Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 455
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Physiol Biochem Zool ; 93(1): 13-22, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31657971

RESUMO

The surface area (SA) theory proposes that resting metabolic rate (RMR) scales with body mass, which parallels the exchange SA of organisms, and that a species with a larger scaling exponent of exchange SA has a larger scaling exponent of RMR. However, the effects of exchange SA on metabolic scaling may be eclipsed because oxygen transfer across the respiratory surface is determined not only by the exchange SA but also by ventilation. We hypothesize that the scaling of both gill surface area (GSA) and ventilation frequency (VF) positively affects the scaling of metabolic rate. In six closely related species of carp maintained under the same experimental conditions, the scaling exponents of RMR and GSA were analyzed. In the goldfish, RMR scaled with body mass by an exponent significantly lower than that of GSA but not different from the exponents of GSA in the remaining five species. The scaling exponent of RMR was positively related to those of both GSA and VF among the species. In addition, the VF-corrected metabolic scaling exponent was positively related to the scaling exponent of GSA among the species. These results suggest that variations in GSA scaling and in VF scaling among species mutually affect metabolic scaling.

2.
Neurosci Lett ; : 134611, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31698026

RESUMO

Continuous theta burst stimulation (cTBS) has been widely recognized as a therapeutic treatment for ischemic stroke, but the underlying mechanism is still elusive. Here, we investigated the protective effects of cTBS in the posterior parietal cortex during the chronic phase of stroke in the photothrombotic ischemic model. Infarction volume and neuron excitability in the peri-infarct area were assessed using immunohistochemistry and whole-cell patch-clamp. Spatial cognitive function was measured using the Morris water maze. Gamma-Amino butyric acid (GABA) interneurons were responsive to cTBS, and cTBS induced elevated phasic inhibition rather than tonic inhibition. Given that GABA-A-mediated phasic inhibition was elevated during the chronic phase of ischemic stroke for 30 days and was beneficial for stroke recovery, we investigated the therapeutic potential of cTBS in promoting functional recovery and found that the elevated phasic inhibition by cTBS improved spatial cognitive function in the photothrombotic stroke mouse model with induction in the posterior parietal cortex. Our study indicates the mechanism by which cTBS may modify the excitability of the brain cortex and provides novel insight into the potential of cTBS to protect against neuronal dysfunction in ischemic stroke.

3.
Nanotechnology ; 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31703224

RESUMO

The performance of hybrid perovskite solar cells (PSCs) is significantly influenced by the crystallization and morphology of perovskite films. Herein, a novel method of CsPbBr3 quantum dots (QDs) assisted nucleation is applied to prepare high quality solution-processed MAPbI3 films by employing CsPbBr3 QDs as an additive into diethyl ether anti-solvent. The appropriate amount of CsPbBr3 QDs can act as effective heterogeneous nucleation centers, leading to the formation of smooth and pinhole-free perovskite films with increased grain size. Furthermore, the growth direction of MAPbI3 grains is regulated by CsPbBr3 QDs, exhibiting preferential orientation of (110) plane. Therefore, the MAPbI3 films with CsPbBr3 QDs modification show reduced defects and increased carrier lifetime. As a result, the champion PSC with a maximum power conversion efficiency (PCE) up to 20.17% is achieved and 85% of its initial PCE is maintained after aging 1000 hours at room temperature under a relative humidity of 50%. This work demonstrates a feasible way to prepare high quality perovskite films for optoelectronic applications.

4.
iScience ; 21: 217-227, 2019 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-31675551

RESUMO

The inorganic metal oxides (IMOs), including titanium dioxide (TiO2) and tin dioxide (SnO2), inevitably induce decomposition of perovskite under UV illumination owing to their photocatalytic activity, and the use of a UV filter will add extra cost and reduce the effective power output. Here, we first reveal that the weak Pb-I bond in I-based perovskite is prone to breakage under UV photocatalysis, leading to serious degradation of the SnO2/perovskite interface. We introduced a chlorine-rich mixed-halide perovskite interlayer (ClMPI), which possesses an excellent tolerance to photocatalysis owing to the strong Pb-Cl bond, between the SnO2 and I-based perovskite. The ClMPI-based device achieves an enhanced efficiency of up to 21.01% (certified 20.17%). Most importantly, the resultant devices can maintain >94% of their initial performance after 180 h under outdoor solar irradiation, >80% after 500 h under UV irradiation, and 500 h under continuous full spectrum illumination at their maximum power points.

5.
Nat Med ; 25(11): 1739-1747, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31700183

RESUMO

Type 2 diabetes is characterized by insulin resistance and a gradual loss of pancreatic beta cell mass and function1,2. Currently, there are no therapies proven to prevent beta cell loss and some, namely insulin secretagogues, have been linked to accelerated beta cell failure, thereby limiting their use in type 2 diabetes3,4. The adipokine adipsin/complement factor D controls the alternative complement pathway and generation of complement component C3a, which acts to augment beta cell insulin secretion5. In contrast to other insulin secretagogues, we show that chronic replenishment of adipsin in diabetic db/db mice ameliorates hyperglycemia and increases insulin levels while preserving beta cells by blocking dedifferentiation and death. Mechanistically, we find that adipsin/C3a decreases the phosphatase Dusp26; forced expression of Dusp26 in beta cells decreases expression of core beta cell identity genes and sensitizes to cell death. In contrast, pharmacological inhibition of DUSP26 improves hyperglycemia in diabetic mice and protects human islet cells from cell death. Pertaining to human health, we show that higher concentrations of circulating adipsin are associated with a significantly lower risk of developing future diabetes among middle-aged adults after adjusting for body mass index (BMI). Collectively, these data suggest that adipsin/C3a and DUSP26-directed therapies may represent a novel approach to achieve beta cell health to treat and prevent type 2 diabetes.

6.
Amino Acids ; 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31576457

RESUMO

Blood-retinal barrier breakdown is the main pathological characteristics of diabetic retinopathy (DR). Asymmetric dimethylarginine (ADMA) was reported to be elevated in DR patients. In this study, we observed the dynamic profile of ADMA, retinal morphology and permeability of BRB at 2, 4 or 8 week of diabetic rats induced by a single intraperitoneal injection of streptozocin (60 mg/kg) and in cultured rat retinal pericytes pretreated with D-glucose (30 mM) for 1, 3, 5 and 7 days or ADMA (3, 10, 30 µM) for 24, 48 and 72 h, trying to explore the effects of ADMA on blood-retinal barrier in DR. Gap junction intercellular communication (GJIC) and the expression of blood-retinal barrier-specific component connexin 43 (Cx43) were examined in diabetic rats or cultured retinal pericytes to elucidate whether ADMA impacted blood-retinal barrier function via damaging Cx43-GJIC. The results showed that with increasing duration of diabetes, the ultrastructure of blood-retinal barrier of diabetic rats appeared cell junction damage, apoptosis of retinal pericytes and breakdown of barrier successively. The increases in retinal permeability, ADMA levels and Cx43 expression, and abnormal GJIC were observed in diabetic rats and retinal pericytes exposed to D-glucose (30 mM). A glucose-like effect was seen using ADMA or another L-arginine analogue NG-monomethyl-L-arginine or dimethylarginine dimethylaminohydrolases (DDAHs) siRNA, implicating that ADMA aggravated the breakdown of blood-retinal barrier via damaging Cx43-GJIC.

7.
Sci Rep ; 9(1): 14070, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31575930

RESUMO

Biochemical remission after transsphenoidal surgery is still unsatisfied in acromegaly patients with macroadenomas, especially with invasive macroadenomas. Concerning the impact of preoperative somatostatin analogues (SSAs) on surgical outcomes, previous studies with limited cases reported conflicting results. To assess current evidence of preoperative medical treatment, we performed a systematic review and meta-analysis of comparative studies. A literature search was conducted in Pubmed, Embase, and the Cochrane Library. Five randomized controlled trials (RCT) and seven non-RCT comparative studies were included. These studies mainly focused on pituitary macroadenomas though a small number of microadenoma cases were included. For safety, preoperative SSAs were not associated with elevated risks of postoperative complications. With respect to efficacy, the short-term cure rate was improved by preoperative SSAs, but the long-term cure rate showed no significant improvement. For invasive macroadenomas, the short-term cure rate was also improved, but the long-term results were not evaluable in clinical practice because adjuvant therapy was generally required. In conclusion, preoperative SSAs are safe in patients with acromegaly, and the favorable impact on surgical results is restricted to the short-term cure rate in macroadenomas and invasive macroadenomas. Further well-designed RCTs to examine long-term results are awaited to update the finding of this meta-analysis.

8.
Brain Res ; 1726: 146488, 2019 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-31586625

RESUMO

Acute ischemic stroke is a leading cause of disability with limited therapeutic options. Continuous theta burst stimulation (cTBS) has recently been shown to be a promising noninvasive therapeutic strategy for neuroprotection in ischemic stroke patients. Here, we investigated the protective effects of cTBS following acute infarction using a photothrombotic stroke (PTS) model in the right posterior parietal cortex (PPC) of C57BL/6 mice. Treatment with cTBS resulted in a reduction in the volume of the infarct region and significantly increased vascular diameter and blood flow velocity in peri-infarct region, as well as decreased the numbers of calcium binding adapter molecule 1 (Iba-1)-positive microglia and glial fibrillary acidic protein (GFAP)-positive astrocytes. Moreover, the number of CD16/32 positive microglia was decreased, whereas the number of CD206 positive microglia was increased. In addition, performance in a water maze task was significantly improved. These results indicated that cTBS protected against PPC infarct region, leading to an improvement in spatial cognitive function, possibly as a result of changes to cerebral microvascular function and inflammatory responses.

9.
Stem Cells ; 2019 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-31648394

RESUMO

Huntington's disease (HD) is a neurodegenerative disorder caused by a mutation in the huntingtin (HTT) gene that results in the production of neurotoxic mutant HTT (mHTT) protein. Suppressing HTT production with antisense oligonucleotides (ASOs) is a promising treatment strategy for HD; however, the difficulty of delivering ASOs to deep brain structures is a major barrier for its clinical application. The glymphatic system of astrocytes involving aquaporin 4 (AQP-4) controls the entry of macromolecules from the cerebrospinal fluid into the brain. Mesenchymal stem cells (MSCs) target astrocytes to inhibit neuroinflammation. Here we examined the glymphatic distribution of ASO in the brain and the therapeutic potential of combining intravenously injection of mesenchymal stem cells (IV-MSC) and ASOs for the treatment of HD. Our results show that Cy3-labeled ASOs entered the brain parenchyma via the perivascular space following cisternal injection, but the brain distribution was significantly lower in AQP-4-/- as compared with wild-type mice. Downregulation of the AQP-4 M23 isoform was accompanied by decreased brain levels of ASOs in BACHD mice as well as an increase in astrogliosis and phosphorylation of nuclear factor κB (NF-κB) p65. IV-MSC treatment restored AQP-4 M23 expression, attenuated astrogliosis, and decreased NF-κB p65 phosphorylation; it also increased the brain distribution of ASOs and enhanced the suppression of mHTT in BACHD mice. These results suggest that modulating glymphatic activity using IV-MSC is a novel strategy for improving the potency of ASO in the treatment of HD.

10.
J Infect Dis ; 2019 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-31586389

RESUMO

T cell immunoglobulin and mucin protein 3 (Tim-3) is an immune checkpoint inhibitor that has therapeutic implications for many tumors and infectious diseases. However, the mechanisms by which Tim-3 promotes immune evasion remain unclear. Here, we demonstrated that Tim-3 inhibits the expression of major histocompatibility complex class I (MHC-I) in macrophages at both the mRNA and protein levels by inhibiting the STAT1-NLRC5 signaling pathway. As a result, MHC-I-restricted antigen presentation by macrophages was inhibited by Tim-3 both in vitro and in L. monocytogenes infection model in vivo. Systemic overexpression of Tim-3 or specific knockout of Tim-3 in macrophages significantly attenuated or enhanced CD8+ T cell activation and infection damage in L. monocytogenes-infected mice, respectively. We thus identified a new mechanism by which Tim-3 promotes Lister Monocytogenes immune evasion. Further studies on this pathway might shed new light on the physio-pathological roles of Tim-3 and suggest new approaches for intervention.

11.
J Headache Pain ; 20(1): 93, 2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31477012

RESUMO

BACKGROUND: Increasing evidence has suggested that the cerebellum is associated with pain and migraine. In addition, the descending pain system of the brainstem is the major site of trigeminal pain processing and modulation and has been discussed as a main player in the pathophysiology of migraine. Cerebellar and brainstem structural changes associated with migraineurs remain to be further investigated. METHODS: Voxel-based morphometry (VBM) (50 controls, 50 migraineurs without aura (MWoAs)) and diffusion tensor imaging (DTI) (46 controls, 46 MWoAs) were used to assess cerebellum and brainstem anatomical alterations associated with MWoAs. We utilized a spatially unbiased infratentorial template toolbox (SUIT) to perform cerebellum and brainstem optimized VBM and DTI analysis. We extracted the average diffusion values from a probabilistic cerebellar white matter atlas to investigate whether MWoAs exhibited microstructure alterations in the cerebellar peduncle tracts. RESULTS: MWoAs showed decreased fractional anisotropy (FA) in the vermis VI extending to the bilateral lobules V and VI of the cerebellum. We also found higher axial diffusivity (AD), mean diffusivity (MD), and radial diffusivity (RD) in the right inferior cerebellum peduncle tract in MWoAs. MWoAs exhibited both reduced gray matter volume and increased AD, MD and RD in the spinal trigeminal nucleus (SpV). CONCLUSION: MWoAs exhibited microstructural changes in the cerebellum and the local brainstem. These structural differences might contribute to dysfunction of the transmission and modulation of noxious information, trigeminal nociception, and conduction and integration of multimodal information in MWoAs. These findings further suggest involvement of the cerebellum and the brainstem in the pathology of migraine without aura.

13.
Chin J Integr Med ; 2019 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-31471834

RESUMO

OBJECTIVE: To evaluate the association between Chinese medicine (CM) therapy and disease-free survival (DFS) outcomes in postoperative patients with non-small cell lung cancer (NSCLC). METHODS: This multiple-center prospective cohort study was conducted in 13 medical centers in China. Patients with stage I, II, or IIIA NSCLC who had undergone radical resection and received conventional postoperative treatment according to the National Comprehensive Cancer Network (NCCN) guidelines were recruited. The recruited patients were divided into a CM treatment group and a control group according to their wishes. Patients in the CM treatment group received continuous CM therapy for more than 6 months or until disease progression. Patients in the control group received CM therapy for less than 1 month. Follow-up was conducted over 3 years. The primary outcome was DFS, with recurrence/metastasis rates as a secondary outcome. RESULTS: Between May 2013 and August 2016, 503 patients were enrolled into the cohort; 266 were classified in the CM treatment group and 237 in the control group. Adjusting for covariates, high exposure to CM was associated with better DFS [hazard ratio (HR) = 0.417, 95% confidential interval (CI): 0.307-0.567)]. A longer duration of CM therapy (6-12 months, 12-18 months, >24 months) was associated with lower recurrence and metastasis rates (HR = 0.225, 0.119 and 0.083, respectively). In a subgroup exploratory analysis, CM therapy was also a protective factor of cancer recurrence and metastasis in both stage I-IIIA (HR=0.50, 95% CI: 0.37-0.67) and stage IIIA NSCLC postoperative patients (HR = 0.48, 95% CI: 0.33-0.71), DFS was even longer among CM treatment group patients. CONCLUSIONS: Longer duration of CM therapy could be considered a protective factor of cancer recurrence and metastasis. CM treatment is associated with improving survival outcomes of postoperative NSCLC patients in China. (Registration No. ChiCTR-OOC-14005398).

14.
Org Lett ; 21(18): 7577-7581, 2019 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-31539931

RESUMO

The challenging structural motif of dictyospiromide (1), a spirosuccinimide alkaloid with antioxidant properties that are associated with activation of the Nrf2/ARE signaling pathway, was assigned using contemporary NMR experiments complemented with anisotropic NMR, chiroptical, and computational methodologies. Anisotropic NMR parameters provided critical orthogonal verification of the configuration of the difficult to assign spiro carbon and the other stereogenic centers in 1.

15.
Dalton Trans ; 48(39): 14595-14599, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31538157

RESUMO

A supramolecular approach to distinguish Na+ from other biologically important metal ions was demonstrated. By designing ligands reasonably, Na+-selective bonding was achieved in the construction of homochiral alkaline-lanthanide heteronuclear helicates, which was further confirmed by mixed-metal self-assembly experiments and 1H-NMR spectra.

16.
J Alzheimers Dis ; 71(3): 1015-1025, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31476158

RESUMO

BACKGROUND: Cerebrovascular diseases play an important role in dementia. Air pollution is associated with cardiovascular disease, with growing links to neurodegeneration. Prior studies demonstrate associations between fine particulate matter (PM2.5) and biomarkers of endothelial injury in the blood; however, no studies have evaluated these biomarkers in cerebrospinal fluid (CSF). OBJECTIVE: We evaluate associations between short-term and long-term PM2.5 exposure with CSF vascular cell adhesion molecule-1 (VCAM-1) and e-selectin in cognitively normal and mild cognitive impairment (MCI)/Alzheimer's disease (AD) individuals. METHODS: We collected CSF from 133 community volunteers at VA Puget Sound between 2001-2012. We assigned short-term PM2.5 from central monitors and long-term PM2.5 based on annual average exposure predictions linked to participant addresses. We performed analyses stratified by cognitive status and adjusted for key covariates with tiered models. Our primary exposure windows for the short-term and long-term analyses were 7-day and 1-year averages, respectively. RESULTS: Among cognitively normal individuals, a 5 µg/m3 increase in 7-day and 1-year average PM2.5 was associated with elevated VCAM-1 (7-day: 35.4 (9.7, 61.1) ng/ml; 1-year: 51.8 (6.5, 97.1) ng/ml). A 5 µg/m3 increase in 1-year average PM2.5, but not 7-day average, was associated with elevated e-selectin (53.3 (11.0, 95.5) pg/ml). We found no consistent associations among MCI/AD individuals. CONCLUSIONS: We report associations between short-term and long term PM2.5 and CSF biomarkers of vascular damage in cognitively normal adults. These results are aligned with prior research linking PM2.5 to vascular damage in other biofluids as well as emerging evidence of the role of PM2.5 in neurodegeneration.

17.
ACS Chem Neurosci ; 2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31491086

RESUMO

The supplementation of exogenous antioxidants to scavenge excessive reactive oxygen species (ROS) is an effective treatment for cerebral ischemia-reperfusion injury (CIRI) in stroke. Piperlongumine (PL), a natural alkaloid, has a great potential as a neuroprotective agent, but it also has obvious toxicity. Moreover, its neuroprotective effects remain to be improved. In this study, we designed a series of novel PL analogs by hybridizing the screened low-toxicity diketene skeleton with antioxidant effect and the 3,4,5-trimethoxyphenyl group, which may increase the antioxidant activity of PL. The intermediate was synthesized by a novel green synthesis method, and 34 compounds were obtained. The compounds without obvious cytotoxicity have remarkable antioxidant effects, especially compared with diketene skeletons and PL. The cytoprotection of the active compound decreased significantly by reduction of the carbon-carbon double bonds of the Michael acceptor in the diketene skeleton. More importantly, further study revealed that compound A9, which has the best activity, can confer protection for cells against oxidative stress and attenuate brain injury in vivo. Overall, this study provided a promising drug candidate for the treatment of CIRI and guided the further development of drug research in oxidative stress-mediated diseases.

18.
Plant Physiol ; 181(3): 1114-1126, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31530628

RESUMO

SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) complex formation is necessary for intracellular membrane fusion and thus has a key role in processes such as secretion. However, little is known about the regulatory factors that bind to Qa-SNAREs, which are also known as syntaxins (SYPs) in plants. Here, we characterized Arabidopsis (Arabidopsis thaliana) Tomosyn protein (AtTMS) and demonstrated that it is a conserved regulator of SYPs in plants. AtTMS binds strongly via its R-SNARE motif-containing C terminus to the Qa domain of PM-resident, pollen-expressed SYP1s (SYP111, SYP124, SYP125, SYP131, and SYP132), which were narrowed down from 12 SYPs. AtTMS is highly expressed in pollen from the bicellular stage onwards, and overexpression of AtTMS under the control of the UBIQUITIN10, MSP1, or LAT52 promoter all resulted in defective pollen after the microspore stage in which secretion was inhibited, leading to the failure of intine deposition and cell plate formation during pollen mitosis I. In tobacco (Nicotiana benthamiana) leaf epidermal cells, overexpression of AtTMS inhibited the secretion of secreted GFP. The defects were rescued by mCherry-tagged SYP124, SYP125, SYP131, or SYP132. In vivo, SYP132 partially rescued the pMSP1:AtTMS phenotype. In addition, AtTMS, lacking a transmembrane domain, was recruited to the plasma membrane by SYP124, SYP125, SYP131, and SYP132 and competed with Vesicle-Associated Membrane Protein721/722 for binding to, for example, SYP132. Together, our results demonstrated that AtTMS might serve as a negative regulator of secretion, whereby active secretion might be fine-tuned during pollen development.

19.
Nature ; 573(7772): 83-86, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31485059

RESUMO

Quasars, which are exceptionally bright objects at the centres (or nuclei) of galaxies, are thought to be produced through the accretion of gas into disks surrounding supermassive black holes1-3. There is observational evidence at galactic and circumnuclear scales4 that gas flows inwards towards accretion disks around black holes, and such an inflow has been measured at the scale of the dusty torus that surrounds the central accretion disk5. At even smaller scales, inflows close to an accretion disk have been suggested to explain the results of recent modelling of the response of gaseous broad emission lines to continuum variations6,7. However, unambiguous observations of inflows that actually reach accretion disks have been elusive. Here we report the detection of redshifted broad absorption lines of hydrogen and helium atoms in a sample of quasars. The lines show broad ranges of Doppler velocities that extend continuously from zero to redshifts as high as about 5,000 kilometres per second. We interpret this as the inward motion of gases at velocities comparable to freefall speeds close to the black hole, constraining the fastest infalling gas to within 10,000 gravitational radii of the black hole (the gravitational radius being the gravitational constant multiplied by the object mass, divided by the speed of light squared). Extensive photoionization modelling yields a characteristic radial distance of the inflow of approximately 1,000 gravitational radii, possibly overlapping with the outer accretion disk.

20.
Food Funct ; 10(9): 6121-6134, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31497829

RESUMO

Collagen hydrolysate has been widely used as a nutraceutical agent against skin aging and has gained increasing attention. Previous research has suggested that oral administration of antioxidant collagen peptides (ACPs) exerted beneficial effects on the photoaging skin structure and collagen. However, the bioactive components in ACP metabolites that are responsible for the repair effects have not been elucidated. In this study, serum containing collagen peptides (CPS) after oral administration and collagen peptides isolated from serum metabolites (SCP) were collected and their effects on cell proliferation, hyaluronic acid secretion and the collagen synthesis pathway in UVA-induced skin fibroblasts (ESF) were evaluated. Furthermore, hydroxyproline (Hyp)-containing collagen peptides from SCP were analyzed and their repair effects were examined. The repair effects of ACP metabolites in serum differed depending on the preparation method and SCP were the active components responsible for the repair effects. SCP displayed repair effects by activating the TGF-ß/Smad pathway to promote procollagen synthesis and suppressing AP-1, MMP-1 and MMP-3 protein expression to prevent collagen degradation, in which SHCP exhibited the strongest bioactivity. In addition, SCP showed repair effects by reactive oxygen species (ROS) scavenging activity and preserving the endogenous antioxidant defense systems. Furthermore, IO (Ile-Hyp) and AOG (Ala-Hyp-Gly) were identified as the active peptides promoting procollagen synthesis by activating the TGF-ß/Smad3 pathway. These results may be useful in screening of anti-photoaging factors in metabolites and producing highly efficient collagen peptide products.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA