Cutaneous photoaging, induced by chronic exposure to ultraviolet (UV) radiation, typically manifests as alterations in both the physical appearance and functional properties of the skin and may predispose individuals to cancer development. Recent studies have demonstrated the reparative potential of exosomes derived from mesenchymal stem cells in addressing skin damage, while specific reports highlight their efficacy in ameliorating skin photoaging. However, the precise role of exosomes derived from human hair follicle mesenchymal stem cells (HFMSC-Exos) in the context of cutaneous photoaging remains largely unexplored. We successfully isolated HFMSC-Exos using the ultracentrifugation technique. In cellular experiments, we assessed the migration of human dermal fibroblasts (HDFs) through scratch and transwell assays, evaluated the angiogenesis of human umbilical vein endothelial cells through angiogenesis assays, and examined the expression levels of collagen and matrix metalloproteinase 1 (MMP-1) using Western blotting and quantitative reverse transcription polymerase chain reaction. Furthermore, we established a nude mouse model of photoaging to observe wrinkle formation on the dorsal surface of the animals, as well as to assess dermal thickness and collagen fiber generation through histological staining. Ultimately, we performed RNA sequencing on skin tissues from mice before and after treatment to elucidate the relevant underlying mechanisms. Our findings revealed that HFMSC-Exos effectively enhanced the migration and proliferation of HDFs and upregulated the expressions of transforming growth factor-β1 (TGF-β1), p-Smad2/p-Smad3, collagen type 1, and collagen type 3 while concurrently down-regulating MMP-1 levels in HDFs. Additionally, mice in the HFMSC-Exo group showed quicker wrinkle healing and increased collagen production. HFMSC-Exos miR-125b-5p was demonstrated to reduce skin photoaging by increasing profibrotic levels via TGF-β1 expression. UV-irradiated HDFs and photoaged nude mouse skin showed low TGF-β1 expressions, whereas overexpression of TGF-β1 in HDFs increased collagen type 1, collagen type 3, and p-Smad2/p-Smad3 expressions while decreasing MMP-1 expression. HDFs overexpressing TGF-β1 produced more collagen and altered the Smad pathway. This study demonstrated, both in vitro and in vivo, that HFMSC-Exos increased collagen formation, promoted HDF cell proliferation and migration, and reversed the senescence of UV-irradiated HDFs. TGF-β1 was identified as a target of HFMSC-Exos miR-125b-5p, which controls photoaging via regulating the Smad pathway. The antiphotoaging capabilities of HFMSC-Exos may occur via the miR-125b-5p/TGF-β1/Smad axis, suggesting a promising therapeutic approach for treating skin photoaging.
Porous titanium alloy implants with simulated trabecular bone fabricated by 3D printing technology have broad prospects. However, due to the fact that some powder adheres to the surface of the workpiece during the manufacturing process, the surface roughness in direct printing pieces is relatively high. At the same time, since the internal pores of the porous structure cannot be polished by conventional mechanical polishing, an alternative method needs to be found. As a surface technology, plasma polishing technology is especially suitable for parts with complex shapes that are difficult to polish mechanically. It can effectively remove particles and fine splash residues attached to the surface of 3D printed porous titanium alloy workpieces. Therefore, it can reduce surface roughness. Firstly, titanium alloy powder is used to print the porous structure of the simulated trabecular bone with a metal 3D printer. After printing, heat treatment, removal of the supporting structure, and ultrasonic cleaning is carried out. Then, plasma polishing is performed, consisting of adding a polishing electrolyte with the pH set to 5.7, preheating the machine to 101.6 °C, fixing the workpiece on the polishing fixture, and setting the voltage (313 V), current (59 A), and polishing time (3 min). After polishing, the surface of the porous titanium alloy workpiece is analyzed by a confocal microscope, and the surface roughness is measured. Scanning electron microscopy is used to characterize the surface condition of porous titanium. The results show that the surface roughness of the whole porous titanium alloy workpiece changed from Ra (average roughness) = 126.9 µm to Ra = 56.28 µm, and the surface roughness of the trabecular structure changed from Ra = 42.61 µm to Ra = 26.25 µm. Meanwhile, semi-molten powders and ablative oxide layers are removed, and surface quality is improved.
Biofilms play a crucial role in the pathogenicity of Staphylococcus epidermidis, while little is known about whether the essential YycFG two-component signal transduction system (TCS) is involved in biofilm formation. We used antisense RNA (asRNA) to silence the yycFG TCS in order to study its regulatory functions in S. epidermidis. Strain 1457 expressing asRNA yycF exhibited a significant delay (~4-5 h) in entry to log phase, which was partially complemented by overexpressing ssaA. The expression of asRNA yycF and asRNA yycG resulted in a 68 and 50% decrease in biofilm formation at 6 h, respectively, while they had no significant inhibitory effect on 12 h biofilm formation. The expression of asRNA yycF led to a ~5-fold increase in polysaccharide intercellular adhesion (PIA) production, but it did not affect the expression of accumulation-associated protein (Aap) or the release of extracellular DNA. Consistently, quantitative real-time PCR showed that silencing yycF resulted in an increased transcription of biofilm-related genes, including icaA, arlR, sarA, sarX, and sbp. An in silico search of the YycF regulon for the conserved YycF recognition pattern and a modified motif in S. epidermidis, along with additional gel shift and DNase I footprinting assays, showed that arlR, sarA, sarX, and icaA are directly regulated by YycF. Our data suggests that YycFG modulates S. epidermidis biofilm formation in an ica-dependent manner.
Background: Enterococcus faecalis has been commonly considered as one of the major pathogens of the urinary tract infection (UTI) in human host worldwide, whereas the molecular characteristics of E. faecalis clinical isolates from the patients with UTI in China remains seldomly reported. This study aimed to investigate the resistance mechanism, molecular characteristics and risk factors of E. faecalis clinical isolates from patients with UTI in China. Methods: A total of 115 non-duplicated E. faecalis clinical isolates from patients with UTI were retrospectively collected in a tertiary hospital in China and their clinical data was further analyzed. The linezolid and tedizolid susceptibility were determined by agar dilution. The resistance genes, including erm (A) , erm (B) , erm (C) , tet (M) , optrA, cfr, cfr (B), poxtA , and MLST-based housekeeping genes were investigated by PCR. Results: In 115 non-duplicated E. faecalis clinical isolates from the patients with UTI in this hospital setting, the frequency of linezolid or tedizolid-resistant/intermediate isolates were 22.61 and 13.04%, respectively, and the frequency of linezolid-resistant/intermediate E. faecalis clinical isolates carrying with erm (A) were 86%. Among the five linezolid-resistant E. faecalis strains found in this study, three optrA- positive isolates and the other two linezolid-resistant strains were G2576U genetic mutations in the V domain of the 23S rRNA genes. The ST clonality analysis indicated that 31.42% (11/35) of ST16 E. faecalis UTI isolates were not susceptible to linezolid. Moreover, the univariable analysis indicated that the high risk factors of linezolid-resistant/intermediate E. faecalis infections involved the indwelling catheter, trachea cannula catheter and the carriage of erm (A) or optrA . Furthermore, the indwelling catheter and trachea cannula catheter were demonstrated as the independent predictors of linezolid-resistant/intermediate E. faecalis strains in patients with UTI by multivariable analysis. Conclusion: Linezolid-resistant/intermediate E. faecalis associated with urinary tract infections of patients in this hospital setting from China might be explained by the high carriage frequency of optrA genes and moreover, indwelling catheter and trachea cannula should be considered as the independent predictors of linezolid-resistant/intermediate E. faecalis infections. The transmission mechanism of linezolid-resistant/intermediate E. faecalis in this hospital setting should be further studied.
In order to improve the spalling resistance of lightweight aggregate concrete at high temperature, two types of modified materials were used to modify clay ceramsite lightweight aggregates by adopting the surface coating modification method. Spalling of the concrete specimens manufactured by using the modified aggregates was observed during a temperature elevation. Mass loss and residual axial compressive strength of the modified concrete specimens after exposure to elevated temperatures were also tested. Concrete specimens consisting of ordinary clay ceramsites and crushed limestone were manufactured as references for comparison. The results showed that the ordinary lightweight concrete specimens and the crushed limestone concrete specimens were completely spalled after exposure to target temperatures above 400°C and 1000°C, respectively, whereas the modified concrete specimens remained intact at 1200°C, at which approximately 25% to 38% of the residual compressive strength was retained. The results indicated that the modified lightweight concrete specimens have exhibited superior mechanical properties and resistance to thermal spalling after exposure to elevated temperatures.
Objective:To evaluate the clinical effects of autologous anterior teeth and hosterior teeth transplantation to connatural and artifical alveolar socket.Methods:The research samples including two parts in each group:Anterior teeth group,26 cases with the anterior loss,and 30 cases with the residual roots or residual crowns;Posterior teeth group,32 cases with the posterior loss,and 38 cases with residual roots or residual crowns.Connatural tooth socket and artifical tooth socket were prepared with the dental implant appliance,the ambush teeth and third molar was extracted and transplanted to the alveolar sockets which had been prepared.Arch bar fix transplantation teeth with composit resin for 4 weeks,pulp therapy for mature tooth after operation 2 weeks.Results:Execpt one tooth in Anterior teeth group was extracted for loose in artifical alveolar socket,all other cases were followed-up in two years.The donor teeth were fixed and had normal chew function.Posterior teeth group:execpt one tooth was extracted for loose in connatural alveolar socket,all other cases were followed-up in two years,the donor teeth were fixed and had normal chew function.Conclusion:Autologous teeth transplantation to connatural and artifical alveolar socket are successful therapy.But the function of teeth being transplantation is different.Anterior teeth group,connatural alveolar socket part is better than artifical alveolar socket part;posterior teeth group,connatural alveolar socket part is less than artifical alveolar socket part.
SARS-CoV-2 induces apoptosis and amplifies the immune response by continuously stressing the endoplasmic reticulum (ER) after invading cells. This study aimed to establish a protein-metabolic pathway associated with ER dysfunction based on the invasion mechanism of SARS-CoV-2.This study included 17 healthy people and 46 COVID-19 patients, including 38 mild patients and 8 severe patients. Proteomics and metabolomics were measured in the patient plasma collected at admission and one week after admission. The patients were further divided into the aggravation and remission groups based on disease progression within one week of admission.Cross-sectional comparison showed that endoplasmic reticulum molecular chaperone-binding immunoglobulin protein (ERC-BiP), angiotensinogen (AGT), ceramide acid (Cer), and C-reactive protein (CRP) levels were significantly increased in COVID-19 patients, while the sphingomyelin (SM) level was significantly decreased (P < 0.05). In addition, longitudinal comparative analysis found that the temporal fold changes of ERC-BiP, AGT, Cer, CRP, and SM were significantly different between the patients in the aggravation and remission groups (P < 0.05). ERC-BiP, AGT, and Cer levels were significantly increased in aggravation patients, while SM was significantly decreased (P < 0.05). Meanwhile, ERC-BiP was significantly correlated with AGT (r = 0.439; P < 0.001).ERC-BiP can be used as a core index to reflect the degree of ER stress in COVID-19 patients, which is of great value for evaluating the functional state of cells. A functional pathway for AGT/ERC-BiP/glycolysis can directly assess the activation of unfolded protein reactions. The ERC-BiP pathway is closer to the intracellular replication pathway of SARS-CoV-2 and may help in the development of predictive protocols for COVID-19 exacerbation.
Porous titanium alloy implants with simulated trabecular bone fabricated by 3D printing technology have broad prospects. However, due to the fact that some powder adheres to the surface of the workpiece during the manufacturing process, the surface roughness in direct printing pieces is relatively high. At the same time, since the internal pores of the porous structure cannot be polished by conventional mechanical polishing, an alternative method needs to be found. As a surface technology, plasma polishing technology is especially suitable for parts with complex shapes that are difficult to polish mechanically. It can effectively remove particles and fine splash residues attached to the surface of 3D printed porous titanium alloy workpieces. Therefore, it can reduce surface roughness. Firstly, titanium alloy powder is used to print the porous structure of the simulated trabecular bone with a metal 3D printer. After printing, heat treatment, removal of the supporting structure, and ultrasonic cleaning is carried out. Then, plasma polishing is performed, consisting of adding a polishing electrolyte with the pH set to 5.7, preheating the machine to 101.6 °C, fixing the workpiece on the polishing fixture, and setting the voltage (313 V), current (59 A), and polishing time (3 min). After polishing, the surface of the porous titanium alloy workpiece is analyzed by a confocal microscope, and the surface roughness is measured. Scanning electron microscopy is used to characterize the surface condition of porous titanium. The results show that the surface roughness of the whole porous titanium alloy workpiece changed from Ra (average roughness) = 126.9 µm to Ra = 56.28 µm, and the surface roughness of the trabecular structure changed from Ra = 42.61 µm to Ra = 26.25 µm. Meanwhile, semi-molten powders and ablative oxide layers are removed, and surface quality is improved.
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