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Research Square Jun 2024Inhibition of translation initiation using eIF4A inhibitors like (-)-didesmethylrocaglamide [(-)-DDR] and (-)-rocaglamide [(-)-Roc] is a potential cancer treatment...
Inhibition of translation initiation using eIF4A inhibitors like (-)-didesmethylrocaglamide [(-)-DDR] and (-)-rocaglamide [(-)-Roc] is a potential cancer treatment strategy as they simultaneously diminish multiple oncogenic drivers. We showed that human and dog osteosarcoma cells expressed high levels of eIF4A1/2, particularly eIF4A2. Genetic depletion of eIF4A1 and/or 2 slowed osteosarcoma cell growth. To advance preclinical development of eIF4A inhibitors, we demonstrated the importance of (-)-chirality in DDR for growth-inhibitory activity. Bromination of DDR at carbon-5 abolished growth-inhibitory activity, while acetylating DDR at carbon-1 was tolerated. Like DDR and Roc, DDR-acetate increased the γH2A.X levels and induced G /M arrest and apoptosis. Consistent with translation inhibition, these rocaglates decreased the levels of several mitogenic kinases, the STAT3 transcription factor, and the stress-activated protein kinase p38. However, phosphorylated p38 was greatly enhanced in treated cells, suggesting activation of stress response pathways. RNA sequencing identified as a top upregulated gene in both DDR- and Roc-treated osteosarcoma cells, but the Rho inhibitor Rhosin did not enhance the growth-inhibitory activity of (-)-DDR or (-)-Roc. Nonetheless, these rocaglates potently suppressed tumor growth in a canine osteosarcoma patient-derived xenograft model. These results suggest that these eIF4A inhibitors can be leveraged to treat both human and dog osteosarcomas.
PubMed: 38947012
DOI: 10.21203/rs.3.rs-4494024/v1 -
Journal of Cell Communication and... Jun 2024Transmembrane-4 L-six family member-1 (TM4SF1) is an atypical tetraspanin that is highly and selectively expressed in proliferating endothelial cells and plays an...
Transmembrane-4 L-six family member-1 (TM4SF1) is an atypical tetraspanin that is highly and selectively expressed in proliferating endothelial cells and plays an essential role in blood vessel development. TM4SF1 forms clusters on the cell surface called TMED (TM4SF1-enriched microdomains) and recruits other proteins that internalize along with TM4SF1 via microtubules to intracellular locations including the nucleus. We report here that tumor growth and wound healing are inhibited in -heterozygous mice. Investigating the mechanisms of TM4SF1 activity, we show that 12 out of 18 signaling molecules examined are recruited to TMED on the surface of cultured human umbilical vein endothelial cells (HUVEC) and internalize along with TMED; notable among them are PLCγ and HDAC6. When TM4SF1 is knocked down in HUVEC, microtubules are heavily acetylated despite normal levels of HDAC6 protein, and, despite normal levels of VEGFR2, are unable to proliferate. Together, our studies indicate that pathological angiogenesis is inhibited when levels of TM4SF1 are reduced as in -heterozygous mice; a likely mechanism is that TM4SF1 regulates the intracellular distribution of signaling molecules necessary for endothelial cell proliferation and migration.
PubMed: 38946725
DOI: 10.1002/ccs3.12031 -
The Plant Journal : For Cell and... Jun 2024Female willows exhibit greater drought tolerance and benefit more from exogenous acetic acid (AA)-improved drought tolerance than males. However, the potential...
Female willows exhibit greater drought tolerance and benefit more from exogenous acetic acid (AA)-improved drought tolerance than males. However, the potential mechanisms driving these sex-specific responses remain unclear. To comprehensively investigate the sexually dimorphic responsive mechanisms of willows to drought and exogenous AA, here, we performed physiological, proteomic, Lys-acetylproteomic, and transgenic analyses in female and male Salix myrtillacea exposed to drought and AA-applicated drought treatments, focusing on protein abundance and lysine acetylation (LysAc) changes. Drought-tolerant females suffered less drought-induced photosynthetic and oxidative damage, did not activate AA and acetyl-CoA biosynthesis, TCA cycle, fatty acid metabolism, and jasmonic acid signaling as strongly as drought-sensitive males. Exogenous AA caused overaccumulation of endogenous AA and inhibition of acetyl-CoA biosynthesis and utilization in males. However, exogenous AA greatly enhanced acetyl-CoA biosynthesis and utilization and further enhanced drought performance of females, possibly determining that AA improved drought tolerance more in females than in males. Interestingly, overexpression of acetyl-CoA synthetase (ACS) could reprogram fatty acids, increase LysAc levels, and improve drought tolerance, highlighting the involvement of ACS-derived acetyl-CoA in drought responses. In addition, drought and exogenous AA induced sexually dimorphic LysAc associated with histones, transcription factors, and metabolic enzymes in willows. Especially, exogenous AA may greatly improve the photosynthetic capacity of S. myrtillacea males by decreasing LysAc levels and increasing the abundances of photosynthetic proteins. While hyperacetylation in glycolysis, TCA cycle, and fatty acid biosynthesis potentially possibly serve as negative feedback to acclimate acetyl-CoA biosynthesis and utilization in drought-stressed males and AA-applicated females. Thus, acetyl-CoA biosynthesis and utilization determine the sexually dimorphic responses of S. myrtillacea to drought and exogenous AA.
PubMed: 38944754
DOI: 10.1111/tpj.16901 -
Journal of Affective Disorders Jun 2024Growing evidence highlights the role of the spleen-brain axis in inflammation-associated depression. The α7-subtype of nicotinic acetylcholine receptor (α7 nAChR,...
BACKGROUND
Growing evidence highlights the role of the spleen-brain axis in inflammation-associated depression. The α7-subtype of nicotinic acetylcholine receptor (α7 nAChR, encoded by the Chrna7 gene) is implicated in systemic inflammation, with Chrna7 knock-out (KO) mice displaying depression-like behaviors. Yet, the influence of spleen nerve on depression-like behaviors in these KO mice remains to be elucidated.
METHODS
We investigated the effects of the splenic nerve denervation (SND) on depression-like behaviors, the protein expression in the prefrontal cortex (PFC), and the gut microbiota composition in Chrna7 KO mice.
RESULTS
SND markedly alleviated depression-like behaviors and the reduced expression of GluA1 and postsynaptic density protein-95 (PSD-95) in the PFC of Chrna7 KO mice. No changes in α-diversity of gut microbiota were noted among the control, KO + sham, and KO + SND groups. However, significant differences in β-diversity of gut microbiota were noted among the groups. Notable alterations in various microbiota (e.g., Fluviimonas_pallidilutea, Maribacter_arcticus, Parvibacter_caecicola) and plasma metabolites (e.g., helicide, N-acetyl-L-aspartic acid, α-D-galactose 1-phosphate, choline, creatine) were observed between KO + sham and KO + SND groups. Interestingly, correlations were found between the relative abundance of specific microbiota and other outcomes, including synaptic proteins, metabolites and behavioral data.
LIMITATIONS
The underlying mechanisms remain to be fully understood.
CONCLUSIONS
Our findings indicate that the splenic nerve contributes to depression-like phenotypes in Chrna7 KO mice via the spleen-gut-brain axis.
PubMed: 38944290
DOI: 10.1016/j.jad.2024.06.091 -
The Journal of Biological Chemistry Jun 2024One of seven natural CO fixation pathways, the anaerobic Wood-Ljungdahl Pathway (WLP) is unique in generating CO as a metabolic intermediate, operating through...
One of seven natural CO fixation pathways, the anaerobic Wood-Ljungdahl Pathway (WLP) is unique in generating CO as a metabolic intermediate, operating through organometallic intermediates, and in conserving (versus utilizing) net ATP. The key enzyme in the WLP is acetyl-CoA synthase (ACS), which uses an active site [2Ni-4Fe-4S] cluster (A-cluster), a CO tunnel, and an organometallic (Ni-CO, Ni-methyl, and Ni-acetyl) reaction sequence to generate acetyl-CoA. Here we reveal that an alcove, which interfaces the tunnel and the A-cluster, is essential for CO fixation and autotrophic growth by the WLP. In vitro spectroscopy, kinetics, binding, and in vivo growth experiments reveal that a Phe229A substitution at one wall of the alcove decreases CO affinity thirty-fold and abolishes autotrophic growth; however, a F229W substitution enhances CO binding 80-fold. Our results indicate the structure of the alcove is exquisitely tuned to concentrate CO near the A-cluster; protect ACS from CO loss during catalysis, provide a haven for inhibitory CO, and stabilize the tetrahedral coordination at the Ni site where CO binds. The directing, concentrating, and protective effects of the alcove explain the inability of F209A to grow autotrophically. The alcove also could help explain current controversies over whether ACS binds CO and methyl through a random or ordered mechanism. Our work redefines what we historically refer to as the metallocenter "active site". The alcove is so crucial for enzymatic function that we propose it is part of the active site. The community should now look for such alcoves in all "gas handling" metalloenzymes.
PubMed: 38944127
DOI: 10.1016/j.jbc.2024.107503 -
Molekuliarnaia Biologiia 2024Melatonin (N-acetyl-5-methoxytryptamine, MEL) is a hormone synthesized by the pineal gland. Due to its oncostatic effect, it can be considered as an antitumor agent and...
Melatonin (N-acetyl-5-methoxytryptamine, MEL) is a hormone synthesized by the pineal gland. Due to its oncostatic effect, it can be considered as an antitumor agent and used for combination therapy. ABT-737, a Bcl-2 inhibitor, promotes cell death after treatment with agents that induce pro-apoptotic signals. In the present study, the combined effect of MEL and ABT-737 on changes in proliferative and mitotic activity, mitochondrial membrane potential, intracellular production of reactive oxygen species (ROS), and cytosolic Ca^(2+) was studied. Moreover, changes in the expression of anti- and pro-apoptotic proteins (Bcl-2 and Bax), autophagy markers (LC3A/B (I, II)), endoplasmic reticulum stress markers (chaperones BIP and PDI, CHOP) were studied under these conditions. The effect of MEL together with ABT-737 led to an increase in the level of cytosolic Ca^(2+), intracellular production of ROS and a decrease in the membrane potential of mitochondria. The content of Bcl-2 increased, while the level of Bax decreased. Activation of CHOP stimulated autophagy and led to a decrease in the synthesis of chaperones BIP and PDI. It is assumed that melatonin can enhance the effect of other chemotherapeutic agents and can be used in the treatment of tumors.
Topics: Humans; Sulfonamides; Melatonin; Nitrophenols; Piperazines; Biphenyl Compounds; Reactive Oxygen Species; Membrane Potential, Mitochondrial; Apoptosis; Proto-Oncogene Proteins c-bcl-2; THP-1 Cells; bcl-2-Associated X Protein; Drug Synergism; Autophagy; Endoplasmic Reticulum Stress; Endoplasmic Reticulum Chaperone BiP; Cell Proliferation; Microtubule-Associated Proteins; Calcium; Neoplasm Proteins; Transcription Factor CHOP
PubMed: 38943585
DOI: No ID Found -
Pancreatology : Official Journal of the... Jun 2024Pancreatic ductal adenocarcinoma (PDAC) is one of the leading cause of cancer death worldwide. PDACs are characterized by centrosome aberrations, but whether...
BACKGROUND
Pancreatic ductal adenocarcinoma (PDAC) is one of the leading cause of cancer death worldwide. PDACs are characterized by centrosome aberrations, but whether centrosome-related genes influence patient outcomes has not been tested.
METHODS
Publicly available RNA-sequencing data of patients diagnosed with PDAC were interrogated with unsupervised approaches to identify centrosome protein-encoding genes with prognostic relevance. Candidate genes were validated by immunohistochemistry and multiplex immunofluorescence in a set of clinical PDAC and normal pancreatic tissues.
RESULTS
Results showed that two genes CEP250 and CEP170, involved in centrosome linker and centriolar subdistal appendages, were expressed at high levels in PDAC tissues and were correlated with prognosis of PDAC patients in independent databases. Large clustered γ-tubulin-labelled centrosomes were linked together by aberrant circular and planar-shaped CEP250 arrangements in CEP250-high expressing PDACs. Furthermore, PDACs displayed prominent centrosome separation and reduced CEP164-centrosomal labelling associated with acetylated-tubulin staining compared to normal pancreatic tissues. Interestingly, in a small validation cohort, CEP250-high expressing patients had shorter disease free- and overall-survival and almost none of those who received gemcitabine plus nab-paclitaxel first-line therapy achieved a clinical response. In contrast, weak CEP250 expression was associated with long-term survivors or responses to medical treatments.
CONCLUSIONS
Alteration of the centriolar cohesion and appendages has effect on the survival of patients with PDAC.
PubMed: 38942662
DOI: 10.1016/j.pan.2024.06.010 -
International Journal of Biological... Jun 2024In India, fish roes are generally considered worthless garbage and disposed of without recovering the valuable molecules, creating environmental and disposal problems....
In India, fish roes are generally considered worthless garbage and disposed of without recovering the valuable molecules, creating environmental and disposal problems. The present investigation aimed to optimize the extraction conditions, partial purification, and characterization of sialoglycoproteins (RRSGP) from Labeo rohita (rohu) roes. RSM generated optimum conditions for maximum RRSGP (70.49 %) extraction, which were 1.25 M NaCl, 1:32.5(w/v) solid-to-liquid ratio, 47.5 °C temperature, and 3 h time. Further, sialoglycoproteins from RRSGPs were partially purified, and result revealed that obtained peak-1 (PRRSGP) using QFF anion exchange chromatography exhibited higher glycoprotein and sialic acid content (p < 0.05). SDS-PAGE pattern of PRRSGP presented dominant bands of 97 kDa and 27 kDa glycoproteins. FTIR spectrum of PRRSGP confirmed the presence of glycated proteins. HPLC analysis revealed that PRRSGP consists of Neu5Ac. Furthermore, β-elimination reaction elucidated that PRRSGP contained N-glycosidic linkage. PRRSGP exhibited tyrosine and glutamate as primary amino acids. Glycan part of PRRSGP presented mannose and N-acetyl galactosamine as dominant neutral and amino sugar, respectively. Furthermore, PRRSGP exhibited antioxidant activity with EC value for DPPH (8.79 mg/ml) and ABTS (2.21 mg/ml). Besides, RRSGP displayed better protein solubility, foaming, and emulsion properties. Therefore, rohu roes are potential source of sialoglycoproteins that can be recovered and used as bio-functional ingredients in food and nutraceutical applications.
PubMed: 38942403
DOI: 10.1016/j.ijbiomac.2024.133462 -
Science Advances Jun 2024Liver fibrosis is characterized by the activation of perivascular hepatic stellate cells (HSCs), the release of fibrogenic nanosized extracellular vesicles (EVs), and...
Liver fibrosis is characterized by the activation of perivascular hepatic stellate cells (HSCs), the release of fibrogenic nanosized extracellular vesicles (EVs), and increased HSC glycolysis. Nevertheless, how glycolysis in HSCs coordinates fibrosis amplification through tissue zone-specific pathways remains elusive. Here, we demonstrate that HSC-specific genetic inhibition of glycolysis reduced liver fibrosis. Moreover, spatial transcriptomics revealed a fibrosis-mediated up-regulation of EV-related pathways in the liver pericentral zone, which was abrogated by glycolysis genetic inhibition. Mechanistically, glycolysis in HSCs up-regulated the expression of EV-related genes such as Ras-related protein Rab-31 () by enhancing histone 3 lysine 9 acetylation on the promoter region, which increased EV release. Functionally, these glycolysis-dependent EVs increased fibrotic gene expression in recipient HSC. Furthermore, EVs derived from glycolysis-deficient mice abrogated liver fibrosis amplification in contrast to glycolysis-competent mouse EVs. In summary, glycolysis in HSCs amplifies liver fibrosis by promoting fibrogenic EV release in the hepatic pericentral zone, which represents a potential therapeutic target.
Topics: Animals; Glycolysis; Liver Cirrhosis; Hepatic Stellate Cells; Extracellular Vesicles; Mice; rab GTP-Binding Proteins; Humans; Disease Models, Animal; Liver; Mice, Inbred C57BL; Male
PubMed: 38941469
DOI: 10.1126/sciadv.adn5228 -
The Journal of Clinical Investigation Jun 2024Clear cell renal cell carcinoma (ccRCC) is an aggressive cancer driven by VHL loss and aberrant HIF-2α signaling. Identifying means to regulate HIF-2α thus has...
Clear cell renal cell carcinoma (ccRCC) is an aggressive cancer driven by VHL loss and aberrant HIF-2α signaling. Identifying means to regulate HIF-2α thus has potential therapeutic benefit. Acetyl-CoA synthetase 2 (ACSS2) converts acetate to acetyl-CoA and is associated with poor patient prognosis in ccRCC. Here we tested the effects of ACSS2 on HIF-2α and cancer cell metabolism and growth in ccRCC models and clinical samples. ACSS2 inhibition reduced HIF-2α levels and suppressed ccRCC cell line growth in vitro, in vivo, and in cultures of primary ccRCC patient tumors. This treatment reduced glycolytic signaling, cholesterol metabolism, and mitochondrial integrity, all of which are consistent with loss of HIF-2α. Mechanistically, ACSS2 inhibition decreased chromatin accessibility and HIF-2α expression and stability. While HIF-2α protein levels are widely regulated through pVHL-dependent proteolytic degradation, we identify a potential pVHL-independent pathway of degradation via the E3 ligase MUL1. We show that MUL1 can directly interact with HIF-2α and that overexpression of MUL1 decreased HIF-2α levels in a manner partially dependent on ACSS2. These findings identify multiple mechanisms to regulate HIF-2α stability and ACSS2 inhibition as a strategy to complement HIF-2α-targeted therapies and deplete pathogenically stabilized HIF-2α.
Topics: Carcinoma, Renal Cell; Humans; Basic Helix-Loop-Helix Transcription Factors; Kidney Neoplasms; Cell Line, Tumor; Acetate-CoA Ligase; Signal Transduction; Animals; Mice; Gene Expression Regulation, Neoplastic; Von Hippel-Lindau Tumor Suppressor Protein; Ubiquitin-Protein Ligases; Neoplasm Proteins
PubMed: 38941296
DOI: 10.1172/JCI164249