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1.
Cell Death Dis ; 13(11): 944, 2022 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-36351893

RESUMO

High expression of CD38 in tissues is a characteristic of aging, resulting in a decline in nicotinamide adenine dinucleotide (NAD) and increasing cellular reactive oxygen species (ROS). However, whether CD38 increases susceptibility to ferroptosis remains largely unexplored. Our previous study showed that CD38 overexpression decreased dihydrofolate reductase (DHFR). In the present study, we confirmed that high expression of CD38 increased ROS levels and induced DHFR degradation, which was prevented by nicotinamide mononucleotide (NMN) replenishment. We further revealed that ROS-mediated sulfonation on Cys7 of DHFR induced its degradation via the autophagy and non-canonical proteasome pathways. Mutation of Cys7 to alanine abolished ROS-induced DHFR degradation. Moreover, oxidative degradation of DHFR was responsible for the increased ferroptosis susceptibility of cells in which CD38 was highly expressed. We also found that CD38 expression was higher in bone-marrow-derived macrophages (BMDMs) from aged mice than those from young mice, while the DHFR level was lower. Consequently, we demonstrated that BMDMs from aged mice were more susceptible to ferroptosis that can be reverted by NMN replenishment, suggesting that CD38 high expression rendered cells more susceptible to ferroptosis. Taken together, these results indicated that CD38-mediated NAD+ decline promoted DHFR oxidative degradation, thus resulting in increased cellular susceptibility to ferroptosis and suggesting that NMN replenishment may protect macrophages from ferroptosis in aged mice.


Assuntos
Ferroptose , NAD , Animais , Camundongos , NAD/metabolismo , Mononucleotídeo de Nicotinamida/farmacologia , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Tetra-Hidrofolato Desidrogenase/genética
3.
ACS Omega ; 7(42): 37509-37519, 2022 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-36312432

RESUMO

Nicotinamide N-methyltransferase (NNMT) is a cytosolic methyltransferase, catalyzing N-methylation of nicotinamide (NAM) to form 1-methylnicotinamide (1-MNAM), in which S-adenosyl-l-methionine (SAM) is the methyl donor. It has been well documented that NNMT is elevated in multiple cancers and promotes tumor aggressiveness. In the present study, we investigated the effects of NNMT overexpression on cellular metabolism and proinflammatory responses. We found that NNMT overexpression reduced NAD+ and SAM levels, and activated the STAT3 signaling pathway. Consequently, STAT3 activation upregulated interleukin 1ß (IL1ß) and cyclooxygenase-2 (COX2), leading to prostaglandin E2 (PGE2) accumulation. On the other hand, NNMT downregulated 15-hydroxyprostaglandin dehydrogenase (15-PGDH) which catalyzes PGE2 into inactive molecules. Moreover, secretomic data indicated that NNMT promoted secretion of collagens, pro-inflammatory cytokines, and extracellular matrix proteins, confirming NNMT aggravated inflammatory responses to promote cell growth, migration, epithelial-mesenchymal transition (EMT), and chemoresistance. Taken together, we showed that NNMT played a pro-inflammatory role in cancer cells by activating the STAT3/IL1ß/PGE2 axis and proposed that NNMT was a potential therapeutic target for cancer treatment.

4.
Front Oncol ; 12: 955943, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36052254

RESUMO

The human epidermal growth factor receptor 2 (HER2) is an important biomarker that plays a pivotal role in therapeutic decision-making for patients with breast cancer (BC). Patients with HER2-low BC can benefit from new HER2 targeted therapy. For ensuring the accurate and reproducible detection of HER2-low cancer, reliable reference materials are required for monitoring the sensitivity and specificity of detection assays. Herein, a lentiviral vector was used to transduce the HER2 gene into MDA-MB-231 cells that exhibited low HER2 density, and the cells were characterized by droplet digital PCR to accurately determine the copy number variation. Then, the formalin-fixed paraffin-embedded (FFPE) samples from xenografts were prepared and evaluated for suitability as candidate reference materials by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). The FFPE reference materials were selected on the basis of IHC score of 2+ and negative FISH result to meet the requirement for HER2-low BC detection. Furthermore, the FFPE reference materials exhibited typical histological structures that resembled the clinical BC specimens. These novel FFPE reference materials displayed the high stability and homogeneity, and they were produced in high quantity. In summary, we generated high-quality reference materials for internal quality control and proficiency testing in HER2-low detection.

5.
STAR Protoc ; 3(3): 101662, 2022 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-36097383

RESUMO

Aggrephagy is a major way to clear protein aggregates. Here, we describe a pipeline of experiments to find autophagy receptors for aggrephagy. Steps include an in vitro reconstitution to recapitulate autophagosome recognizing aggregates and receptor identification steps based on flow cytometry and mass spectrometry. We also describe functional validation steps based on immunofluorescence and immunoblot. The protocol provides a practical way to identify aggrephagy receptors. For complete details on the use and execution of this protocol, please refer to Ma et al. (2022).


Assuntos
Macroautofagia , Agregados Proteicos , Animais , Autofagossomos/metabolismo , Autofagia/fisiologia , Proteínas de Transporte/metabolismo , Mamíferos/metabolismo
6.
Sci China Life Sci ; 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-36115893

RESUMO

B-cell lymphoma 10 (Bcl10) is a scaffolding protein that functions as an upstream regulator of NF-κB signaling by forming a complex with Mucosa-associated lymphoid tissue lymphoma translocation protein 1 (Malt1) and CARD-coiled coil protein family. This study showed that Bcl10 was involved in type I interferon (IFN) expression in response to DNA virus infection and that Bcl10-deficient mice were more susceptible to Herpes simplex virus 1 (HSV-1) infection than control mice. Mechanistically, DNA virus infection can trigger Bcl10 recruitment to the STING-TBK1 complex, leading to Bcl10 phosphorylation by TBK1. The phosphorylated Bcl10 undergoes droplet-like condensation and forms oligomers, which induce TBK1 phosphorylation and translocation to the perinuclear region. The activated TBK1 phosphorylates IRF3, which induces the expression of type I IFNs. This study elucidates that Bcl10 induces an innate immune response by undergoing droplet-like condensation and participating in signalosome formation downstream of the cGAS-STING pathway.

8.
Angew Chem Int Ed Engl ; 61(40): e202206205, 2022 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-35962463

RESUMO

Ubiquitin (Ub)-like protein ISG15 (interferon-stimulated gene 15) regulates innate immunity and links with the evasion of host response by viruses such as SARS-CoV-2. Dissecting ISGylation pathways recently received increasing attention which can inform related disease interventions, but such studies necessitate the preparation and development of various ISG15 protein tools. Here, we find that the leader protease (Lbpro ) encoded by foot-and-mouth disease virus can promote ligation reactions between recombinant ISG15 and synthetic glycyl compounds, generating protein tools such as ISG15-propargylamide and ISG15-rhodamine110, which are needed for cellular proteomic studies of deISGylases, and the screening and evaluation of inhibitors against SARS-CoV-2 papain-like protease (PLpro). Furthermore, this strategy can be also used to load ISG15 onto the lysine of a synthetic peptide through an isopeptide bond, and prepare Ub and NEDD8 (ubiquitin-like protein Nedd8) protein tools.


Assuntos
COVID-19 , Peptídeo Hidrolases , Animais , Catálise , Citocinas/metabolismo , Interferons , Lisina , Proteína NEDD8 , Peptídeo Hidrolases/metabolismo , Proteômica , SARS-CoV-2 , Ubiquitinas/química
9.
Proteomics Clin Appl ; 16(6): e2100099, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35920599

RESUMO

PURPOSE: Antiretroviral therapy (ART) prevents human immunodeficiency virus (HIV)-1 onward transmission and disease progression, leading to excellent prognosis in people living with HIV-1 (PWH). However, side effects, complications, and impaired immune reconstitution persist in some patients treated with ART. We aimed to profile proteome changes in plasma before and after ART to identify the molecular pathways altered by ART. EXPERIMENTAL DESIGN: Quantitative proteomics analysis based on tandem mass tag (TMT) labeling was used to profile proteome changes of paired plasma samples from HIV-1 patients before receiving ART and after ART treatment. RESULTS: A total of 1398 protein groups (PGs) were identified, in which 18 proteins were downregulated and 50 were upregulated in plasma from ART treated patients. Based on Ingenuity Pathway analysis (IPA), gap junction signaling and actin cytoskeleton signaling were enriched among upregulated proteins, while downregulated proteins were mainly participated in IL-15 signaling pathway. Patients with the low level of CSF1R and the high levels of MINPP1 and TGM3 showed better CD4+ T-cell recovery. CONCLUSIONS: The present study provided plasma proteome changes after ART to elucidate the underlying mechanistic pathways in response to ART, and also identified potential targets to prompt immune reconstitution.


Assuntos
Infecções por HIV , HIV-1 , Humanos , Proteoma/metabolismo , Linfócitos T CD4-Positivos/metabolismo , Infecções por HIV/tratamento farmacológico , Proteômica , Terapia Antirretroviral de Alta Atividade/efeitos adversos , Transglutaminases/metabolismo , Transglutaminases/uso terapêutico
10.
Oncogene ; 41(38): 4336-4348, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35945453

RESUMO

Esophageal squamous cell carcinoma (ESCC) is one of the most fatal malignancies worldwide. Recently, our group identified purine-rich element binding protein alpha (PURα), a single-stranded DNA/RNA-binding protein, to be significantly associated with the progression of ESCC. Additional immunofluorescence staining demonstrated that PURα forms cytoplasmic stress granules to suppress mRNA translation initiation. The expression level of cytoplasmic PURα in ESCC tumor tissues was significantly higher than that in adjacent epithelia and correlated with a worse patient survival rate by immunohistochemistry. Functionally, PURα strongly preferred to bind to UG-/U-rich motifs and mRNA 3´UTR by CLIP-seq analysis. Moreover, PURα knockout significantly increased the protein level of insulin-like growth factor binding protein 3 (IGFBP3). In addition, it was further demonstrated that PURα-interacting proteins are remarkably associated with translation initiation factors and ribosome-related proteins and that PURα regulates protein expression by interacting with translation initiation factors, such as PABPC1, eIF3B and eIF3F, in an RNA-independent manner, while the interaction with ribosome-related proteins is significantly dependent on RNA. Specifically, PURα was shown to interact with the mRNA 3´UTR of IGFBP3 and inhibit its expression by suppressing mRNA translation initiation. Together, this study identifies cytoplasmic PURα as a modulator of IGFBP3, which could be a promising therapeutic target for ESCC treatment.


Assuntos
Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Regiões 3' não Traduzidas , DNA de Cadeia Simples , Proteínas de Ligação a DNA/genética , Neoplasias Esofágicas/patologia , Carcinoma de Células Escamosas do Esôfago/genética , Humanos , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , Biossíntese de Proteínas , Purinas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Grânulos de Estresse , Fatores de Transcrição
11.
Nano Lett ; 22(17): 7144-7150, 2022 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-35868014

RESUMO

To propose the concept of single-atom-kernelled nanocluster, we synthesized a Pd-based trimetal nanocluster with a single-Ag atom-kernel for the first time by introducing some steric hindrance factors and employing a joint alloying strategy that combines the coreduction with an antigalvanic reduction (AGR). Although the AGR-derived Pd-based trimetal nanoclusters with single-silver atom kernels have low contents of gold, they show higher activity and selectivity than those of the bimetal precursor nanocluster in the electrocatalytical reduction of CO2 to CO. Furthermore, it is revealed that the kernel single atoms from both Au4Pd6(TBBT)12 and Au3AgPd6(TBBT)12 are not the active sites for catalysis, but greatly influence the catalytical performance by effecting the electronic configuration. Thus, it is demonstrated that the single-atom-kernelled nanocluster can not only improve the precious metal utilization (even to 100%) but also better the properties and provide insight into the structure-property correlation for metal nanoclusters.


Assuntos
Ouro , Prata , Catálise , Ouro/química , Prata/química
12.
J Control Release ; 349: 876-889, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35907592

RESUMO

NAD(P)H:quinone oxidoreductase 1 (NQO1) is an enzyme significantly overexpressed in pancreatic ductal adenocarcinoma (PDAC) tumors compared to the associated normal tissues. NQO1 bioactivatable drugs, such as ß-lapachone (ß-lap), can be catalyzed to generate reactive oxygen species (ROS) for direct tumor killing. However, the extremely narrow therapeutic window caused by methemoglobinemia and hemolytic anemia severely restricts its further clinical translation despite considerable efforts in the past 20 years. Previously, we demonstrated that albumin could be utilized to deliver cytotoxic drugs selectively into KRAS-mutant PDAC with a much expanded therapeutic window due to KRAS-enhanced macropinocytosis and reduced neonatal Fc receptor (FcRn) expression in PDAC. Herein, we analyzed the expression patterns of albumin and FcRn across major organs in LSL-KrasG12D/+;LSL-Trp53R172H/+;Pdx-1-Cre (KPC) mice. The tumors were the predominant tissues with both elevated albumin and reduced FcRn expression, thus making them an ideal target for albumin-based drug delivery. Quantitative proteomics analysis of tissue samples from 5 human PDAC patients further confirmed the elevated albumin/FcRn ratio. Given such a compelling biological rationale, we designed a nanoparticle albumin-bound prodrug of ß-lap, nab-(pro-ß-lap), to achieve PDAC targeted delivery and expand the therapeutic window of ß-lap. We found that nab-(pro-ß-lap) uptake was profoundly enhanced by KRAS mutation. Compared to the solution formulation of the parent drug ß-lap, nab-(pro-ß-lap) showed enhanced safety due to much lower rates of methemoglobinemia and hemolytic anemia, which was confirmed both in vitro and in vivo. Furthermore, nab-(pro-ß-lap) significantly inhibited tumor growth in subcutaneously implanted KPC xenografts and enhanced the pharmacodynamic endpoints (e.g., PARP1 hyperactivation, γ-H2AX). Thus, nab-(pro-ß-lap), with improved safety and antitumor efficacy, offers a drug delivery strategy with translational viability for ß-lap in pancreatic cancer therapy.


Assuntos
Carcinoma Ductal Pancreático , Metemoglobinemia , Naftoquinonas , Neoplasias Pancreáticas , Pró-Fármacos , Albuminas/metabolismo , Animais , Carcinoma Ductal Pancreático/tratamento farmacológico , Linhagem Celular Tumoral , Humanos , Metemoglobinemia/tratamento farmacológico , Camundongos , NAD/metabolismo , NAD/uso terapêutico , NAD(P)H Desidrogenase (Quinona)/genética , NAD(P)H Desidrogenase (Quinona)/metabolismo , Naftoquinonas/farmacologia , Naftoquinonas/uso terapêutico , Neoplasias Pancreáticas/patologia , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Quinonas/uso terapêutico , Espécies Reativas de Oxigênio/metabolismo
13.
Free Radic Biol Med ; 188: 14-23, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35697292

RESUMO

Flavonoids are widely distributed in plants as secondary metabolites and have various biological benefits such as anti-tumor, anti-oxidant, anti-inflammatory and anti-aging. We previously reported that 4,4'-dimethoxychalcone (DMC) suppressed cancer cell proliferation by aggravating oxidative stress and inducing G2/M cell cycle arrest. In the present study, we explored the underlying mechanisms by which DMC inhibited cancer cell growth. Given that ferrochelatase (FECH) is a potential target of DMC identified by thermal proteome profiling (TPP) method, herein, we confirmed that DMC inhibited the enzymatic activity of FECH. Furthermore, we proved that DMC induced Keap1 degradation via ubiquitin-proteasome system, which led to the nuclear translocation of Nrf2 and upregulated Nrf2 targeted gene HMOX1. FECH inhibition and HMOX1 upregulation resulted in iron overload and triggered ferroptosis in cancer cells. Collectively, we revealed that DMC induced ferroptosis by synergistically activating Keap1/Nrf2/HMOX1 pathway and inhibiting FECH. Our findings indicate that FECH contributes to the non-canonical ferroptosis induction, shed light on the mechanisms of DMC inhibiting cancer cell growth, and set an example for studying biological functions of flavonoids.


Assuntos
Ferroptose , Neoplasias , Antioxidantes/farmacologia , Ferroquelatase/metabolismo , Flavonoides/farmacologia , Fator de Transcrição de Proteínas de Ligação GA , Heme Oxigenase-1/genética , Heme Oxigenase-1/metabolismo , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais
14.
Nat Cell Biol ; 24(6): 968-980, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35697785

RESUMO

In mammals, translational control plays critical roles during oocyte-to-embryo transition (OET) when transcription ceases. However, the underlying regulatory mechanisms remain challenging to study. Here, using low-input Ribo-seq (Ribo-lite), we investigated translational landscapes during OET using 30-150 mouse oocytes or embryos per stage. Ribo-lite can also accommodate single oocytes. Combining PAIso-seq to interrogate poly(A) tail lengths, we found a global switch of translatome that closely parallels changes of poly(A) tails upon meiotic resumption. Translation activation correlates with polyadenylation and is supported by polyadenylation signal proximal cytoplasmic polyadenylation elements (papCPEs) in 3' untranslated regions. By contrast, translation repression parallels global de-adenylation. The latter includes transcripts containing no CPEs or non-papCPEs, which encode many transcription regulators that are preferentially re-activated before zygotic genome activation. CCR4-NOT, the major de-adenylation complex, and its key adaptor protein BTG4 regulate translation downregulation often independent of RNA decay. BTG4 is not essential for global de-adenylation but is required for selective gene de-adenylation and production of very short-tailed transcripts. In sum, our data reveal intimate interplays among translation, RNA stability and poly(A) tail length regulation underlying mammalian OET.


Assuntos
Desenvolvimento Embrionário , Oócitos , Regiões 3' não Traduzidas/genética , Animais , Embrião de Mamíferos/metabolismo , Desenvolvimento Embrionário/genética , Regulação da Expressão Gênica no Desenvolvimento , Mamíferos/genética , Mamíferos/metabolismo , Camundongos , Oócitos/metabolismo , Poliadenilação , Biossíntese de Proteínas , RNA Mensageiro/genética
15.
J Proteome Res ; 21(7): 1759-1770, 2022 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-35699728

RESUMO

Altered adaptive homeostasis contributes to aging and lifespan regulation. In the present study, to characterize the mechanism of aging in mouse liver, we performed quantitative proteomics and found that the most upregulated proteins were related to the oxidation-reduction process. Further analysis revealed that malondialdehyde (MDA) and protein carbonyl (PCO) levels were increased, while nuclear Nrf2 and downstream genes were significantly increased, indicating that oxidative stress induced Nrf2 activation in aged mouse liver. Importantly, nicotinamide mononucleotide (NMN) administration decreased the oxidative stress and the nuclear Nrf2 and Nrf2 downstream gene levels. Indeed, aged mice treated with NMN improved stress resistance against acetaminophen (APAP)-induced liver injury, indicating that NMN restored Nrf2-mediated adaptive homeostasis. Further studies found that NMN increased Sirt3 activities to deacetylate age-associated acetylation at K68 and K122 in Sod2, while its effects on nuclear Nrf2 levels were diminished in Sirt3-deficient mice, suggesting that NMN-enhanced adaptive homeostasis was Sirt3-dependent. Taken together, we demonstrated that Nrf2-regulated adaptive homeostasis was decreased in aged mouse liver and NMN supplementation restored liver redox homeostasis via the Sirt3-Nrf2 axis and protected aged liver from oxidative stress-induced injury.


Assuntos
Doença Hepática Crônica Induzida por Substâncias e Drogas , Sirtuína 3 , Animais , Homeostase , Camundongos , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Mononucleotídeo de Nicotinamida/metabolismo , Mononucleotídeo de Nicotinamida/farmacologia , Oxirredução , Estresse Oxidativo , Sirtuína 3/genética , Sirtuína 3/metabolismo
16.
Nat Chem Biol ; 18(9): 972-980, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35739357

RESUMO

Ubiquitination-dependent histone crosstalk plays critical roles in chromatin-associated processes and is highly associated with human diseases. Mechanism studies of the crosstalk have been of the central focus. Here our study on the crosstalk between H2BK34ub and Dot1L-catalyzed H3K79me suggests a novel mechanism of ubiquitination-induced nucleosome distortion to stimulate the activity of an enzyme. We determined the cryo-electron microscopy structures of Dot1L-H2BK34ub nucleosome complex and the H2BK34ub nucleosome alone. The structures reveal that H2BK34ub induces an almost identical orientation and binding pattern of Dot1L on nucleosome as H2BK120ub, which positions Dot1L for the productive conformation through direct ubiquitin-enzyme contacts. However, H2BK34-anchored ubiquitin does not directly interact with Dot1L as occurs in the case of H2BK120ub, but rather induces DNA and histone distortion around the modified site. Our findings establish the structural framework for understanding the H2BK34ub-H3K79me trans-crosstalk and highlight the diversity of mechanisms for histone ubiquitination to activate chromatin-modifying enzymes.


Assuntos
Histonas , Nucleossomos , Cromatina , Microscopia Crioeletrônica , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Humanos , Ubiquitina/metabolismo , Ubiquitinação
17.
Cells ; 11(10)2022 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-35626691

RESUMO

It is known that the activities of nicotine adenine dinucleotide (NAD+)-dependent deacetylase decline in the aging mouse liver, and nicotinamide mononucleotide (NMN)-mediated activation of deacetylase has been shown to increase healthspans. However, age-induced changes of the acetylomic landscape and effects of NMN treatment on protein acetylation have not been reported. Here, we performed immunoprecipitation coupled with label-free quantitative LC-MS/MS (IPMS) to identify the acetylome and investigate the effects of aging and NMN on liver protein acetylation. In total, 7773 acetylated peptides assigned to 1997 proteins were commonly identified from young and aged livers treated with vehicle or NMN. The major biological processes associated with proteins exhibiting increased acetylation from aged livers were oxidation-reduction and metabolic processes. Proteins with decreased acetylation from aged livers mostly participated in transport and translation processes. Furthermore, NMN treatment inhibited the aging-related increase of acetylation on proteins regulating fatty acid ß oxidation, the tricarboxylic acid (TCA) cycle and valine degradation. In particular, NAD (P) transhydrogenase (NNT) was markedly hyperacetylated at K70 in aged livers, and NMN treatment decreased acetylation intensity without altering protein levels. Acetylation at cytochrome 3a25 (Cyp3a25) at K141 was also greatly increased in aged livers, and NMN treatment totally arrested this increase. Our extensive identification and analysis provide novel insight and potential targets to combat aging and aging-related functional decline.


Assuntos
NAD , Mononucleotídeo de Nicotinamida , Animais , Cromatografia Líquida , Fígado/metabolismo , Camundongos , NAD/metabolismo , Mononucleotídeo de Nicotinamida/farmacologia , Espectrometria de Massas em Tandem
18.
Oncogene ; 41(25): 3433-3444, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35589951

RESUMO

RIO Kinase 1 (RIOK1) is involved in various pathologies, including cancer. However, the role of RIOK1 in radioresistance of colorectal cancer (CRC) remains largely unknown. In this study, we reported that RIOK1 was overexpressed in rectal cancer tissue with weaker tumor regression after neoadjuvant chemoradiotherapy (neoCRT). Moreover, higher RIOK1 expression predicted a poor prognosis in patients with rectal cancer. Blockade of RIOK1 using Toyocamycin, a pharmacological inhibitor of RIOK1, or by knocking down its expression, decreased the resistance of CRC cells to radiotherapy in vitro and in vivo. A mechanistic study revealed that RIOK1 regulates radioresistance by suppressing the p53 signaling pathway. Furthermore, we found that RIOK1 and Ras-GAP SH3 domain binding protein 2 (G3BP2) interact with each other. RIOK1 phosphorylates G3BP2 at Thr226, which increases the activity of G3BP2. RIOK1-mediated phosphorylation of G3BP2 facilitated ubiquitination of p53 by murine double minute 2 protein (MDM2). Altogether, our study revealed the clinical significance of RIOK1 in CRC, and therapies targeting RIOK1 might alleviate the CRC tumor burden in patients.


Assuntos
Neoplasias Colorretais , Proteínas Serina-Treonina Quinases/metabolismo , Neoplasias Retais , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Linhagem Celular Tumoral , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/radioterapia , Humanos , Camundongos , Fosforilação , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Proteínas de Ligação a RNA/metabolismo , Proteína Supressora de Tumor p53/metabolismo
19.
J Nutr Biochem ; 107: 109056, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35609856

RESUMO

Obesity poses a global health challenge and is a major risk factor for diabetes mellitus, cardiovascular diseases, hypertension, stroke and certain kinds of cancers. Although the effects of nicotinamide (NAM) on liver metabolism and diseases were well documented, its effects on adipose tissue are yet to be characterized. Herein, we found that NAM supplementation significantly reduced fat mass and improved glucose tolerance in obese mice. Proteomic analysis revealed that NAM supplementation upregulates mitochondrial proteins while quantitative polymerase chain reaction showed that PPARα and PGC1α were both upregulated in adipose tissues, proposing that NAM increased mitochondrial biogenesis in adipose tissue. Indeed, NAM treatment increased proteins related to mitochondrial functions including oxidative phosphorylation, fatty acid oxidation, and TCA cycle. Furthermore, isotope-tracing assisted metabolic profiling revealed that NAM activated NAMPT and increased cellular NAD+ level by 30%. Unexpectedly, we found that NAM also increased glucose derived amino acids to enhance glutathione synthesis for maintaining cellular redox homeostasis. Taken together, our results demonstrated that NAM reprogramed cellular metabolism, enhanced adipose mitochondrial functions to ameliorate symptoms associated with obesity.


Assuntos
NAD , Niacinamida , Tecido Adiposo/metabolismo , Animais , Glucose/metabolismo , Camundongos , NAD/metabolismo , Niacinamida/metabolismo , Niacinamida/farmacologia , Nicotinamida Fosforribosiltransferase/metabolismo , Obesidade/metabolismo , Biogênese de Organelas , Proteômica
20.
J Invest Dermatol ; 142(10): 2744-2755.e9, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35469906

RESUMO

Sequence variation in SLC45A2 are responsible for oculocutaneous albinism type 4 in many species and are associated with melanoma susceptibility, but the molecular mechanism is unclear. In this study, we used Slc45a2-deficient melanocyte and mouse models to elucidate the roles of SLC45A2 in melanogenesis and melanoma metastasis. We found that the acidified cellular environment impairs the activity of key melanogenic enzyme tyrosinase in Slc45a2-deficient melanocytes. SLC45A2 is identified as a proton/glucose exporter in melanosomes, and its ablation increases the acidification of melanosomal pH through enhanced glycolysis. Intriguingly, 13C-glucose-labeled metabolic flux and biochemical assays show that melanosomes are active glucose-metabolizing organelles, indicating that elevated glycolysis mainly occurs in melanosomes owing to Slc45a2 deficiency. Moreover, Slc45a2 deficiency significantly upregulates the activities of glycolytic enzymes and phosphatidylinositol 3-kinase/protein kinase B signaling to promote glycolysis-dependent survival and metastasis of melanoma cells. Collectively, our study reveals that the proton/glucose exporter SLC45A2 mediates melanin synthesis and melanoma metastasis primarily by modulating melanosomal glucose metabolism.


Assuntos
Melanoma , Melanossomas , Animais , Glucose/metabolismo , Glicólise , Concentração de Íons de Hidrogênio , Melaninas/metabolismo , Melanócitos/metabolismo , Melanoma/genética , Melanoma/metabolismo , Melanossomas/metabolismo , Camundongos , Monofenol Mono-Oxigenase/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Prótons
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