SZ-685C inhibits the growth of non-functioning pituitary adenoma by down-regulating miR-340-3p and inducing autophagy.

Background: SZ-685C, an anthracycline compound derived from the mangrove endophytic fungus Halorosellinia sp. (No. 1403) collected from the South China Sea, has shown strong anticancer activities. Non-functioning pituitary adenomas (NFPAs) are a type of tumor that can be challenging to manage clinically and have a significant unmet medical need. Our research has found that SZ-685C showed an inhibitory effect on the viability, migration ability, and proliferation ability of a human non-functioning pituitary tumor-derived folliculostellate (PDFS) cell line. Methods: SZ-685C was prepared and purified from the mangrove endophytic fungus No. 1403. PDFS cells were exposed to SZ-685C, and the effect of SZ-685C on PDFS cells was evaluated. RNA sequencing was used to analyze the miRNA expression profile in PDFS cells of the control group and SZ-685C-treated group. Quantitative polymerase chain reaction (qPCR) was performed to verify the expression of selected miR-340-3p. The effects of SZ-685C on PDFS cells after overexpression of miR-340-3p were evaluated. Dual-luciferase reporter assays showed PPP1CB is a direct target of miR-340-3p. Finally, the action pathway of the selected miR-340-3p was predicted and evaluated through bioinformatics analysis. Results: SZ-685C reduced cell viability in PDFS cells, accompanied by inhibition of migration ability and proliferation ability. The IC50 value for 24 h is 9.144 ± 0.991 µM, and for 48 h is 4.635 ± 0.551 µM. SZ-685C increased the protein levels of Beclin 1, the ratio of LC3-II to LC3-I, and LAMP-1, and down-regulated p62. MiRNA sequencing and further validation showed that miR-340-3p significantly decreased in PDFS cells treated with SZ-685C. After overexpression of miR-340-3p, the inhibition of viability, migration ability, proliferation ability, and autophagy-promoting effect of SZ-685C on PDFS cells were weakened. SZ-685C caused a decrease in PPP1CB expression and activation of the ERK pathway in PDFS cells, and this trend was reversed after overexpression of miR-340-3p. Conclusions: SZ-685C downregulates the expression of miR-340-3p in PDFS cells, thereby reducing the expression of PPP1CB and activating the ERK pathway to promote autophagic cell death, leading to inhibition of PDFS cell growth.

Effects of acrylamide exposure during pregnancy and lactation on the development of myelin sheath of corpus callosum in offspring rats.

Acrylamide is an alkene known to induce neurotoxicity in humans and experimental animals. However, the effects of acrylamide on the development of myelin sheath are unclear. The present study was to explore the effects of acrylamide exposure during pregnancy and lactation on the development of myelin sheath in offspring rats. Four groups of thirty-two pregnant Sprague-Dawley rats were exposed to 0, 4.5, 9 and 18 mg/kg BW acrylamide by gavage from gestational day 15 to postnatal day 13. The corpus callosum of nine offspring rats per group were dissected in postpartum day 14. Structural changes and lipid contents in myelin sheaths were examined by transmission electron microscopy(TEM) and Luxol Fast Blue staining(LFB). The expression of MBP and PLP was evaluated by immunohistochemistry and Western blotting. TEM showed that the myelin sheaths in the 18 mg/kg group were disordered compared with control group. Luxol Fast Blue staining gradually decreased with increasing acrylamide maternal exposure. The immunohistochemistry and Western Blotting results showed that maternal exposure to acrylamide caused a decreasing trend in MBP and PLP in the corpus callosum of rats at postnatal day 14. Furthermore, these reduced protein levels may be neurodevelopmental toxicity's mechanism in response to maternal exposure to acrylamide.

Protective effect of rutin on spinal motor neuron in rats exposed to acrylamide and the underlying mechanism.

The present study aimed to investigate the protective effect of rutin on the injury of spinal motor neuron in rats exposed to acrylamide (ACR) the underlying mechanism. Fifty male Sprague-Dawley rats, aged 7-8 weeks, were randomly divided into control group, ACR group (20 mg/kg), low dose(100 mg/kg), medium dose (200 mg/kg) and high dose(400 mg/kg) rutin groups, ten rats in each group. The rats were given intragastric administration for 21 days. Every week, a neurobehavioral test was conducted. Nissl staining was used to observe the morphological changes in motor neurons in the L4-L6 segment of the spinal cord. Immunohistochemistry was used to identify AChE and ChAT in the rat spinal cord. Western blot was used to identify the expression of AChE, ChAT, P-ERK, ERK, and Nrf2 proteins in the rat spinal cord. The commercial kits were used to detect the presence of SOD, GSH, and LDH in the rat spinal cord. At the start of the second week, the medium and high dosage rutin group's rats' gait scores significantly decreased as compared to those of the ACR group. When rutin dosage was increased, the Nissl staining revealed that Nissl bodies was staining intensified compared to the ACR group. Immunohistochemistry and Western blot analysis revealed that AChE and ChAT expression changed when rutin dose was raised, but P-ERK and Nrf2 expression steadily increased in the spinal cord of rats in the medium and high dose groups compared to the ACR group. In the spinal cord of rats in each dosage group compared to the ACR group, the findings of the oxidative stress indices demonstrated that the expression levels of SOD and GSH rose with the increase of rutin dose, while the expression of LDH reduced with the rise of rutin dose. Rutin has an anti-oxidative impact through up-regulating the expression of P-ERK and Nrf2 proteins in the ERK/Nrf2 pathway, which may be connected to its protective action on motor neurons in the spinal cord of rats exposed to ACR.

Anti-Tumor Secondary Metabolites Originating from Fungi in the South China Sea's Mangrove Ecosystem.

A mangrove is a unique ecosystem with abundant resources, in which fungi are an indispensable microbial part. Numerous mangrove fungi-derived secondary metabolites are considerable sources of novel bioactive substances, such as polyketides, terpenoids, alkaloids, peptides, etc., which arouse people's interest in the search for potential natural anti-tumor drugs. This review includes a total of 44 research publications that described 110 secondary metabolites that were all shown to be anti-tumor from 39 mangrove fungal strains belonging to 18 genera that were acquired from the South China Sea between 2016 and 2022. To identify more potential medications for clinical tumor therapy, their sources, unique structures, and cytotoxicity qualities were compiled. This review could serve as a crucial resource for the research status of mangrove fungal-derived natural products deserving of further development.

Toxic effects of subacute exposure to acrylamide on motor endplates of the gastrocnemius in rats.

Acrylamide (ACR) is a recognized toxin that is known to induce neurotoxicity in humans and experimental animals. This study aimed to investigate the toxic effects of subacute exposure of the motor endplate (MEP) of the gastrocnemius in rats to ACR. All rats were randomly divided into control, 9, 18, and 36 mg/kg ACR groups, and ACR was administered by gastric gavage for 21 days. The behavioral tests were performed weekly. On the 22nd day, the wet weight of the gastrocnemius was measured. The changes in muscle fiber structure, nerve endings, and MEP in the gastrocnemius were examined by hematoxylin-eosin (HE) and gold chloride staining. Acetylcholinesterase (AChE) content in the gastrocnemius was detected by AChE staining. The expression of AChE and calcitonin gene-related peptide was detected by immunohistochemistry and western blot. Rats exposed to ACR showed a significant increase in gait scores and hind limb splay distance compared with the control group, and the wet weight of the gastrocnemius was reduced, HE staining showed that the muscle fiber structure of the gastrocnemius became thin and the arrangement was dense with nuclear aggregation, gold chloride staining showed that nerve branches decreased and became thin, nerve fibers became short and light, the number of MEPs was decreased, the staining became light, and the structure was not clear. AChE staining showed that the number of MEPs was significantly reduced after exposure to ACR, the shape became small, and the AChE content decreased in a dose-dependent manner. Immunohistochemistry and western blot analysis results of the expression levels of AChE and CGRP showed a decreasing trend as compared to the control group with increasing ACR exposure dose. The reduction in protein levels may be the mechanism by which ACR has a toxic effect on the MEP in the gastrocnemius of rats.