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1.
J Cell Physiol ; : e31426, 2024 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-39221900

RESUMO

Dysregulation of alternative pre-mRNA splicing plays a critical role in the progression of cancers, yet the underlying molecular mechanisms remain largely unknown. It is reported that metastasis-associated in colon cancer 1 (MACC1) is a novel prognostic and predictive marker in many types of cancers, including lung adenocarcinoma. Here, we reveal that the oncogene MACC1 specifically drives the progression of lung adenocarcinoma through its control over cancer-related splicing events. MACC1 depletion inhibits lung adenocarcinoma progression through triggering IRAK1 from its long isoform, IRAK1-L, to the shorter isoform, IRAK1-S. Mechanistically, MACC1 interacts with splicing factor HNRNPH1 to prevent the production of the short isoform of IRAK1 mRNA. Specifically, the interaction between MACC1 and HNRNPH1 relies on the involvement of MACC1's SH3 domain and HNRNPH1's GYR domain. Further, HNRNPH1 can interact with the pre-mRNA segment (comprising exon 11) of IRAK1, thereby bridging MACC1's regulation of IRAK1 splicing. Our research not only sheds light on the abnormal splicing regulation in cancer but also uncovers a hitherto unknown function of MACC1 in tumor progression, thereby presenting a novel potential therapeutic target for clinical treatment.

2.
BMC Plant Biol ; 24(1): 800, 2024 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-39179986

RESUMO

BACKGROUND: The mitogen-activated protein kinase (MAPK) cascade is crucial cell signal transduction mechanism that plays an important role in plant growth and development, metabolism, and stress responses. The MAPK cascade includes three protein kinases, MAPK, MAPKK, and MAPKKK. The three protein kinases mediate signaling to downstream response molecules by sequential phosphorylation. The MAPK gene family has been identified and analyzed in many plants, however it has not been investigated in alfalfa. RESULTS: In this study, Medicago sativa MAPK genes (referred to as MsMAPKs) were identified in the tetraploid alfalfa genome. Eighty MsMAPKs were divided into four groups, with eight in group A, 21 in group B, 21 in group C and 30 in group D. Analysis of the basic structures of the MsMAPKs revealed presence of a conserved TXY motif. Groups A, B and C contained a TEY motif, while group D contained a TDY motif. RNA-seq analysis revealed tissue-specificity of two MsMAPKs and tissue-wide expression of 35 MsMAPKs. Further analysis identified MsMAPK members responsive to drought, salt, and cold stress conditions. Two MsMAPKs (MsMAPK70 and MsMAPK75) responds to salt and cold stresses; two MsMAPKs (MsMAPK60 and MsMAPK73) responds to cold and drought stresses; four MsMAPKs (MsMAPK1, MsMAPK33, MsMAPK64 and MsMAPK71) responds to salt and drought stresses; and two MsMAPKs (MsMAPK5 and MsMAPK7) responded to all three stresses. CONCLUSION: This study comprehensively identified and analysed the alfalfa MAPK gene family. Candidate genes related to abiotic stresses were screened by analysing the RNA-seq data. The results provide key information for further analysis of alfalfa MAPK gene functions and improvement of stress tolerance.


Assuntos
Medicago sativa , Proteínas Quinases Ativadas por Mitógeno , Estresse Fisiológico , Medicago sativa/genética , Medicago sativa/enzimologia , Medicago sativa/fisiologia , Proteínas Quinases Ativadas por Mitógeno/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Estresse Fisiológico/genética , Família Multigênica , Regulação da Expressão Gênica de Plantas , Genoma de Planta , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Filogenia , Secas
3.
Plant Physiol Biochem ; 215: 109048, 2024 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-39159534

RESUMO

Saline-alkali stress is one of the main abiotic stresses that limits plant growth. Salt stress has been widely studied, but alkaline salt degradation caused by NaHCO3 has rarely been investigated. In the present study, the alfalfa cultivar 'Zhongmu No. 1' was treated with 50 mM NaHCO3 (0, 4, 8, 12 and 24 h) to study the resulting enzyme activity and changes in mRNA, miRNA and metabolites in the roots. The results showed that the enzyme activity changed significantly after alkali stress treatment. The genomic analysis revealed 14,970 differentially expressed mRNAs (DEMs), 53 differentially expressed miRNAs (DEMis), and 463 differentially accumulated metabolites (DAMs). Combined analysis of DEMs and DEMis revealed that 21 DEMis negatively regulated 42 DEMs. In addition, when combined with Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of DEMs and DAMs, we found that phenylpropanoid biosynthesis, flavonoid biosynthesis, starch and sucrose metabolism and plant hormone signal transduction played important roles in the alkali stress response. The results of this study further elucidated the regulatory mechanism underlying the plant response to alkali stress and provided valuable information for the breeding of new saline-alkaline tolerance plant varieties.

4.
Proc Natl Acad Sci U S A ; 121(36): e2406343121, 2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39186654

RESUMO

The extinction risk of the giant panda has been demoted from "endangered" to "vulnerable" on the International Union for Conservation of Nature Red List, but its habitat is more fragmented than ever before, resulting in 33 isolated giant panda populations according to the fourth national survey released by the Chinese government. Further comprehensive investigations of the genetic background and in-depth assessments of the conservation status of wild populations are still necessary and urgently needed. Here, we sequenced the genomes of 612 giant pandas with an average depth of ~26× and generated a high-resolution map of genomic variation with more than 20 million variants covering wild individuals from six mountain ranges and captive representatives in China. We identified distinct genetic clusters within the Minshan population by performing a fine-grained genetic structure. The estimation of inbreeding and genetic load associated with historical population dynamics suggested that future conservation efforts should pay special attention to the Qinling and Liangshan populations. Releasing captive individuals with a genetic background similar to the recipient population appears to be an advantageous genetic rescue strategy for recovering the wild giant panda populations, as this approach introduces fewer deleterious mutations into the wild population than mating with differentiated lineages. These findings emphasize the superiority of large-scale population genomics to provide precise guidelines for future conservation of the giant panda.


Assuntos
Conservação dos Recursos Naturais , Genoma , Ursidae , Ursidae/genética , Animais , Conservação dos Recursos Naturais/métodos , Genoma/genética , China , Espécies em Perigo de Extinção , Variação Genética , Genética Populacional/métodos , Dinâmica Populacional , Sequenciamento Completo do Genoma/métodos
5.
Microb Cell Fact ; 23(1): 212, 2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-39061053

RESUMO

Being generally regarded as safe, Kluyveromyces lactis has been widely taken for food, feed, and pharmaceutical applications, owing to its ability to achieve high levels of protein secretion and hence being suitable for industrial production of heterologous proteins. Production platform strains can be created through genetic engineering; while prototrophic cells without chromosomally accumulated antibiotics resistance genes have been generally preferred, arising the need for dominant counterselection. We report here the establishment of a convenient counterselection system based on a Frs2 variant, Frs2v, which is a mutant of the alpha-subunit of phenylalanyl-tRNA synthase capable of preferentially incorporating a toxic analog of phenylalanine, r-chloro-phenylalanine (4-CP), into proteins to bring about cell growth inhibition. We demonstrated that expression of Frs2v from an episomal plasmid in K. lactis could make the host cells sensitive to 2 mM 4-CP, and a Frs2v-expressing plasmid could be efficiently removed from the cells immediately after a single round of cell culturing in a 4-CP-contianing YPD medium. This Frs2v-based counterselection helped us attain scarless gene replacement in K. lactis without any prior engineering of the host cells. More importantly, counterselection with this system was proven to be functionally efficient also in Saccharomyces cerevisiae and Komagataella phaffii, suggestive of a broader application scope of the system in various yeast hosts. Collectively, this work has developed a strategy to enable rapid, convenient, and high-efficiency construction of prototrophic strains of K. lactis and possibly many other yeast species, and provided an important reference for establishing similar methods in other industrially important eukaryotic microbes.


Assuntos
Kluyveromyces , Plasmídeos , Kluyveromyces/genética , Kluyveromyces/metabolismo , Plasmídeos/genética , Fenilalanina-tRNA Ligase/genética , Fenilalanina-tRNA Ligase/metabolismo , Engenharia Genética/métodos , Fenilalanina/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo
6.
Angew Chem Int Ed Engl ; 63(12): e202317775, 2024 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-38286749

RESUMO

There is an unmet need for easy-to-visualize drug carriers that can deliver therapeutic cargoes deep into solid tumors. Herein, we report the preparation of ultrasmall luminescent imine-based lanthanide nanocages, Eu60 and Tb60 (collectively Ln60 ), designed to encapsulate anticancer chemotherapeutics for tumor therapy. The as-prepared nanocages possess large cavities suitable for the encapsulation of doxorubicin (DOX), yielding DOX@Ln60 nanocages with diameters around 5 nm. DOX@Ln60 are efficiently internalized by breast cancer cells, allowing the cells to be visualized via the intrinsic luminescent property of Ln(III). Once internalized, the acidic intracellular microenvironment promotes imine bond cleavage and the release of the loaded DOX. DOX@Ln60 inhibits DNA replication and triggers tumor cell apoptosis. In a murine triple negative breast cancer (TNBC) model, DOX@Ln60 was found to inhibit tumor growth with negligible side effects on normal tissues. It proved more effective than various controls, including DOX and Ln60 . The present nanocages thus point the way to the development of precise nanomedicines for tumor imaging and therapy.


Assuntos
Elementos da Série dos Lantanídeos , Nanopartículas , Animais , Camundongos , Linhagem Celular Tumoral , Sistemas de Liberação de Medicamentos/métodos , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Portadores de Fármacos/química , Iminas , Nanopartículas/química
7.
Sci Adv ; 9(50): eadj2908, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-38091396

RESUMO

Modern analog computing, by gaining momentum from nonvolatile resistive memory devices, deals with matrix computations. In-memory analog computing has been demonstrated for solving some basic but ordinary matrix problems in one step. Among the more complicated matrix problems, compressed sensing (CS) is a prominent example, whose recovery algorithms feature high-order matrix operations and hardware-unfriendly nonlinear functions. In light of the local competitive algorithm (LCA), here, we present a closed-loop, continuous-time resistive memory circuit for solving CS recovery in one step. Recovery of one-dimensional (1D) sparse signal and 2D compressive images has been experimentally demonstrated, showing elapsed times around few microseconds and normalized mean squared errors of 10-2. The LCA circuit is one or two orders of magnitude faster than conventional digital approaches. It also substantially outperforms other (electronic or exotically photonic) analog CS recovery methods in terms of speed, energy, and fidelity, thus representing a highly promising technology for real-time CS applications.

8.
Sensors (Basel) ; 23(23)2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38067927

RESUMO

Hyperspectral images provide a wealth of spectral and spatial information, offering significant advantages for the purpose of tracking objects. However, Siamese trackers are unable to fully exploit spectral features due to the limited number of hyperspectral videos. The high-dimensional nature of hyperspectral images complicates the model training process. In order to address the aforementioned issues, this article proposes a hyperspectral object tracking (HOT) algorithm callled SiamPKHT, which leverages the SiamCAR model by incorporating pyramid shuffle attention (PSA) and knowledge distillation (KD). First, the PSA module employs pyramid convolutions to extract multiscale features. In addition, shuffle attention is adopted to capture relationships between different channels and spatial positions, thereby obtaining good features with a stronger classification performance. Second, KD is introduced under the guidance of a pre-trained RGB tracking model, which deals with the problem of overfitting in HOT. Experiments using HOT2022 data indicate that the designed SiamPKHT achieves better performance compared to the baseline method (SiamCAR) and other state-of-the-art HOT algorithms. It also achieves real-time requirements at 43 frames per second.

9.
GigaByte ; 2023: gigabyte97, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38023064

RESUMO

The Brown-Spotted Pit viper (Protobothrops mucrosquamatus), also known as the Chinese habu, is a widespread and highly venomous snake distributed from Northeastern India to Eastern China. Genomics research can contribute to our understanding of venom components and natural selection in vipers. Here, we collected, sequenced and assembled the genome of a male P. mucrosquamatus individual from China. We generated a highly continuous reference genome, with a length of 1.53 Gb and 41.18% of repeat elements content. Using this genome, we identified 24,799 genes, 97.97% of which could be annotated. We verified the validity of our genome assembly and annotation process by generating a phylogenetic tree based on the nuclear genome single-copy genes of six other reptile species. The results of our research will contribute to future studies on Protobothrops biology and the genetic basis of snake venom.

10.
GigaByte ; 2023: gigabyte99, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38033372

RESUMO

In China, 65 types of venomous snakes exist, with the Chinese Cobra Naja atra being prominent and a major cause of snakebites in humans. Furthermore, N. atra is a protected animal in some areas, as it has been listed as vulnerable by the International Union for Conservation of Nature. Recently, due to the medical value of snake venoms, venomics has experienced growing research interest. In particular, genomic resources are crucial for understanding the molecular mechanisms of venom production. Here, we report a highly continuous genome assembly of N. atra, based on a snake sample from Huangshan, Anhui, China. The size of this genome is 1.67 Gb, while its repeat content constitutes 37.8% of the genome. A total of 26,432 functional genes were annotated. This data provides an essential resource for studying venom production in N. atra. It may also provide guidance for the protection of this species.

11.
GigaByte ; 2023: gigabyte88, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37711277

RESUMO

The study of the currently known >3,000 species of snakes can provide valuable insights into the evolution of their genomes. Deinagkistrodon acutus, also known as Sharp-nosed Pit Viper, one hundred-pacer viper or five-pacer viper, is a venomous snake with significant economic, medicinal and scientific importance. Widely distributed in southeastern China and South-East Asia, D. acutus has been primarily studied for its venom. Here, we employed next-generation sequencing to assemble and annotate a highly continuous genome of D. acutus. The genome size is 1.46 Gb; its scaffold N50 length is 6.21 Mb, the repeat content is 42.81%, and 24,402 functional genes were annotated. This study helps to further understand and utilize D. acutus and its venom at the genetic level.

12.
Biol Direct ; 18(1): 59, 2023 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-37723551

RESUMO

BACKGROUND: The thymus is required for T cell development and the formation of the adaptive immunity. Stromal cells, which include thymic epithelial cells (TECs) and mesenchymal stromal cells (MSCs), are essential for thymic function. However, the immunomodulatory function of thymus-derived MSCs (T-MSCs) has not been fully explored. METHODS: MSCs were isolated from mouse thymus and their general characteristics including surface markers and multi-differentiation potential were characterized. The immunomodulatory function of T-MSCs stimulated by IFN-γ and TNF-α was evaluated in vitro and in vivo. Furthermore, the spatial distribution of MSCs in the thymus was interrogated by using tdTomato-flox mice corssed to various MSC lineage Cre recombinase lines. RESULTS: A subset of T-MSCs express Nestin, and are mainly distributed in the thymic medulla region and cortical-medulla junction, but not in the capsule. The Nestin-positive T-MSCs exhibit typical immunophenotypic characteristics and differentiation potential. Additionally, when stimulated with IFN-γ and TNF-α, they can inhibit activated T lymphocytes as efficiently as BM-MSCs, and this function is dependent on the production of nitric oxide (NO). Additionally, the T-MSCs exhibit a remarkable therapeutic efficacy in acute liver injury and inflammatory bowel disease (IBD). CONCLUSIONS: Nestin-positive MSCs are mainly distributed in medulla and cortical-medulla junction in thymus and possess immunosuppressive ability upon stimulation by inflammatory cytokines. The findings have implications in understanding the physiological function of MSCs in thymus.


Assuntos
Células-Tronco Mesenquimais , Óxido Nítrico , Animais , Camundongos , Nestina , Fator de Necrose Tumoral alfa , Imunidade Adaptativa
13.
GigaByte ; 2023: gigabyte92, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37753478

RESUMO

The Oriental rat snake Ptyas mucosa is a common non-venomous snake of the colubrid family, spanning most of South and Southeast Asia. P. mucosa is widely bred for its uses in traditional medicine, scientific research, and handicrafts. Therefore, genome resources of P. mucosa could play an important role in the efficacy of traditional medicine and the analysis of the living environment of this species. Here, we present a highly continuous P. mucosa genome with a size of 1.74 Gb. Its scaffold N50 length is 9.57 Mb, and the maximal scaffold length is 78.3 Mb. Its CG content is 37.9%, and its gene integrity reaches 86.6%. Assembled using long-reads, the total length of the repeat sequences in the genome reaches 735 Mb, and its repeat content is 42.19%. Finally, 24,869 functional genes were annotated in this genome. This study may assist in understanding P. mucosa and supporting medicinal research.

14.
Int J Mol Sci ; 24(16)2023 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-37628861

RESUMO

Heat shock transcription factors (HSFs) are important regulatory factors in plant stress responses to various biotic and abiotic stresses and play important roles in growth and development. The HSF gene family has been systematically identified and analyzed in many plants but it is not in the tetraploid alfalfa genome. We detected 104 HSF genes (MsHSFs) in the tetraploid alfalfa genome ("Xinjiangdaye" reference genome) and classified them into three subgroups: 68 in HSFA, 35 in HSFB and 1 in HSFC subgroups. Basic bioinformatics analysis, including genome location, protein sequence length, protein molecular weight and conserved motif identification, was conducted. Gene expression analysis revealed tissue-specific expression for 13 MsHSFs and tissue-wide expression for 28 MsHSFs. Based on transcriptomic data analysis, 21, 11 and 27 MsHSFs responded to drought stress, cold stress and salt stress, respectively, with seven responding to all three. According to RT-PCR, MsHSF27/33 expression gradually increased with cold, salt and drought stress condition duration; MsHSF6 expression increased over time under salt and drought stress conditions but decreased under cold stress. Our results provide key information for further functional analysis of MsHSFs and for genetic improvement of stress resistance in alfalfa.


Assuntos
Medicago sativa , Tetraploidia , Fatores de Transcrição de Choque Térmico/genética , Medicago sativa/genética , Resposta ao Choque Frio/genética , Estresse Salino , Interleucina-6
15.
Cell Death Discov ; 9(1): 269, 2023 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-37507432

RESUMO

Muscle stem cells (MuSCs) have been demonstrated to exert impressive therapeutic efficacy in disease settings through orchestrating inflammatory microenvironments. Nevertheless, the mechanisms underlying the immunoregulatory property of MuSCs remain largely uncharacterized. Here, we showed that interleukin-4-induced-1 (IL4I1), an essential enzyme that catalyzes indole metabolism in humans, was highly expressed in human MuSCs exposed to IFN-γ and TNF-α. Functionally, the MuSCs were found to inhibit the infiltration of neutrophils into sites of inflammation in a IL4I1-dependent manner and thus ameliorate acute lung injury in mice. Mechanistically, the indole metabolites, including indole-3-pyruvic acid (I3P) and indole-3-aldehyde (I3A), produced by IL4I1, acted as ligands to activate aryl hydrocarbon receptor (AHR), leading to augmented expression of TNF-stimulated gene 6 (TSG-6) in inflammatory cytokine-primed MuSCs. Furthermore, I3P administration alone suppressed neutrophil infiltration into damaged lungs. I3P could also reduce the level of reactive oxygen species in neutrophils. Therefore, our study has uncovered a novel mechanism by which MuSCs acquire their immunoregulatory property and may help to develop or optimize MuSC-based therapies for inflammatory diseases.

16.
Appl Microbiol Biotechnol ; 107(18): 5687-5700, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37480371

RESUMO

The microbial-induced carbonate precipitation (MICP) has acquired significant attention due to its immense potential in sustainable engineering applications, particularly in soil improvement. However, the precise control of microbial-induced calcium carbonate precipitation remains a formidable challenge in engineering practices, owing to the uncertain movement paths of bacteria and the nonuniform distribution of soil pores. Taking inspiration from targeted therapy in medicine, this paper presents novel research on the development and validation of magnetically responsive bacteria. These bacteria demonstrate the ability to target calcium carbonate precipitation in a microfluidic chip, thereby promoting an environmentally friendly and ecologically sustainable biomineralization paradigm. The study focuses on investigating the migration of magnetite nanoparticles (MNPs) in aqueous solutions and enhancing the stability of MNP culture liquids. A specially designed microfluidic chip is utilized to simulate natural sand particles and their pores, while an external magnetic field is applied to precisely control the movement path of the artificial magnetic bacteria, enabling targeted precipitation of calcium carbonate at the micron-scale. Verification of the engineered artificial magnetic bacteria and their ability to induce calcium carbonate precipitation is conducted through SEM-EDS analysis, microfluidic chip observations, and the application of the K-means algorithm and ImageJ software to analyze calcium carbonate formation. The influence of the concentration of magnetic nanoparticles on the calcium carbonate production rate was also studied. The results confirm the potential of the artificial magnetic bacteria for future engineering applications. KEY POINTS: • Sporosarcina pasteurii is first time successfully engineered into artificial magnetic bacteria. • The artificial magnetic bacteria show excellent performance of targeted transportation and directional deposition of CaCO3 in microfluidic chip. • The emergence of artificial magnetic bacteria promotes paradigm shift of next generation environmentally friendly biomineralization.


Assuntos
Carbonato de Cálcio , Solo , Algoritmos , Bactérias , Campos Magnéticos
17.
Front Genet ; 14: 1154067, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37065482

RESUMO

Background: Diminished ovarian reserve is one of the most important causes of female infertility. In the etiology study of DOR, besides age, it is known that chromosomal abnormality, radiotherapy, chemotherapy and ovarian surgery can result in DOR. For young women without obvious risk factors, gene mutation should be considered as a possible cause. However, the specific molecular mechanism of DOR has not been fully elucidated. Methods: In order to explore the pathogenic variants related to DOR, twenty young women under 35 years old affected by DOR without definite factors damaging ovarian reserve were recruited as the research subjects, and five women with normal ovarian reserve were recruited as the control group. Whole exome sequencing was applied as the genomics research tool. Results: As a result, we obtained a set of mutated genes that may be related to DOR, where the missense variant on GPR84 was selected for further study. It is found that GPR84Y370H variant promotes the expression of proinflammatory cytokines (TNF-α, IL12B, IL-1ß) and chemokines (CCL2, CCL5), as well as the activation of NF-κB signaling pathway. Conclusion: In conclusion, GPR84Y370H variant was identified though analysis for WES results of 20 DOR patients. The deleterious variant of GPR84 could be the potential molecular mechanism of non-age-related pathological DOR through its role in promoting inflammation. The findings of this study can be used as a preliminary research basis for the development of early molecular diagnosis and treatment target selection of DOR.

18.
Macromol Rapid Commun ; 44(1): e2200159, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35881534

RESUMO

In the present work, molecular dynamics simulations are carried out based on the bead-spring model to indicate how the entanglement lockup manifests in the late stage of fast Rouse-Weissnberg number (WiR >>1) uniaxial melt stretching of entangled polymer melts. At high strains, distinct features show up to reveal the emergence of an increasingly tightened entanglement network. Chain tension can build up, peaking at the middle of the chain, to a level for chain scission, through accumulated interchain interactions, as if there is a tug-of-war ongoing for each load-bearing chain. Thanks to the interchain uncrossability, network junctions form by the pairing of two or more hairpins. It is hypothesized that the interchain entanglement at junctions can lockup through prevailing twist-like interchain couplings as long as WiR > 9. In this limit, a significant fraction of chains act like cyclic chains to form a network held by interchain uncrossability, and appreciable chain tension emerges.


Assuntos
Simulação de Dinâmica Molecular , Polímeros
19.
Macromol Rapid Commun ; 44(1): e2200293, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35696350

RESUMO

The processing-structure-property relationship using poly(lactic acid) (PLA) and poly(ethylene terephthalate) (PET) is explored. Specifically, both pre-extension and preshear of amorphous PLA and PET above their glass transition temperatures Tg , carried out in the affine deformation limit, can induce a specific type of cold crystallization during annealing, i.e., nanoconfined crystallization (NCC) where crystal sizes are limited to a nanoscopic scale in all dimensions so as to render the processed PLA and PET optically transparent. The new polymer structure after premelt deformation can show considerably enhanced mechanical properties. For example, premelt stretching produces geometric condensation of the chain network. This structural alternation can profoundly change the mechanical characteristics, e.g., turning brittle PLA ductile. In contrast, after preshear of amorphous PLA above Tg , the NCC containing PLA remains brittle, showing the importance to have geometric condensation from processing. Both AFM imaging and SAXS measurements are performed to verify that premelt deformation of PLA and PET indeed results in NCC from annealing that permits the strain-induced cold crystallization to take place on the length scale of the mesh size of the deformed chain network.


Assuntos
Poliésteres , Polietilenotereftalatos , Cristalização , Espalhamento a Baixo Ângulo , Difração de Raios X , Poliésteres/química , Etilenos
20.
Mol Cancer Res ; 21(3): 199-213, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36445330

RESUMO

The dysregulated endocytic traffic of oncogenic receptors, such as the EGFR family especially HER2, contributes to the uncontrolled activation of the downstream oncogenic signaling and progression of various carcinomas, including 90% of ovarian carcinoma. However, the key regulators in the intracellular trafficking of HER2 and their impacts for cancer progression remain largely unknown. In this study, through a genome-wide CRISPR/Cas9 screening for key genes affecting the peritoneal disseminated metastasis of ovarian carcinoma, we identified a member of COMMD family, that is, COMMD3, as a key regulator in the endosomal trafficking of HER2. In the patients with high-grade serous ovarian carcinoma (HGSOC), the expression of COMMD3 is dramatically decreased in the peritoneal disseminated ovarian carcinoma cells comparing with that in the primary ovarian carcinoma cells. COMMD3 greatly inhibits the proliferation, migration, and epithelial-mesenchymal transition (EMT) of HGSOC cells, and dramatically suppresses the tumor growth, the formation of malignant ascites, and the peritoneal dissemination of cancer cells in the orthotopic murine model of HGSOC. Further transcriptome analysis reveals that silencing COMMD3 boosts the activation of HER2 downstream signaling. As a component in the Retriever-associated COMMD/CCDC22/CCDC93 complex responsible for the recognition and recycling of membrane receptors, COMMD3 physically interacts with HER2 for directing it to the slow recycling pathway, leading to the attenuated downstream tumor-promoting signaling. IMPLICATIONS: Collectively, this study reveals a novel HER2 inactivation mechanism with a high value for the clinic diagnosis of new ovarian carcinoma types and the design of new therapeutic strategy.


Assuntos
Neoplasias Ovarianas , Feminino , Humanos , Camundongos , Animais , Carcinoma Epitelial do Ovário , Neoplasias Ovarianas/patologia , Transdução de Sinais , Proteínas de Transporte/metabolismo , Receptores ErbB/genética , Receptores ErbB/metabolismo , Linhagem Celular Tumoral
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