Friend or foe: The role of stress granule in neurodegenerative disease.

Stress granules (SGs) are dynamic membraneless organelles that form in response to cellular stress. SGs are predominantly composed of RNA and RNA-binding proteins that assemble through liquid-liquid phase separation. Although the formation of SGs is considered a transient and protective response to cellular stress, their dysregulation or persistence may contribute to various neurodegenerative diseases. This review aims to provide a comprehensive overview of SG physiology and pathology. It covers the formation, composition, regulation, and functions of SGs, along with their crosstalk with other membrane-bound and membraneless organelles. Furthermore, this review discusses the dual roles of SGs as both friends and foes in neurodegenerative diseases and explores potential therapeutic approaches targeting SGs. The challenges and future perspectives in this field are also highlighted. A more profound comprehension of the intricate relationship between SGs and neurodegenerative diseases could inspire the development of innovative therapeutic interventions against these devastating diseases.

NRF2 has a splicing regulatory function involving the survival of motor neuron (SMN) in non-small cell lung cancer.

The nuclear factor erythroid 2-like 2 (NFE2L2; NRF2) signaling pathway is frequently deregulated in human cancers. The critical functions of NRF2, other than its transcriptional activation, in cancers remain largely unknown. Here, we uncovered a previously unrecognized role of NRF2 in the regulation of RNA splicing. Global splicing analysis revealed that NRF2 knockdown in non-small cell lung cancer (NSCLC) A549 cells altered 839 alternative splicing (AS) events in 485 genes. Mechanistic studies demonstrated that NRF2 transcriptionally regulated SMN mRNA expression by binding to two antioxidant response elements in the SMN1 promoter. Post-transcriptionally, NRF2 was physically associated with the SMN protein. The Neh2 domain of NRF2, as well as the YG box and the region encoded by exon 7 of SMN, were required for their interaction. NRF2 formed a complex with SMN and Gemin2 in nuclear gems and Cajal bodies. Furthermore, the NRF2-SMN interaction regulated RNA splicing by expressing SMN in NRF2-knockout HeLa cells, reverting some of the altered RNA splicing. Moreover, SMN overexpression was significantly associated with alterations in the NRF2 pathway in patients with lung squamous cell carcinoma from The Cancer Genome Atlas. Taken together, our findings suggest a novel therapeutic strategy for cancers involving an aberrant NRF2 pathway.

Diverse CMT2 neuropathies are linked to aberrant G3BP interactions in stress granules.

Complex diseases often involve the interplay between genetic and environmental factors. Charcot-Marie-Tooth type 2 neuropathies (CMT2) are a group of genetically heterogeneous disorders, in which similar peripheral neuropathology is inexplicably caused by various mutated genes. Their possible molecular links remain elusive. Here, we found that upon environmental stress, many CMT2-causing mutant proteins adopt similar properties by entering stress granules (SGs), where they aberrantly interact with G3BP and integrate into SG pathways. For example, glycyl-tRNA synthetase (GlyRS) is translocated from the cytoplasm into SGs upon stress, where the mutant GlyRS perturbs the G3BP-centric SG network by aberrantly binding to G3BP. This disrupts SG-mediated stress responses, leading to increased stress vulnerability in motoneurons. Disrupting this aberrant interaction rescues SG abnormalities and alleviates motor deficits in CMT2D mice. These findings reveal a stress-dependent molecular link across diverse CMT2 mutants and provide a conceptual framework for understanding genetic heterogeneity in light of environmental stress.

Evaluation of response of dynamics change in bioaugmentation process in diesel-polluted seawater via high-throughput sequencing: Degradation characteristic, community structure, functional genes.

Identification of microorganisms that contribute to the whole microbial community is important. In this study, dynamic changes in bioaugmentation process in diesel-polluted seawater collected from two different sites were assessed via simulation experiments. Ultraviolet spectrophotometry and analysis using the molecular operating environment software revealed that the degradation rate of diesel due to bioaugmentation was higher than 70 % after 45 days because of the formation of hydrogen bonds among biosurfactants and diesel components. Community structure and functional genes were analysed via high-throughput sequencing. Results showed that community diversity recovered during bioaugmentation. Principal coordinate analysis showed that the difference in microbial community between the two sites was considerably smaller than that when diesel was added and bioaugmentation was conducted. After bioaugmentation, the main families playing key roles in degradation that became dominant were Alcanivoracaceae, Rhodobiaceae, and Rhodospirillaceae. Moreover, the abundance of functional genes remarkably increased at two different sites.

High-Flux Hemodialysis Benefits Hemodialysis Patients by Reducing Serum FGF-23 Levels and Reducing Vascular Calcification.

BACKGROUND: High- and low-flux hemodialysis (HFHD and LFHD, respectively) are dialysis procedures designed to eliminate blood toxins that accumulate in end-stage renal disease. HFHD may reduce vascular calcification by removing serum fibroblast growth factor 23 (FGF-23). However, whether HFHD is better than LFHD is still under debate. We therefore compared the efficacy of HFHD and LFHD in controlling FGF-23 and vascular calcification. MATERIAL AND METHODS: Fifty hemodialysis patients were recruited and randomly treated with either HFHD or LFHD. Fasting venous blood was collected at baseline, six months, and twelve months after the treatment. We then measured levels of FGF-23, calcium, phosphorus, parathyroid hormone, and alkaline phosphatase. Further, abdominal lateral radiographs were taken to calculate aorta abdominalis calcification scores (AACs). RESULTS: Compared to the LFHD group, FGF-23 and AACs in the HFHD group significantly decreased after 12 months treatment (p=0.049 and p=0.002, respectively). AACs were positively correlated with FGF-23 in all patients (p=0.004), the HFHD group alone (p=0.040), and the LFHD group alone (p=0.037). We also found that older patients, patients with higher blood phosphorus levels, and higher FGF-23 levels had an increased risk of aorta abdominalis calcification (p=0.048, p=0.003, p=0.001, respectively). HFHD was more able to reduce the risk of aorta abdominalis calcification than LFHD (p=0.003). CONCLUSIONS: FGF-23 is an independent risk factor for the development of vascular calcification. HFHD may benefit hemodialysis patients by reducing serum FGF-23 levels and controlling vascular calcification.

Effects of tung oilseed FAD2 and DGAT2 genes on unsaturated fatty acid accumulation in Rhodotorula glutinis and Arabidopsis thaliana.

Genetic engineering to produce valuable lipids containing unsaturated fatty acids (UFAs) holds great promise for food and industrial applications. Efforts to genetically modify plants to produce desirable UFAs with single enzymes, however, have had modest success. The key enzymes fatty acid desaturase (FAD) and diacylglycerol acyltransferase (DGAT) are responsible for UFA biosynthesis (a push process) and assembling fatty acids into lipids (a pull process) in plants, respectively. To examine their roles in UFA accumulation, VfFAD2 and VfDGAT2 genes cloned from Vernicia fordii (tung tree) oilseeds were conjugated and transformed into Rhodotorula glutinis and Arabidopsis thaliana via Agrobacterium tumefaciens. Real-time quantitative PCR revealed variable gene expression levels in the transformants, with a much higher level of VfDGAT2 than VfFAD2. The relationship between VfFAD2 expression and linoleic acid (C18:2) increases in R. glutinis (R (2) = 0.98) and A. thaliana (R (2) = 0.857) transformants was statistically linear. The VfDGAT2 expression level was statistically correlated with increased total fatty acid content in R. glutinis (R (2) = 0.962) and A. thaliana (R (2) = 0.8157) transformants. With a similar expression level between single- and two-gene transformants, VfFAD2-VfDGAT2 co-transformants showed a higher linolenic acid (C18:3) yield in R. glutinis (174.36 % increase) and A. thaliana (14.61 % increase), and eicosatrienoic acid (C20:3) was enriched (17.10 % increase) in A. thaliana. Our data suggest that VfFAD2-VfDGAT2 had a synergistic effect on UFA metabolism in R. glutinis, and to a lesser extent, A. thaliana. These results show promise for further genetic engineering of plant lipids to produce desirable UFAs.

FAD2-DGAT2 genes coexpressed in endophytic Aspergillus fumigatus derived from tung oilseeds.

Recent efforts to genetically engineer plants that contain fatty acid desaturases to produce valuable fatty acids have made only modest progress. Diacylglycerol acyltransferase 2 (DGAT2), which catalyzes the final step in triacylglycerol (TAG) assembly, might potentially regulate the biosynthesis of desired fatty acids in TAGs. To study the effects of tung tree (Vernicia fordii) vfDGAT2 in channeling the desired fatty acids into TAG, vfDGAT2 combined with the tung tree fatty acid desaturase-2 (vfFAD2) gene was co-introduced into Aspergillus fumigatus, an endophytic fungus isolated from healthy tung oilseed. Two transformants coexpressing vfFAD2 and vfDGAT2 showed a more than 6-fold increase in linoleic acid production compared to the original A. fumigatus strain, while a nearly 2-fold increase was found in the transformant expressing only vfFAD2. Our data suggest that vfDGAT2 plays a pivotal role in promoting linoleic acid accumulation in TAGs. This holds great promise for further genetic engineering aimed at producing valuable fatty acids.

Selection of reliable reference genes for gene expression studies using real-time PCR in tung tree during seed development.

Quantitative real-time PCR (RT-qPCR) has become an accurate and widely used technique to analyze expression levels of selected genes. It is very necessary to select appropriate reference genes for gene expression normalization. In the present study, we assessed the expression stability of 11 reference genes including eight traditional housekeeping genes and three novel genes in different tissues/organs and developing seeds from four cultivars of tung tree. All 11 reference genes showed a wide range of Ct values in all samples, indicating that they differently expressed. Three softwares--geNorm, NormFinder and BestKeeper--were used to determine the stability of these references except for ALB (2S albumin), which presented a little divergence. The results from the three softwares showed that ACT7 (Actin7a), UBQ (Ubiquitin), GAPDH (glyceraldehyde-3-phosphate dehydrogenase) and EF1α (elongation factor 1-α) were the most stable reference genes across all of the tested tung samples and tung developing seeds, while ALB (2S albumin) was unsuitable as internal controls. ACT7, EF1ß (elongation factor1-beta), GAPDH and TEF1 (transcription elongation factor 1) were the top four choices for different tissues/organs whereas LCR69 did not favor normalization of RT-qPCR in these tissues/organs. Meanwhile, the expression profiles of FAD2 and FADX were realized using stable reference genes. The relative quantification of the FAD2 and FADX genes varied according to the internal controls and the number of internal controls. The results further proved the importance of the choice of reference genes in the tung tree. These stable reference genes will be employed in normalization and quantification of transcript levels in future expression studies of tung genes.

Chemical composition of essential oils of Litsea cubeba harvested from its distribution areas in China.

Litsea cubeba (Lour.) Pers. is a promising industrial crop with fruits rich in essential oils. The chemical composition of essential oils of L. cubeba (EOLC) were determined for fruits harvested from eight regions in China. The overall essential oil content, obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS), ranged from 3.04% to 4.56%. In total, 59 compounds were identified, the dominant components being monoterpenes (94.4-98.4%), represented mainly by neral and geranial (78.7-87.4%). D-Limonene was unexpectedly a lesser constituent (0.7-5.3%) in fruits, which differed from previous reports (6.0-14.6%). Several components were only detected in certain regions and compounds such as o-cymene and eremophilene have never before been reported in EOLC. These results demonstrate significant regional variation in the chemical composition of EOLC. This investigation provides important information with regard to the bioactivity, breeding work and industrial applications of L. cubeba.