Project description:Beta-hydroxybutyrate (BHB) is a ketone body synthesized during fasting or strenuous exercise. Our previous study demonstrated that a cyclic ketogenic diet (KD), which induces BHB levels similar to fasting every other week, reduces midlife mortality and improves memory in aging mice. BHB actively regulates gene expression and inflammatory activation through non-energetic signaling pathways. Neither of these activities has been well-characterized in the brain and they may represent mechanisms by which BHB affects brain function during aging. First, we analyzed hepatic gene expression in an aging KD-treated mouse cohort using bulk RNA-seq. In addition to the downregulation of TOR pathway activity, cyclic KD reduces inflammatory gene expression in the liver. We observed via flow cytometry that KD also modulates age-related systemic T cell functions. Next, we investigated whether BHB affects brain cells transcriptionallyin vitro. Gene expression analysis in primary human brain cells (microglia, astrocytes, neurons) using RNA-seq shows that BHB causes a mild level of inflammation in all three cell types. However, BHB inhibits the more pronounced LPS-induced inflammatory gene activation in microglia. Furthermore, we confirmed that BHB similarly reduces LPS-induced inflammation in primary mouse microglia and bone marrow-derived macrophages (BMDMs). BHB is recognized as an inhibitor of histone deacetylase (HDAC), an inhibitor of NLRP3 inflammasome, and an agonist of the GPCR Hcar2. Nevertheless, in microglia, BHB's anti-inflammatory effects are independent of these known mechanisms. Finally, we examined the brain gene expression of 12-month-old male mice fed with one-week and one-year cyclic KD. While a one-week KD increases inflammatory signaling, a one-year cyclic KD reduces neuroinflammation induced by aging. In summary, our findings demonstrate that BHB mitigates the microglial response to inflammatory stimuli, like LPS, possibly leading to decreased chronic inflammation in the brain after long-term KD treatment in aging mice.
Project description:Understanding mechanisms that determine the response of cells to ferroptotic stress is a timely issue that has significant ramifications for biology and pathology. We investigated these mechanisms in the context of breast cancer where tumors are comprised of diverse populations of cancer cells that differ in their ferroptosis sensitivity. Using single-cell RNA-sequencing, we determined that cancer cell populations with luminal differentiation are more resistant to ferroptosis than other cells within a heterogeneous tumor. Subsequent bioinformatic analysis and experimentation revealed that GATA3, a transcription factor that promotes luminal differentiation, has a causal role in ferroptosis resistance in luminal breast cancer cells. In pursuit of the mechanism involved, we found that GATA3 represses the expression of integrin β1 and its downstream signaling cascade. This observation led us to demonstrate that integrin β1 signaling is necessary for sensitivity to ferroptosis in basal breast cancer cells because it regulates a FAK/ROCK pathway that sustains the expression of ACSL4, a lipid-modifying enzyme that is essential for ferroptosis. The repression of integrin β1 by GATA3 inhibits this signaling pathway rendering cells ferroptosis resistant. Together, these data provide insight into mechanisms of ferroptosis sensitivity and resistance that are linked to the cell biology and signaling pathways of the diverse types of cells present in breast tumors.
Project description:Using the HiSeqTM 2000 sequencing platform, the anther transcriptome of photo thermo sensitive genic male sterile lines (PTGMS) rice Y58S and P64S (Peiâai 64S) were analyzed at the fertility sensitive stage under cold stress.These datas would be most beneficial for further studies investigating the molecular mechanisms of rice responses to cold stress.
Project description:In order to shed light on the DNA methylation pathway mediating Pi starvation-induced changes in DNA methylation, the phosphate starvation experiment was repeated using an RNAi line that knocks DCL3a, a key factor involved in the canonical RdDM pathway.
Project description:We performed RNA-Seq of P. trichocarpa calluses that were firstly induced from roots. Then the total RNAs were isolated from the control and salt-stressed calluses (200 mM NaCl for 6, 12, 24, and 48 h) using a CTAB procedure. Note: All samples in SRA were assigned the same sample accession (SRS938530). This is incorrect as there are different samples, hence âSource Nameâ was replaced with new values. Comment[ENA_SAMPLE] contains the original SRA sample accessions.
Project description:Phosphate (Pi) deficiency alters root hair length and frequency as a means of increasing the absorptive surface area of roots. Three partly redundant single R3 MYB proteins, CAPRICE (CPC), ENHANCER OF TRY AND CPC1 (ETC1) and TRIPTYCHON (TRY), positively regulate the root hair cell fate by participating in a lateral inhibition mechanism. To identify putative targets and processes that are controlled by these three transcription factors (TFs), we conducted transcriptional profiling of roots from Arabidopsis thaliana wild-type plants, and cpc, etc1 and try mutants grown under Pi-replete and Pi-deficient conditions using RNA-seq.
Project description:Chinese cordyceps is of particular interest for its confined distribution, mysterious lifecycle, ecological importance and developmental biology. The large scale artificial cultivation of this fungus has been succeeded in China until recently but with low efficiency and high cost being ascribed to too much unsolved biological issues, such as gene expression during development and the sexuality reproduction. The success of artificial cultivation provides the convenient for sampling during the different development stages.
Project description:Membrane protection against oxidative damage is tightly buffered by glutathione peroxidase 4 (GPX4), and endogenous radical-trapping antioxidants such as ubiquinone, vitamin E and K. Deficiencies in these protective systems have been linked to the accumulation of phospholipid peroxidation and ferroptosis induction. Recently, ferroptosis suppressor protein 1 (FSP1) was identified as a key player in this process, preventing phospholipid peroxidation and ferroptosis by regenerating radical-trapping antioxidants. Yet, regulators of FSP1 have remained largely unknown, and their identification is critical for understanding the mechanism regulating phospholipid peroxidation and ferroptosis. In this study, we conducted a CRISPR-Cas9 screen to uncover factors influencing FSP1 function, identifying vitamin B2 (riboflavin) as a yet-unaccounted modulator of ferroptosis sensitivity. We demonstrate that vitamin B2, unlike other vitamins that directly act as radical-trapping antioxidants, facilitates the recycling of lipid-soluble antioxidants by directly supporting FSP1 stability and activity, thereby mitigating phospholipid peroxidation. Thus, we uncovered a direct role of vitamin B2 in maintaining membrane integrity and supporting membrane tolerance to lipid peroxidation and ferroptosis resistance. Our findings provide a rational strategy to modulate the FSP1-antioxidant recycling pathway, with potential implications for treating cancer and other diseases where ferroptosis plays a pivotal role.
Project description:Genome-wide analysis of skin color-related lncRNA and mRNA expression in Koi carp, Cyprinus carpio L. LncRNAs information linked to fish skin color regulation is over-limited. In this study, Illumina sequencing and bioinformatics were primarily conducted on black, white and red skin colors of Koi carp. A total of 590,415,050 clean reads, 446,614 putative transcripts, 4,252 known and 72,907 novel lncRNAs were simultaneously obtained, respectively. Out of these genes, 92 significant differentially expressed lncRNAs and 722 mRNAs were excavated. Ccr_lnc5622441, Ccr_lnc765201 were found up-regulated in black and red skins; Ccr_lnc14074601 were up-regulated in white skin; and premelanosome proteins a (Pmela), tyrosinase (Tyr) were up-regulated in black skin, etc. Quantitative real-time PCR (qRT-PCR) further validated 12 differentially expressed genes were consistent with RNA-seq. Moreover, 70 lncRNAs on 107 target mRNAs in cis and 79 lncRNAs on 41,625 target mRNAs in trans were investigated, the networks revealed one lncRNAs can connected with numerous mRNAs, vice versa. These findings broadened the lncRNAs landscape of skin colors and provided new insights into the mechanisms underlying lncRNAs mediated pigmentation and differentiation in Koi carp.