translation of FAH. After treatment, almost all C-to-T conversions created a start codon and restored Fah expression, which efficiently ameliorated the disease without inducing off-target mutations. Our study demonstrated that base editing-mediated creation of de novo functional elements would be an applicable new strategy for genetic disease therapy.

The neuroprotective effects of novel estrogen receptor GPER1 in mouse retinal ganglion cell degeneration.

PURPOSE: To investigate the potential protective effect of novel G protein coupled estrogen receptor (GPER1) against the neurotoxicity induced by NMDA in the mouse retina. METHODS: We induce retinal ganglion cells (RGCs) toxic injury through intravitreal injection of NMDA or acute ocular hypertension (AOH) induced by anterior chamber infusion with saline. Endogenous ligand 17-ß-estradiol (E2), GPER1 agonist (G-1), and E2 with GPER1 antagonist (G-15) or classic estrogen receptor α and ß (ERα and ERß) antagonist tamoxifen (TAM) were subcutaneous administered before NMDA to identify the possible involved receptors. Immunofluorescence staining was performed to explore the survival of RGCs and Müller cell gliosis. TUNEL staining was used to evaluate the RGC apoptosis. The involved molecular pathway was detected via antibody array expression profiling. RESULTS: Activation of estrogen receptor by E2 or G-1 could significantly rescue the RGCs injury in NMDA administration. The protective effect was carried exclusively by GPER1 activation. E2 application can still mimicked the protective function when estrogen receptor α and ß (ERα and ERß) blocked by tamoxifen (TAM), while the effects was blocked by GPER1 antagonist G-15. Moreover, the TUNEL positive RGCs and GFAP expression level were both attenuated in G-1 application and the effects could be reversed by G-15. In addition, application of the PI3K/Akt antagonist LY294002 counteracted the effect of G-1. And a number of apoptosis regulatory factors decreased dramatically in the G-1 group, including Bad, Caspase 3, Caspase 7, Smad2, P-53 and TAK1. Also, similar protective effect of G-1 was spotted in acute ocular hypertension (AOH) model. CONCLUSION: Estrogen played a protective role via a novel estrogen receptor, GPER1, instead of classical receptors ERα or ERß. Activation of GPER1 attenuated RGCs apoptosis and Müller cells gliosis, indicating GPER1 as a potential treatment target in RGCs degeneration diseases.

Development and Characterization of MDR1 (Mdr1a/b) CRISPR/Cas9 Knockout Rat Model.

Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein-9 nuclease (Cas9) technology is widely used as a tool for gene editing in rat genome site-specific engineering. Multidrug resistance 1 [MDR1 (also known as P-glycoprotein)] is a key efflux transporter that plays an important role not only in the transport of endogenous and exogenous substances, but also in tumor MDR. In this report, a novel MDR1 (Mdr1a/b) double-knockout (KO) rat model was generated by the CRISPR/Cas9 system without any off-target effect detected. Western blot results showed that MDR1 was completely absent in the liver, small intestine, brain, and kidney of KO rats. Further pharmacokinetic studies of digoxin, a typical substrate of MDR1, confirmed the deficiency of MDR1 in vivo. To determine the possible compensatory mechanism of Mdr1a/b (-/-) rats, the mRNA levels of the CYP3A subfamily and transporter-related genes were compared in the brain, liver, kidney, and small intestine of KO and wild-type rats. In general, a new Mdr1a/b (-/-) rat model has been successfully generated and characterized. This rat model is a useful tool for studying the function of MDR1 in drug absorption, tumor MDR, and drug target validation.

SH479, a Betulinic Acid Derivative, Ameliorates Experimental Autoimmune Encephalomyelitis by Regulating the T Helper 17/Regulatory T Cell Balance.

CD4+ T helper cells, especially T helper 17 (TH17) cells, combined with immune regulatory network dysfunction, play key roles in autoimmune diseases including multiple sclerosis (MS). Betulinic acid (BA), a natural pentacyclic triterpenoid, has been reported to be involved in anti-inflammation, in particular having an inhibitory effect on proinflammatory cytokine interleukin 17 (IL-17) and interferon-γ (IFN-γ) production. In this study, we screened BA derivatives and found a BA derivative, SH479, that had a greater inhibitory effect on TH17 differentiation. Our further analysis showed that SH479 had a greater inhibitory effect on TH17 and TH1, and a more stimulatory effect on regulatory T (Treg) cells. To evaluate the effects of SH479 on autoimmune diseases in vivo, we employed the extensively used MS mouse model experimental autoimmune encephalomyelitis (EAE). Our results showed that SH479 ameliorated clinical and histologic signs of EAE in both prevention and therapeutic protocols by regulating the TH17/Treg balance. SH479 dose-dependently reduced splenic lymphocyte proinflammatory factors and increased anti-inflammatory factors. Moreover, SH479 specifically inhibited splenic lymphocyte viability from EAE mice but not normal splenic lymphocyte viability. At the molecular level, SH479 inhibited TH17 differentiation by regulating signal transducer and activator of transcription-3 (STAT3) phosphorylation, DNA binding activity, and recruitment to the Il-17a promoter in CD4+ T cells. Furthermore, SH479 promoted the STAT5 signaling pathway and inhibited the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway. Together, our data demonstrated that SH479 ameliorated EAE by regulating the TH17/Treg balance through inhibiting the STAT3 and NF-κB pathways while activating the STAT5 pathway, suggesting that SH479 is a potential novel drug candidate for autoimmune diseases including MS.