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1.
Proc Natl Acad Sci U S A ; 121(37): e2400654121, 2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-39236238

RESUMO

The Caenorhabditis elegans HMP-2/HMP-1 complex, akin to the mammalian [Formula: see text]-catenin-[Formula: see text]-catenin complex, serves as a critical mechanosensor at cell-cell adherens junctions, transducing tension between HMR-1 (also known as cadherin in mammals) and the actin cytoskeleton. Essential for embryonic development and tissue integrity in C. elegans, this complex experiences tension from both internal actomyosin contractility and external mechanical microenvironmental perturbations. While offering a valuable evolutionary comparison to its mammalian counterpart, the impact of tension on the mechanical stability of HMP-1 and HMP-2/HMP-1 interactions remains unexplored. In this study, we directly quantified the mechanical stability of full-length HMP-1 and its force-bearing modulation domains (M1-M3), as well as the HMP-2/HMP-1 interface. Notably, the M1 domain in HMP-1 exhibits significantly higher mechanical stability than its mammalian analog, attributable to interdomain interactions with M2-M3. Introducing salt bridge mutations in the M3 domain weakens the mechanical stability of the M1 domain. Moreover, the intermolecular HMP-2/HMP-1 interface surpasses its mammalian counterpart in mechanical stability, enabling it to support the mechanical activation of the autoinhibited M1 domain for mechanotransduction. Additionally, the phosphomimetic mutation Y69E in HMP-2 weakens the mechanical stability of the HMP-2/HMP-1 interface, compromising the force-transmission molecular linkage and its associated mechanosensing functions. Collectively, these findings provide mechanobiological insights into the C. elegans HMP-2/HMP-1 complex, highlighting the impact of salt bridges on mechanical stability in [Formula: see text]-catenin and demonstrating the evolutionary conservation of the mechanical switch mechanism activating the HMP-1 modulation domain for protein binding at the single-molecule level.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Mecanotransdução Celular , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/química , Proteínas de Caenorhabditis elegans/genética , Animais , Caenorhabditis elegans/metabolismo , Mecanotransdução Celular/fisiologia , Imagem Individual de Molécula , Ligação Proteica , Caderinas/metabolismo , Caderinas/química , Caderinas/genética , Junções Aderentes/metabolismo , Citoesqueleto de Actina/metabolismo , Citoesqueleto de Actina/química , Proteínas do Citoesqueleto , alfa Catenina
2.
Acta Neuropathol Commun ; 12(1): 148, 2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-39256867

RESUMO

Malignant transformation (MT) is commonly seen in IDH-mutant gliomas. There has been a growing research interest in revealing its underlying mechanisms and intervening prior to MT at the early stages of the transforming process. Here we established a unique pair of matched 3D cell models: 403L, derived from a low-grade glioma (LGG), and 403H, derived from a high-grade glioma (HGG), by utilizing IDH-mutant astrocytoma samples from the same patient when the tumor was diagnosed as WHO grade 2 (tumor mutational burden (TMB) of 3.96/Mb) and later as grade 4 (TMB of 70.07/Mb), respectively. Both cell models were authenticated to a patient's sample retaining endogenous expression of IDH1 R132H. DNA methylation profiles of the parental tumors referred to LGG and HGG IDH-mutant glioma clusters. The immunopositivity of SOX2, NESTIN, GFAP, OLIG2, and beta 3-Tubulin suggested the multilineage potential of both models. 403H was more prompt to cell invasion and developed infiltrative HGG in vivo. The differentially expressed genes (DEGs) from the RNA sequencing analysis revealed the tumor invasion and aggressiveness related genes exclusively upregulated in the 403H model. Pathway analysis showcased an enrichment of genes associated with epithelial-mesenchymal transition (EMT) and Notch signaling pathways in 403H and 403L, respectively. Mass spectrometry-based targeted metabolomics and hyperpolarized (HP) 1-13C pyruvate in-cell NMR analyses demonstrated significant alterations in the TCA cycle and fatty acid metabolism. Citrate, glutamine, and 2-HG levels were significantly higher in 403H. To our knowledge, this is the first report describing the development of a matched pair of 3D patient-derived cell models representative of MT and temozolomide (TMZ)-induced hypermutator phenotype (HMP) in IDH-mutant glioma, providing insights into genetic and metabolic changes during MT/HMP. This novel in vitro model allows further investigation of the mechanisms of MT at the cellular level.


Assuntos
Neoplasias Encefálicas , Transformação Celular Neoplásica , Glioma , Isocitrato Desidrogenase , Mutação , Humanos , Isocitrato Desidrogenase/genética , Isocitrato Desidrogenase/metabolismo , Glioma/genética , Glioma/patologia , Glioma/metabolismo , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/metabolismo , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/patologia , Transformação Celular Neoplásica/metabolismo , Animais
4.
Heliyon ; 10(10): e30848, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38770293

RESUMO

There have been divergent views by various human rights scholars and actors on how to address the question of vulnerability among indigenous and minority groups in Rwanda. Even though factors influencing vulnerability among these groups have received increasing scholarly attention, findings from these studies fall short of reflecting on the role of identity and discrimination. Whereas the government in Rwanda after the 1994 genocide sought to enhance unity and reconciliation by outlawing all ethnic identities, and instead conflating all vulnerable groups into a nomenclature namely, a Historically Marginalised People (HMP), a divergent group of scholars, human rights activists, the United Nations and African Union's instruments of human rights describe this approach as antithetical to the promotion and protection of the rights of indigenous and minority groups. Using the human rights-based approach, this paper critically interrogates the issue of identity and how it has affected the enjoyment of the rights among the minority and indigenous Batwa people in Rwanda. The study employed a qualitative research design with data collected through Focus Group Discussions (FGDs) as well as in-depth interviews (IDIs). Respondents included members of the Batwa community, officials of selected public institutions, leaders in Non-Governmental Organisations (NGOs), and cooperative societies working towards the promotion of rights of the HMP. Data analysis involved the process of transcription and coding of data and the eventual reflexive thematic analysis. The findings show that the rights of the Batwa community to recognition and self-identity have varied meanings and implications to different members of the community as well as officials from public institutions and other relevant actors. To the existing research, the study affirms that the inconsistencies surrounding the Batwa's identity have accentuated their vulnerability. In terms of policy, the study suggests that in the short run, the Batwa community may require enhanced special temporary social protection measures in order to ameliorate their conundrum arising from identity ambiguity without compromising Rwanda's national unity. Further studies, should consider the role of land, forest and culture in further marginalising the Batwa, as well as quantitative methodology for inferential analysis.

5.
Am J Transplant ; 24(7): 1127-1131, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38514015

RESUMO

As an alternative to static cold storage (SCS), advanced perfusion techniques such as normothermic regional perfusion and ex-situ perfusion (normothermic or hypothermic) have emerged as a way to improve the ischemic injury suffered by donation after circulatory death (DCD) livers. Multiple studies have been published that have demonstrated superior post-DCD liver transplant outcomes when using advanced perfusion compared with SCS. In particular, these studies have shown lower rates of ischemic cholangiopathy with advanced perfusion. In addition to the improved post-liver transplant outcomes, studies have also demonstrated higher rates of liver utilization from DCD donors when advanced perfusion is used compared with SCS. Given the high rates of graft loss in patients who develop ischemic cholangiopathy, the significant reduction seen in DCD donor livers that have undergone advanced perfusion represents a key step in more broad utilization of these livers. With such compelling evidence from multiple trials, it seems reasonable to ask the question: should advanced perfusion be the standard of care for DCD liver transplant?


Assuntos
Transplante de Fígado , Preservação de Órgãos , Perfusão , Doadores de Tecidos , Obtenção de Tecidos e Órgãos , Humanos , Preservação de Órgãos/métodos , Perfusão/métodos , Padrão de Cuidado , Obtenção de Tecidos e Órgãos/normas , Obtenção de Tecidos e Órgãos/métodos , Doadores de Tecidos/provisão & distribuição
6.
Artigo em Inglês | MEDLINE | ID: mdl-38397634

RESUMO

Health Improvement Through Employee Control (HITEC) is a 16-year program directed toward the health of corrections personnel and developed through the application of the principles of Participatory Action Research (PAR) and participatory ergonomics. Its impetus has always been the adverse health status of the corrections workforce: early mortality, depression, obesity, and hypertension. The HITEC program trained small "Design Teams" (DTs) of front-line personnel in participatory methods for intervention design for health improvement and organizational change in line with the Total Worker Health® principles. Periodic surveys and physical testing were introduced for longitudinal assessments. Comparative interventions at comparable sites included DTs without a priori assignation, problem-focused kaizen effectiveness teams (KETs), and bargaining unit-centered DTs. DT resilience and the replacement of members who transferred facilities or retired was aided by novel cooperative administrative structures. DT-generated interventions included stress lounges, changes in critical event report writing, a joint program with trained inmates to improve air quality, and training in staff mental health and sleep behavior. A specialized peer-to-peer Health Mentoring Program (HMP) paired new officers with trained peers. Many interventions and program features were institutionalized, thus improving prospects for self-supporting program longevity. Participatory interventions designed and supported by the corrections workforce were found to be both feasible and exceptionally effective.


Assuntos
Saúde Ocupacional , Humanos , Connecticut , Avaliação de Programas e Projetos de Saúde/métodos , Local de Trabalho , Promoção da Saúde/métodos
7.
Plant Biotechnol J ; 22(3): 751-758, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37932934

RESUMO

Heading date (or flowering time) is a key agronomic trait that affects seasonal and regional adaption of rice cultivars. An unoptimized heading date can either not achieve a high yield or has a high risk of encountering abiotic stresses. There is a strong demand on the mild to moderate adjusting the heading date in breeding practice. Genome editing is a promising method which allows more precise and faster changing the heading date of rice. However, direct knock out of major genes involved in regulating heading date will not always achieve a new germplasm with expected heading date. It is still challenging to quantitatively adjust the heading date of elite cultivars with best adaption for broader region. In this study, we used a CRISPR-Cas9 based genome editing strategy called high-efficiency multiplex promoter-targeting (HMP) to generate novel alleles at cis-regulatory regions of three major heading date genes: Hd1, Ghd7 and DTH8. We achieved a series of germplasm with quantitative variations of heading date by editing promoter regions and adjusting the expression levels of these genes. We performed field trials to screen for the best adapted lines for different regions. We successfully expanded an elite cultivar Ningjing8 (NJ8) to a higher latitude region by selecting a line with a mild early heading phenotype that escaped from cold stress and achieved high yield potential. Our study demonstrates that HMP is a powerful tool for quantitatively regulating rice heading date and expanding elite cultivars to broader regions.


Assuntos
Oryza , Oryza/metabolismo , Locos de Características Quantitativas , Sistemas CRISPR-Cas/genética , Melhoramento Vegetal , Regiões Promotoras Genéticas/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Flores/genética
8.
Microbiol Spectr ; 12(1): e0302423, 2024 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-38054720

RESUMO

ABSTRACT: In pathogenic bacteria, the flavohemoglobin Hmp is crucial in metabolizing the cytotoxic levels of nitric oxide (NO) produced in phagocytic cells, contributing to bacterial virulence. Hmp expression is predominantly regulated by the Rrf2 family transcription repressor NsrR in an NO-dependent manner; however, the underlying molecular mechanism in enterobacteria remains poorly understood. In this study, we identified Val43 of Salmonella Typhimurium NsrR (StNsrR) as a critical amino acid residue for regulating Hmp expression. The Val43-to-Ala-substituted mutant NsrR isolated through random and site-directed mutagenesis showed high binding affinity to the target DNA irrespective of NO exposure, resulting in a severe reduction in hmp transcription and slow NO metabolism in Salmonella under NO-producing conditions. Conversely, the Val43-to-Glu-substituted NsrR caused effects similar to nsrR null mutation, which directed hmp transcription and NO metabolism in a constitutive way. Comparative analysis of the primary sequences of NsrR and another NO-sensing Rrf2 family regulator, IscR, from diverse bacteria, revealed that Val43 of enterobacterial NsrR corresponds to Ala in Pseudomonas aeruginosa or Streptomyces coelicolor NsrR and Glu in enterobacterial IscR, all of which are located in the DNA recognition helix α3. The predicted structure of StNsrR in complex with the hmp DNA suggests dissimilar spatial stoichiometry in the interactions of Val43 and its substituted residues with the target DNA, consistent with the observed phenotypic changes in StNsrR Val43 mutants. Our findings highlight the discriminative roles of the NsrR recognition helix in regulating species-specific target gene expression, facilitating effective NO detoxification strategies in bacteria across diverse environments. IMPORTANCE: The precise regulation of flavohemoglobin Hmp expression by NsrR is critical for bacterial fitness, as excessive Hmp expression in the absence of NO can disturb bacterial redox homeostasis. While the molecular structure of Streptomyces coelicolor NsrR has been recently identified, the specific molecular structures of NsrR proteins in enterobacteria remain unknown. Our discovery of the crucial role of Val43 in the DNA recognition helix α3 of Salmonella NsrR offers valuable insights into the Hmp modulation under NO stress. Furthermore, the observed amino acid polymorphisms in the α3 helices of NsrR proteins across different bacterial species suggest the diverse evolution of NsrR structure and gene regulation in response to varying levels of NO pressure within their ecological niches.


Assuntos
Óxido Nítrico , Salmonella typhimurium , Salmonella typhimurium/genética , Salmonella typhimurium/metabolismo , Proteínas de Bactérias/metabolismo , Bactérias/metabolismo , Oxirredução , Regulação Bacteriana da Expressão Gênica
9.
Front Bioeng Biotechnol ; 11: 1296880, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38090711

RESUMO

The model of intracellular metabolic network based on enzyme kinetics parameters plays an important role in understanding the intracellular metabolic process of Corynebacterium glutamicum, and constructing such a model requires a large number of enzymological parameters. In this work, the genes encoding the relevant enzymes of the EMP and HMP metabolic pathways from Corynebacterium glutamicum ATCC 13032 were cloned, and engineered strains for protein expression with E.coli BL21 and P.pastoris X33 as hosts were constructed. The twelve enzymes (GLK, GPI, TPI, GAPDH, PGK, PMGA, ENO, ZWF, RPI, RPE, TKT, and TAL) were successfully expressed and purified by Ni2+ chelate affinity chromatography in their active forms. In addition, the kinetic parameters (V max, K m, and K cat) of these enzymes were measured and calculated at the same pH and temperature. The kinetic parameters of enzymes associated with EMP and the HMP pathway were determined systematically and completely for the first time in C.glutamicum. These kinetic parameters enable the prediction of key enzymes and rate-limiting steps within the metabolic pathway, and support the construction of a metabolic network model for important metabolic pathways in C.glutamicum. Such analyses and models aid in understanding the metabolic behavior of the organism and can guide the efficient production of high-value chemicals using C.glutamicum as a host.

10.
Front Cardiovasc Med ; 10: 1248606, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38028479

RESUMO

Heart transplantation, the gold standard treatment for end-stage heart failure, is limited by heart graft shortage, justifying expansion of the donor pool. Currently, static cold storage (SCS) of hearts from donations after brainstem death remains the standard practice, but it is usually limited to 240 min. Prolonged cold ischemia and ischemia-reperfusion injury (IRI) have been recognized as major causes of post-transplant graft failure. Continuous ex situ perfusion is a new approach for donor organ management to expand the donor pool and/or increase the utilization rate. Continuous ex situ machine perfusion (MP) can satisfy the metabolic needs of the myocardium, minimizing irreversible ischemic cell damage and cell death. Several hypothermic or normothermic MP methods have been developed and studied, particularly in the preclinical setting, but whether MP is superior to SCS remains controversial. Other approaches seem to be interesting for extending the pool of heart graft donors, such as blocking the paths of apoptosis and necrosis, extracellular vesicle therapy, or donor heart-specific gene therapy. In this systematic review, we summarize the mechanisms involved in IRI during heart transplantation and existing targeting therapies. We also critically evaluate all available data on continuous ex situ perfusion devices for adult donor hearts, highlighting its therapeutic potential and current limitations and shortcomings.

11.
J Agric Food Chem ; 71(48): 19088-19100, 2023 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-37972931

RESUMO

Glycans have been proven to play special roles in keeping human health as a class of nutritional and bioactive ingredients in many food materials. However, their broad use in the food industry is hindered by the lack of comprehensive analytical methods for high-quality food glycomics studies and large-quantity raw materials for their production. This study focuses on structural identification and quantitative comparison of bioactive N-glycans in seven species of livestock and poultry plasma as potential natural glycan resources by a novel comprehensive relative quantification strategy based on stable isotope labeling with nondeuterated and deuterated 4-methyl-1-(2-hydrazino-2-oxoethyl)-pyridinium bromide (d0/d7-HMP) in combination with linkage-specific derivatization of sialic acid residues. Methodological validation of the method in terms of detection sensitivity, signal resolution, quantification linearity, precision, and accuracy on model neutral and complicated sialylated glycans demonstrated its advantages over the existing methods. Based on this method, a series of bioactive N-glycans were found in seven species of livestock and poultry plasma, and their differences in structure, abundance percentages, and relative contents of N-glycans were revealed, demonstrating their excellent applicability for comprehensive food glycomics analysis and great exploitation potential of these plasma samples as large-quantity raw materials in producing bioactive N-glycans for application in food and pharmaceutical industries.


Assuntos
Gado , Aves Domésticas , Animais , Humanos , Polissacarídeos/química , Ácido N-Acetilneuramínico , Glicômica/métodos
12.
Int J Mol Sci ; 24(17)2023 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-37686444

RESUMO

Poor tendon-bone interface (TBI) integration is one of the major causes contributing to unsatisfactory healing quality in patients after anterior cruciate ligament (ACL) reconstruction. Type H vessels have been recently found to closely modulate bone formation via regulation of the osteo-angiogenic crosstalk, so the strategies favoring type H vessel formation may be promising therapeutic approaches for improved graft osteointegration. In this study, we reported for the first time the treatment outcome of slit guidance ligand 3 (slit3), a novel proangiogenic factor favoring type H vessel formation, in TBI healing in mice with ACL reconstruction. The mice (n = 87) were divided into three groups for various treatments: hydrogel microparticles (HMP, control group), slit3@HMP, and slit3 neutralizing antibody@HMP (slit3-AB@HMP). Histological analysis, gait performance, radiographic measurement, and biomechanical testing were performed to assess the TBI healing quality. Increased bony ingrowth and reduced fibrous scar tissue was formed at the TBI in the slit3@HMP group when compared to the HMP group. Meanwhile, the slit3-AB@HMP inhibited the osseous ingrowth and increased fibrous scar tissue formation relative to the HMP group. Compared to the HMP group, the slit3@HMP favored type H vessel formation at the TBI while the slit3-AB@HMP impeded it. According to micro-CT assessment, compared to the HMP group, the slit3@HMP significantly increased the peri-tunnel bone mass while the slit3-AB@HMP significantly reduced the peri-tunnel bone mass. The mice in the slit3@HMP group showed the best gait performance in terms of stance time, stride length, paw print area, and stance pressure. Dynamic laxity measurement and tensile testing showed the slit3@HMP group exhibited significantly reduced laxity displacement and improved failure load and stiffness relative to the other two groups. Collectively, the injection of slit3 could be used to enhance tendon-bone integration, which may be ascribed to modulation of angiogenesis-osteogenesis crosstalk coupled by type H vessels.


Assuntos
Cicatriz , Hidrogéis , Animais , Camundongos , Ligantes , Osso e Ossos/diagnóstico por imagem , Tendões
13.
Free Radic Biol Med ; 205: 90-99, 2023 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-37253411

RESUMO

Nitric oxide (·NO) is a prevalent antimicrobial that is known to damage iron-containing enzymes in amino acid (AA) biosynthesis pathways. With Escherichia coli, ·NO is detoxified in aerobic environments by Hmp, which is an enzyme that is synthesized de novo in response to ·NO. With this knowledgebase, it is expected that the availability of AAs in the extracellular environment would enhance ·NO detoxification, because AAs would foster translation of Hmp. However, we observed that ·NO detoxification by E. coli was far slower in populations grown and treated in the presence of AAs (AA+) in comparison to those grown and stressed in the absence of AAs (AA-). Further experiments revealed that AA+ populations had difficulty translating proteins under ·NO stress, and that ·NO activated the stringent response in AA+ populations. Additional work revealed significant ATP depletion in ·NO-stressed AA+ cultures that far exceeded that of ·NO-stressed AA- populations. Transcription, translation, and RelA were not found to be significant contributors to the ATP depletion observed, whereas AA import was implicated as a significant ATP consumption pathway. Alleviating ATP depletion while maintaining access to AAs partially restored ·NO detoxification, which suggested that ATP depletion contributed to the translational difficulties observed in ·NO-stressed AA+ populations. These data reveal an unexpected interaction within the ·NO response network of E. coli that stimulates a stringent response by RelA in conditions where AAs are plentiful.


Assuntos
Proteínas de Escherichia coli , Hemeproteínas , Escherichia coli/genética , Escherichia coli/metabolismo , Óxido Nítrico/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Aminoácidos/metabolismo , NADH NADPH Oxirredutases/metabolismo , Hemeproteínas/metabolismo , Di-Hidropteridina Redutase/metabolismo , Trifosfato de Adenosina/metabolismo
14.
Cells ; 12(7)2023 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-37048168

RESUMO

Heavy metal-associated proteins (HMPs) participate in heavy metal detoxification. Although HMPs have been identified in several plants, no studies to date have identified the HMPs in Brassica rapa (B. rapa). Here, we identified 85 potential HMPs in B. rapa by bioinformatic methods. The promoters of the identified genes contain many elements associated with stress responses, including response to abscisic acid, low-temperature, and methyl jasmonate. The expression levels of BrHMP14, BrHMP16, BrHMP32, BrHMP41, and BrHMP42 were upregulated under Cu2+, Cd2+, Zn2+, and Pb2+ stresses. BrHMP06, BrHMP30, and BrHMP41 were also significantly upregulated after drought treatment. The transcripts of BrHMP06 and BrHMP11 increased mostly under cold stress. After applying salt stress, the expression of BrHMP02, BrHMP16, and BrHMP78 was induced. We observed increased BrHMP36 expression during the self-incompatibility (SI) response and decreased expression in the compatible pollination (CP) response during pollen-stigma interactions. These changes in expression suggest functions for these genes in HMPs include participating in heavy metal transport, detoxification, and response to abiotic stresses, with the potential for functions in sexual reproduction. We found potential co-functional partners of these key players by protein-protein interaction (PPI) analysis and found that some of the predicted protein partners are known to be involved in corresponding stress responses. Finally, phosphorylation investigation revealed many phosphorylation sites in BrHMPs, suggesting post-translational modification may occur during the BrHMP-mediated stress response. This comprehensive analysis provides important clues for the study of the molecular mechanisms of BrHMP genes in B. rapa, especially for abiotic stress and pollen-stigma interactions.


Assuntos
Brassica rapa , Brassica rapa/genética , Brassica rapa/metabolismo , Polinização , Estresse Fisiológico/genética , Estresse Salino , Pólen
15.
J Clin Exp Hepatol ; 13(2): 335-349, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36950485

RESUMO

The acceptance of liver transplantation as the standard of care for end-stage liver diseases has led to a critical shortage of donor allografts. To expand the donor organ pool, many countries have liberalized the donor criteria including extended criteria donors and donation after circulatory death. These marginal livers are at a higher risk of injury when they are preserved using the standard static cold storage (SCS) preservation techniques. In recent years, research has focused on optimizing organ preservation techniques to protect these marginal livers. Machine perfusion (MP) of the expanded donor liver has witnessed considerable advancements in the last decade. Research has showed MP strategies to confer significant advantages over the SCS techniques, such as longer preservation times, viability assessment and the potential to recondition high risk allografts prior to implantation. In this review article, we address the topic of MP in liver allograft preservation, with emphasis on current trends in clinical application. We discuss the relevant clinical trials related to the techniques of hypothermic MP, normothermic MP, hypothermic oxygenated MP, and controlled oxygenated rewarming. We also discuss the potential applications of ex vivo therapeutics which may be relevant in the future to further optimize the allograft prior to transplantation.

16.
Metabolites ; 13(3)2023 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-36984891

RESUMO

2-hydroxybutyric acid (2HB) serves as an important regulatory factor in a variety of diseases. The circulating level of 2HB in serum is significantly higher in multiple diseases, such as cancer and type 2 diabetes (T2D). However, there is currently no systematic study on 2HB-producing bacteria that demonstrates whether gut bacteria contribute to the circulating 2HB pool. To address this question, we used BLASTP to reveal the taxonomic profiling of 2HB-producing bacteria in the human microbiome, which are mainly distributed in the phylum Proteobacteria and Firmicutes. In vitro experiments showed that most gut bacteria (21/32) have at least one path to produce 2HB, which includes Aspartic acid, methionine, threonine, and 2-aminobutyric acid. Particularly, Fusobacterium nucleatum has the strongest ability to synthesize 2HB, which is sufficient to alter colon 2HB concentration in mice. Nevertheless, neither antibiotic (ABX) nor Fusobacterium nucleatum gavage significantly affected mouse serum 2HB levels during the time course of this study. Taken together, our study presents the profiles of 2HB-producing bacteria and demonstrates that gut microbiota was a major contributor to 2HB concentration in the intestinal lumen but a relatively minor contributor to serum 2HB concentration.

17.
J Clin Med ; 12(3)2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36769557

RESUMO

While adoption of machine perfusion technologies into clinical practice in the United States has been much slower than in Europe, recent changes in the transplant landscape as well as device availability following FDA approval have paved the way for rapid growth. Machine perfusion may provide one mechanism to maximize the utilization of potential donor liver grafts. Indeed, multiple studies have shown increased organ utilization with the implementation of technologies such as ex-situ normothermic machine perfusion (NMP), ex-situ hypothermic machine perfusion (HMP) and in-situ normothermic regional perfusion (NRP). The current review describes the history and development of machine perfusion utilization in the Unites States along with future directions. It also describes the differences in landscape between Europe and the United States and how this has shaped clinical application of these technologies.

18.
Gels ; 10(1)2023 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-38247752

RESUMO

Hydrogel microparticles (HMPs) stand out as promising entities in the realm of bone tissue regeneration, primarily due to their versatile capabilities in delivering cells and bioactive molecules/drugs. Their significance is underscored by distinct attributes such as injectability, biodegradability, high porosity, and mechanical tunability. These characteristics play a pivotal role in fostering vasculature formation, facilitating mineral deposition, and contributing to the overall regeneration of bone tissue. Fabricated through diverse techniques (batch emulsion, microfluidics, lithography, and electrohydrodynamic spraying), HMPs exhibit multifunctionality, serving as vehicles for drug and cell delivery, providing structural scaffolding, and functioning as bioinks for advanced 3D-printing applications. Distinguishing themselves from other scaffolds like bulk hydrogels, cryogels, foams, meshes, and fibers, HMPs provide a higher surface-area-to-volume ratio, promoting improved interactions with the surrounding tissues and facilitating the efficient delivery of cells and bioactive molecules. Notably, their minimally invasive injectability and modular properties, offering various designs and configurations, contribute to their attractiveness for biomedical applications. This comprehensive review aims to delve into the progressive advancements in HMPs, specifically for bone regeneration. The exploration encompasses synthesis and functionalization techniques, providing an understanding of their diverse applications, as documented in the existing literature. The overarching goal is to shed light on the advantages and potential of HMPs within the field of engineering bone tissue.

19.
Front Transplant ; 2: 1060992, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38993918

RESUMO

Thoracic organ transplantation, including lung, heart, and heart-lung transplants are highly regarded as gold standard treatments for patients suffering from heart failure or chronic end stage lung conditions. The relatively high prevalence of conditions necessitating thoracic organ transplants combined with the lack of available organs has resulted in many either dying or becoming too ill to receive a transplant while on the waiting list. There is a dire need to increase both the number of organs available and the utilization of such organs. Improved preservation techniques beyond static storage have shown great potential to lengthen the current period of viability of thoracic organs while outside the body, promising better utilization rates, increased donation distance, and improved matching of donors to recipients. Ex-situ organ perfusion (ESOP) can also make some novel therapeutic strategies viable, and the combination of the ESOP platform with such reconditioning therapies endeavors to better improve functional preservation of organs in addition to making more organs viable for transplantation. Given the abundance of clinical and pre-clinical studies surrounding reconditioning of thoracic organs in combination with ESOP, we summarize in this review important concepts and research regarding thoracic organ machine perfusion in combination with reconditioning therapies.

20.
Antibiotics (Basel) ; 11(8)2022 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-36009913

RESUMO

In order to improve the anticaries effects of fluoridated products, the supplementation of these products has been considered a promising alternative for caries control. This study evaluated the effects of sodium hexametaphosphate (HMP) and/or fluoride (F) on the inorganic components and pH of Streptococcus mutans and Candida albicans dual-species biofilms. The biofilms were treated 72, 78, and 96 h after the beginning of their formation with 0.25, 0.5, or 1% HMP-containing solutions with or without F (500 ppm, as sodium fluoride). F-containing solutions (500 ppm and 1100 ppm) and artificial saliva were used as controls. The biofilms were exposed to a 20% sucrose solution after the third treatment. Along with the biofilm pH, the concentrations of F, calcium, phosphorus (P), and HMP were determined. HMP, combined with F, increased F levels and decreased P levels in the biofilm fluid compared to that of the solution with 500 ppm F. Exposure to sucrose decreased the concentrations of all ions in the biomass, except for HMP; 1% HMP, combined with F, promoted the highest pH. It can be concluded that HMP affected the inorganic composition of the biofilm and exerted a buffering effect on the biofilm pH.

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