BACKGROUND:The mesenchymal stem cell secretome contains bioactive substances,cytokines,and growth factors.Three-dimensional cell culture can regulate the secretion of these components,potentially enhancing the ability to promote injury repair.OBJECTIVE:To investigate the repair effect of three-dimensional cultured human umbilical cord mesenchymal stem cell secretome on skin injuries in mice.METHODS:Human umbilical cord mesenchymal stem cells were cultured in conventional two-dimensional culture dishes and 96-well U-bottom cell culture plates,from which their secretory components were subsequently collected.The expression of skin damage repair related secretory factors in umbilical cord mesenchymal stem cells was analyzed using RT-qPCR.The protein expression level of skin damage repair related factors in umbilical cord mesenchymal stem cell secretome was detected using enzyme-linked immunosorbent assay.The potential of human umbilical cord mesenchymal stem cell secretome to repair vascular injuries was evaluated using an immortalized human umbilical vein endothelial cell migration model.A mouse skin injury model was established,and the human umbilical cord mesenchymal stem cell secretome was injected subcutaneously.Repair effects on skin injury were assessed through wound healing rates and histopathological analysis.RESULTS AND CONCLUSION:(1)After three days of cultivation,human umbilical cord mesenchymal stem cells cultured in two dimensions exhibited a fibroblast-like,swirling growth pattern,whereas three-dimensional culture led to the formation of uniform microspheres.(2)Compared with two-dimensional culture,three-dimensional culture significantly increased the mRNA expression of transforming growth factor β and basic fibroblast growth factor in human umbilical cord mesenchymal stem cells.(3)Compared with two-dimensional culture,three-dimensional cultured human umbilical cord mesenchymal stem cell secretome significantly enhanced the protein expression of vascular endothelial growth factor,interleukin-10,and granulocyte-macrophage colony-stimulating factor in the human umbilical cord mesenchymal stem cell secretome.(4)Compared with two-dimensional culture,three-dimensional cultured human umbilical cord mesenchymal stem cell secretome significantly promoted the migration of immortalized human umbilical cord mesenchymal stem cells.(5)Compared with the untreated control group and the two-dimensional cultured human umbilical cord mesenchymal stem cell secretome,the three-dimensional cultured human umbilical cord mesenchymal stem cell secretome can significantly accelerate the skin wound healing rate and wound skin structure remodeling in mice.These results indicate that three-dimensional culture can enhance the expression of paracrine factors of human umbilical cord mesenchymal stem cells,and their secretome can significantly promote the repair of mouse skin damage.

ObjectiveTo investigate the molecular mechanism by which Yifei Xuanfei Jiangzhuo prescription regulates the nuclear factor-κB （NF-κB）/NOD-like receptor protein 3 （NLRP3） signaling pathway to improve neuronal function in vascular dementia （VaD） rats. MethodsA VaD model was established by intermittently clamping the bilateral common carotid arteries （CCA） combined with bilateral vascular occlusion （2-VO）. Eighty-four SD rats were randomly divided into a blank group， sham group， model group， piracetam group （0.2 g·kg^-1）， and low-， medium-， and high-dose Yifei Xuanfei Jiangzhuo prescription groups （6.09， 12.18， and 24.36 g·kg^-1）. Drug administration began on day 7 after surgery， once daily for 28 consecutive days. Behavioral experiments were used to evaluate learning and spatial memory. Hematoxylin-eosin （HE） staining was applied to observe pathological morphological changes in the CA1 region of the hippocampus. Transmission electron microscopy was used to examine the ultrastructure of hippocampal neurons. Terminal deoxynucleotidyl transferase dUTP nick end labeling （TUNEL） was used to detect neuronal apoptosis in the CA1 region. Immunohistochemistry was performed to determine the positive expression rate of neuronal nuclear antigen （NeuN）. Immunofluorescence single staining was used to assess nuclear expression of NF-κB p65 in brain tissue. Western blot was used to detect the protein expression levels of inhibitor of κB kinase （IKK）， NF-κB p65， NLRP3， Caspase-1， apoptosis-associated speck-like protein （ASC）， and interleukin-1β （IL-1β）. ResultsCompared with the blank group， the model group showed a significant reduction in platform-crossing frequency （P0.01）， aggravated hippocampal injury， a significant increase in neuronal apoptosis （P0.05）， decreased NeuN positivity in the CA1 region （P0.05）， increased nuclear expression of NF-κB p65 （P0.05）， and significantly elevated expression of p-IKK， p-NF-κB p65， NLRP3， cleaved Caspase-1， ASC， and cleaved IL-1β （P0.05）. Compared with the model group， all drug-treated groups improved learning and spatial memory in VaD rats， alleviated hippocampal pathological injury and neuronal apoptosis， and protected neuronal ultrastructure. Yifei Xuanfei Jiangzhuo prescription at doses of 12.18 and 24.36 g·kg^-1 reduced hippocampal expression levels of p-IKK， p-NF-κB p65， NLRP3， Caspase-1， ASC， and cleaved IL-1β in VaD rats （P0.05）， showing dose-dependent inhibition of the NF-κB/NLRP3 signaling pathway. ConclusionYifei Xuanfei Jiangzhuo prescription may exert neuroprotective effects by regulating the NF-κB/NLRP3 signaling pathway， thereby reducing neuroinflammation and inhibiting hippocampal neuronal apoptosis.

ObjectiveTo investigate the molecular mechanism by which Yifei Xuanfei Jiangzhuo prescription regulates the nuclear factor-κB （NF-κB）/NOD-like receptor protein 3 （NLRP3） signaling pathway to improve neuronal function in vascular dementia （VaD） rats. MethodsA VaD model was established by intermittently clamping the bilateral common carotid arteries （CCA） combined with bilateral vascular occlusion （2-VO）. Eighty-four SD rats were randomly divided into a blank group， sham group， model group， piracetam group （0.2 g·kg^-1）， and low-， medium-， and high-dose Yifei Xuanfei Jiangzhuo prescription groups （6.09， 12.18， and 24.36 g·kg^-1）. Drug administration began on day 7 after surgery， once daily for 28 consecutive days. Behavioral experiments were used to evaluate learning and spatial memory. Hematoxylin-eosin （HE） staining was applied to observe pathological morphological changes in the CA1 region of the hippocampus. Transmission electron microscopy was used to examine the ultrastructure of hippocampal neurons. Terminal deoxynucleotidyl transferase dUTP nick end labeling （TUNEL） was used to detect neuronal apoptosis in the CA1 region. Immunohistochemistry was performed to determine the positive expression rate of neuronal nuclear antigen （NeuN）. Immunofluorescence single staining was used to assess nuclear expression of NF-κB p65 in brain tissue. Western blot was used to detect the protein expression levels of inhibitor of κB kinase （IKK）， NF-κB p65， NLRP3， Caspase-1， apoptosis-associated speck-like protein （ASC）， and interleukin-1β （IL-1β）. ResultsCompared with the blank group， the model group showed a significant reduction in platform-crossing frequency （P0.01）， aggravated hippocampal injury， a significant increase in neuronal apoptosis （P0.05）， decreased NeuN positivity in the CA1 region （P0.05）， increased nuclear expression of NF-κB p65 （P0.05）， and significantly elevated expression of p-IKK， p-NF-κB p65， NLRP3， cleaved Caspase-1， ASC， and cleaved IL-1β （P0.05）. Compared with the model group， all drug-treated groups improved learning and spatial memory in VaD rats， alleviated hippocampal pathological injury and neuronal apoptosis， and protected neuronal ultrastructure. Yifei Xuanfei Jiangzhuo prescription at doses of 12.18 and 24.36 g·kg^-1 reduced hippocampal expression levels of p-IKK， p-NF-κB p65， NLRP3， Caspase-1， ASC， and cleaved IL-1β in VaD rats （P0.05）， showing dose-dependent inhibition of the NF-κB/NLRP3 signaling pathway. ConclusionYifei Xuanfei Jiangzhuo prescription may exert neuroprotective effects by regulating the NF-κB/NLRP3 signaling pathway， thereby reducing neuroinflammation and inhibiting hippocampal neuronal apoptosis.

BACKGROUND:The mesenchymal stem cell secretome contains bioactive substances,cytokines,and growth factors.Three-dimensional cell culture can regulate the secretion of these components,potentially enhancing the ability to promote injury repair.OBJECTIVE:To investigate the repair effect of three-dimensional cultured human umbilical cord mesenchymal stem cell secretome on skin injuries in mice.METHODS:Human umbilical cord mesenchymal stem cells were cultured in conventional two-dimensional culture dishes and 96-well U-bottom cell culture plates,from which their secretory components were subsequently collected.The expression of skin damage repair related secretory factors in umbilical cord mesenchymal stem cells was analyzed using RT-qPCR.The protein expression level of skin damage repair related factors in umbilical cord mesenchymal stem cell secretome was detected using enzyme-linked immunosorbent assay.The potential of human umbilical cord mesenchymal stem cell secretome to repair vascular injuries was evaluated using an immortalized human umbilical vein endothelial cell migration model.A mouse skin injury model was established,and the human umbilical cord mesenchymal stem cell secretome was injected subcutaneously.Repair effects on skin injury were assessed through wound healing rates and histopathological analysis.RESULTS AND CONCLUSION:(1)After three days of cultivation,human umbilical cord mesenchymal stem cells cultured in two dimensions exhibited a fibroblast-like,swirling growth pattern,whereas three-dimensional culture led to the formation of uniform microspheres.(2)Compared with two-dimensional culture,three-dimensional culture significantly increased the mRNA expression of transforming growth factor β and basic fibroblast growth factor in human umbilical cord mesenchymal stem cells.(3)Compared with two-dimensional culture,three-dimensional cultured human umbilical cord mesenchymal stem cell secretome significantly enhanced the protein expression of vascular endothelial growth factor,interleukin-10,and granulocyte-macrophage colony-stimulating factor in the human umbilical cord mesenchymal stem cell secretome.(4)Compared with two-dimensional culture,three-dimensional cultured human umbilical cord mesenchymal stem cell secretome significantly promoted the migration of immortalized human umbilical cord mesenchymal stem cells.(5)Compared with the untreated control group and the two-dimensional cultured human umbilical cord mesenchymal stem cell secretome,the three-dimensional cultured human umbilical cord mesenchymal stem cell secretome can significantly accelerate the skin wound healing rate and wound skin structure remodeling in mice.These results indicate that three-dimensional culture can enhance the expression of paracrine factors of human umbilical cord mesenchymal stem cells,and their secretome can significantly promote the repair of mouse skin damage.

Objective This study conducted molecular biological identification of the viruses carried by Culex pipiens pallens specimens collected in Shunyi District, Beijing in 2023, and observed the changes in the infection rate of the viruses carried by Cx. pipiens pallens at different collection times. Methods Cx. pipiens pallens were collected using carbon dioxide mosquito traps. The mosquito samples were ground in batches and analyzed by molecular biology technologies. The virus infection rate at different collection times was analyzed statistically. Results 17 strains of Culex pipiens pallens densovirus(CppDNV)were identified from Cx. pipiens pallens samples collected in Shunyi District, Beijing, in 2023. The nucleotide sequence analysis of the virus genome coding region showed that CppDNV was a single-stranded DNA virus with a total length of 3 335 nt, encoding 2 non-structural proteins(NS1, NS2)and 1 capsid protein(VP). The nucleotide(amino acid)sequence lengths of the three proteins were 2 376 nt(791 aa),1 092 nt(363 aa)and 1 071 nt(356 aa), respectively. Phylogenetic analysis showed that CppDNV was located in genus Brevihamaparvovirus. Statistical analysis showed no significant difference in infection rates across collection times(χ2=4.429, P=0.194). Conclusions CppDNV was identified in Cx. pipiens pallens in Beijing, and it was stably maintained in this natural population.

The fibrillization of α-synuclein(α-syn)is a key pathological hallmark of Parkinson's disease.Although biointerfaces play a crucial role in α-syn aggregation,the chiral regulation mechanisms remain insufficiently explored.In this work,chiral carbon dots(CD)were employed to construct nanoscale chiral interfaces,and surface-enhanced infrared absorption spectroscopy combined with nanoscale infrared spectroscopy was utilized to investigate the conformational transition ofα-syn at chiral interfaces.The results demonstrated that α-syn primarily adsorbed onto the chiral interfaces via electrostatic interactions,while spatial selectivity further modulated its conformational evolution.Notably,the D-CD interface exhibited high affinity,stabilizingα-syn in its helical conformation,whereas the L-CD and DL-CD interfaces,due to their weaker affinity,exposed aggregation-prone regions,thereby promotingβ-sheet formation and leading to the generation of oligomers and fibrils.This work elucidated the regulatory role of chiral interfaces inα-syn aggregation,providing theoretical insights for the design of protein aggregation inhibitors.

Using surface-enhanced infrared absorption spectroscopy in conjunction with electrochemical techniques,this study investigates the origins of variations in electrocatalytic activity of 4-nitrothiophenol(4-NTP)under the influence of three cations:Li+,Na+,and tetramethylammonium(TMA+).The findings highlight the significant impact of specific interactions between cations and the electrode surface on electrocatalytic activity.By constructing vibrational Stark spectra,the study reveals the impact of cations on the structure of the electric double layer and the interfacial electric field.Further spectroscopic and electrochemical characterizations demonstrate that differences in the hydrophilic and hydrophobic properties of cations influence their specific interactions with the interface.Notably,TMA+,through specific interactions,acts as a mediator for charge transfer,effectively reducing the charge transfer resistance of the system and thereby enhancing electrocatalytic activity to some extent.These results elucidate the influence of specific cation/interface interactions and cation properties on electrocatalytic reactions,contributing to a deeper understanding of cation effects at electrochemical charged interfaces.

Objective:To investigate the changes in accommodative facility after implantation of V4c implantable collamer lens (ICL) using the intelligent flipper (iFLIP).Methods:A serial case-control study was conducted.Forty patients (80 eyes) who underwent ICL implantation of V4c for myopia correction and completed the follow-up were enrolled at the Affiliated Hospital of Guizhou Medical University from April 2022 to April 2023.Monocular and binocular accommodative facility, adjustment time, and relaxation time were measured with iFLIP before operation and at 1 week, 1 month, 3 months, and 6 months after operation.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of the Affiliated Hospital of Guizhou Medical University (No.2023-983).Written informed consent was obtained from each subject.Results:Monocular and binocular uncorrected visual acuity at 1 week, 1 month, 3 months and 6 months after surgery were significantly improved compared with before surgery, and the differences were statistically significant (all P<0.05).Monocular and binocular postoperative accommodative facility gradually increased over time, and the increase gradually decreased and gradually stabilized.Before operation and 1 week, 1 month, 3 months, and 6 months after operation, the monocular accommodative facility was (7.99±3.42), (10.19±4.25), (12.03±4.24), (13.10±4.66) and (13.64±4.40)cpm, and the binocular accommodative facility was (9.01±3.63), (9.56±3.38), (11.58±4.00), (13.31±3.64), and (14.03±3.72)cpm, respectively, with statistically significant overall differences ( F=24.02, 14.46; both P<0.001).Monocular accommodative facility was higher than before surgery at each time point after surgery, and was higher than 1 week after surgery at 1, 3, and 6 months after surgery, with statistically significant differences (all P<0.05).Binocular accommodative facility was higher at 1, 3, and 6 months after surgery than that before surgery and 1 week after surgery, and higher at 3 and 6 months after surgery than that at 1 month after surgery, with statistically significant differences (all P<0.05).With the extension of postoperative time, the monocular and binocular adjustment time and relaxation time gradually shortened, and the shortening gradually decreased and stabilized.Monocular adjustment time and relaxation time were shorter than before surgery at all time points after surgery.The monocular adjustment time was shorter at 1, 3 and 6 months after surgery than that at 1 week after surgery and shorter at 3 and 6 months after surgery than that at 1 month after surgery, and the monocular relaxation time was shorter at 3 and 6 months after surgery than that at 1 week after surgery, and the differences were statistically significant (all P<0.05).The binocular adjustment time was shorter at 1, 3 and 6 months after surgery than before surgery and at 1 week after surgery, shorter at 3 and 6 months after surgery than at 1 month after surgery and the binocular relaxation time was shorter at all time points after surgery than that before surgery, showing statistically significant differences (all P<0.05). Conclusions:After ICL implantation, uncorrected visual acuity, accommodative facility, adjustment time and relaxation time all improve throughout the preoperative period and eventually stabilize.

OBJECTIVE: To explore the protective effects and underlying mechanisms of H ₂S against lipid peroxidation-mediated carbonyl stress in the uranium-treated NRK-52E cells. METHODS: Cell viability was evaluated using CCK-8 assay. Apoptosis was measured using flow cytometry. Reagent kits were used to detect carbonyl stress markers malondialdehyde, 4-hydroxynonenal, thiobarbituric acid reactive substances, and protein carbonylation. Aldehyde-protein adduct formation and alcohol dehydrogenase, aldehyde dehydrogenase 2, aldo-keto reductase, nuclear factor E2-related factor 2 (Nrf2), and cystathionine β-synthase (CBS) expression were determined using western blotting or real-time PCR. Sulforaphane (SFP) was used to activate Nrf2. RNA interference was used to inhibit CBS expression. RESULTS: GYY4137 (an H ₂S donor) pretreatment significantly reversed the uranium-induced increase in carbonyl stress markers and aldehyde-protein adducts. GYY4137 effectively restored the uranium-decreased Nrf2 expression, nuclear translocation, and ratio of nuclear to cytoplasmic Nrf2, accompanied by a reversal of the uranium-decreased expression of CBS and aldehyde-metabolizing enzymes. The application of CBS siRNA efficiently abrogated the SFP-enhanced effects on the expression of CBS, Nrf2 activation, nuclear translocation, and ratio of nuclear to cytoplasmic Nrf2 and concomitantly reversed the SFP-enhanced effects of the uranium-induced mRNA expression of aldehyde-metabolizing enzymes. Simultaneously, CBS siRNA reversed the SFP-mediated alleviation of the uranium-induced increase in reactive aldehyde levels, apoptosis rates, and uranium-induced cell viability. CONCLUSION H ₂S induces Nrf2 activation and nuclear translocation, which modulates the expression of aldehyde-metabolizing enzymes and the CBS/H ₂S axis. Simultaneously, the Nrf2-controlled CBS/H ₂S axis may at least partially promote Nrf2 activation and nuclear translocation. These events form a cycle-regulating mode through which H ₂S attenuates the carbonyl stress-mediated NRK-52E cytotoxicity triggered by uranium.
NF-E2-Related Factor 2/genetics* ; Animals ; Hydrogen Sulfide/pharmacology* ; Rats ; Signal Transduction/drug effects* ; Lipid Peroxidation/drug effects* ; Cell Line ; Uranium/toxicity* ; Antioxidant Response Elements ; Kidney/metabolism* ; Oxidative Stress/drug effects* ; Cell Survival/drug effects* ; Apoptosis/drug effects*