ObjectiveTo explore the role of cucurbitacin B （CuB） in inducing ferroptosis in 4T1 cells and its mechanism. MethodsThe effects of CuB（0.2， 0.4， 0.8 μmol·L^-1）on the proliferation ability of 4T1 cells in vitro were detected using the methyl thiazolyl tetrazolium （MTT） assay. The clonogenic ability of 4T1 cells was detected by the plate cloning assay， and the levels of lactate dehydrogenase （LDH） in 4T1 cells were detected by the use of a kit. The mitochondrial membrane potential and reactive oxygen species （ROS） levels in 4T1 cells were detected by flow cytometry， and the mitochondrial ultrastructure of 4T1 cells was observed by transmission electron microscopy. The western blot was used to detect the expression of ferroptosis-related protein p53 in 4T1 cells， solute carrier family 7 member 11 （SCL7A11）， glutathione peroxidase 4 （GPX4）， long-chain acyl-CoA synthetase 4 （ACSL4）， transferrin receptor protein 1 （TFR1）， and ferritin heavy chain 1 （FTH1）. ResultsCompared with that in the blank group， the survival rate of 4T1 cells in CuB groups was significantly decreased （P<0.05）， and the number of cell clones in CuB groups was significantly reduced （P<0.01）. In addition， compared with that in the blank group， the leakage of LDH in cells in CuB groups was significantly increased （P<0.01）， and the mitochondrial membrane potential of cells in CuB groups decreased significantly （P<0.01）. Cellular ROS levels were significantly elevated in CuB groups （P<0.01）. The mitochondria of cells in CuB groups were obviously wrinkled， and the mitochondrial cristae were reduced or even disappeared. Compared with that in the blank group， the protein expression of p53， ACSL4， and TFR1 were significantly up-regulated in CuB groups （P<0.05）， and that of SLC7A11， GPX4， and FTH1 were significantly down-regulated （P<0.05）. ConclusionCuB may inhibit SLC7A11 and GPX4 expression by up-regulating the expression of p53， which in turn regulates the p53/SLC7A11/GPX4 signaling pathway axis and accelerates the generation of lipid peroxidation substrate by up-regulating the expression of ACSL4. It up-regulates TFR1 expression to promote cellular uptake of Fe³⁺ and down-regulates the expression of FTH1 to reduce the ability of iron storage， resulting in an elevated free Fe²⁺ level. It catalyzes the Fenton reaction， generates excess ROS， imbalances the antioxidant system and iron metabolism， and then induces ferroptosis in 4T1 cells.

ObjectiveTo explore the role of cucurbitacin B （CuB） in inducing ferroptosis in 4T1 cells and its mechanism. MethodsThe effects of CuB（0.2， 0.4， 0.8 μmol·L^-1）on the proliferation ability of 4T1 cells in vitro were detected using the methyl thiazolyl tetrazolium （MTT） assay. The clonogenic ability of 4T1 cells was detected by the plate cloning assay， and the levels of lactate dehydrogenase （LDH） in 4T1 cells were detected by the use of a kit. The mitochondrial membrane potential and reactive oxygen species （ROS） levels in 4T1 cells were detected by flow cytometry， and the mitochondrial ultrastructure of 4T1 cells was observed by transmission electron microscopy. The western blot was used to detect the expression of ferroptosis-related protein p53 in 4T1 cells， solute carrier family 7 member 11 （SCL7A11）， glutathione peroxidase 4 （GPX4）， long-chain acyl-CoA synthetase 4 （ACSL4）， transferrin receptor protein 1 （TFR1）， and ferritin heavy chain 1 （FTH1）. ResultsCompared with that in the blank group， the survival rate of 4T1 cells in CuB groups was significantly decreased （P<0.05）， and the number of cell clones in CuB groups was significantly reduced （P<0.01）. In addition， compared with that in the blank group， the leakage of LDH in cells in CuB groups was significantly increased （P<0.01）， and the mitochondrial membrane potential of cells in CuB groups decreased significantly （P<0.01）. Cellular ROS levels were significantly elevated in CuB groups （P<0.01）. The mitochondria of cells in CuB groups were obviously wrinkled， and the mitochondrial cristae were reduced or even disappeared. Compared with that in the blank group， the protein expression of p53， ACSL4， and TFR1 were significantly up-regulated in CuB groups （P<0.05）， and that of SLC7A11， GPX4， and FTH1 were significantly down-regulated （P<0.05）. ConclusionCuB may inhibit SLC7A11 and GPX4 expression by up-regulating the expression of p53， which in turn regulates the p53/SLC7A11/GPX4 signaling pathway axis and accelerates the generation of lipid peroxidation substrate by up-regulating the expression of ACSL4. It up-regulates TFR1 expression to promote cellular uptake of Fe³⁺ and down-regulates the expression of FTH1 to reduce the ability of iron storage， resulting in an elevated free Fe²⁺ level. It catalyzes the Fenton reaction， generates excess ROS， imbalances the antioxidant system and iron metabolism， and then induces ferroptosis in 4T1 cells.

Tissue engineering achieves tissue repair and regeneration through the utilization of three essential components: stem cells, scaffold materials, and growth factors. Inducing the adipogenic differentiation of mesenchymal stem cells (MSCs) and constructing engineered adipose tissue represent innovative strategies for addressing soft tissue defects within the field of plastic surgery. Natural biomaterials exhibit physicochemical properties resembling those of the extracellular matrix, thereby fostering the proliferation and differentiation of stem cells. These natural biomaterials serve as suitable scaffold materials for tissue engineering applications. This review provided a comprehensive summary of the characteristics of various natural biomaterials, including decellularized matrix, extracellular matrix derivatives, filamentous proteins, alginate, chitosan, and bacterial cellulose. It further offered a review of research studies pertaining to their capacity to induce adipogenic differentiation in MSCs, thereby offering insights for the selection of materials in subsequent investigations.

Objective:To explore the role of metagenomic next-generation sequencing (mNGS) in the diagnosis of pathogens in primary infectious diseases of the spine (IDS) and to reveal its pathogen spectrum.Methods:This is a retrospective multi-center case series study. Clinical data of 380 patients with primary IDS who were treated at four medical centers in China from December 2019 to April 2024 were retrospectively analyzed. Among them, 82 cases were from the Department of Spine Surgery at the Affiliated Hospital of Qingdao University, 129 cases were from the Orthopedics Section Ⅱ (Bone Infection), Public Health Clinical Center Affiliated to Shandong University, 112 cases were from the Department of Spine Surgery, Fuzhou Second General Hospital, and 57 cases were from the Department of Orthopedic Surgery, Shanghai Sixth People′s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine. There were 238 males and 242 females, with an age of (61.4±13.1) years (range: 10 to 91 years). Specimens from the site of spinal infection were obtained for pathogen culture, pathological examination, and mNGS detection preoperatively or intraoperatively in all patients. The number, types, and positive rates of pathogens detected by the two methods were analyzed and compared using the Chi-square test.Results:Among the 380 patients, 320 had confirmed pathogenic bacteria, with the highest proportion being pyogenic bacterial infections, accounting for 76.9% (246/320). The most common pathogen was Staphylococcus aureus, accounting for 22.8% (73/320). Brucella accounted for 13.8% (44/320); Mycobacterium tuberculosis accounted for 6.3% (20/320). Fungal infections accounted for 3.4% (11/320), mainly Aspergillus and Candida. In addition, Mycoplasma was detected in 3 cases (0.9%) and Benacox body in 4 cases (1.2%). The pathogen spectrum constructed by mNGS covered 46 types of pathogens, higher than the 22 types detected by traditional methods. The positive rate of mNGS was 80.8% (308/381), significantly higher than the 27.9% (106/381) of traditional methods ( χ2=182.53, P<0.01). Conclusions:mNGS improves the positive rate of pathogen diagnosis in IDS, detecting a broader spectrum of pathogens, and serves as a valuable complement to traditional diagnostic methods. Combining both methods in the diagnosis of IDS can maximize detection rates, providing robust evidence for precise anti-infective treatment.

Tissue engineering achieves tissue repair and regeneration through the utilization of three essential components: stem cells, scaffold materials, and growth factors. Inducing the adipogenic differentiation of mesenchymal stem cells (MSCs) and constructing engineered adipose tissue represent innovative strategies for addressing soft tissue defects within the field of plastic surgery. Natural biomaterials exhibit physicochemical properties resembling those of the extracellular matrix, thereby fostering the proliferation and differentiation of stem cells. These natural biomaterials serve as suitable scaffold materials for tissue engineering applications. This review provided a comprehensive summary of the characteristics of various natural biomaterials, including decellularized matrix, extracellular matrix derivatives, filamentous proteins, alginate, chitosan, and bacterial cellulose. It further offered a review of research studies pertaining to their capacity to induce adipogenic differentiation in MSCs, thereby offering insights for the selection of materials in subsequent investigations.

Objective:To investigate the association of urinary cadmium level with body mass index (BMI) and body circumferences among the older adults over 65 years old in 9 longevity areas of China.Methods:Subjects were older adults over 65 years old from the Healthy Aging and Biomarkers Cohort Study (HABCS) between 2017 and 2018 conducted in 9 longevity areas in China. A total of 1 968 older adults were included in this study. Information including socio-demographic characteristics, lifestyles, diet intake, and health status was collected by using questionnaires and physical examinations. Urine samples were collected to detect urinary cadmium and creatinine levels. Body circumferences included waist circumference, hip circumference and calf circumference. Subjects were divided into three groups (low:<0.77 μg/g·creatinine, middle:0.77-1.69 μg/g·creatinine, high:≥1.69 μg/g·creatinine) by tertiles of creatinine-adjusted urinary cadmium concentration. Multiple linear regression models were used to analyze the association of creatinine-adjusted urinary cadmium level with BMI and body circumferences. The dose-response relationship of creatinine-adjusted urinary cadmium concentration with BMI and body circumferences was analyzed by using restrictive cubic splines fitting multiple linear regression model.Results:The mean age of subjects was (83.34±11.14) years old. The median (Q1, Q3) concentration of creatinine-adjusted urinary cadmium was 1.13 (0.63, 2.09) μg/g·creatinine, and the BMI was (22.70±3.82) kg/m 2. The mean values of waist circumference, hip circumference, and calf circumference were (85.42±10.68) cm, (92.67±8.90) cm, and (31.08±4.76) cm, respectively. After controlling confounding factors, the results of the multiple linear regression model showed that for each increment of 1 μg/g·creatinine in creatinine-adjusted urinary cadmium, the change of BMI, waist circumference, hip circumference, and calf circumference in the high-level group was -0.28 (-0.37, -0.19) kg/m 2, -0.74 (-0.96, -0.52) cm, -0.78 (-0.96, -0.61) cm, and -0.20 (-0.30, -0.11) cm, respectively. The restrictive cubic splines curve showed a negative nonlinear association of creatinine-adjusted urinary cadmium with BMI ( Pnonlinear<0.001) and negative linear associations of creatinine-adjusted urinary cadmium with waist circumference ( Plinear<0.001), hip circumference ( Plinear<0.001), and calf circumference ( Plinear<0.001). Conclusion:Urinary cadmium level is significantly associated with decreased BMI, waist circumference, hip circumference and calf circumference among older adults over 65 years old in 9 longevity areas of China.

Objective·To investigate the changes of adipose tissues in mice after high-fat diet before and during pregnancy and the potential effects on adipose tissues in their offspring.Methods·C57BL/6J female mice were randomly assigned to the normal diet(CON group,n=12)or the high-fat diet(HFD group,n=12)for 5 weeks.The two groups were further subdivided according to pregnancy:a normal diet non-pregnancy group(CON-UN group),a normal diet pregnancy group(CON-P group),a high-fat diet non-pregnancy group(HFD-UN group),and a high-fat diet pregnancy group(HFD-P group).The original diet was maintained during pregnancy and lactation.White adipose tissues(WAT)and brown adipose tissues(BAT)were collected from visceral and scapula of mice after 5 weeks of feeding or E18.5d.Offspring from both dietary groups were placed on a normal diet after weaning,and their adipose tissues were collected at the 11th week.H-E staining was used to observe the changes of adipocytes.Flow cytometry was employed to detect the proportions of CD4+T cells,CD8+T cells,total T cells,CD4+T/CD8+T and NK cells in WAT.RT-PCR was used to assess the expression of IL-6 and IL-1β mRNA in WAT.Results·After 5 weeks on a high-fat diet,the body weight of female mice in the HFD group was higher than that in the CON group(P<0.05).Both WAT and BAT weights were markedly increased in the HFD groups before and during pregnancy(both P<0.05).In the WAT from HFD-UN and HFD-P groups,the number of cells within the same visual field decreased,the size of adipose cells varied,the proportion of fat droplets increased and the cell volume expanded.The proportion of lipid drop area to total visual field in the HFD-UN group and HFD-P group was compared with the CON-UN group and CON-P group,respectively,and the difference was statistically significant(all P<0.05).BAT in the HFD-UN and HFD-P groups showed a relatively chaotic arrangement and varying adipocyte sizes,although cell volume remained unchanged.The proportions of CD8+T cells and total T cells in adipose tissues were elevated in the HFD-UN and HFD-P groups,accompanied by increased mRNA levels of IL-6 and IL-1β,respectively,compared with the CON-UN and CON-P groups,and the differences were statistically significant(all P<0.05).NK cells proportions decreased at reproductive age(HFD-UN group)but increased significantly during pregnancy(HFD-P group),showing a divergent trend.Despite a return to a normal diet after weaning,offspring from the high-fat diet group had significantly higher weight of body,WAT and BAT,compared to those of normal diet(all P<0.05),and the volume of WAT was significantly enlarged.Conclusion·A high-fat diet can induce the changes of adipocyte structure and immune cell ratio,and elevate inflammation levels in adipose tissues before and during pregnancy,which also impacts the adipose structure in offspring.Adipose tissue may be a new vector mediating the intergenerational transmission of obesity.

Objective To investigate the effects of melatonin on the cognitive dysfunction induced by D-galactose in mice and the underlying mechanisms involved.Methods Eight-week-old male C57BL/6 mice were randomly divided into three groups:the control group,D-galactose group and D-galactose+melatonin group.D-galactose was administered by intraperitoneal injection(100 mg/kg),and melatonin was administered by gavage(10 mg/kg)once a day for three months.The Morris water maze was used to assess cognitive function.The effect of melatonin on synaptic plasticity was observed by long-term potentia-tion(LTP).The expression levels of PSD95,SYN,SIRT1 and BDNF in the hippocampus and cortex of the mice were determined by Western blotting.Results Compared with the control group,the D-gal group presented a longer escape latency,significantly shorter target quadrant dwell time(P＜0.05),impaired LTP(P＜0.01),and significantly lower PSD95,Synaptophysin and BD-NF protein levels in the hippocampus and cortical tissues(P＜0.05).The escape latency of the mice in the D-gal+MLT group significantly decreased(P＜0.05),and LTP induction significantly improved(P＜0.01).PSD95,Synaptophysin,SIRT1 and BD-NF protein levels in the hippocampus and cortex were significantly increased in the D-gal+MLT group(P＜0.05).Conclusion Melatonin can significantly improve the cognitive function of mice treated with D-galactose via a mechanism related to increasing the expression level of SIRT1-BDNF and improving the synaptic plasticity of mice,as shown by increased LTP in the hippocam-pal CA1 region.

Objective:To explore the role of metagenomic next-generation sequencing (mNGS) in the diagnosis of pathogens in primary infectious diseases of the spine (IDS) and to reveal its pathogen spectrum.Methods:This is a retrospective multi-center case series study. Clinical data of 380 patients with primary IDS who were treated at four medical centers in China from December 2019 to April 2024 were retrospectively analyzed. Among them, 82 cases were from the Department of Spine Surgery at the Affiliated Hospital of Qingdao University, 129 cases were from the Orthopedics Section Ⅱ (Bone Infection), Public Health Clinical Center Affiliated to Shandong University, 112 cases were from the Department of Spine Surgery, Fuzhou Second General Hospital, and 57 cases were from the Department of Orthopedic Surgery, Shanghai Sixth People′s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine. There were 238 males and 242 females, with an age of (61.4±13.1) years (range: 10 to 91 years). Specimens from the site of spinal infection were obtained for pathogen culture, pathological examination, and mNGS detection preoperatively or intraoperatively in all patients. The number, types, and positive rates of pathogens detected by the two methods were analyzed and compared using the Chi-square test.Results:Among the 380 patients, 320 had confirmed pathogenic bacteria, with the highest proportion being pyogenic bacterial infections, accounting for 76.9% (246/320). The most common pathogen was Staphylococcus aureus, accounting for 22.8% (73/320). Brucella accounted for 13.8% (44/320); Mycobacterium tuberculosis accounted for 6.3% (20/320). Fungal infections accounted for 3.4% (11/320), mainly Aspergillus and Candida. In addition, Mycoplasma was detected in 3 cases (0.9%) and Benacox body in 4 cases (1.2%). The pathogen spectrum constructed by mNGS covered 46 types of pathogens, higher than the 22 types detected by traditional methods. The positive rate of mNGS was 80.8% (308/381), significantly higher than the 27.9% (106/381) of traditional methods ( χ2=182.53, P<0.01). Conclusions:mNGS improves the positive rate of pathogen diagnosis in IDS, detecting a broader spectrum of pathogens, and serves as a valuable complement to traditional diagnostic methods. Combining both methods in the diagnosis of IDS can maximize detection rates, providing robust evidence for precise anti-infective treatment.

Objective:To investigate the association of urinary cadmium level with body mass index (BMI) and body circumferences among the older adults over 65 years old in 9 longevity areas of China.Methods:Subjects were older adults over 65 years old from the Healthy Aging and Biomarkers Cohort Study (HABCS) between 2017 and 2018 conducted in 9 longevity areas in China. A total of 1 968 older adults were included in this study. Information including socio-demographic characteristics, lifestyles, diet intake, and health status was collected by using questionnaires and physical examinations. Urine samples were collected to detect urinary cadmium and creatinine levels. Body circumferences included waist circumference, hip circumference and calf circumference. Subjects were divided into three groups (low:<0.77 μg/g·creatinine, middle:0.77-1.69 μg/g·creatinine, high:≥1.69 μg/g·creatinine) by tertiles of creatinine-adjusted urinary cadmium concentration. Multiple linear regression models were used to analyze the association of creatinine-adjusted urinary cadmium level with BMI and body circumferences. The dose-response relationship of creatinine-adjusted urinary cadmium concentration with BMI and body circumferences was analyzed by using restrictive cubic splines fitting multiple linear regression model.Results:The mean age of subjects was (83.34±11.14) years old. The median (Q1, Q3) concentration of creatinine-adjusted urinary cadmium was 1.13 (0.63, 2.09) μg/g·creatinine, and the BMI was (22.70±3.82) kg/m 2. The mean values of waist circumference, hip circumference, and calf circumference were (85.42±10.68) cm, (92.67±8.90) cm, and (31.08±4.76) cm, respectively. After controlling confounding factors, the results of the multiple linear regression model showed that for each increment of 1 μg/g·creatinine in creatinine-adjusted urinary cadmium, the change of BMI, waist circumference, hip circumference, and calf circumference in the high-level group was -0.28 (-0.37, -0.19) kg/m 2, -0.74 (-0.96, -0.52) cm, -0.78 (-0.96, -0.61) cm, and -0.20 (-0.30, -0.11) cm, respectively. The restrictive cubic splines curve showed a negative nonlinear association of creatinine-adjusted urinary cadmium with BMI ( Pnonlinear<0.001) and negative linear associations of creatinine-adjusted urinary cadmium with waist circumference ( Plinear<0.001), hip circumference ( Plinear<0.001), and calf circumference ( Plinear<0.001). Conclusion:Urinary cadmium level is significantly associated with decreased BMI, waist circumference, hip circumference and calf circumference among older adults over 65 years old in 9 longevity areas of China.