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Post-burn hypertrophic scars often exhibit abnormal pigmentation. Exosomes play important roles in maintaining normal physiological homeostasis and in the pathological development of diseases. This study investigated the effects of the exosomes derived from hypertrophic scar fibroblasts (HTSFs) on melanocytes, which are pigment-producing cells. Normal fibroblasts (NFs) and HTSFs were isolated and cultured from normal skin and hypertrophic scar (HTS) tissue. Both the NF- and HTSF-exosomes were isolated from a cell culture medium and purified using a column-based technique. The normal human epidermal melanocytes were treated with both exosomes at a concentration of 100 µg/mL at different times. The cell proliferation, melanin content in the medium, apoptotic factors, transcription factors, melanin synthesis enzymes, signaling, signal transduction pathways, and activators of transcription factors (STAT) 1, 3, 5, and 6 were investigated. Compared with the Dulbecco's phosphate-buffered saline (DPBS)-treated controls and NF-exosomes, the HTSF-exosomes decreased the melanocyte proliferation and melanin secretion. The molecular patterns of apoptosis, proliferation, melanin synthesis, Smad and non-Smad signaling, and STATs were altered by the treatment with the HTSF-exosomes. No significant differences were observed between the DPBS-treated control and NF-exosome-treated cells. HTSF-derived exosomes may play a role in the pathological epidermal hypopigmentation observed in patients with HTS.
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Proliferação de Células , Cicatriz Hipertrófica , Exossomos , Fibroblastos , Melaninas , Melanócitos , Transdução de Sinais , Humanos , Exossomos/metabolismo , Melanócitos/metabolismo , Fibroblastos/metabolismo , Melaninas/biossíntese , Melaninas/metabolismo , Cicatriz Hipertrófica/metabolismo , Cicatriz Hipertrófica/patologia , Apoptose , Epiderme/metabolismo , Epiderme/patologia , Células Cultivadas , MelanogêneseRESUMO
PURPOSE: A pressure of approximately 15-25 mmHg is used for effective compression therapy to prevent and treat hypertrophic scar formation in patients with burns. However, conventional facial compression garments present challenges owing to inadequate pressure distribution in curved areas such as the cheeks, around the mouth, and the slope of the nose. This study aimed to evaluate the utility of a custom-made 3D compression mask equipped with pressure sensors to treat facial burn scars. METHODS: This single-blinded, prospective randomized controlled trial was conducted between May and October 2023, involving 48 burn scars in 12 inpatients with facial burns. We created the custom-made 3D compression mask equipped with pressure sensors, inner lined with biocompatible silicon, and a harness system using 3D printing technology, which can continuously monitor whether an appropriate pressure of 15-25 mmHg maintains. The biological scar properties, Vancouver Scar Scale (VSS), and Patient and Observer Scar Assessment Scale (POSAS) scores in patients with facial burns were assessed before applying the compression mask and garment and at 4 and 12 weeks after application. RESULTS: Pre-application assessment of biological scar properties, VSS, and POSAS revealed no statistically significant differences between the 3D mask and control groups (p > 0.05 for all). Throughout the 12-week application, skin hydration and scar thickness significantly increased (p < 0.001) and reduced (p = 0.010), respectively, in the 3D mask group compared to the control group. Additionally, significant improvements in scar pliability (p = 0.004) and height (p = 0.009) of VSS, itching (p = 0.047), scar stiffness (p = 0.001), thickness (p = 0.011), and irregularity (p < 0.001) of POSAS-patient component, and scar thickness (p = 0.001), pliability (p = 0.012), and surface area (p = 0.027) of the POSAS-observer component were observed in 3D mask group throughout the 12-week application compared to the control group. CONCLUSION: The customized 3D compression mask equipped with pressure sensors significantly improved scar thickness, skin hydration, and various assessment scale parameters throughout the 12-week application.
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In billion years of evolution, eukaryotes preserved the chromosome ends with arrays of guanine repeats surrounded by thymines and adenines, which can form stacks of four-stranded planar structure known as G-quadruplex (G4). The rationale behind the evolutionary conservation of the G4 structure at the telomere remained elusive. Our recent study has shed light on this matter by revealing that telomere G4 undergoes oscillation between at least two distinct folded conformations. Additionally, tumor suppressor BRCA2 exhibits a unique mode of interaction with telomere G4. To elaborate, BRCA2 directly interacts with G-triplex (G3)-derived intermediates that form during the interconversion of the two different G4 states. In doing so, BRCA2 remodels the G4, facilitating the restart of stalled replication forks. In this review, we succinctly summarize the findings regarding the dynamicity of telomeric G4, emphasize its importance in maintaining telomere replication homeostasis, and the physiological consequences of losing G4 dynamicity at the telomere.
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Proteína BRCA2 , Replicação do DNA , Quadruplex G , Telômero , Humanos , Telômero/metabolismo , Telômero/genética , Proteína BRCA2/metabolismo , Proteína BRCA2/genética , AnimaisRESUMO
Robot-assisted gait training (RAGT) has been proven effective in improving gait function in not only patients with central nervous system damage, but also in patients who have undergone musculoskeletal surgery. Nevertheless, evidence supporting the efficacy of such training in burn patients remains insufficient. This report aimed to evaluate the effect of RAGT in burn patients with spinal cord injuries (SCI) caused by electrical trauma. We reported a case of two patients. The total duration of each session was about 1 h 30 min. This included 10 min to put on the exoskeleton, 30 min of robot-assisted training using SUBAR®, 10 min to remove the exoskeleton, 10 min to observe whether complications such as skin abrasion, ulcer, or pain occur in the scar area after RAGT, and 30 min of conventional physiotherapy, at a rate of 5 days a week for 12 weeks. All measurements were assessed before training (0 week) and after training (12 weeks). The American Spinal Cord Injury Association (ASIA) lower extremity motor score (LEMS), passive range of motions (ROMs) of different joints (hip, knee, and ankle), ambulatory motor index (AMI), functional ambulation categories (FAC), and 6 min walking (6 MWT) distances were evaluated to measure the degree of gait function through training. In both patients, manual muscle test measurement and joint ROM in the lower extremities improved after 12 weeks training. The first patient scored 0 in the FAC before training. After 12 weeks of training, he could walk independently indoors, improving to an FAC score of 4. He also reached 92.16 m in the 6 MWT. LEMS improved from 22 before training to 30 after training, and AMI score improved from 12 before training to 16 after training. In the second patient, an independent walking function was not acquired. LEMS improved from 10 before training to 26 after training. AMI scores were the same at 10 points before and after training. The results suggested the possibility of achieving clinical effects in terms of improving lower extremity muscle strength, joint ROMs, and gait performance in patients with SCI caused by electrical trauma.
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Skin microbiome dysbiosis has deleterious effects, and the factors influencing burn scar formation, which affects the scar microbiome composition, are unknown. Therefore, we investigated the effects of various factors influencing scar formation on the scar microbiome composition in patients with burns. We collected samples from the burn scar center and margin of 40 patients with burns, subgrouped by factors influencing scar formation. Scar microbiome composition-influencing factors were analyzed using univariate and multivariate analyses. Skin graft, hospitalization period, intensive care unit (ICU) admission, burn degree, sex, age, total body surface area burned (TBSA), time post-injury, transepidermal water loss, the erythrocyte sedimentation rate, and C-reactive protein levels were identified as factors influencing burn scar microbiome composition. Only TBSA and ICU admission were associated with significant differences in alpha diversity. Alpha diversity significantly decreased with an increase in TBSA and was significantly lower in patients admitted to the ICU than in those not admitted to the ICU. Furthermore, we identified microorganisms associated with various explanatory variables. Our cross-sectional systems biology study confirmed that various variables influence the scar microbiome composition in patients with burns, each of which is associated with various microorganisms. Therefore, these factors should be considered during the application of skin microbiota for burn scar management.
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Queimaduras , Cicatriz , Humanos , Cicatriz/patologia , Estudos Transversais , Estudos Retrospectivos , HospitalizaçãoRESUMO
The aim of this study was to evaluate the characteristics of gait patterns in Charcot-Marie-Tooth disease type 1A (CMT1A) patients according to disease severity. Twenty-two CMT1A patients were enrolled and classified into two groups, according to the disease severity. The healthy control group consisted of 22 subjects with no gait impairment. Full barefoot three-dimensional gait analysis with temporospatial, kinematic, and kinetic data was performed among the mild and moderate CMT1A group and the control group. Minimal hip abduction, maximal hip extension generation, peak knee flexion moment at stance, ankle dorsiflexion at initial contact, maximal ankle plantarflexion at push-off and maximal ankle rotation moment at stance in the CMT1A group showed a significant difference compared to the control group (p < 0.05). In the moderate group, there were greater maximal hip flexion angles in swing, and smaller dorsiflexion angles at initial contact compared to the control group and mild group. CMT patients had typical gait characteristics and their gait patterns were different according to severity. The analysis of gait patterns in patients with CMT1A will help to understand gait function and provide important information for the treatment of patients with CMT in the future.
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BACKGROUND: Lysosomes are closely linked to autophagic activity, which plays a vital role in pancreatic ductal adenocarcinoma (PDAC) biology. The survival of PDAC patients is still poor, and the identification of novel genetic factors for prognosis and treatment is highly required to prevent PDAC-related deaths. This study investigated the germline variants related to lysosomal dysfunction in patients with PDAC and to analyze whether they contribute to the development of PDAC. METHODS: The germline putative pathogenic variants (PPV) in genes involved in lysosomal storage disease (LSD) was compared between patients with PDAC (n = 418) and healthy controls (n = 845) using targeted panel and whole-exome sequencing. Furthermore, pancreatic organoids from wild-type and KrasG12D mice were used to evaluate the effect of lysosomal dysfunction on PDAC development. RNA sequencing (RNA-seq) analysis was performed with established PDAC patient-derived organoids (PDOs) according to the PPV status. RESULTS: The PPV in LSD-related genes was higher in patients with PDAC than in healthy controls (8.13 vs. 4.26%, Log2 OR = 1.65, P = 3.08 × 10-3). The PPV carriers of LSD-related genes with PDAC were significantly younger than the non-carriers (mean age 61.5 vs. 65.3 years, P = 0.031). We further studied a variant of the lysosomal enzyme, galactosylceramidase (GALC), which was the most frequently detected LSD variant in our cohort. Autophagolysosomal activity was hampered when GALC was downregulated, which was accompanied by paradoxically elevated autophagic flux. Furthermore, the number of proliferating Ki-67+ cells increased significantly in pancreatic organoids derived from Galc knockout KrasG12D mice. Moreover, GALC PPV carriers tended to show drug resistance in both PDAC cell line and PDAC PDO, and RNA-seq analysis revealed that various metabolism and gene repair pathways were upregulated in PDAC PDOs harboring a GALC variant. CONCLUSIONS: Genetically defined lysosomal dysfunction is frequently observed in patients with young-onset PDAC. This might contribute to PDAC development by altering metabolism and impairing autophagolysosomal activity, which could be potentially implicated in therapeutic applications for PDAC.
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Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Camundongos , Animais , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas p21(ras) , Neoplasias Pancreáticas/patologia , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Células Germinativas/metabolismo , Lisossomos/metabolismo , Lisossomos/patologia , Neoplasias PancreáticasRESUMO
BACKGROUND: Cytoplasmic polyadenylation element binding (CPEB) proteins are sequence-specific RNA-binding proteins that control translation via cytoplasmic polyadenylation. We previously reported that CPEB1 or CPEB4 knockdown suppresses TAK1 and SMAD signaling in an in vitro study. OBJECTIVE: This study aimed to investigate whether suppression of CPEB1 or CPEB4 expression inhibits scar formation in a mice model of acute dermal wound healing. METHODS: CPEB1 and CPEB4 expression levels were suppressed by siRNA treatment. Skin wounds were created by pressure-induced ulcers in mice. Images of the wound healing were obtained using a digital camera and contraction was measured by ImageJ. mRNA and protein expression was analyzed using quantitative real time polymerase chain reaction and western blotting, respectively. RESULTS: Wound contraction was significantly decreased by pre-treatment with CPEB1 or CPEB4 siRNA compared to the control. Suppression of CPEB1 or CPEB4 expression decreased TAK1 signaling by reducing the levels of TLR4 and TNF-α, phosphorylated TAK1, p38, ERK, JNK, and NF-κB-p65. Decreased levels of phosphorylated SMAD2 and SMAD3 indicated a reduction in SMAD signaling as well. Consequently, the expression of α-SMA, fibronectin, and type I collagen decreased. CONCLUSION: CPEB1 siRNA or CPEB4 siRNA inhibit scar formation by modulating the TAK1 and SMAD signaling pathways. Our study highlights CPEB1 and CPEB4 as potential therapeutic targets for the treatment of scar formation.
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Sex differences are observed in various spectrums of skin diseases, and there are differences in wound healing rate. Herein, sex differences were identified for the newly healed skin microbiome of burn patients. Fifty-two skin samples (26 normal skin, 26 burn scars) were collected from 26 burn patients (12 male, 14 female) and microbiota analysis was performed. The correlation between skin microbiota and biomechanical properties of burn scars was also investigated. There were no significant differences in clinical characteristics between male and female patients. Considering the biomechanical properties of burn scars and normal skin around it performed before sample collection, the mean erythema level of men's normal skin was significantly higher than that of women, whereas the mean levels of melanin, transepidermal water loss and skin hydration showed no significant sex differences. The erythrocyte sedimentation rate was significantly higher in females than that in males. Alpha diversity showed no significant differences between normal skin and burn scars in the male group. However, the scar was significantly higher than that of normal skin in the female group. Microbial network analysis revealed that the male group had more complex microbial network than the female group. Additionally, in the male group, the edge density and clustering coefficient were higher in burn scars when compared to normal skin, than the female group. There were sex differences in the results of microbiome of normal skin and burn scars. Some of the altered microbiota have been correlated with the biomechanical properties of burn scars. In conclusion, sex difference in the burn scar microbiome was confirmed. These results suggest that burn treatment strategies should vary with sex.
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Queimaduras , Cicatriz Hipertrófica , Microbiota , Feminino , Humanos , Masculino , Cicatriz/patologia , Caracteres Sexuais , Cicatrização , Pele/patologia , Queimaduras/patologia , Cicatriz Hipertrófica/patologiaRESUMO
Epidermal keratinocytes are highly activated, hyper-proliferated, and abnormally differentiated in the post-burn hypertrophic scar (HTS); however, the effects of scar fibroblasts (SFs) on keratinocytes through cell-cell interaction in HTS remain unknown. Here, we investigated the effects of HTSF-derived exosomes on the proliferation and differentiation of normal human keratinocytes (NHKs) compared with normal fibroblasts (NFs) and their possible mechanism to provide a reference for clinical intervention of HTS. Fibroblasts were isolated and cultured from HTS and normal skin. Both HTSF-exosomes and NF-exosomes were extracted via a column-based method from the cell culture supernatant. NHKs were treated for 24 or 48 h with 100 µg/mL of cell-derived exosomes. The expression of proliferation markers (Ki-67 and keratin 14), activation markers (keratins 6, 16, and 17), differentiation markers (keratins 1 and 10), apoptosis factors (Bax, Bcl2, caspase 14, and ASK1), proliferation/differentiation regulators (p21 and p27), and epithelial-mesenchymal transition (EMT) markers (E-cadherin, N-cadherin, and vimentin) was investigated. Compared with NF-exosomes, HTSF-exosomes altered the molecular pattern of proliferation, activation, differentiation, and apoptosis, proliferation/differentiation regulators of NHKs, and EMT markers differently. In conclusion, our findings indicate that HTSF-derived exosomes may play a role in the epidermal pathological development of HTS.
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Cicatriz Hipertrófica , Exossomos , Humanos , Cicatriz Hipertrófica/metabolismo , Exossomos/metabolismo , Queratinócitos/metabolismo , Fibroblastos/metabolismo , Queratinas/metabolismo , Proliferação de Células , Células CultivadasRESUMO
PURPOSE: This study aimed to determine the effect of combined treatment with non-ablative laser and human stem cell-conditioned medium (HSCM) on tissue regeneration after burn-induced hypertrophic scar (HTS) formation. METHODS: Fourteen patients with HTSs on both sides of the same body part were subjected to three sessions of non-ablative laser treatment, with an interval of four weeks between each treatment. Following laser treatment, HSCM and normal saline were applied to the HTSs of the right (experimental) and left side (control), respectively. Over the next 6 days, HSCM and moisturizer were applied to experimental scars, while only moisturizer was applied to control scars. Skin characteristics were evaluated before laser treatment and on the seventh day after the third laser treatment. RESULTS: No significant intergroup differences were noted in the initial evaluation (P > 0.05). We found significant differences between the pre- and post-treatment measurements of erythema (P < 0.001), trans-epidermal water loss (TEWL; P < 0.001), and Cutometer® parameters (all parameters; P <0.05) of experimental scars. Control scars also showed significant differences between pre- and post-treatment measurements of thickness (P = 0.01), erythema (P < 0.001), TEWL (P < 0.001), and Cutometer® parameters (all parameters; P < 0.05). Changes (pre- to post-treatment) in scar thickness between the experimental (-0.003 ± 0.09) and control scars (0.04 ± 0.12) were significant (P = 0.01). CONCLUSION: These results suggest that HSCM has a positive effect on short-term results when applied after laser treatment of hypertrophic scars.
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Queimaduras , Cicatriz Hipertrófica , Terapia a Laser , Lasers de Gás , Humanos , Cicatriz Hipertrófica/patologia , Meios de Cultivo Condicionados , Queimaduras/cirurgia , Eritema , Resultado do TratamentoRESUMO
PURPOSE: Hypertrophic scars that occur after burns are less flexible and less elastic than normal skin. Objective measurement tools are required to assess hypertrophic scars after thermal injury. Cutometer® MPA 580 has been widely used for evaluating the properties of hypertrophic scars. Ultrasonography can evaluate elasticity, stiffness, and structure of tissues simultaneously using elastography and B-mode. This study aimed to investigate the intra-rater reliability and validity of elastography to visualize hypertrophic scars. METHODS: Sixteen participants with a total of 96 scars were evaluated. The measurement sequence was elastography, Cutometer®, and elastography every 10 min. We then analyzed the intra-rater reliability using intraclass correlation coefficients (ICC). The results measured using elastography on the hypertrophic scars and surrounding normal skin were compared. The relationships between the elastographic and Cutometer® measurements using the 2-and 8-mm probes were compared. RESULTS: The intra-rater reliability of elastographic measurements was acceptable for clinical use in terms of strain ratio (SR), shear-wave elastography (SWE), shear-wave speed (SWS), and SWE ratio ( ICC = 0.913, ICC=0.933, ICC = 0.842, and ICC = 0.921). The average SWS and SWE in hypertrophic scars were significantly greater than that for normal skin ( p < 0.001 and p < 0.001). SWE showed correlations with the R0 (r = -0.32, p = 0.002) and R8 (r = -0.30, p = 0.003) measured with the 8-mm probe. The SWE ratio was correlated with the R7 (r = -0.34, p = 0.001) measured with the 2-mm probe. The thickness of hypertrophic scars showed correlations with the R5 (r = 0.33, p < 0.001), R6 (r = 0.44, p < 0.001) and R8 (r = -0.35, p < 0.001) measured with the 8-mm probe. R0-R9 measured with 2-mm Cutometer® probes were not correlated with scar thickness ( r < 0.30, P > 0.05). The total scores of mVSS showed correlations with the R0 (r = 0.35, p < 0.001), R1(r = 0.32., p = 0.001), R3 (r = 0.38, p < 0.001), R4 (r = 0.38, p < 0.001), R8 (r = 0.34, p = 0.001), and R9 (r = 0.34, p = 0.001) measured with the 2-mm probe. R0-R9 measured with 8-mm Cutometer® probes were not correlated with mVSS ( r < 0.30, P > 0.05). The thickness of hypertrophic scars showed correlations with the SWE (r = 0.38, p < 0.001) and SWE ratio (r = 0.35, p < 0.001). Elastographic findings were not correlated with mVSS ( r < 0.30, P > 0.05). CONCLUSION: In this study, together with the Cutometer®, ultrasound was confirmed as an evaluation tool that can objectively compare and analyze the difference between normal skin and hypertrophic scars.
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Queimaduras , Cicatriz Hipertrófica , Humanos , Cicatriz Hipertrófica/etiologia , Reprodutibilidade dos Testes , Queimaduras/complicações , Variações Dependentes do Observador , UltrassonografiaRESUMO
Compression therapy for burn scars can accelerate scar maturation and improve clinical symptoms (pruritus and pain). This study objectively verified the effect of pressure garment therapy in maintaining a therapeutic pressure range for hypertrophic scars. Sixty-five participants (aged 20~70 years) with partial- or full-thickness burns, Vancouver scar scale score of ≥4, and a hypertrophic scar of ≥4 cm × 4 cm were enrolled. Compression pressure was measured weekly using a portable pressure-monitoring device to regulate this pressure at 15~25 mmHg for 2 months. In the control group, the compression garment use duration and all other burn rehabilitation measures were identical except for compression monitoring. No significant difference was noted in the initial evaluations between the two groups (p > 0.05). The improvements in the amount of change in scar thickness (p = 0.03), erythema (p = 0.03), and sebum (p = 0.02) were significantly more in the pressure monitoring group than in the control group. No significant differences were noted in melanin levels, trans-epidermal water loss, or changes measured using the Cutometer® between the two groups. The efficacy of compression garment therapy for burn-related hypertrophic scars can be improved using a pressure-monitoring device to maintain the therapeutic range.
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Background: Robot-assisted gait training (RAGT) is more effective in the range of motion (ROM) and isometric strength in patients with burns than conventional training. However, concerns have been raised about whether RAGT might negatively affect the scars of patients with burns. Therefore, we investigated the effects of RAGT-induced mechanical load on the biomechanical properties of burn scars. Methods: This was a single-blind, randomized clinical trial conducted on inpatients admitted to the Department of Rehabilitation Medicine between September 2020 and August 2021. RAGT was conducted for 30 min per day, five days a week for 12 weeks and the control group received conventional gait training for 12 weeks. The pre-training ROM of lower extremity joints was evaluated and the levels of melanin, erythema, trans-epidermal water loss, scar distensibility and elasticity were assessed before training and at 4 and 12 weeks after training. Finally, 19 patients in the gait assistance robot (GAR) group and 20 patients in the control group completed the 12-week trial and all evaluations. Results: There were no significant differences in the epidemiologic characteristics, pre-training ROM of joints and pre-training biomechanical properties of the burn scar between the groups (p > 0.05 for all). None of the patients experienced skin abrasion around the burn scar where the fastening belts were applied or musculoskeletal or cardiovascular adverse events during the training. Scar thickness significantly increased in both groups (p = 0.037 and p = 0.019) and scar distensibility significantly decreased in the control group (p = 0.011) during the training. Hysteresis was significantly decreased in the GAR group during the training (p = 0.038). The GAR and control groups showed significant difference in the change in the values of hysteresis between pre-training and 12 weeks after training (p = 0.441 and p = 0.049). Conclusions: RAGT significantly decreased hysteresis in hypertrophic burn scars and did not cause a significant decrease in skin distensibility. Moreover, no skin complications around the burn scars were detected during RAGT. Trial registration: This study registered on the Clinical Research Information Service (KCT0005204).
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Chronic pain is common after burn injuries, and post-burn neuropathic pain is the most important complication that is difficult to treat. Scrambler therapy (ST) is a non-invasive modality that uses patient-specific electrocutaneous nerve stimulation and is an effective treatment for many chronic pain disorders. This study used magnetic resonance imaging (MRI) to evaluate the pain network-related mechanisms that underlie the clinical effect of ST in patients with chronic burn-related pain. This prospective, double-blinded, randomized controlled trial (ClinicalTrials.gov: NCT03865693) enrolled 43 patients who were experiencing chronic neuropathic pain after unilateral burn injuries. The patients had moderate or greater chronic pain (a visual analogue scale (VAS) score of ≥5), despite treatment using gabapentin and other physical modalities, and were randomized 1:1 to receive real or sham ST sessions. The ST was performed using the MC5-A Calmare device for ten 45 min sessions (Monday to Friday for 2 weeks). Baseline and post-treatment parameters were evaluated subjectively using the VAS score for pain and the Hamilton Depression Rating Scale; MRI was performed to identify objective central nervous system changes by measuring the cerebral blood volume (CBV). After 10 ST sessions (two weeks), the treatment group exhibited a significant reduction in pain relative to the sham group. Furthermore, relative to the pre-ST findings, the post-ST MRI evaluations revealed significantly decreased CBV in the orbito-frontal gyrus, middle frontal gyrus, superior frontal gyrus, and gyrus rectus. In addition, the CBV was increased in the precentral gyrus and postcentral gyrus of the hemisphere associated with the burned limb in the ST group, as compared with the CBV of the sham group. Thus, a clinical effect from ST on burn pain was observed after 2 weeks, and a potential mechanism for the treatment effect was identified. These findings suggest that ST may be an alternative strategy for managing chronic pain in burn patients.
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Burn injuries and their treatment are extremely painful. This study aimed to determine whether virtual reality (VR) could reduce pain during robot-assisted gait training (RAGT) in burn patients by analyzing the cerebral blood flow (CBF) in the prefrontal cortex over time using functional near-infrared spectroscopy (fNIRS). The patients included in this study complained of a pain score ≥5 on a visual analog scale (VAS) during RAGT, which was performed 10 times for 2 weeks. Each session consisted of 15 min of VR application, with a 2-min break, and 15 min without VR. The average values of oxyhemoglobin and deoxyhemoglobin concentrations in the prefrontal cortex on fNIRS were calculated at four stages: temporal delay time with only RAGT, RAGT without VR, temporal delay time with RAGT and VR, and RAGT with VR. The pain scores and CBF were evaluated in sessions 1, 5, and 10 of the RAGT. The mean VAS pain scores were significantly lower (p < 0.05) in the experimental condition than in the control condition. Oxyhemoglobin in the prefrontal lobe significantly increased when RAGT was performed with VR. In conclusion, VR may be a strong nonpharmacological pain reduction technique for burn patients during physical therapy.
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BRCA2-deficient cells precipitate telomere shortening upon collapse of stalled replication forks. Here, we report that the dynamic interaction between BRCA2 and telomeric G-quadruplex (G4), the non-canonical four-stranded secondary structure, underlies telomere replication homeostasis. We find that the OB-folds of BRCA2 binds to telomeric G4, which can be an obstacle during replication. We further demonstrate that BRCA2 associates with G-triplex (G3)-derived intermediates, which are likely to form during direct interconversion between parallel and non-parallel G4. Intriguingly, BRCA2 binding to G3 intermediates promoted RAD51 recruitment to the telomere G4. Furthermore, MRE11 resected G4-telomere, which was inhibited by BRCA2. Pathogenic mutations at the OB-folds abrogated the binding with telomere G4, indicating that the way BRCA2 associates with telomere is innate to its tumor suppressor activity. Collectively, we propose that BRCA2 binding to telomeric G4 remodels it and allows RAD51-mediated restart of the G4-driven replication fork stalling, simultaneously preventing MRE11-mediated breakdown of telomere.
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Quadruplex G , Replicação do DNA , Homeostase , Telômero/genética , Homeostase do TelômeroRESUMO
Post-burn hypertrophic scars are characterized by excessive accumulation of extracellular matrix secreted by fibroblasts. Exosomes are membrane lipid extracellular vesicles that play a pivotal role in cellular communication. Previous studies revealed the role of stem cell-derived exosomes in repairing damaged tissues, and also showed that cancer cell-derived exosomes could affect the disease pathogenesis. However, the functional properties of exosomes derived from hypertrophic scar fibroblasts (HTSFs) have not yet been studied extensively. In this study, we aimed to investigate whether HTSFs-derived exosomes can change the fibrosis-related signaling pathways in human normal fibroblasts (HNFs). HTSFs and HNFs were isolated from human hypertrophic scar tissues. HTSFs-derived exosomes were extracted and treated to HNFs. Reverse transcription-quantitative polymerase chain reaction and western blotting were used to detect mRNA and protein expression, respectively, and cell proliferation and mobility were also assessed. Exosome treatment markedly increased cell proliferation and migration, and induced small mother against decapentaplegic (SMAD) signaling by increasing the levels of phosphorylated SMAD2 and SMAD1/5/8. The levels of TAK1 signaling components were also increased after exosome treatment to HNFs, including phosphorylated TAK1, p38, ERK, and JNK. HTSFs-derived exosomes further induced the epithelial-mesenchymal transition by decreasing the expression level of E-cadherin and increasing the expression levels of N-cadherin and vimentin. Consequently, the expression levels of fibronectin, type â collagen, and type â ¢ collagen were increased. Our results demonstrate the fibrotic property of HTSFs-derived exosomes, which suggests a potential functional role in hypertrophic scar development and a new therapeutic target.
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Cicatriz Hipertrófica , Exossomos , Células Cultivadas , Cicatriz Hipertrófica/metabolismo , Exossomos/metabolismo , Fibroblastos/metabolismo , Fibrose , Humanos , Transdução de SinaisRESUMO
The encystation of Acanthamoeba leads to the development of metabolically inactive and dormant cysts from vegetative trophozoites under unfavorable conditions. These cysts are highly resistant to anti-Acanthamoeba drugs and biocides. Therefore, the inhibition of encystation would be more effective in treating Acanthamoeba infection. In our previous study, a sirtuin family protein-Acanthamoeba silent-information regulator 2-like protein (AcSir2)-was identified, and its expression was discovered to be critical for Acanthamoeba castellanii proliferation and encystation. In this study, to develop Acanthamoeba sirtuin inhibitors, we examine the effects of sirtinol, a sirtuin inhibitor, on trophozoite growth and encystation. Sirtinol inhibited A. castellanii trophozoites proliferation (IC50=61.24 µM). The encystation rate of cells treated with sirtinol significantly decreased to 39.8% (200 µM sirtinol) after 24 hr of incubation compared to controls. In AcSir2-overexpressing cells, the transcriptional level of cyst-specific cysteine protease (CSCP), an Acanthamoeba cysteine protease involved in the encysting process, was 11.6- and 88.6-fold higher at 48 and 72 hr after induction of encystation compared to control. However, sirtinol suppresses CSCP transcription, resulting that the undegraded organelles and large molecules remained in sirtinol-treated cells during encystation. These results indicated that sirtinol sufficiently inhibited trophozoite proliferation and encystation, and can be used to treat Acanthamoeba infections.
Assuntos
Acanthamoeba castellanii , Sirtuínas , Animais , Benzamidas , Proliferação de Células , Naftóis , Sirtuínas/genética , Sirtuínas/metabolismo , Trofozoítos/metabolismoRESUMO
Phosphatidylinositol 3-kinase-related protein kinases (PIKKs) play critical roles in various metabolic pathways related to cell proliferation and survival. The TELO2-TTI1-TTI2 (TTT) complex has been proposed to recognize newly synthesized PIKKs and to deliver them to the R2TP complex (RUVBL1-RUVBL2-RPAP3-PIH1D1) and the heat shock protein 90 chaperone, thereby supporting their folding and assembly. Here, we determined the cryo-EM structure of the TTT complex at an average resolution of 4.2 Å. We describe the full-length structures of TTI1 and TELO2, and a partial structure of TTI2. All three proteins form elongated helical repeat structures. TTI1 provides a platform on which TELO2 and TTI2 bind to its central region and C-terminal end, respectively. The TELO2 C-terminal domain (CTD) is required for the interaction with TTI1 and recruitment of Ataxia-telangiectasia mutated (ATM). The N- and C-terminal segments of TTI1 recognize the FRAP-ATM-TRRAP (FAT) domain and the N-terminal HEAT repeats of ATM, respectively. The TELO2 CTD and TTI1 N- and C-terminal segments are required for cell survival in response to ionizing radiation.