BACKGROUND:Autologous bone,allogeneic bone or artificial bone has been used to promote bone defect repair in the clinic,but the rate of non-healing is still high.The key is to ignore the importance of periosteum in the bone healing process.In the early stage of the project,the project team constructed an electrospinning membrane loaded with vascular endothelial growth factor to highly simulate the intramembranous osteogenesis of natural periosteum at the bone defect site,which promoted bone regeneration to a certain extent.However,the injured area often faces the dilemma of severe inflammatory response mediated by macrophages and lack of seed cells,resulting in the risk of inactivation or diffusion of delivered biological factors.Therefore,it is necessary to further optimize and coordinate the immune regulation and angiogenesis functions of biomimetic periosteum to promote bone repair.OBJECTIVE:To investigate the physicochemical properties of stem cell-engineered bionic periosteum and its role in regulating the inflammatory microenvironment to promote bone repair.METHODS:By combining L-polylactic acid-based microsol electrospinning,type Ⅰ collagen self-assembly and gel stem cell transplantation technology,a bionic periosteum(M@C-B)was constructed,in which the core layer loaded with vascular endothelial growth factor and the shell layer delivered bone marrow mesenchymal stem cells to regulate the immune microenvironment of bone defects.The physicochemical properties of the periosteum were characterized by scanning electron microscopy,transmission electron microscopy,and Fourier transform infrared spectroscopy.A co-culture system was established between the bionic periosteum and macrophages,bone marrow mesenchymal stem cells and human umbilical vein endothelial cells to explore immune regulation and in vitro osteogenic and angiogenic abilities.Finally,the osteogenic properties of the stem cell engineered bionic periosteum were further verified in a rat femoral condyle defect model.RESULTS AND CONCLUSION:(1)Transmission electron microscopy results showed that the micro-sol electrospinning(MS)formed a distinct core-shell structure.Scanning electron microscopy indicated that after the assembly of the collagen-l artificial periosteum(M@C)on the surface of the vascular endothelial growth factor-loaded micro-sol,a distinct"spider web-like"fibrous structure was deposited.Infrared spectroscopy further confirmed the successful self-assembly of collagen-l.Release experiments demonstrated that the M@C group mitigated the burst release phenomenon compared to the MS group,maintaining internal vascular endothelial growth factor activity and sustained release.(2)Live/dead cell staining and CCK-8 assay showed that bone marrow mesenchymal stem cells proliferated well and survived on three types of artificial periosteum:MS,purely aligned poly(L-lactic acid)(PLLA)surface self-assembled collagen-l artificial periosteum(PLLA@C),and vascular endothelial growth factor-loaded micro-sol fiber surface self-assembled collagen-l-bone marrow mesenchymal stem cells artificial periosteum(M@C-B).Among them,the M@C-B group had the highest number of live cells and the fastest proliferation rate.(3)Alkaline phosphatase staining,alizarin red staining,and osteopontin immunofluorescence staining showed that the PLLA@C and M@C-B groups significantly promoted osteogenic differentiation of bone marrow mesenchymal stem cells.Angiogenesis experiments demonstrated that the vascular endothelial growth factor-loaded groups(MS and M@C-B)had longer blood vessel lengths and more reticular vascular-like structures with more cross-linked nodes,with the M@C-B group being the most prominent.(4)Immunofluorescence and flow cytometry showed that artificial periosteum in the M@C-B group significantly inhibited the pro-inflammatory macrophage phenotype and promoted the polarization of macrophages towards the anti-inflammatory M2 phenotype.(5)In vivo studies further confirmed that the M@C-B group showed superior bone mineral density,trabecular thickness,relative bone volume,and trabecular spacing compared to other groups.(6)These results indicate that bone marrow mesenchymal stem cell-engineered artificial periosteum,through the rapid regulation of the bone defect immune microenvironment by the collagen-l-bone marrow mesenchymal stem cells outer phase and the sustained release of vascular endothelial growth factor by the micro-sol electrospinning core-shell structure of the inner phase,synergistically promotes bone healing.

BACKGROUND:Autologous bone,allogeneic bone or artificial bone has been used to promote bone defect repair in the clinic,but the rate of non-healing is still high.The key is to ignore the importance of periosteum in the bone healing process.In the early stage of the project,the project team constructed an electrospinning membrane loaded with vascular endothelial growth factor to highly simulate the intramembranous osteogenesis of natural periosteum at the bone defect site,which promoted bone regeneration to a certain extent.However,the injured area often faces the dilemma of severe inflammatory response mediated by macrophages and lack of seed cells,resulting in the risk of inactivation or diffusion of delivered biological factors.Therefore,it is necessary to further optimize and coordinate the immune regulation and angiogenesis functions of biomimetic periosteum to promote bone repair.OBJECTIVE:To investigate the physicochemical properties of stem cell-engineered bionic periosteum and its role in regulating the inflammatory microenvironment to promote bone repair.METHODS:By combining L-polylactic acid-based microsol electrospinning,type Ⅰ collagen self-assembly and gel stem cell transplantation technology,a bionic periosteum(M@C-B)was constructed,in which the core layer loaded with vascular endothelial growth factor and the shell layer delivered bone marrow mesenchymal stem cells to regulate the immune microenvironment of bone defects.The physicochemical properties of the periosteum were characterized by scanning electron microscopy,transmission electron microscopy,and Fourier transform infrared spectroscopy.A co-culture system was established between the bionic periosteum and macrophages,bone marrow mesenchymal stem cells and human umbilical vein endothelial cells to explore immune regulation and in vitro osteogenic and angiogenic abilities.Finally,the osteogenic properties of the stem cell engineered bionic periosteum were further verified in a rat femoral condyle defect model.RESULTS AND CONCLUSION:(1)Transmission electron microscopy results showed that the micro-sol electrospinning(MS)formed a distinct core-shell structure.Scanning electron microscopy indicated that after the assembly of the collagen-l artificial periosteum(M@C)on the surface of the vascular endothelial growth factor-loaded micro-sol,a distinct"spider web-like"fibrous structure was deposited.Infrared spectroscopy further confirmed the successful self-assembly of collagen-l.Release experiments demonstrated that the M@C group mitigated the burst release phenomenon compared to the MS group,maintaining internal vascular endothelial growth factor activity and sustained release.(2)Live/dead cell staining and CCK-8 assay showed that bone marrow mesenchymal stem cells proliferated well and survived on three types of artificial periosteum:MS,purely aligned poly(L-lactic acid)(PLLA)surface self-assembled collagen-l artificial periosteum(PLLA@C),and vascular endothelial growth factor-loaded micro-sol fiber surface self-assembled collagen-l-bone marrow mesenchymal stem cells artificial periosteum(M@C-B).Among them,the M@C-B group had the highest number of live cells and the fastest proliferation rate.(3)Alkaline phosphatase staining,alizarin red staining,and osteopontin immunofluorescence staining showed that the PLLA@C and M@C-B groups significantly promoted osteogenic differentiation of bone marrow mesenchymal stem cells.Angiogenesis experiments demonstrated that the vascular endothelial growth factor-loaded groups(MS and M@C-B)had longer blood vessel lengths and more reticular vascular-like structures with more cross-linked nodes,with the M@C-B group being the most prominent.(4)Immunofluorescence and flow cytometry showed that artificial periosteum in the M@C-B group significantly inhibited the pro-inflammatory macrophage phenotype and promoted the polarization of macrophages towards the anti-inflammatory M2 phenotype.(5)In vivo studies further confirmed that the M@C-B group showed superior bone mineral density,trabecular thickness,relative bone volume,and trabecular spacing compared to other groups.(6)These results indicate that bone marrow mesenchymal stem cell-engineered artificial periosteum,through the rapid regulation of the bone defect immune microenvironment by the collagen-l-bone marrow mesenchymal stem cells outer phase and the sustained release of vascular endothelial growth factor by the micro-sol electrospinning core-shell structure of the inner phase,synergistically promotes bone healing.

G protein-coupled receptors (GPCRs) are significant drug targets, but their potential in cancer therapy remains underexplored. Conventional GPCR agonists or antagonists have shown limited effectiveness in cancer treatment, necessitating new GPCR-targeting strategies for more effective therapies. This study discovers that Yersinia pestis LcrV, a crucial linker protein for plague infection, acts as a biased agonist of a GPCR, the formyl peptide receptor 1 (FPR1). The LcrV protein induces unique conformational changes in FPR1, resulting in G proteins being activated in a distinctive state without subunit dissociation. This leads to a biased signaling profile characterized by cyclic adenosine monophosphate (cAMP) responses and β-arrestin2 recruitment, but not calcium mobilization. In FPR1-expressing triple-negative breast cancer (TNBC) cells, LcrV bi-directionally modulates intracellular signaling pathways, downregulating extracellular signal-regulated kinases (ERK1/2) and Akt pathways while upregulating Jun N-terminal kinase (JNK) and p38 pathways. This dual modulation results in cell cycle arrest and the inhibition of TNBC cell proliferation. In TNBC xenograft mouse models, long-term LcrV treatment inhibits tumor growth more effectively than a conventional FPR1 antagonist. Additionally, LcrV treatment reprograms tumor cells by reducing stemness-associated proteins OCT4 and c-MYC. Our findings highlight the potential of biased GPCR agonists as a novel GPCR-targeting strategy for cancer treatment.

ObjectiveTo investigate the effect of Liuwei Dihuangwan drug-containing serum （LDP） on epithelial-mesenchymal transition （EMT） and the expression of cancer stem cell （CSC） properties in 4T1 cells from triple-negative breast cancer by intervening myeloid-derived suppressor cells （MDSCs）. MethodsSPF-grade female SD rats were randomly divided into three groups， which were given 0.39， 1.94， 3.89 g·kg^-1·d^-1 suspension of Liuwei Dihuangwan for 7 days， respectively， to prepare low-， medium-， and high-dose LDPs. 4T1 cells were inoculated subcutaneously into the mammary glands of SPF-grade female Balb/c mice to construct a transplantation tumor model. Bone marrow cells were extracted from the tibia and femur and induced into MDSCs in vitro. The cell counting kit-8 （CCK-8） assay was used to detect the viability of 4T1 cells and MDSCs. The number of MDSCs and the expressions of CSC surface markers CD44 and CD24 in 4T1 cells were detected by flow cytometry （FC）. The migration， invasion， and proliferation of 4T1 cells were detected by cell scratch assay， Transwell invasion assay， and plate colony-forming assay， respectively. Western blot （WB） was used to detect the protein expression of transforming growth factor-β （TGF-β）， nuclear factor-κB （NF-κB）， C-X-C motif chemokine ligand 2 （CXCL2）， E-cadherin， and N-cadherin. The expression of EMT-related proteins E-cadherin and N-cadherin were detected by immunofluorescence （IF）. ResultsCompared with the normal group， LDP showed no significant inhibitory effect on the cell viability of 4T1 cells， but it significantly reduced the viability and number of MDSCs and reduced the number of MDSCs， as well as the expression of TGF-β （P<0.05， P<0.01）. The migration， invasion， and proliferation of 4T1 cells were increased after co-culture with MDSCs （P<0.05， P<0.01）. The expressions of NF-κB， CXCL2， and N-cadherin and the proportion of CSC （CD44⁺CD24^-） were elevated （P<0.05， P<0.01）， while the expression of E-cadherin was decreased （P<0.05）. After the intervention of MDSCs with LDP， followed by co-culture with 4T1 cells， the migration， invasion， and proliferation of 4T1 cells were obviously reduced （P<0.01）. The expressions of NF-κB， CXCL2， and N-cadherin were decreased （P<0.05， P<0.01）， and the expression of E-cadherin was increased （P<0.05， P<0.01）. There was no statistical difference in the proportion of CSC （CD44⁺CD24^-） in 4T1 cells. However， the proportion of CSC （CD44⁺CD24^-） was decreased in the co-culture system of 4T1 cells and MDSCs with LDP intervention （P<0.05， P<0.01）. ConclusionLDP can reduce the viability and number of MDSCs and the expression of TGF-β， NF-κB， and CXCL2， reverse EMT， and reduce the characteristic expression of CSC to inhibit the migration， invasion， and proliferation of 4T1 cells.

ObjectiveTo investigate the effect of Liuwei Dihuangwan drug-containing serum （LDP） on epithelial-mesenchymal transition （EMT） and the expression of cancer stem cell （CSC） properties in 4T1 cells from triple-negative breast cancer by intervening myeloid-derived suppressor cells （MDSCs）. MethodsSPF-grade female SD rats were randomly divided into three groups， which were given 0.39， 1.94， 3.89 g·kg^-1·d^-1 suspension of Liuwei Dihuangwan for 7 days， respectively， to prepare low-， medium-， and high-dose LDPs. 4T1 cells were inoculated subcutaneously into the mammary glands of SPF-grade female Balb/c mice to construct a transplantation tumor model. Bone marrow cells were extracted from the tibia and femur and induced into MDSCs in vitro. The cell counting kit-8 （CCK-8） assay was used to detect the viability of 4T1 cells and MDSCs. The number of MDSCs and the expressions of CSC surface markers CD44 and CD24 in 4T1 cells were detected by flow cytometry （FC）. The migration， invasion， and proliferation of 4T1 cells were detected by cell scratch assay， Transwell invasion assay， and plate colony-forming assay， respectively. Western blot （WB） was used to detect the protein expression of transforming growth factor-β （TGF-β）， nuclear factor-κB （NF-κB）， C-X-C motif chemokine ligand 2 （CXCL2）， E-cadherin， and N-cadherin. The expression of EMT-related proteins E-cadherin and N-cadherin were detected by immunofluorescence （IF）. ResultsCompared with the normal group， LDP showed no significant inhibitory effect on the cell viability of 4T1 cells， but it significantly reduced the viability and number of MDSCs and reduced the number of MDSCs， as well as the expression of TGF-β （P<0.05， P<0.01）. The migration， invasion， and proliferation of 4T1 cells were increased after co-culture with MDSCs （P<0.05， P<0.01）. The expressions of NF-κB， CXCL2， and N-cadherin and the proportion of CSC （CD44⁺CD24^-） were elevated （P<0.05， P<0.01）， while the expression of E-cadherin was decreased （P<0.05）. After the intervention of MDSCs with LDP， followed by co-culture with 4T1 cells， the migration， invasion， and proliferation of 4T1 cells were obviously reduced （P<0.01）. The expressions of NF-κB， CXCL2， and N-cadherin were decreased （P<0.05， P<0.01）， and the expression of E-cadherin was increased （P<0.05， P<0.01）. There was no statistical difference in the proportion of CSC （CD44⁺CD24^-） in 4T1 cells. However， the proportion of CSC （CD44⁺CD24^-） was decreased in the co-culture system of 4T1 cells and MDSCs with LDP intervention （P<0.05， P<0.01）. ConclusionLDP can reduce the viability and number of MDSCs and the expression of TGF-β， NF-κB， and CXCL2， reverse EMT， and reduce the characteristic expression of CSC to inhibit the migration， invasion， and proliferation of 4T1 cells.

ObjectiveTo investigate the mechanism by which Liuwei Dihuang Erzhiwan combination inhibit the lung metastasis of spontaneous breast cancer in mice by regulating the recruitment of myeloid-derived suppressor cells （MDSCs）. MethodThree hundred and eighty SPF-grade 10-month-old female breeders of Kunming mouse were palpated at the mammary gland site once every 3 days. Mice that have not had a lump touched after being raised for 6 months are used as control group. After tumor development， the mice were randomized into model， positive control （paclitaxel， intraperitoneal injection at 0.01 g·kg^-1 every other day for 22 d）， Liuwei Dihuangwan （0.65 g·kg^-1·d^-1 by gavage）， Erzhiwan （5.41 g·kg^-1·d^-1 by gavage）， and Liuwei Dihuang Erzhiwan combination （6.05 g·kg^-1·d^-1 by gavage） groups. The mice were euthanised when the tumor reached a diameter of about 15 mm， and the tumor and lung tissues were collected. The survival time， tumor mass， and lung metastasis rate of tumor-bearing mice were recorded. Hematoxylin-eosin （HE） staining was used to observe the histopathological and morphological changes of mouse tumor and lung tissues. Immunofluorescence （IF） was used to detect the distribution of MDSCs in tissues of mice in each group by double-staining of MDSCs cells with lymphocyte antigen 6 complex site G6D （Ly6G） and CD11 antigen-like family member B （CD11b）. Western blot was employed to determine the protein levels of matrix metalloproteinase-9 （MMP-9）， transforming growth factor-β （TGF-β）， zinc finger transcription factor 1 （Snail1）， and E-cadherin in the tumor tissue and CC motif chemokine 9 （CCL9） and CC motif chemokine receptor 1 （CCR1） in the lung tissue. ResultDuring the modelling period， the paclitaxel group and Chinese medicine intervention groups had longer median number of days of survival and lower tumor weight， lung metastasis rate， and lung nodule than the model group （P<0.05， P<0.01）. HE staining showed an increase in tumor cell necrosis in the paclitaxel group and the Liuwei Dihuang Erzhiwan combination group. The paclitaxel group and Chinese medicine intervention groups had lower fluorescence intensity of MDSCs in the tumor tissue than the model group （P<0.05， P<0.01）. Compared with the normal control group， the model group showed increased fluorescence intensity of MDSCs in the metastatic lung tissue （P<0.01）， which， however， was decreased in the paclitaxel group and Chinese medicine intervention groups （P<0.01）. The model group showed higher protein levels of MMP-9， TGF-β， and Snail1 and lower protein level of E-cadherin in the tumor tissue than in the normal control group （P<0.01）. Compared with model group， paclitaxel and Chinese medicine interventions downregulated the protein levels of MMP-9， TGF-β， and Snail1 （P<0.05， P<0.01） and upregulated the protein level of E-cadherin in the tumor tissue （P<0.01）. Moreover， the Liuwei Dihuang Erzhiwan combination group had lower protein levels of TGF-β and Snail1 than the Liuwei Dihuangwan group and Erzhiwan group （P<0.05）. In the metastatic lung tissue， the expression of CCL9 and CCR1 was higher in the model group than in the normal control group， paclitaxel group， and Chinese medicine intervention groups （P<0.05， P<0.01）. ConclusionLiuwei Dihuang Erzhiwan combination inhibit tumor growth， prolong survival time， and reduce the occurrence of lung metastasis in the mouse model of spontaneous breast cancer by reducing the recruitment of MDSCs in the tumor and lung tissues and modulating the phenotypes of epithelial-mesenchymal transition （EMT）-related molecules and the expression of CCL9/CCR1.

Objective To investigate the effect of visceral fat area (VFA) on perioperative related indi-cators and short-term prognosis of patients with colorectal cancer (CRC).Methods Clinical data of 102 pa-tients who underwent laparoscopic radical surgery for CRC in the First Affiliated Hospital of Baotou Medical College from September 2020 to August 2023 were retrospectively analyzed.All patients underwent preopera-tive abdominal CT examination,and the transverse CT images at the level of the third lumbar vertebra (L3) were selected.VFA was measured using Slice-O-Matic software,and patients were divided into the high VFA group (VFA≥100 cm2) and the low VFA group (VFA<100 cm2) based on the measurement results.Clinical data,patho-logical data,surgical data,postoperative complications,and perioperative coagulation and inflammation indicators were collected.Results Compared with the low VFA group,the high VFA group had higher BMI,longer hospital stay,greater intraoperative blood loss,and fewer lymph node dissections (P<0.05).The WBC and PCT lev-els before and after surgery in the high VFA group were higher than those in the low VFA group (P<0.05). Compared with preoperative levels,WBC,C-reactive protein (CRP),PCT,plasma prothrombin time (PT), plasma fibrinogen (FIB),and international standardized ratio (INR) increased and PLT decreased in both groups after surgery,the differences were statistically significance (P<0.05);Compared with preoperative conditions,the activated partial prothrombin time (APTT) in the high VFA group and the thrombin time (TT) decreased in the low VFA group decreased after surgery,the differences were statistically significant (P<0.05).The total incidence of postoperative complications (21.2％) and the incidence of incision compli-cations (15.4％) in the high VFA group were higher than that in the low VFA group (4.0％,2.0％),the differences were statistically significant (P<0.05).Conclusion Colorectal cancer patients with high VFA during the perioperative period exhibit higher levels of inflammation indicators and poorer prognosis.

A case of ichthyosis follicularis,alopecia and photophobia syndrome caused by a novel mutation c.1165C＞T in the membrane-bound transcription factor protease site 2 (MBTPS2) gene was firstly reported.The proband presented with dry skin,congenital hairlessness,follicular keratotic papules,photophobia,epilepsy,and mental and motor retardation.Next-generation and Sanger sequencing analysis confirmed that the proband and his mother both had a c.1165C＞T (p.pro389Ser) mutation in exon 9 of the MBTPS2 gene.According to the clinical manifestations of the patient and genetic characteristics of the MBTPS2 gene mutation,the patient was diagnosed with ichthyosis follicularis,alopecia and photophobia syndrome.

Clinical features of and genetic mutations in two cases of pseudohypoparathyroidism type Ⅰ a(PHP Ⅰ a) with early-onset skin nodules were analyzed.Both of the two patients were males,and their ages at onset were 2 and 3 months respectively.They both presented with early-onset skin nodules as the main clinical manifestation,and were clinically characterized by a round face,short neck and early obesity.Histopathological examination of skin lesions showed subcutaneous ectopic osteogenesis in both patients.The first patient had low blood calcium,high blood phosphorus,high parathyroid hormone (PTH),and gene sequencing showed a heterozygous mutation c.399delT causing a T base deletion at position 399 in exon 5 of the GNAS gene.The second patient had normal blood calcium and phosphorus levels as well as normal PTH levels at early stage,and gene sequencing showed a heterozygous mutation c.939delT causing a T base deletion at position 939 in exon 9 of the GNAS gene.The blood PTH level was found to increase in the second patient after 1-year follow-up.Both the patients were confirmedly diagnosed with PHP Ⅰa.After treatment with vitamin D3,no new skin nodules occurred,and the blood calcium and phosphorus levels returned to normal.

Objective To analyze how enterovirus D68 (EV-D68) protease 2A affects the anti-vi-ral interferon typeⅠ(IFN-Ⅰ) pathway in 293T cells following infection. Methods Western blot was used to detect the expression of recombinant protease 2A, IFN-α and signal transducers and activators of tran-scription 1 (STAT1) at protein level. Expression of EV-D68 viral protein (VP1) and protease 2A was ana-lyzed by immunofluorescence at different time points. Cytopathic effects were recorded to calculate 50％ cell culture infective dose ( CCID50 ) . Expression of the genes involved in the anti-viral IFN-Ⅰ pathway was measured by real-time PCR (RT-PCR). Results The recombinant plasmid pCLIPf-2A was successfully constructed and the expression of recombinant protease 2A could be detected by Western blot 24 h after transfection. The recombinant protease 2A promoted the proliferation of EV-D68 at the late stage of infection and induced the production of IFN-α. Expression of the genes involved in the anti-viral IFN-Ⅰ pathway at mRNA level was up- or down-regulated to different degrees with various trends in different groups following infection. Expression of STAT1 was enhanced in all groups. Conclusions EV-D68 protease 2A promoted the activation of anti-viral IFN-Ⅰpathway in response to viral infection and enhanced the proliferation of virus at the late stage of infection.