Glufosinate-ammonium causes liver injury in zebrafish by blocking the Nrf2 pathway.

Glufosinate-ammonium (GLA) is a widely used herbicide, but less research has been done on its harmful effects on non-target organisms, especially aquatic organisms. In this study, 600 adult zebrafish were exposed to different concentration of GLA (0, 1.25, 2.5, 5, 10, and 20 mg/L) for 7 days, and the livers were dissected on the eighth day to examine the changes in liver structure, function, oxidative stress, inflammation, apoptosis, and Nrf2 pathway, and finally to clarify the mechanism of GLA induced liver injury in zebrafish. The levels of alanine aminotransferase, aspartate aminotransferase, reactive oxygen species, malondialdehyde, inflammatory factors (IL-6 and TNF-α), and caspase-3 gradually increased, while the levels of superoxide dismutase, catalase, glutathione, and glutathione peroxidase gradually decreased with the increase of GLA concentration. The Nrf2 pathway was activated at low concentrations (1.25-5 mg/L) and significantly inhibited at high concentrations (10 and 20 mg/L). These results suggested that GLA could cause oxidative stress, inflammation, and apoptosis in zebrafish liver. Therefore, GLA can cause liver injury in zebrafish, and at high concentrations, the inhibition of Nrf2 pathway is one of the important causes of liver injury.

Dexmedetomidine Alleviates Acute Stress-Induced Acute Kidney Injury by Attenuating Inflammation and Oxidative Stress via Inhibiting the P2X7R/NF-κB/NLRP3 Pathway in Rats.

This study aimed to investigate the potential protective effects of Dexmedetomidine (DEX) against acute kidney injury (AKI) induced by acute stress (AS). Wistar rats were divided into five groups: Control, DEX, AS, AS + DEX, and AS + A438079. The results showed that AS led to AKI by increasing inflammatory biomarkers and oxidative stress-related indicators. The acute stress model in rats was successfully established. Renal function, histopathology, oxidative stress, and inflammation were assessed. Localization of P2X7 receptor (P2X7R) was determined by immunofluorescence. Additionally, the key inflammatory proteins of the P2X7R/NF-κB/NLRP3 signaling pathway were measured by Western blotting. DEX significantly improved kidney function, alleviated kidney injury, and reduced oxidative stress and inflammation. DEX inhibited the activation of the P2X7R, decreased the expression of NF-κB, NLRP3 inflammasome, and Caspase-1, and inhibited the expression of interleukin-1ß (IL-1ß) and tumor necrosis factor α (TNFα). Furthermore, DEX also alleviated AS-induced AKI by inhibiting the excessive production of reactive oxygen species (ROS) and reducing oxidative stress. In conclusion, DEX attenuates AS-induced AKI by mitigating inflammation and oxidative stress through the inhibition of the P2X7R/NF-κB/NLRP3 pathway in rats.

Chlorogenic Acid Alleviates Chronic Stress-Induced Intestinal Damage by Inhibiting the P38MAPK/NF-κB Pathway.

Chronic stress can cause intestinal barrier damage. MAPK and NF-κB are closely related to it. Chlorogenic acid (CGA), a dietary polyphenol, has been shown to have intestinal protective effects, but whether by regulating MAPK and NF-κB is not known. Therefore, in this experiment, 24 Wistar rats were randomly divided into 4 groups (C group, CS group, CS + SB203580, and CS + CGA group). Rats in the CS group were restrained stress for 6 h per day for 21 days. Rats in the CS + SB203580 group were given SB203582 (0.5 mg/kg, intraperitoneal injection) 1 h before restraint stress every other day. Rats in the CS + CGA group were given CGA (100 mg/kg, gavage) 1 h before restraint stress. In chronic stress, intestinal barrier damage was evident, while being restored after CGA treatment. After chronic stress, the levels of p-P38 were increased (P < 0.01), while the levels of p-JNK and p-ERK were not changed. The levels of p-p38 were elevated after CGA treatment (P < 0.01). These results suggested that p38MAPK played an important role in chronic stress-induced intestinal injury, and CGA could inhibit p38MAPK activity. Therefore, we chose SB203582 (P38MAPK inhibitor) to elucidate the role of p38. After chronic stress, intestinal tight junction key proteins Occludin, ZO-1, and Claudin3 protein and gene expression were reduced (P < 0.01), while being elevated after CGA or SB203582 intervention (P < 0.05). After CGA treatment, the levels of p-IκB, p-p65, p-p38, and TNF-α were reduced (P < 0.01). SB203582 intervention reduced p-p65 and TNF-α levels significantly (P < 0.01). These results suggested that CGA could inhibit the NF-κB pathway by suppressing p38MAPK, thereby alleviating chronic stress-induced intestinal damage.

Culture conditions of mouse ESCs impact the tumor appearance in vivo.

Various culture conditions by small molecules have been explored to extend pluripotency of stem cells, but their impacts on cell fate in vivo remain elusive. We systematically compared the effects of various culture conditions on the pluripotency and cell fate in vivo of mouse embryonic stem cells (ESCs) by tetraploid embryo complementation assay. Conventional ESC cultures in serum/LIF-based condition produced complete ESC mice and also the survival to adulthood at the highest rates of all other chemical-based cultures. Moreover, long-term examination of the survived ESC mice demonstrated that conventional ESC cultures did not lead to visible abnormality for up to 1.5-2 years, whereas the prolonged chemical-based cultures developed retroperitoneal atypical teratomas or leiomyomas. The chemical-based cultures exhibited transcriptomes and epigenomes that typically differed from those of conventional ESC cultures. Our results warrant further refinement of culture conditions in promoting the pluripotency and safety of ESCs in future applications.

Oncostatin M Maintains Naïve Pluripotency of mESCs by Tetraploid Embryo Complementation (TEC) Assay.

It has been well established that leukemia inhibitory factor (LIF) is essential for maintaining naïve pluripotency of embryonic stem cells (ESCs). Oncostatin M (OSM) is a member of the IL-6 family of cytokines which share gp130 as a receptor subunit, and the OSM-gp130 complex can recruit either LIF receptor ß or OSM receptor ß. Here we show that OSM can completely replace LIF to maintain naïve pluripotency of ESCs. Mouse ESCs (mESCs) cultured in the presence of LIF or OSM not only express pluripotency genes at similar levels but also exhibit the same developmental pluripotency as evidenced by the generation of germline competent chimeras, supporting previous findings. Moreover, we demonstrate by tetraploid embryo complementation assay, the most stringent functional test of authentic pluripotency that mESCs cultured in OSM produce viable all-ESC pups. Furthermore, telomere length and telomerase activity, which are also crucial for unlimited self-renewal and genomic stability of mESCs, do not differ in mESCs cultured under OSM or LIF. The transcriptome of mESCs cultured in OSM overall is very similar to that of LIF, and OSM activates Stat3 signaling pathway, like LIF. Additionally, OSM upregulates pentose and glucuronate interconversion, ascorbate and aldarate metabolism, and steroid and retinol metabolic pathways. Although the significance of these pathways remains to be determined, our data shows that OSM can maintain naïve pluripotent stem cells in the absence of LIF.