Pexidartinib hydrochloride exposure induces developmental toxicity and immunotoxicity in zebrafish embryos via activation of Wnt signaling.

Pexidartinib, a macrophage colony-stimulating factor receptor (CSF-1R) inhibitor, is indicated for the treatment of tendon sheath giant cell tumor (TGCT). However, few studies on the toxicity mechanisms of pexidartinib for embryonic development. In this study, the effects of pexidartinib on embryonic development and immunotoxicity in zebrafish were investigated. Zebrafish embryos at 6 h post fertilization (6 hpf) were exposed to 0, 0.5, 1.0, and 1.5 µM concentrations of pexidartinib, respectively. The results showed that different concentrations of pexidartinib induced the shorter body, decreased heart rate, reduced number of immune cells and increase of apoptotic cells. In addition, we also detected the expression of Wnt signaling pathway and inflammation-related genes, and found that these genes expression were significantly upregulated after pexidartinib treatment. To test the effects of embryonic development and immunotoxicity due to hyperactivation of Wnt signaling after pexidartinib treatment, we used IWR-1, Wnt inhibitor, for rescue. Results show that IWR-1 could not only rescue developmental defects and immune cell number, but also downregulate the high expression of Wnt signaling pathway and inflammation-related caused by pexidartinib. Collectively, our results suggest that pexidartinib induces the developmental toxicity and immunotoxicity in zebrafish embryos through hyperactivation of Wnt signaling, providing a certain reference for the new mechanisms of pexidartinib function.

miR-494-5p mediates the antioxidant activity of EPA by targeting the mitochondrial elongation factor 1 gene MIEF1 in HepG2 cells.

Eicosapentaenoic acid (EPA) shows antioxidant activity, which may be attributed to its regulatory effect on microRNA expression. Our preliminary study indicated that EPA upregulated miR-494-5p, which was possibly involved in the regulation of cellular stress responses. The current study aimed to address whether miR-494-5p was targeted by EPA to regulate cellular oxidative stress and its possible functional mechanism. The results showed that miR-494-5p mediated the antioxidant effect of EPA and miR-494-5p reduction deteriorated EPA-induced increase in the cellular antioxidant capacity of HepG2 cells. Moreover, the mitochondrial elongation factor 1 (MIEF1) gene was a target gene of miR-494-5p. Both miR-494-5p overexpression and MIEF1 knockdown significantly enhanced cellular antioxidant capacity, as indicated by a reduction in the reactive oxygen species level and an increase in the total cellular antioxidant capacity, along with enhancing antioxidant enzymes. Thus, miR-494-5p and MIEF1 had opposite effects on cellular antioxidant capacity. Furthermore, their regulatory effects on oxidative stress may have been attributed to modulation of mitochondrial function, biogenesis and homeostasis. Taken together, the findings indicated that miR-494-5p mediated EPA activity and promoted cellular antioxidant capacity by inhibiting the expression of MIEF1, which further modulated mitochondrial structure and activity. This study may provide novel insights into the post-translational regulation of antioxidation reactions, which involves the coordinated control of mitochondria.

Developing population identification tool based on polymorphism of rDNA for traditional Chinese medicine: Artemisia annua L.

BACKGROUND: Artemisia annua, a well-known traditional Chinese medicine, is the main source for production of artemisinin, an anti-malaria drug. A. annua is distributed globally, with great diversity of morphological characteristics and artemisinin contents. Diverse traits among A. annua populations impeded the stable production of artemisinin, which needs an efficient tool to identify strains and assess population genetic homogeneity. PURPOSE: In this study, ribosomal DNA (rDNA), were characterized for A. annua for strains identification and population genetic homogeneity assessment. METHODS: The ribosomal RNA (rRNA) genes were identified using cmscan and assembled using rDNA unit of LQ-9 as a reference. rDNA among Asteraceae species were compared performing with 45S rDNA. The rDNA copy number was calculated based on sequencing depth. The polymorphisms of rDNA sequences were identified with bam-readcount, and confirmed by Sanger sequencing and restriction enzyme experiment. The ITS2 amplicon sequencing was used to verify the stability of ITS2 haplotype analysis. RESULTS: Different from other Asteraceae species, 45S and 5S linked-type rDNA was only found in Artemisia genus. Rich polymorphisms of copy number and sequence of rDNA were identified in A. annua population. The haplotype composition of internal transcribed spacer 2 (ITS2) region which had moderate sequence polymorphism and relative short size was significantly different among A. annua strains. A population discrimination method was developed based on ITS2 haplotype analysis with high-throughput sequencing. CONCLUSION: This study provides comprehensive characteristics of rDNA and suggests that ITS2 haplotype analysis is ideal tool for A. annua strain identification and population genetic homogeneity assessment.

Eicosapentaenoic acid (EPA) exhibits antioxidant activity via mitochondrial modulation.

Reactive oxygen species (ROS) are mitochondrial respiration byproducts, the accumulation of which may cause oxidative damage and is associated with several chronic health problems. As an essential unsaturated fatty acid, eicosapentaenoic acid (EPA) provides various physiological functions; however, its exact regulatory role remains elusive. The current study aimed to address how EPA regulates cellular antioxidant capacity and the possible mechanisms of action. Upon 48 h of EPA treatment, the ROS levels of HepG2 cells were reduced by at least 40%; the total cellular antioxidant capacity was increased by approximately 50-70%, accompanied by enhanced activities and expression of major antioxidant enzymes. Furthermore, the mitochondrial membrane potential and the mitochondrial biogenesis were dramatically improved in EPA-treated cells. These data suggest that EPA improves cellular antioxidant capacity by enhancing mitochondrial function and biogenesis, which sheds light on EPA as a dietary complement to relieve the oxidative damage caused by chronic diseases.

Absorbable Artificial Dura Versus Nonabsorbable Artificial Dura in Decompressive Craniectomy for Severe Traumatic Brain Injury: A Retrospective Cohort Study in Two Centers.

Background: Severe traumatic brain injury (TBI) patients usually need decompressive craniectomy (DC) to decrease intracranial pressure. Duraplasty is an important step in DC with various dura substitute choices. This study aims to compare absorbable dura with nonabsorbable dura in duraplasty for severe TBI patients. Methods: One hundred and three severe TBI patients who underwent DC and dura repair were included in this study. Thirty-nine cases used absorbable artificial dura (DuraMax) and 64 cases used nonabsorbable artificial dura (NormalGEN). Postoperative complications, mortality and Karnofsky Performance Scale (KPS) score in one year were compared in both groups. Results: Absorbable dura group had higher complication rates in transcalvarial cerebral herniation (TCH) (43.59% in absorbable dura group vs. 17.19% in nonabsorbable dura group, P = 0.003) and CSF leakage (15.38% in absorbable dura group vs. 1.56% in nonabsorbable dura group, P = 0.021). But severity of TCH described with hernial distance and herniation volume demonstrated no difference in both groups. There was no statistically significant difference in rates of postoperative intracranial infection, hematoma progression, secondary operation, hydrocephalus, subdural hygroma and seizure in both groups. KPS score in absorbable dura group (37.95 ± 28.58) was statistically higher than nonabsorbable dura group (49.05 ± 24.85) in one year after operation (P = 0.040), while no difference was found in the rate of functional independence (KPS ≥ 70). Besides, among all patients in this study, TCH patients had a higher mortality rate (P = 0.008), lower KPS scores (P < 0.001) and lower functionally independent rate (P = 0.049) in one year after surgery than patients without TCH. Conclusions: In terms of artificial biological dura, nonabsorbable dura is superior to absorbable dura in treatment of severe TBI patients with DC. Suturable nonabsorbable dura has fewer complications of TCH and CFS leakage, and manifest lower mortality and better prognosis. Postoperative TCH is an important complication in severe TBI which usually leads to a poor prognosis.

Antioxidant Activity of Docosahexaenoic Acid (DHA) and Its Regulatory Roles in Mitochondria.

Reactive oxygen species (ROS) are single-electron-bearing oxidation-reduction products that are mainly produced in mitochondria. Excessive ROS accumulation may lead to oxidative damage. Docosahexaenoic acid (DHA) is an essential component of brain phospholipids and is mainly derived from the diet. Its antioxidant activities have been extensively studied. However, its regulatory roles in mitochondria and the underlying mechanism remain to be elucidated. In this study, the DHA's effect on cellular antioxidant capacity and mitochondrial functions was examined in HepG2 cells. The results showed that 100 µM DHA decreased cellular and mitochondrial ROS levels to 75.2 ± 9.4% (P < 0.05) and 55.1 ± 1.4% (P < 0.01), respectively. It also increased the total antioxidant capacity by 55.6 ± 0.1 and 49.2 ± 1.1% (P < 0.05), based on ABTS and FRAP assay results, respectively. Consistently, it increased the activities and gene expression of major antioxidant enzymes by at least 35 and 40% (P < 0.05), respectively. Furthermore, DHA promoted mitochondrial functions and biogenesis. These data suggested that DHA's antioxidant activity can be attributed to its enhancement of mitochondrial functions and biogenesis. This study may shed light on the molecular mechanisms underlying DHA's function in improving resistance to and relieving the symptoms of chronic disease.