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1.
J Immunother Cancer ; 12(5)2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38702144

RESUMO

BACKGROUND: Natural killer (NK) cells are key effector cells of antitumor immunity. However, tumors can acquire resistance programs to escape NK cell-mediated immunosurveillance. Identifying mechanisms that mediate this resistance enables us to define approaches to improve immune-mediate antitumor activity. In previous studies from our group, a genome-wide CRISPR-Cas9 screen identified Charged Multivesicular Body Protein 2A (CHMP2A) as a novel mechanism that mediates tumor intrinsic resistance to NK cell activity. METHODS: Here, we use an immunocompetent mouse model to demonstrate that CHMP2A serves as a targetable regulator of not only NK cell-mediated immunity but also other immune cell populations. Using the recently characterized murine 4MOSC model system, a syngeneic, tobacco-signature murine head and neck squamous cell carcinoma model, we deleted mCHMP2A using CRISPR/Cas9-mediated knock-out (KO), following orthotopic transplantation into immunocompetent hosts. RESULTS: We found that mCHMP2A KO in 4MOSC1 cells leads to more potent NK-mediated tumor cell killing in vitro in these tumor cells. Moreover, following orthotopic transplantation, KO of mCHMP2A in 4MOSC1 cells, but not the more immune-resistant 4MOSC2 cells enables both T cells and NK cells to better mediate antitumor activity compared with wild type (WT) tumors. However, there was no difference in tumor development between WT and mCHMP2A KO 4MOSC1 or 4MOSC2 tumors when implanted in immunodeficient mice. Mechanistically, we find that mCHMP2A KO 4MOSC1 tumors transplanted into the immunocompetent mice had significantly increased CD4+T cells, CD8+T cells. NK cell, as well as fewer myeloid-derived suppressor cells (MDSC). CONCLUSIONS: Together, these studies demonstrate that CHMP2A is a targetable inhibitor of cellular antitumor immunity.


Assuntos
Modelos Animais de Doenças , Neoplasias de Cabeça e Pescoço , Células Matadoras Naturais , Carcinoma de Células Escamosas de Cabeça e Pescoço , Animais , Camundongos , Carcinoma de Células Escamosas de Cabeça e Pescoço/imunologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/imunologia , Neoplasias de Cabeça e Pescoço/genética , Células Matadoras Naturais/imunologia , Humanos , Linhagem Celular Tumoral , Imunocompetência
2.
World J Surg ; 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38658171

RESUMO

BACKGROUND: There is uncertainty in the relative benefits and harms of hyperthermic intraoperative peritoneal chemotherapy (HIPEC) when added to cytoreductive surgery (CRS) +/- systemic chemotherapy or systemic chemotherapy alone in people with peritoneal metastases from colorectal, gastric, or ovarian cancers. METHODS: We searched randomized controlled trials (RCTs) in the medical literature until April 14, 2022 and applied methods used for high-quality systematic reviews. FINDINGS: We included a total of eight RCTs (seven RCTs included in quantitative analysis as one RCT did not provide data in an analyzable format). All comparisons other than ovarian cancer contained only one trial. For gastric cancer, there is high uncertainty about the effect of CRS + HIPEC + systemic chemotherapy. For stage III or greater epithelial ovarian cancer undergoing interval cytoreductive surgery, CRS + HIPEC + systemic chemotherapy probably decreases all-cause mortality compared to CRS + systemic chemotherapy. For colorectal cancer, CRS + HIPEC + systemic chemotherapy probably results in little to no difference in all-cause mortality and may increase the serious adverse events proportions compared to CRS +/- systemic chemotherapy, but probably decreases all-cause mortality compared to fluorouracil-based systemic chemotherapy alone. INTERPRETATION: The role of CRS + HIPEC in gastric peritoneal metastases is uncertain. CRS + HIPEC should be standard of care in women with stage III or greater epithelial ovarian cancer undergoing interval CRS. CRS + systemic chemotherapy should be standard of care for people with colorectal peritoneal metastases, with HIPEC given only as part of a RCT focusing on subgroups and regimes. PROSPERO REGISTRATION: CRD42019130504.

3.
PLoS Pathog ; 19(7): e1011351, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37410700

RESUMO

Identification of host determinants of coronavirus infection informs mechanisms of pathogenesis and may provide novel therapeutic targets. Here, we demonstrate that the histone demethylase KDM6A promotes infection of diverse coronaviruses, including SARS-CoV, SARS-CoV-2, MERS-CoV and mouse hepatitis virus (MHV) in a demethylase activity-independent manner. Mechanistic studies reveal that KDM6A promotes viral entry by regulating expression of multiple coronavirus receptors, including ACE2, DPP4 and Ceacam1. Importantly, the TPR domain of KDM6A is required for recruitment of the histone methyltransferase KMT2D and histone deacetylase p300. Together this KDM6A-KMT2D-p300 complex localizes to the proximal and distal enhancers of ACE2 and regulates receptor expression. Notably, small molecule inhibition of p300 catalytic activity abrogates ACE2 and DPP4 expression and confers resistance to all major SARS-CoV-2 variants and MERS-CoV in primary human airway and intestinal epithelial cells. These data highlight the role for KDM6A-KMT2D-p300 complex activities in conferring diverse coronaviruses susceptibility and reveal a potential pan-coronavirus therapeutic target to combat current and emerging coronaviruses. One Sentence Summary: The KDM6A/KMT2D/EP300 axis promotes expression of multiple viral receptors and represents a potential drug target for diverse coronaviruses.


Assuntos
COVID-19 , Coronavírus da Síndrome Respiratória do Oriente Médio , Animais , Humanos , Camundongos , Enzima de Conversão de Angiotensina 2/metabolismo , Dipeptidil Peptidase 4/metabolismo , Histona Desmetilases/metabolismo , Coronavírus da Síndrome Respiratória do Oriente Médio/metabolismo , Receptores Virais/genética , Receptores Virais/metabolismo , SARS-CoV-2/metabolismo
4.
J Robot Surg ; 17(2): 629-635, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36253574

RESUMO

Robotic surgery training has lacked evidence-based standardisation. We aimed to determine the effectiveness of adjunctive interactive virtual classroom training (VCT) in concordance with the self-directed Fundamentals of Robotic Surgery (FRS) curriculum. The virtual classroom is comprised of a studio with multiple audio-visual inputs to which participants can connect remotely via the BARCO weConnect platform. Eleven novice surgical trainees were randomly allocated to two training groups (A and B). In week 1, both groups completed a robotic skills induction. In week 2, Group A received training with the FRS curriculum and adjunctive VCT; Group B only received access to the FRS curriculum. In week 3, the groups received the alternate intervention. The primary outcome was measured using the validated robotic-objective structured assessment of technical skills (R-OSAT) at the end of week 2 (time-point 1) and 3 (time-point 2). All participants completed the training curriculum and were included in the final analyses. At time-point 1, Group A achieved a statistically significant greater mean proficiency score compared to Group B (44.80 vs 35.33 points, p = 0.006). At time-point 2, there was no significant difference in mean proficiency score in Group A from time-point 1. In contrast, Group B, who received further adjunctive VCT showed significant improvement in mean proficiency by 9.67 points from time-point 1 (95% CI 5.18-14.15, p = 0.003). VCT is an effective, accessible training adjunct to self-directed robotic skills training. With the steep learning curve in robotic surgery training, VCT offers interactive, expert-led learning and can increase training effectiveness and accessibility.


Assuntos
Procedimentos Cirúrgicos Robóticos , Robótica , Treinamento por Simulação , Humanos , Procedimentos Cirúrgicos Robóticos/métodos , Estudos Prospectivos , Simulação por Computador , Competência Clínica , Robótica/educação , Currículo
5.
Indian J Otolaryngol Head Neck Surg ; 74(Suppl 2): 1073-1081, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36452684

RESUMO

Trans-nasal endoscopic surgery (TNES) is a helpful diagnostic and therapeutic modality in otorhinolaryngology surgeries and requires controlled hypotension for better visualization of the surgical field. Recent literature shows evidence of intravenous Lignocaine infusion to produce the controlled hypotension. The study aims to assess and compare the effects of Lignocaine (LIG) and Dexmedetomidine (DEX) infusion with respect to surgical field quality. 101 Consenting adult patients undergoing elective TNES were double-blinded, randomly allocated in one of the two groups and received either DEX infusion of 0.5ug/kg/hr (n = 51) or LIG infusion of 1.5 mg/kg/h (n = 50) after a loading dose. Surgical field score (SVF) as the primary outcome and secondary outcomes such as variations in hemodynamic parameters, the requirement for rescue agents and total blood loss were recorded. Both the groups were comparable with respect to patient demographics, total duration of anesthesia and surgery. SVF scores were significantly better in the LIG group during the first 105 min of the surgery (p < 0.05). In response to intubation, hemodynamic parameters were lower in LIG group. The requirement of other adjuvant drugs, total blood loss (166.40 ml vs. 251.17 ml) and extubation time were also significantly lower in the LIG group. The study concludes that intravenous Lignocaine gives a better surgical field in the first 105 min of surgery, comparable hemodynamics and decreased blood loss in patients undergoing TNES as compared to Dexmedetomidine infusion. Hence its role as an agent for controlled hypotension during TNES surgery is promising.

6.
J Dev Biol ; 10(2)2022 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-35735915

RESUMO

Across the animal kingdom, lizards are the only amniotes capable of regenerating their lost tail through epimorphosis. Of the many reptiles, the northern house gecko, Hemidactylus flaviviridis, is an excellent model system that is used for understanding the mechanism of epimorphic regeneration. A stage-specific transcriptome profile was generated in the current study following an autotomized tail with the HiSeq2500 platform. The reads obtained from de novo sequencing were filtered and high-quality reads were considered for gene ontology (GO) annotation and pathway analysis. Millions of reads were recorded for each stage upon de novo assembly. Up and down-regulated transcripts were categorized for early blastema (EBL), blastema (BL) and differentiation (DF) stages compared to the normal tail (NT) by differential gene expression analysis. The transcripts from developmentally significant pathways such as FGF, Wnt, Shh and TGF-ß/BMP were present during tail regeneration. Additionally, differential expression of transcripts was recorded from biological processes, namely inflammation, cell proliferation, apoptosis and cell migration. Overall, the study reveals the stage-wise transcriptome analysis in conjunction with cellular processes as well as molecular signaling pathways during lizard tail regeneration. The knowledge obtained from the data can be extrapolated to configure regenerative responses in other amniotes, including humans, upon loss of a complex organ.

7.
J Surg Educ ; 79(5): 1166-1176, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35691892

RESUMO

BACKGROUND: Mentoring is critically important for the personal and professional development of a surgeon. Early career stage mentoring by same-gender role models may help ameliorate the gender imbalance in surgery based on our understanding of barriers for women pursuing surgical careers. A novel method of establishing these relationships is speed mentoring. This study aims to examine the impact of a one-day speed-mentoring session with same gender mentors on a cohort's perceptions of a career in surgery. DESIGN: This prospective pre-post study compared attitudes and perceptions of a career in surgery before and after a speed-mentoring session with female surgeons. Mentees were assigned into groups of 1 or 2 and were paired with a female surgeon for 8 minutes. Each mentee group then rotated to another mentor for the same amount of time and this process continued for a total of twelve sessions. Mentees completed a 19-point questionnaire before and after the speed mentoring intervention. SETTING: This multicenter study included participants from across the United Kingdom. PARTICIPANTS: Inclusion criteria were female gender and medical student or foundation year doctor (internship year 1 or 2) status. Three hundred and forty participants participated in the intervention, 191 were included in the analysis. RESULTS: Following intervention, the percentage of participants who agreed that having a family would negatively impact a woman's surgical career progression significantly decreased from 46.6% to 23.0%. The percentage of participants who agreed that an "old boys' club" attitude exists in surgery also significantly decreased (73.8%-58.1%). The percentage of participants who agreed it was more difficult for a woman to succeed in her surgical career than a man significantly decreased (73.8%-64.9%). One hundred and eighty-three (96%) participants agreed that mentorship is important for career progression and 153 (71.2%) participants stated that they did not have someone who they considered a mentor. CONCLUSIONS: Conducting a speed mentoring program with same-gender role models significantly changed female medical students' and junior doctors' perceptions of women in surgery. The results suggest that such programs may be effective tools for facilitating mentor-mentee relationships and could be employed by surgical organizations to encourage a diverse uptake into surgery.


Assuntos
Internato e Residência , Tutoria , Feminino , Humanos , Masculino , Mentores , Avaliação de Programas e Projetos de Saúde , Estudos Prospectivos
9.
J Surg Educ ; 79(3): 791-801, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34857499

RESUMO

OBJECTIVE: This study evaluated the efficacy of virtual classroom training (VCT) in comparison to face-to-face training (FFT) and non-interactive computer-based learning (CBL) for basic surgical skills training. DESIGN: This was a parallel-group, non-inferiority, prospective randomised controlled trial with three intervention groups conducted in 2021. There were three intervention groups with allocation ratio 1:1:1. Outcome adjudicators were blinded to intervention assignment. Interventions consisted of 90-minute training sessions. VCT was delivered via the BARCO weConnect platform, FFT was provided in-person by expert instructors and CBL was carried out by participants independently. The primary outcome was post-intervention Objective Structured Assessment of Technical Skills score, adjudicated by two experts and adjusted for baseline proficiency. The assessed task was to place three interrupted sutures with hand-tied knots. SETTING: This multicentre study recruited from five medical schools in London. PARTICIPANTS: Inclusion criteria were medical student status and access to a personal computer and smartphone. One hundred fifty-nine eligible individuals applied online. Seventy-two participants were randomly selected and stratified by subjective and objective suturing experience prior to permuted block randomization. RESULTS: Twenty-four participants were allocated to each intervention, all were analysed per-protocol. The sample was 65.3% female with mean age 21.3 (SD 2.1). VCT was non-inferior to FFT (adjusted difference 0.44, 95% CI: -0.54 to 1.75, delta 0.675), VCT was superior to CBL (adjusted difference 1.69, 95% CI: 0.41-2.96) and FFT was superior to CBL (adjusted difference 1.25, 95% CI: 0.20-2.29). The costs per-attendee associated with VCT, FFT and CBL were £22.15, £39.69 and £16.33 respectively. Instructor hours used per student for VCT and FFT were 0.25 and 0.75, respectively. CONCLUSIONS: VCT provides greater accessibility and resource efficiency compared to FFT, with similar educational benefit. VCT has the potential to improve global availability and accessibility of surgical skills training.


Assuntos
Estudantes de Medicina , Adulto , Competência Clínica , Feminino , Humanos , Londres , Masculino , Estudos Prospectivos , Adulto Jovem
10.
Zoology (Jena) ; 148: 125947, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34333369

RESUMO

The role of COX-2 induced PGE2 in the site-specific regulation of inflammatory mediators that facilitate disparate wound healing in the tail and limb of a lizard was studied by analysing their levels during various stages of healing. The activity of COX-2 and concentration of PGE2 surged during the early healing phase of tail along with the parallel rise in EP4 receptor. PGE2-EP4 interaction is corelated to early resolution (by 3 dpa) of inflammation by rising the antiinflammatory mediator IL-10. This likely causes reduction in proinflammatory mediators viz., iNOS, TNF-α, IL-6, IL-17 and IL-22. Conversely, in the limb, COX-2 derived PGE2 likely causes rise in inflammation through EP2 receptor-based signalling, as all the proinflammatory mediators stay elevated through the course of healing (till 9 dpa), while expression of IL-10 is reduced. This study brings to light the novel roles of IL-17 and IL-22 in programming wound healing. As IL-17 reduces in tail, IL-22 behaves in reparative way, causing conducive environment for scar-free wound healing. On the contrary, synergic elevation of both IL-17 and Il-22 form a micro-niche suitable for scarred wound healing in limb, thus obliterating its regenerative potential.


Assuntos
Ciclo-Oxigenase 2/metabolismo , Citocinas/metabolismo , Extremidades , Lagartos , Cauda , Cicatrização/fisiologia , Animais , Ciclo-Oxigenase 2/genética , Citocinas/genética , Feminino , Regulação da Expressão Gênica/fisiologia , Masculino
11.
JMIR Res Protoc ; 10(7): e28671, 2021 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-34292162

RESUMO

BACKGROUND: Traditional face-to-face training (FFT) for basic surgical skills is inaccessible and resource-intensive. Noninteractive computer-based learning is more economical but less educationally beneficial. Virtual classroom training (VCT) is a novel method that permits distanced interactive expert instruction. VCT may optimize resources and increase accessibility. OBJECTIVE: We aim to investigate whether VCT is superior to computer-based learning and noninferior to FFT in improving proficiency in basic surgical skills. METHODS: This is a protocol for a parallel-group, noninferiority, randomized controlled trial. A sample of 72 undergraduates will be recruited from 5 medical schools in London. Participants will be stratified by subjective and objective suturing experience level and allocated to 3 intervention groups at a 1:1:1 ratio. VCT will be delivered using the BARCO weConnect software, and FFT will be provided by expert instructors. Optimal student-to-teacher ratios of 12:1 for VCT and 4:1 for FFT will be maintained. The assessed task will be interrupted suturing with hand-tied knots. RESULTS: The primary outcome will be the postintervention Objective Structured Assessment of Technical Skills score, adjudicated by 2 experts blinded to the study and adjusted for baseline proficiency. The noninferiority margin (δ) will be defined using historical data. CONCLUSIONS: This study will serve as a comprehensive appraisal of the suitability of virtual basic surgical skills classroom training as an alternative to FFT. Our findings will assist the development and implementation of further resource-efficient, accessible, virtual basic surgical skills training programs during the COVID-19 pandemic and in the future. TRIAL REGISTRATION: International Standard Randomized Controlled Trial Number ISRCTN12448098; https://www.isrctn.com/ISRCTN12448098. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/28671.

13.
Eur Urol Open Sci ; 27: 43-52, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33997823

RESUMO

BACKGROUND: Salvage robot-assisted radical prostatectomy (sRARP) is a potential treatment option for locally recurrent prostate cancer (PCa) after nonsurgical primary treatment. There are minimal data comparing outcomes between propensity-matched sRARP and primary robot-assisted radical prostatectomy (RARP). OBJECTIVE: The primary objective is to compare perioperative, oncological, and functional outcomes of sRARP with primary RARP, and the secondary is to compare outcomes between sRARP after whole and focal gland therapy. DESIGN SETTING AND PARTICIPANTS: A 1:1 propensity-matched comparison was carried out of 135 sRARP cases with primary RARP cases from a cohort of 3852 consecutive patients from a high-volume tertiary centre. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Perioperative, oncological, and functional outcomes including complication rates, positive surgical margins, biochemical recurrence (BCR), continence, and erectile dysfunction (ED) were retrospectively collected. RESULTS AND LIMITATIONS: There were no significant differences in patient characteristics between sRARP and primary RARP groups. In the salvage and primary groups, median (interquartile range) follow-up periods were 521 (304-951) and 638 (394-951) d, grade III-V Clavien-Dindo complication rates were 1.5% and 0% (p = 0.310), BCR rates were 31.9% and 14.1% (p < 0.001) at the last follow-up, pad-free continence rates were 78.8% and 84.3% at 2 yr (p = 0.337), and ED rates were 94.8% and 76.3% (p < 0.001), respectively. Comparing the whole and focal gland groups, BCR rates were 36.7% and 29.1% (p = 0.687) at follow-up, pad-free continence rates were 53.1% and 89.3% at 2 yr (p < 0.001), and ED rates were 98% and 93% (p = 0.214), respectively. CONCLUSIONS: Salvage RARP has similar perioperative outcomes to primary RARP with inferior potency rates. Post-focal therapy sRARP has similar recurrence and continence rates to primary RARP. Post-whole gland therapy, complication, and recurrence rates are higher, and there is a higher risk of urinary incontinence. PATIENT SUMMARY: We report the largest propensity-matched comparison of salvage robot-assisted radical prostatectomy (RARP) after focal and whole gland therapy. Salvage RARP is a feasible procedure for the treatment of locally recurrent prostate cancer in high-volume centres; however, patients should be counselled appropriately as to the different outcomes.

14.
Korean J Anesthesiol ; 74(3): 191-203, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33596628

RESUMO

As of 2018 cancer is responsible for almost 9.6 million deaths annually and, with an aging population, the incidence of cancer is expected to continue to rise. Surgery is an important treatment modality for patients with solid organ cancers. It has been postulated that, due to potentially overlapping processes underlying the development of malignancy and the therapeutic pathways of various anesthetic agents, the choice of anesthetic type and method of administration may affect post-operative outcomes in patients with cancer. This is a literature review of the most recent evidence extracted from various databases including PubMed, EMBASE, and the Cochrane, as well as journals and book reference lists. The review highlights the pathophysiological processes underpinning cancer development and the molecular actions of anesthetic agents, pre-clinical and retrospective studies investigating cancer and anesthetics, as well as ongoing clinical trials. Overall, there are conflicting results regarding the impact of regional vs. general anesthesia on cancer recurrence, whilst the majority of data suggest a benefit of the use of intravenous propofol over inhalational volatile anesthetics. The biological changes associated with the surgical inflammatory response offer a unique opportunity to intervene to counteract any potentially cancer-promoting effects.


Assuntos
Anestésicos Inalatórios , Neoplasias , Propofol , Idoso , Anestesia Geral , Humanos , Neoplasias/epidemiologia , Neoplasias/cirurgia , Estudos Retrospectivos
15.
J Dent Anesth Pain Med ; 20(4): 223-231, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32934988

RESUMO

BACKGROUND: The most frequent complication of nasotracheal intubation (NTI) is epistaxis. Epinephrine nasal gauze packing has been used conventionally as a pre-treatment for reducing epistaxis, but it carries a disadvantage of pain and anxiety in patients. However, xylometazoline drops are easier to administer and more convenient for patients. We aimed at comparing the effectiveness of xylometazoline drops and epinephrine merocele packing in reducing bleeding and postoperative complications in our population. METHODS: Our study enrolled 120 patients in a double-blind randomized controlled trial. We randomly allocated ASA1 or 2 adult patients into 2 groups: Group X and Group E. Group X received 0.1% xylometazoline nasal drops, and epinephrine (1:10,000) merocele nasal packing was used in Group E. The primary outcome was the incidence of bleeding during NTI; the severity of bleeding, navigability, bleeding during extubation, and postoperative complications were secondary outcomes. We used IBM SPSS and Minitab software for statistical analysis, and P < 0.05 was considered statistically significant. RESULTS: We analyzed the data of 110 patients: 55 in Group X and 55 in Group E. The two groups did not have different bleeding incidence (56.4% vs 60.0%; P = 0.70); however, the incidence of severe bleeding was less with xylometazoline than with epinephrine (3.63% vs 14.54%; P < 0.05). We also observed less bleeding during extubation (38.2% vs 68.5%; P < 0.05) with xylometazoline. Other secondary outcomes were akin to both groups. CONCLUSION: The incidence of severe and post-extubation bleeding was significantly less with xylometazoline. Hence, it may be an effective alternative for reducing the incidence and severity of epistaxis during NTI.

17.
Acta Histochem ; 122(1): 151464, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31780191

RESUMO

Lizards restore their lost tail by the recruitment of multipotent cells which are selectively differentiated into varied cell types so as to sculpt a new tail. The precise coordination of the events involved in this complex process requires crosstalk between many signaling molecules and differential regulation of several mediators that facilitate the achievements of various milestones of regeneration. Fibroblast growth factor-2 is one such signaling molecule which activates a number of intracellular signaling pathways. Herein, the regulatory role of FGF2 during tail regeneration in Hemidactylus flaviviridis was investigated. Upon inhibition of FGFR using SU5402, the FGF2 levels were found to be significantly reduced at both transcript and protein level. Further, the compromised levels of the gelatinases, namely MMP2 and MMP9 in the tail tissues of treated lizards indicate that FGF2 regulates the activity of these enzymes perhaps to facilitate the recruitment of multipotent mesenchymal cells (blastema). The in vivo 5BrdU incorporation assay showed a lower cell proliferation rate in FGF2 signal inhibited animals during all the proliferative stages of regeneration studied. This observation was substantiated by decreased levels of PCNA in treated group. Moreover, from the combined results of Caspase-3 localization and its expression levels in the regenerates of control and SU5402 treated lizards it can be deduced that FGF2 signal regulates apoptosis as well during early stages of regeneration. Overall, the current study indicates beyond doubt that FGF2 signaling plays a pivotal role in orchestrating the matrix reorganization and cell cycle turnover during lizard tail regeneration.


Assuntos
Ciclo Celular , Matriz Extracelular/patologia , Fator 2 de Crescimento de Fibroblastos/metabolismo , Lagartos/metabolismo , Regeneração , Proteínas de Répteis/metabolismo , Transdução de Sinais , Cauda/fisiologia , Animais
18.
Organogenesis ; 15(2): 35-42, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31331233

RESUMO

Studies using fish fin as a model to understand the nuance of epimorphosis are gaining interest of lately. This study illustrates for the first time the daily changes in the tissue architecture of regenerating tail fin of Poecilia latipinna. Wound epithelium is formed within 24 hpa that eventually gets stratified into apical epithelial cap by 48 hpa. In the subsequent day, proliferating cells accumulate in front of each fin-ray marking the beginning of blastema. Distally these cells express signs of cartilage condensation by 4 dpa. However, ossification and subsequent transformation of actinotrichia to lepidotrichia was observed on 5 dpa. Subsequently, the regenerate grew at variable rate until it achieved the original size on 25 dpa. This result would serve as a worthwhile standard reference for further explorative studies that demand manipulation of a regulatory signal at a defined time point.


Assuntos
Nadadeiras de Animais/crescimento & desenvolvimento , Poecilia/crescimento & desenvolvimento , Regeneração , Animais , Desenvolvimento Ósseo , Cartilagem/crescimento & desenvolvimento , Proliferação de Células , Epitélio/crescimento & desenvolvimento , Morfogênese
19.
Zoology (Jena) ; 133: 17-26, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30979387

RESUMO

Bone morphogenetic proteins play a pivotal role in the epimorphic regeneration in vertebrates. Blastema formation is central to the epimorphic regeneration and crucially determines its fate. Despite an elaborate understanding of importance of Bone morphogenetic protein signaling in regeneration, its specific role during the blastema formation remains to be addressed. Regulatory role of BMP signaling during blastema formation was investigated using LDN193189, a potent inhibitor of BMP receptors. The study involved morphological observation, in vivo proliferation assay by incorporation of BrdU, comet assay, qRT-PCR and western blot. Blastemal outgrowth was seen reduced due to LDN193189 treatment, typified by dimensional differences, reduced number of proliferating cells and decreased levels of PCNA. Additionally, proapoptotic markers were found to be upregulated signifying a skewed cellular turnover. Further, the cell migration was seen obstructed and ECM remodeling was disturbed as well. These findings were marked by differential transcript as well as protein expressions of the key signaling and regulatory components, their altered enzymatic activities and other microscopic as well as molecular characterizations. Our results signify, for the first time, that BMP signaling manifests its effect on blastema formation by controlling the pivotal cellular processes possibly via PI3K/AKT. Our results indicate the pleiotropic role of BMPs specifically during blastema formation in regulating cell migration, cell proliferation and apoptosis, and lead to the generation of a molecular regulatory map of determinative molecules.


Assuntos
Proteínas Morfogenéticas Ósseas/metabolismo , Poecilia/fisiologia , Nadadeiras de Animais/efeitos dos fármacos , Animais , Proteínas Morfogenéticas Ósseas/genética , Ciclo Celular , Fragmentação do DNA , Matriz Extracelular , Feminino , Masculino , Pirazóis/farmacologia , Pirimidinas/farmacologia , Regeneração
20.
Drug Chem Toxicol ; 42(6): 565-576, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29498548

RESUMO

Currently, scientists show keen interest in the drugs that inhibit multiple kinases, LDN193189, being an example. It combats certain cancers in vitro as well as in vivo, making it a prerequisite for researchers to study the toxic potential of this drug in animal models. As most of the drugs metabolized by liver cause hepatic injury, LDN193189-induced hepatotoxicity was examined using a teleost fish, Poecilia latipinna. As a prelude, calculation of LD50 showed a value of 95.22 mg/kg body weight and three doses were decided based on it for further evaluations. All these groups were tested for antioxidant enzyme levels and were significantly raised for mid- and high-dose group. Similar trend was recorded for ALP, AST, and ALT levels. Furthermore, some key indicators of drug metabolism in liver were tested for their expression in response to LDN193189 treatment. Among these, Cyt-C, CYP3A4, CYP1B1 and CYP1A1 were elevated in mid- and high dose, except CYP21A1, which declined remarkably. Moreover, histological profile of the liver reflected high degree of inflammation due to drug treatment, but this was found only at high dose. In summary, LDN193189, at 2.5 mg/kg body weight, did not cause any adverse hepatotoxicity, rendering it safe for use as an anti-proliferative agent - an activity for which it has already shown promising results in the same animal model. The low-dose group previously studied for its anti-proliferative property showed no adverse effect in liver, whereas the mid- and high dose induced moderate or severe hepatotoxicity in P. latipinna.


Assuntos
Antineoplásicos/toxicidade , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Pirazóis/toxicidade , Pirimidinas/toxicidade , Animais , Antineoplásicos/administração & dosagem , Antioxidantes/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Relação Dose-Resposta a Droga , Feminino , Dose Letal Mediana , Fígado/efeitos dos fármacos , Fígado/patologia , Masculino , Poecilia , Pirazóis/administração & dosagem , Pirimidinas/administração & dosagem
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