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.

ObjectiveIn the context of the digital transformation of education, this study aims to construct a triadic interactive teaching model for surgical animal surgery in clinical medicine using modern information technology. It explores the effectiveness of different teaching methods in improving students' practical skills, aseptic awareness, and teamwork abilities, providing a reference for the reform of clinical practice education. MethodsA quasi-experimental research design was adopted. A total of 80 students from the eight-year clinical medicine program at Nanjing University were selected, including the Class of 2020 (control group, n=40) and the Class of 2021 (experimental group, n=40). The control group received traditional teaching methods, while the experimental group implemented the "Teacher-Student-AI" triadic interactive teaching model. This model utilized a smart teaching platform for personalized pre-class preparation , as well as data-driven post-class review and feedback throughout the entire teaching process. The "assessment indicators and scoring criteria for the surgical animal surgery course" were used to evaluate teaching effectiveness, with independent samples t-tests used for statistical analysis. ResultsPre-course assessments revealed no statistically significant differences in baseline theoretical knowledge or practical skills between the two groups (P>0.05). Upon completion of the course, the experimental group achieved higher scores than the control group across three key dimensions: practical skills (47.98±1.34 vs 46.92±2.51, P=0.022), aseptic awareness (17.84±1.16 vs 16.94±2.29, P=0.029), and teamwork (16.82±1.44 vs 15.95±1.22, P=0.004). However, no statistically significant difference was observed in the scores for humane care awareness between the two groups (8.24±0.70 vs 8.16±0.53, P=0.589). ConclusionThe AI-based triadic interactive teaching model can, to some extent, address the limitations of traditional surgical animal surgery education. It plays a positive role in enhancing medical students' surgical skills, aseptic awareness, and collaborative abilities. This model facilitates the transition from traditional to personalized teaching and offers a practical framework for the digital reform of clinical practice education.

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 Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe²⁺), whereas clMagR favors ferric iron (Fe³⁺) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe²⁺-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe²⁺/Fe³⁺ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.

Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe²⁺), whereas clMagR favors ferric iron (Fe³⁺) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe²⁺-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe²⁺/Fe³⁺ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.

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.

Objective To investigate the species composition of mosquitoes and breeding conditions of larvae in the rice planting areas of Beijing, and to provide a scientific basis for mosquito control in rice fields. Methods Adult mosquitoes were collected using CO2-baited light traps, and mosquito larvae(including pupae)were sampled via the dipping method. Results A total of 4 genera and 6 species of adult mosquitoes were captured in the study area. The dominant species were Culex pipiens pallens, Cx. tritaeniorhynchus, and Anopheles sinensis. The average adult mosquito density was 5.11 specimens per trap-hour, with slightly lower density in July compared to August. For larvae and pupae,3 genera and 4 species were identified, dominated by Cx. tritaeniorhynchus, An. sinensis, and Aedes vexans. Conclusions The mosquito species composition in Beijing′s rice planting areas is diverse. Mosquito control strategies should prioritize the management of adult mosquitoes, while density control of mosquito larvae in paddy fields can be achieved through intermittent irrigation techniques.

ObjectiveTo analyze the adverse reactions associated with the clinical use of Banxia （Rhizoma Pinelliae）- Wutou （Aconitum） in the same formula， with the aim of providing a reference for the safety of their clinical application. MethodsLiterature on the clinical application of antagonistic herbs "Banxia-Wutou" used in the same formula， published from January 1st， 2014， to June 30th， 2023， was retrieved from databases including CNKI， VIP， Wanfang， SinoMed， PubMed， Cochrane Library， and Embase. A database was established， and information related to adverse reactions was extracted， including descriptions， classifications， specific manifestations， management and outcomes， patients' primary diseases （western medicine diseases and traditional Chinese medicine diagnoses and syndromes）， and medication information （dosage， ratio， administration routes， and dosage forms）. ResultsA total of 79 researches simultaneously used antagonistic herbs Banxia-Wutou in the same formula and reported associated advers reactions. Gastrointestinal adverse reactions were the most common， with 8 studies reporting management of adverse reactions and 3 studies reporting improvement with no intervention. Among the 11 researches， the adverse reaction relieved to extant， while other 69 researches didn't report the managment of adverse reaction and its prognosis. For the primary disease in western medicine system， chronic bronchitis and chronic obstructive pulmonary disease （COPD） were most common， while gastric pain was the most common symptom in traditional Chinese medicine with spleen and kidney deficiency and spleen stomach cold deficiency being the most frequent syndromes. The most common Banxia dosage was 10 g， while for the Wutou， Fuzi （Radix Aconiti Lateralis Praeparata） was predominant with the highest dose at 15 g. The most frequent herbal combination was Banxia-fuzi， with a 1∶1 ratio. The main administration route was oral， and the primary dosage form was decoction. ConclusionGastrointestinal adverse reactions are the most common in the clinical use of Banxia-Wutou antagonistic herb combinations. Research on the safety of "Banxia-Wutou" combinations should focus on respiratory system diseases and spleen-stomach related conditions.

Hypothalamic neural stem cells (htNSCs) are a type of glial-like neural stem cell located in the hypothalamus, possessing unique biological characteristics. They not only have the capacity to proliferate and differentiate but can also migrate into the parenchymal regions of the hypothalamus, further developing into neurons and successfully integrating into neural circuits. HtNSCs play multiple key physiological roles in the adult hypothalamus, including contributing to the formation of the blood-hypothalamic barrier (BHB), which is crucial for maintaining the stability of the hypothalamic environment. Through the BHB, htNSCs facilitate the effective diffusion of small molecules between the blood, cerebrospinal fluid, and hypothalamic parenchyma, thereby ensuring the proper transmission of nutrients and signaling molecules. In addition, htNSCs can sense fluctuations in blood glucose levels and regulate the release of neuropeptides accordingly, thus influencing the body’s energy metabolism and endocrine balance. However, as the body ages, the function of htNSCs gradually declines. Studies have shown that the aging of htNSCs has significant adverse effects on energy metabolism, sex hormone secretion, and overall hypothalamic function. During the aging process, the proliferative and differentiative capacities of htNSCs diminish, leading to reduced neuronal replenishment and subsequently impairing the hypothalamus’s ability to regulate energy balance. Furthermore, aging htNSCs may secrete inflammatory factors that disrupt the endocrine functions of the hypothalamus, thereby affecting sex hormone secretion. This impact extends beyond the hypothalamus itself and may exert widespread effects on the entire endocrine system through pathways such as the hypothalamic-pituitary-gonadal axis. Fortunately, research has found that transplanting young htNSCs can effectively alleviate neurological and skeletal muscle dysfunction associated with aging. This transplantation therapy replenishes active htNSCs, restoring normal hypothalamic function and thereby improving the body’s energy metabolism and neuromuscular function. These findings offer new perspectives and potential therapeutic strategies for anti-aging interventions. In recent years, the role of htNSCs in regulating energy metabolism and promoting aging has attracted significant attention from researchers. Studies have shown that the aging of htNSCs is closely linked to the development of various diseases. For instance, in obesity and metabolic syndrome, htNSC dysfunction may lead to disturbances in energy metabolism. Moreover, the aging of htNSCs has also been associated with the onset of neurodegenerative diseases. Therefore, in-depth research into the mechanisms underlying htNSC aging is crucial for understanding the pathogenesis of these conditions. This article briefly reviews the classification of htNSCs, the impacts of their aging on bodily functions, their relationship with related diseases, and the regulatory mechanisms that promote htNSC regeneration. Some strategies aimed at promoting htNSC regeneration and counteracting their aging appear to influence the overall aging phenotype of organisms. For example, studies have shown that modulating specific signaling pathways or gene expression can promote htNSC regeneration, thereby delaying the aging process. Additionally, certain natural products or pharmacological agents may also influence htNSC aging. Further research on htNSC aging will enhance our understanding of the hypothalamus’s role in systemic aging and elucidate the reasons behind gender differences in aging patterns. Moreover, these studies may offer novel approaches and therapeutic targets for improving energy metabolism disorders and treating diseases associated with gonadal hormone abnormalities. In summary, htNSCs play a vital role in the physiological functions of the hypothalamus and the aging process. Further investigation into the mechanisms and regulatory pathways of htNSC aging will aid in the development of new anti-aging therapies and provide innovative strategies for the treatment of related diseases.

ObjectiveTo investigate the chemical constituents of Chuanxiong Rhizoma-Paeoniae Radix Rubra（CRPRR） that cross the blood-brain barrier in rats with ischemic stroke， their brain-protective effects， and their impact on inflammatory factors including tumor necrosis factor-α （TNF-α）， interleukin-1β （IL-1β）， and interleukin-18 （IL-18） based on ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry （UPLC-Q-TOF-MS） and pharmacodynamic experiments. MethodsA focal cerebral ischemia-reperfusion injury model was established in rats via the middle cerebral artery occlusion/reperfusion （MCAO/R） method using intraluminal suture. Neurological function was evaluated using behavioral scoring. UPLC-Q-TOF-MS was employed to identify the chemical constituents of CRPRR that crossed the blood-brain barrier and entered the cerebrospinal fluid in MCAO/R model rats. Male Sprague-Dawley rats were randomly divided into six groups： sham operation group， model group， low-， medium-， and high-dose CRPRR groups （1.35， 2.7， 5.4 g·kg^-1， respectively）， and an edaravone group （5 mg·kg^-1）， with 12 rats in each group. The sham and model groups received normal saline， while the treatment groups received the respective doses of CRPRR once daily by gavage for three consecutive weeks. The brain-protective effects of CRPRR were assessed using the Longa five-point scoring method， open field test， Morris water maze， 2，3，5-triphenyltetrazolium chloride （TTC） staining， hematoxylin and eosin （HE） staining， and transmission electron microscopy. ResultsNine chemical constituents were identified in the cerebrospinal fluid containing CRPRR， namely paeoniflorin， senkyunolide F， senkyunolide G， paeonimetabolin Ⅰ， paeoniflorin derivative， senkyunolide H， benzoylpaeoniflorin， senkyunolide A， and ligustilide. Animal experiment results showed that compared with the sham operation group， the model group exhibited disordered neuronal arrangement， severe vacuolation， nuclear pyknosis， and evident mitochondrial swelling. Chromatin aggregation and peripheralization were also observed. Neurological scores and the number of crossings in the central region were significantly increased （P<0.01）， while platform crossings were significantly decreased （P<0.01）， and clear infarct areas were present （P<0.01）. Serum levels and protein expression of TNF-α， IL-1β， and IL-18 were significantly elevated （P<0.01）. Compared with the model group， all dose groups of CRPRR showed marked improvement in neuronal morphology which was close to the normal level， with mitochondrial swelling alleviated and chromatin distribution more uniform. The medium- and high-dose groups significantly reduced neurological scores （P<0.01）， while the low-， medium-， and high-dose groups significantly reduced the number of central crossings （P<0.01） and infarct volume （P<0.01）， and decreased TNF-α， IL-1β， and IL-18 levels （P<0.05， P<0.01） compared with the model group. Furthermore， the medium- and high-dose groups significantly reduced TNF-α protein expression （P<0.05，P<0.01）， and the high-dose group significantly reduced IL-1β and IL-18 protein expression （P<0.01）. ConclusionThis study confirmed that CRPRR improves neurological function and alleviates brain tissue damage in MCAO/R rats. Its mechanism may be associated with the downregulation of inflammatory factors TNF-α， IL-1β， and IL-18， as well as the presence of nine active chemical constituents in cerebrospinal fluid， namely paeoniflorin， senkyunolide F， senkyunolide G， paeonimetabolin Ⅰ， paeoniflorin derivative， senkyunolide H， benzoylpaeoniflorin， senkyunolide A， and ligustilide， which are closely related to their brain-protective effects.