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1.
Aging Cell ; 23(2): e14032, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38010905

RESUMO

Cell-based therapies are essential for tissue regeneration and wound healing during aging. Autologous transplantation of aging cells is ineffective due to their increased senescence and reduced tissue remodeling capabilities. Alternatively, implanting reprogrammed aged cells provides unique opportunities. In this paper, we demonstrate the implantation of partially reprogrammed aged human dermal fibroblasts into in vitro aged skin models for tissue regeneration and wound healing. The partially reprogrammed cells were obtained using our previously reported, highly efficient mechanical approach. Implanted cells showed enhanced expression of extracellular matrix proteins in the large area of aged tissue. In addition, the implanted cells at wound sites showed increased extracellular matrix protein synthesis and matrix alignment. Transcriptome analysis, combined with chromatin biomarkers, revealed these implanted cells upregulated tissue regeneration and wound healing pathways. Collectively our results provide a novel, nongenetic, partial reprogramming of aged cells for cell-based therapies in regenerative medicine.


Assuntos
Pele , Cicatrização , Humanos , Proliferação de Células , Pele/metabolismo , Matriz Extracelular/metabolismo , Fibroblastos/metabolismo
2.
Sci Rep ; 12(1): 17318, 2022 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-36243826

RESUMO

Long-term sustained mechano-chemical signals in tissue microenvironment regulate cell-state transitions. In recent work, we showed that laterally confined growth of fibroblasts induce dedifferentiation programs. However, the molecular mechanisms underlying such mechanically induced cell-state transitions are poorly understood. In this paper, we identify Lef1 as a critical somatic transcription factor for the mechanical regulation of de-differentiation pathways. Network optimization methods applied to time-lapse RNA-seq data identify Lef1 dependent signaling as potential regulators of such cell-state transitions. We show that Lef1 knockdown results in the down-regulation of fibroblast de-differentiation and that Lef1 directly interacts with the promoter regions of downstream reprogramming factors. We also evaluate the potential upstream activation pathways of Lef1, including the Smad4, Atf2, NFkB and Beta-catenin pathways, thereby identifying that Smad4 and Atf2 may be critical for Lef1 activation. Collectively, we describe an important mechanotransduction pathway, including Lef1, which upon activation, through progressive lateral cell confinement, results in fibroblast de-differentiation.


Assuntos
Mecanotransdução Celular , beta Catenina , Diferenciação Celular/genética , Fator 1 de Ligação ao Facilitador Linfoide/genética , Fator 1 de Ligação ao Facilitador Linfoide/metabolismo , Transdução de Sinais , Fatores de Transcrição/metabolismo , beta Catenina/genética , beta Catenina/metabolismo
3.
Eur J Med Chem ; 241: 114614, 2022 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-35939994

RESUMO

Microtubules (MTs) are dynamic filaments of the cytoskeleton, which are formed by the polymerization of their building block tubulin. Perturbation of MT dynamics by MT-targeting agents (MTAs) leads to cell cycle arrest or cell death, a strategy that is pursued in chemotherapy. We recently performed a combined computational and crystallographic fragment screening approach and identified several tubulin-binding fragments. Here, we sought to capitalize on this study with the aim to demonstrate that low affinity tubulin-binding fragments can indeed be used as valuable starting points for the development of active, lead-like antitubulin small molecules. To this end, we report on a new, rationally designed series of 2-aminobenzimidazole derivatives that destabilize MTs by binding tubulin at the colchicine-binding site (CBS). We applied a fragment growing strategy by combining X-ray crystallography and computer-aided drug design. Preliminary structure-activity-relationship studies afforded compound 18 that inhibits HeLa cell viability with a submicromolar activity (IC50 of 0.9 µM). X-ray crystallography confirmed the compound pose in the CBS, while immunostaining experiments suggested a molecular mechanism of action alike classical CBS ligands with antimitotic and antitumor activity associated with MTs destabilization. This promising outcome underpins that our previously performed combined computational and crystallographic fragment screening approach provides promising starting points for developing new MTAs binding to the CBS of tubulin and, eventually, to further tubulin pockets.


Assuntos
Antineoplásicos , Colchicina , Antineoplásicos/química , Sítios de Ligação , Proliferação de Células , Colchicina/metabolismo , Células HeLa , Humanos , Microtúbulos/metabolismo , Relação Estrutura-Atividade , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/química
4.
Angew Chem Int Ed Engl ; 61(25): e202204052, 2022 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-35404502

RESUMO

In this study, we capitalized on our previously performed crystallographic fragment screen and developed the antitubulin small molecule Todalam with only two rounds of straightforward chemical synthesis. Todalam binds to a novel tubulin site, disrupts microtubule networks in cells, arrests cells in G2/M, induces cell death, and synergizes with vinblastine. The compound destabilizes microtubules by acting as a molecular plug that sterically inhibits the curved-to-straight conformational switch in the α-tubulin subunit, and by sequestering tubulin dimers into assembly incompetent oligomers. Our results describe for the first time the generation of a fully rationally designed small molecule tubulin inhibitor from a fragment, which displays a unique molecular mechanism of action. They thus demonstrate the usefulness of tubulin-binding fragments as valuable starting points for innovative antitubulin drug and chemical probe discovery campaigns.


Assuntos
Moduladores de Tubulina , Tubulina (Proteína) , Morte Celular , Microtúbulos/metabolismo , Ligação Proteica , Tubulina (Proteína)/química , Moduladores de Tubulina/química
5.
J Shoulder Elbow Surg ; 31(1): 8-16, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34587534

RESUMO

BACKGROUND: Gamification has become increasingly popular in rehabilitation and is viewed as a tool to improve patient activation, motivation, and engagement. The aim of this study was to compare the efficacy of validated exergames played through a system using "depth sensor" and bespoke software against standard physiotherapy in patients treated with arthroscopic shoulder surgery. This included the following common conditions: subacromial impingement syndrome, calcific tendinopathy, and rotator cuff tear. METHODS: Following arthroscopic shoulder surgery, patients were randomized into 1 of 2 groups: In the standard rehabilitation group, patients were followed up for 12 weeks after surgery with standard postoperative physiotherapy and underwent electronic measurements of their active range of movement (ROM). In the exergame group, patients followed a postoperative regimen of exergames using the principles of gamification with physiotherapy support. Patients were given an exergame schedule prescribed by their therapist on Medical Interactive Recovery Assistant (MIRA) software (MIRA Rehab, London, UK) paired with a Microsoft Kinect sensor (Microsoft, Redmond, WA, USA). The primary outcome was active ROM objectively measured by MIRA and Kinect. Secondary outcome measures included the Oxford Shoulder Score, the Disabilities of the Arm, Shoulder and Hand score, and the EQ-VAS score at 12 weeks after surgery. RESULTS: A total of 71 patients were recruited to the study. We excluded 7 patients based on intraoperative findings. Thirty-three patients were treated with exergames, and 31 patients underwent conventional physiotherapy. There was no significant difference between the 2 groups in baseline ROM. Postoperatively, there was no significant difference in any of the cardinal planes of movement (forward flexion, P = .64; abduction, P = .33; and external rotation, P = .75). The mean Oxford Shoulder Score improved from 29.25 to 38.2 in the control group (P = .001) and from 27.1 to 35.1 in the trial group (P = .01); there was no significant difference between the groups at 12 weeks (P = .246). The mean Disabilities of the Arm, Shoulder and Hand score improved from 38.13 to 16.98 in the control group (P = .001) and from 42.3 to 22.54 in the trial group (P = .007); there was no significant difference between the 2 groups (P = .328). There was no significant difference in the EQ-VAS score in either group at any time point (P = .5866). CONCLUSION: This randomized controlled trial demonstrates that exergames can be used effectively in the rehabilitation of patients following arthroscopic shoulder surgery. Outcomes, judged by ROM and patient-reported outcome measures, are equivalent to conventional physiotherapy rehabilitation protocols. This health care innovation has the potential to relieve some of the heavy burden placed on physiotherapy departments for "routine" postoperative care in shoulder surgery.


Assuntos
Jogos Eletrônicos de Movimento , Lesões do Manguito Rotador , Artroscopia , Gamificação , Humanos , Amplitude de Movimento Articular , Manguito Rotador/cirurgia , Lesões do Manguito Rotador/cirurgia , Ombro , Resultado do Tratamento
6.
Proc Natl Acad Sci U S A ; 117(19): 10131-10141, 2020 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-32350144

RESUMO

Over the course of the aging process, fibroblasts lose contractility, leading to reduced connective-tissue stiffness. A promising therapeutic avenue for functional rejuvenation of connective tissue is reprogrammed fibroblast replacement, although major hurdles still remain. Toward this, we recently demonstrated that the laterally confined growth of fibroblasts on micropatterned substrates induces stem-cell-like spheroids. In this study, we embedded these partially reprogrammed spheroids in collagen-I matrices of varying densities, mimicking different three-dimensional (3D) tissue constraints. In response to such matrix constraints, these spheroids regained their fibroblastic properties and sprouted to form 3D connective-tissue networks. Interestingly, we found that these differentiated fibroblasts exhibit reduced DNA damage, enhanced cytoskeletal gene expression, and actomyosin contractility. In addition, the rejuvenated fibroblasts show increased matrix protein (fibronectin and laminin) deposition and collagen remodeling compared to the parental fibroblast tissue network. Furthermore, we show that the partially reprogrammed cells have comparatively open chromatin compaction states and may be more poised to redifferentiate into contractile fibroblasts in 3D-collagen matrix. Collectively, our results highlight efficient fibroblast rejuvenation through laterally confined reprogramming, which has important implications in regenerative medicine.


Assuntos
Diferenciação Celular , Reprogramação Celular , Fibroblastos/citologia , Medicina Regenerativa , Rejuvenescimento/fisiologia , Idoso , Animais , Proliferação de Células , Células Cultivadas , Colágeno Tipo I/metabolismo , Matriz Extracelular/metabolismo , Fibroblastos/metabolismo , Fibronectinas/metabolismo , Humanos , Laminina/metabolismo , Camundongos , Células NIH 3T3 , Esferoides Celulares/citologia , Esferoides Celulares/metabolismo
7.
Qual Health Res ; 29(14): 2057-2069, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31154898

RESUMO

The NHS routinely evaluates the quality of life of patients receiving hip or knee replacement surgery using patient-reported outcome measures (PROMs), but some hospital completion rates are only 30%, restricting data usefulness. Statistics limit insights into how and why data are missing, so qualitative methods were used to explore this issue. Observation periods preceded semistructured interviews with 34 preoperative patients attending an orthopedic outpatient clinic. Interview themes covered: completion time/timing, orientation, setting, measures, and practicalities. Triangulated against observations, pragmatic barriers, and facilitators were considered. Refined themes included completion conditions, patient support, and national delivery. Simple improvements (e.g., quiet zone) could improve completion rates and reducing missing data. Reorganizing preoperative leaflets and their systematic distribution via standardized procedures could reassure patients, enhancing PROMs acceptance, while reducing inquiries and subsequent staff burden. Findings have implications for interpreting national statistics. They indicate that further debate about mandating preoperative PROMs is due.


Assuntos
Procedimentos Ortopédicos/psicologia , Medidas de Resultados Relatados pelo Paciente , Adulto , Idoso , Idoso de 80 Anos ou mais , Artroplastia de Quadril/psicologia , Artroplastia de Quadril/normas , Artroplastia do Joelho/psicologia , Artroplastia do Joelho/normas , Atitude Frente a Saúde , Feminino , Humanos , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Procedimentos Ortopédicos/normas , Qualidade da Assistência à Saúde , Qualidade de Vida , Reino Unido
8.
Med Biol Eng Comput ; 57(4): 819-835, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30415434

RESUMO

Low-intensity therapeutic ultrasound has demonstrated an impetus in bone signaling and tissue healing for decades now. Though this technology is clinically well proven, still there are breaches in studies to understand the fundamental principle of how osteoblast tissue regenerates physiologically at the cellular level with ultrasound interaction as a form of acoustic wave stimuli. Through this article, we illustrate an analysis for cytomechanical changes of cell membrane periphery as a basic first physical principle for facilitating late downstream biochemical pathways. With the help of in situ single-cell direct analysis in a microfluidic confinement, we demonstrate that alteration of low-intensity pulse ultrasound (LIPUS) frequency would physically perturb cell membrane and establish inherent cell oscillation. We experimentally demonstrate here that, at LIPUS resonance near 1.7 MHz (during 1-3 MHz alteration), cell membrane area would expand to 6.85 ± 0.7% during ultrasound exposure while it contracts 44.68 ± 0.8% in post actuation. Conversely, cell cross-sectional area change (%) from its previous morphology during and after switching off LIPUS was reversibly different before and after resonance. For instance, at 1.5 MHz, LIPUS exposure produced 1.44 ± 0.5% expansion while in contrast 2 MHz instigates 1.6 ± 0.3% contraction. We conclude that alteration of LIPUS frequency from 1-3 MHz keeping other ultrasound parameters like exposure time, pulse repetition frequency (PRF), etc., constant, if applied to a microconfined biological single living cell, would perturb physical structure reversibly based on the system resonance during and post exposure ultrasound pulsing. We envision, in the near future, our results would constitute the foundation of mechanistic effects of low-intensity therapeutic ultrasound and its allied potential in medical applications. Graphical Abstract Frequency Dependent Characterization of Area Strain in Cell Membrane by Microfluidic Based Single Cell Analysis.


Assuntos
Forma Celular , Células/citologia , Actinas/metabolismo , Fenômenos Biomecânicos , Linhagem Celular Tumoral , Tamanho Celular , Citoesqueleto/metabolismo , Humanos , Fatores de Tempo , Ultrassom
9.
Proc Natl Acad Sci U S A ; 115(21): E4741-E4750, 2018 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-29735717

RESUMO

Cells in tissues undergo transdifferentiation programs when stimulated by specific mechanical and biochemical signals. While seminal studies have demonstrated that exogenous biochemical factors can reprogram somatic cells into pluripotent stem cells, the critical roles played by mechanical signals in such reprogramming process have not been well documented. In this paper, we show that laterally confined growth of fibroblasts on micropatterned substrates induces nuclear reprogramming with high efficiency in the absence of any exogenous reprogramming factors. We provide compelling evidence on the induction of stem cell-like properties using alkaline phosphatase assays and expression of pluripotent markers. Early onset of reprogramming was accompanied with enhanced nuclear dynamics and changes in chromosome intermingling degrees, potentially facilitating rewiring of the genome. Time-lapse analysis of promoter occupancy by immunoprecipitation of H3K9Ac chromatin fragments revealed that epithelial, proliferative, and reprogramming gene promoters were progressively acetylated, while mesenchymal promoters were deacetylated by 10 days. Consistently, RNA sequencing analysis showed a systematic progression from mesenchymal to stem cell transcriptome, highlighting pathways involving mechanisms underlying nuclear reprogramming. We then demonstrated that these mechanically reprogrammed cells could be maintained as stem cells and can be redifferentiated into multiple lineages with high efficiency. Importantly, we also demonstrate the induction of cancer stemness properties in MCF7 cells grown in such laterally confined conditions. Collectively, our results highlight an important generic property of somatic cells that, when grown in laterally confined conditions, acquire stemness. Such mechanical reprogramming of somatic cells demonstrated here has important implications in tissue regeneration and disease models.


Assuntos
Neoplasias da Mama/genética , Linhagem da Célula , Reprogramação Celular , Cromatina/genética , Células-Tronco Pluripotentes Induzidas/citologia , Transcriptoma , Animais , Transdiferenciação Celular , Epigênese Genética , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Células-Tronco Pluripotentes Induzidas/fisiologia , Camundongos , Células NIH 3T3 , Células Tumorais Cultivadas
10.
J Orthop ; 15(1): 239-241, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29657476

RESUMO

OBJECTIVE: We aimed to assess the effectiveness of PRP injections in lateral epicondylitis of the elbow as it was felt after PRP introduction the numbers of patients requiring surgery for had reduced. METHODS: We conducted a retrospective review of cases from the 1st January 2008 to 31st December 2015. The numbers of patients undergoing surgical release and the numbers of patients requiring PRP injections were recorded each year and the numbers of patients requiring surgery was compared pre and post PRP injection to ascertain if PRP introduction reduced surgical intervention. RESULTS: Prior to PRP, a yearly mean of 12.75 patients underwent surgery, since PRP this reduced to 4.25 patients, P < 0.001. This leads to an absolute risk reduction of 0.773 and number needed to treat of 1.3. PRP injection successfully reduced symptoms in 56/64 (87.5%) patients in our study. CONCLUSION: We consider PRP injection, for intractable lateral epicondylitis of the elbow, not only a safe but also very effective tool in reducing symptoms and have shown it has reduced the need for surgical intervention in this difficult cohort of patients.

11.
J Shoulder Elbow Surg ; 26(12): e382-e389, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28865963

RESUMO

BACKGROUND: This study compared the accuracy of measuring shoulder range of movement (ROM) with a simple laptop-sensor combination vs. trained observers (shoulder physiotherapists and shoulder surgeons) using motion capture (MoCap) laboratory equipment as the gold standard. METHODS: The Microsoft Kinect sensor (Microsoft Corp., Redmond, WA, USA) tracks 3-dimensional human motion. Ordinarily used with an Xbox (Microsoft Corp.) video game console, Medical Interactive Recovery Assistant (MIRA) software (MIRA Rehab Ltd., London, UK) allows this small sensor to measure shoulder movement with a standard computer. Shoulder movements of 49 healthy volunteers were simultaneously measured by trained observers, MoCap, and the MIRA device. Internal rotation was assessed with the shoulder abducted 90° and external rotation with the shoulder adducted. Visual estimation and MIRA measurements were compared with gold standard MoCap measurements for agreement using Bland-Altman methods. RESULTS: There were 1670 measurements analyzed. The MIRA evaluations of all 4 cardinal shoulder movements were significantly more precise, with narrower limits of agreement, than the measurements of trained observers. MIRA achieved ±11° (95% confidence interval [CI], 8.7°-12.6°) for forward flexion vs. ±16° (95% CI, 14.6°-17.6°) by trained observers. For abduction, MIRA showed ±11° (95% CI, 8.7°-12.8°) against ±15° (95% CI, 13.4°-16.2°) for trained observers. MIRA attained ±10° (95% CI, 8.1°-11.9°) during external rotation measurement, whereas trained observers only reached ±21° (95% CI, 18.7°-22.6°). For internal rotation, MIRA achieved ±9° (95% CI, 7.2°-10.4°), which was again better than TOs at ±18° (95% CI, 16.0°-19.3°). CONCLUSIONS: A laptop combined with a Microsoft Kinect sensor and the MIRA software can measure shoulder movements with acceptable levels of accuracy. This technology, which can be easily set up, may also allow precise shoulder ROM measurement outside the clinic setting.


Assuntos
Amplitude de Movimento Articular , Articulação do Ombro/fisiologia , Software , Adulto , Feminino , Humanos , Masculino , Microcomputadores , Movimento , Observação , Reprodutibilidade dos Testes , Rotação
12.
Mol Carcinog ; 56(2): 389-401, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27182794

RESUMO

Abrus agglutinin (AGG), a type II ribosome-inactivating protein has been found to induce mitochondrial apoptosis. In the present study, we documented that AGG-mediated Akt dephosphorylation led to ER stress resulting the induction of autophagy-dependent cell death through the canonical pathway in cervical cancer cells. Inhibition of autophagic death with 3-methyladenine (3-MA) and siRNA of Beclin-1 and ATG5 increased AGG-induced apoptosis. Further, inhibiting apoptosis by Z-DEVD-FMK and N-acetyl cysteine (NAC) increased autophagic cell death after AGG treatment, suggesting that AGG simultaneously induced autophagic and apoptotic death in HeLa cells. Additionally, it observed that AGG-induced autophagic cell death in Bax knock down (Bax-KD) and 5-FU resistant HeLa cells, confirming as an alternate cell killing pathway to apoptosis. At the molecular level, AGG-induced ER stress in PERK dependent pathway and inhibition of ER stress by salubrinal, eIF2α phosphatase inhibitor as well as siPERK reduced autophagic death in the presence of AGG. Further, our in silico and colocalization study showed that AGG interacted with pleckstrin homology (PH) domain of Akt to suppress its phosphorylation and consequent downstream mTOR dephosphorylation in HeLa cells. We showed that Akt overexpression could not augment GRP78 expression and reduced autophagic cell death by AGG as compared to pcDNA control, indicating Akt modulation was the upstream signal during AGG's ER stress mediated autophagic cell death. In conclusion, we established that AGG stimulated cell death by autophagy might be used as an alternative tumor suppressor mechanism in human cervical cancer. © 2016 Wiley Periodicals, Inc.


Assuntos
Antineoplásicos/farmacologia , Autofagia/efeitos dos fármacos , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Lectinas de Plantas/farmacologia , Domínios de Homologia à Plecstrina/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Inativadoras de Ribossomos Tipo 2/farmacologia , Abrus/química , Antineoplásicos/isolamento & purificação , Chaperona BiP do Retículo Endoplasmático , Feminino , Células HeLa , Humanos , Modelos Moleculares , Lectinas de Plantas/isolamento & purificação , Proteínas Proto-Oncogênicas c-akt/química , Proteínas Inativadoras de Ribossomos Tipo 2/isolamento & purificação , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/patologia , eIF-2 Quinase/metabolismo
13.
Mater Sci Eng C Mater Biol Appl ; 58: 648-58, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26478356

RESUMO

The present study delineates the synthesis and characterization of cobalt doped proangiogenic-osteogenic hydroxyapatite. Hydroxyapatite samples, doped with varying concentrations of bivalent cobalt (Co(2+)) were prepared by the ammoniacal precipitation method and the extent of doping was measured by ICP-OES. The crystalline structure of the doped hydroxyapatite samples was confirmed by XRD and FTIR studies. Analysis pertaining to the effect of doped hydroxyapatite on cell cycle progression and proliferation of MG-63 cells revealed that the doping of cobalt supported the cell viability and proliferation up to a threshold limit. Furthermore, such level of doping also induced differentiation of the bone cells, which was evident from the higher expression of differentiation markers (Runx2 and Osterix) and better nodule formation (SEM study). Western blot analysis in conjugation with ELISA study confirmed that the doped HAp samples significantly increased the expression of HIF-1α and VEGF in MG-63 cells. The analysis described here confirms the proangiogenic-osteogenic properties of the cobalt doped hydroxyapatite and indicates its potential application in bone tissue engineering.


Assuntos
Materiais Biocompatíveis/química , Cobalto/química , Durapatita/química , Osteogênese/efeitos dos fármacos , Engenharia Tecidual/métodos , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/toxicidade , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Durapatita/farmacologia , Hemólise/efeitos dos fármacos , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo
14.
J Control Release ; 214: 62-75, 2015 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-26160306

RESUMO

Anticancer treatment using embolic drug-eluting beads (DEBs) has shown multifarious advantages compared to systemic chemotherapy. However, there is a growing need for a better understanding of the physical parameters governing drug-elution from embolic devices under physiologically relevant fluidic conditions. In the present study, we investigated the spatiotemporal dynamics of doxorubicin hydrochloride elution from drug-loaded hydrogel embolic beads within a microfluidic device consisting of a network of interconnected microchannels which replicates the architectural properties of microvascular systems. Drug-elution has been investigated experimentally at a single-bead level, using in-house developed microscopy- and spectrofluorimetry-based methods. Results demonstrated that the kinetics of drug-elution and the amount of eluted drug strongly depended on the location of the embolic event within the embolised channel (e.g. fractional amount of eluted drug after 3h was equal to ~0.2 and ~0.6 for completely-confined and partially-confined bead, respectively). Drug-elution from partially-confined bead showed a counterintuitive dependence on the local Reynolds number (and thus on the mean fluid velocity), as a result of dynamic changes in bead compressibility causing the displacement of the bead from the primary embolic site. Conversely, the kinetics of drug-elution from fully-confined bead was less affected by the local Reynolds number and bead displayed faster elution from the surface area exposed to the systemic flow, which was associated with the formation of fluid eddies nearby the bead post embolisation.


Assuntos
Antibióticos Antineoplásicos/administração & dosagem , Antibióticos Antineoplásicos/química , Quimioembolização Terapêutica/métodos , Doxorrubicina/administração & dosagem , Doxorrubicina/química , Algoritmos , Capilares/metabolismo , Sistemas de Liberação de Medicamentos , Desenho de Fármacos , Injeções Intravenosas , Cinética , Dispositivos Lab-On-A-Chip , Microfluídica , Microesferas , Modelos Biológicos , Espectrometria de Fluorescência
15.
Carbohydr Polym ; 127: 1-10, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25965450

RESUMO

The therapeutic benefits of glycans have garnered much attention over the last few decades with most studies being reported in 2D cultures or in animal models. The present work is therefore aimed to assess the effects of an immunomodulatory heteroglycan in a 3D milieu. Briefly, HT29 tumor spheroids were incubated with THP-1 macrophages at 1:1 ratio in a culture medium supplemented with immune stimulants such as heteroglycans or LPS. Spheroidal distortion, migration of tumor cells from the periphery of the spheroids and 46% of higher macrophage invasiveness was noted in heteroglycan-treated co-cultures with respect to control cultures. Histological sections of the treated co-cultures revealed the presence of high apoptotic tumor cells in the spheroidal periphery. CD11c and CD68 staining further suggested the predominance of macrophages in the vicinity of the apoptotic tumor cells. Such an in vitro created tissue system may thereby confirm the effectiveness of heteroglycan in activating the immune cells to exhibit tumor cytotoxic properties.


Assuntos
Imunomodulação , Macrófagos/imunologia , Polissacarídeos/imunologia , Esferoides Celulares/imunologia , Animais , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Cocultura , Células HT29 , Humanos , Macrófagos/citologia , Camundongos , Modelos Biológicos , Pleurotus/química , Polissacarídeos/química , Polissacarídeos/isolamento & purificação
16.
Chem Biol Interact ; 222: 97-105, 2014 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-25305377

RESUMO

10kDAGP, a tryptic digest of Abrus precatorius lectin 'Agglutinin' is known to induce apoptosis by mitochondria-dependent pathways in human cervical cancer (HeLa) cells. The present study was focused on deciphering the detailed molecular mechanism of apoptosis induction in vitro by 10kDAGP and also its in vivo therapeutic efficacy. For in vivo model, HeLa cell encapsulated hollow fiber was implanted in Swiss Albino mice and treated with 10kDAGP. Our results showed that 10kDAGP was able to enter the cell within a span of 20min and co-localized with mitochondria after 90min. of incubation. A drastic loss of mitochondrial membrane potential was noted within 6h of 10kDAGP administration along with an increase in ROS generation. ROS further led to symptoms of early apoptosis by deregulating Akt (Protein Kinase B) and activating c-Jun N-terminal Kinase (JNK), p38 Mitogen Activated Protein Kinase (MAPK), p53, and autophagy starting from ∼8h of incubation. Besides in vitro conditions, 10kDAGP activated JNK to mediate cancer cell killing in vivo. Therefore, 10kDAGP can be an excellent therapeutic agent as it can act through different ways in the cellular system. Future studies are directed to screen out active peptides from the pool of peptides and to study whether the mode of action is in synergistic way or in individual forms.


Assuntos
Apoptose/efeitos dos fármacos , Peptídeos/farmacologia , Lectinas de Plantas/farmacologia , Abrus , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Apoptose/fisiologia , Autofagia/efeitos dos fármacos , Células HeLa , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Peptídeos/química , Lectinas de Plantas/química , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteína Supressora de Tumor p53/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
17.
Biomicrofluidics ; 8(3): 034107, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24959308

RESUMO

An on-chip lectin microarray based glycomic approach is employed to identify glyco markers for different gastritis and gastric cancer. Changes in protein glycosylation have impact on biological function and carcinogenesis. These altered glycosylation patterns in serum proteins and membrane proteins of tumor cells can be unique markers of cancer progression and hence have been exploited to diagnose various stages of cancer through lectin microarray technology. In the present work, we aimed to study the alteration of glycan structure itself in different stages of gastritis and gastric cancer thoroughly. In order to perform the study from both serum and tissue glycoproteins in an efficient and high-throughput manner, we indigenously developed and employed lectin microarray integrated on a microfluidic lab-on-a-chip platform. We analyzed serum and gastric biopsy samples from 8 normal, 15 chronic Type-B gastritis, 10 chronic Type-C gastritis, and 6 gastric adenocarcinoma patients and found that the glycoprofile obtained from tissue samples was more distinctive than that of the sera samples. We were able to establish signature glycoprofile for the three disease groups, that were absent in healthy normal individuals. In addition, our findings elucidated certain novel signature glycan expression in chronic gastritis and gastric cancer. In silico analysis showed that glycoprofile of chronic gastritis and gastric adenocarcinoma formed close clusters, confirming the previously hypothesized linkage between them. This signature can be explored further as gastric cancer marker to develop novel analytical tools and obtain in-depth understanding of the disease prognosis.

18.
Chem Biol Interact ; 210: 96-102, 2014 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-24434245

RESUMO

Concanavalin A (Con A), a mannose or glucose specific legume lectin, is well known for its anti-proliferative and cytotoxic effect on different types of cancer cells, through its binding to the membrane receptors leading to a major stimulus for the induction of distinct metabolic responses. Recently it has been also been proved that, Con A induces autophagy in hepatoma cells through internalization and mitochondria mediated pathway involving a mitochondrial interacting protein named Bcl2/E1B-19kDa protein-interacting protein 3 (BNIP3). Through this current endeavor, we propose a membrane associated pathway involved in Con A induced autophagy, taking Human cervical cancer (HeLa) cell as a cancer model. Here, we deciphered the role of membrane mediated phosphatidylinositol 3 kinase (PI3K)/Akt/mTOR (mammalian target of rapamycin) and MEK/Extracellular signal-regulated kinases (ERK) pathway in Con A induced autophagy in HeLa cells. Subsequently, we found that Con A treatment suppresses the PI3K/Akt/mTOR and up regulates the MEK/ERK pathway leading to the activation of autophagy. This study will further help us to understand the mechanism behind the autophagic pathway induced by Con A and simultaneously it will strengthen its effective use as a prospective cancer chemo-therapeutic.


Assuntos
Autofagia/efeitos dos fármacos , Concanavalina A/farmacologia , Sistema de Sinalização das MAP Quinases/fisiologia , Fosfatidilinositol 3-Quinase/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Antineoplásicos/farmacologia , Western Blotting , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Células HeLa , Humanos , Modelos Biológicos
19.
Integr Biol (Camb) ; 6(3): 289-99, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24445362

RESUMO

The dynamic physical microenvironment of bone affects the activity of osteoblast cells, yet little is known about how osteoblast mechanotransduction depends on different features of a dynamic stimulus. Here we investigated the effect of physiologically relevant oscillatory flow shear stress on the calcium mobility in osteoblast cells within a microfluidic platform that mimics the confined environment of bone matrix. We characterized the spatiotemporal evolution of intracellular calcium 'flickers', an important signature of cell activation, in response to steady, pulsatile, and oscillatory shear stress. We found that oscillatory flow induces surprisingly higher flicker activity than other flow types. We could further attribute this phenomenon to the opening of a stretch activated ion channel, namely TRPM7. We also found that localization of TRPM7 within the cholesterol-enriched lipid raft domains of plasma membranes is essential for its activity. Collectively our findings elucidated a candidate mechanism for the flow mediated stimulation of osteoblast cells. They therefore have implications towards unveiling various facets of bone formation and remodelling in healthy and diseased conditions, including bone-metastasis of various cancer types, diabetes, and inflammatory autoimmune diseases.


Assuntos
Cálcio/metabolismo , Osteoblastos/metabolismo , Canais de Cátion TRPM/metabolismo , Matriz Óssea/citologia , Matriz Óssea/metabolismo , Compostos de Boro/farmacologia , Bloqueadores dos Canais de Cálcio/farmacologia , ATPases Transportadoras de Cálcio/antagonistas & inibidores , Linhagem Celular , Microambiente Celular , Inibidores Enzimáticos/farmacologia , Estrenos/farmacologia , Gadolínio/farmacologia , Técnicas de Silenciamento de Genes , Humanos , Líquido Intracelular/metabolismo , Canais Iônicos/metabolismo , Mecanotransdução Celular , Microdomínios da Membrana/metabolismo , Técnicas Analíticas Microfluídicas , Osteoblastos/efeitos dos fármacos , Proteínas Serina-Treonina Quinases , Pirrolidinonas/farmacologia , Estresse Mecânico , Canais de Cátion TRPM/antagonistas & inibidores , Canais de Cátion TRPM/genética , Tapsigargina/farmacologia , Fosfolipases Tipo C/antagonistas & inibidores , Verapamil/farmacologia
20.
Carbohydr Polym ; 94(2): 857-65, 2013 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-23544643

RESUMO

Glucans isolated from various mushroom and mycelia sources are interestingly being studied nowadays as a potent therapeutic agent. The present work was focused on the isolation, characterization and immunomodulatory study of a novel water soluble glucan from the pure mycelia of Pleurotus ostreatus. The extracted glucan was found to have a high molecular weight of ∼2.7 × 10(6)Da and mainly comprised of glucose, mannose and fucose in a ratio of 3:2:1 with both ß and α linkages. Presence of terminal or interior glucose, mannose and fucose residues was also revealed using a high throughput miniaturized platform of lectin microarray. The heteroglucan folded into a triple helical conformation and exhibited enhanced immune cell activation and anti-tumor potential in tumor bearing mice model. Thus, potential biological functions incorporated in these glucan molecules acts in accord with its structural property and exploration of such structure-function relationship will unveil its diverse mechanism of action.


Assuntos
Glucanos/química , Lectinas/metabolismo , Pleurotus/metabolismo , Animais , Configuração de Carboidratos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Fucose/química , Glucanos/uso terapêutico , Glucanos/toxicidade , Glucose/química , Fatores Imunológicos/química , Fatores Imunológicos/uso terapêutico , Fatores Imunológicos/toxicidade , Lectinas/química , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Manose/química , Camundongos , Óxido Nítrico/metabolismo , Sarcoma/tratamento farmacológico , Sarcoma/imunologia
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