Low-density lipoprotein receptor-related protein 1(LRP1)is a multifunctional endocytic receptor whose dysfunction is linked to developmental dysplasia of the hip,osteoporosis and osteoarthritis.Our work addresses the ...Low-density lipoprotein receptor-related protein 1(LRP1)is a multifunctional endocytic receptor whose dysfunction is linked to developmental dysplasia of the hip,osteoporosis and osteoarthritis.Our work addresses the critical question of how these skeletal pathologies emerge.Here,we show the abundant expression of LRP1 in skeletal progenitor cells at mouse embryonic stage E10.5 and onwards,especially in the perichondrium,the stem cell layer surrounding developing limbs essential for bone formation.Lrp1 deficiency in these stem cells causes joint fusion,malformation of cartilage/bone template and markedly delayed or lack of primary ossification.展开更多
Loss-of-function variants of low-density lipoprotein receptor-related protein 5(LRP5)can lead to reduced bone formation,culminating in diminished bone mass.Our previous study reported transcription factor osterix(SP7)...Loss-of-function variants of low-density lipoprotein receptor-related protein 5(LRP5)can lead to reduced bone formation,culminating in diminished bone mass.Our previous study reported transcription factor osterix(SP7)-binding sites on the LRP5 promoter and its pivotal role in upregulating LRP5 expression during implant osseointegration.However,the potential role of SP7 in ameliorating LRP5-dependent osteoporosis remained unknown.In this study,we used mice with a conditional knockout(c KO)of LRP5 in mature osteoblasts,which presented decreased osteogenesis.The in vitro experimental results showed that SP7 could promote LRP5 expression,thereby upregulating the osteogenic markers such as alkaline phosphatase(ALP),Runt-related transcription factor 2(Runx2),andβ-catenin(P<0.05).For the in vivo experiment,the SP7 overexpression virus was injected into a bone defect model of LRP5 c KO mice,resulting in increased bone mineral density(BMD)(P<0.001)and volumetric density(bone volume(BV)/total volume(TV))(P<0.001),and decreased trabecular separation(Tb.Sp)(P<0.05).These data suggested that SP7 could ameliorate bone defect healing in LRP5 c KO mice.Our study provides new insights into potential therapeutic opportunities for ameliorating LRP5-dependent osteoporosis.展开更多
Streptococcus suis serotype 2(SS2)is a zoonotic pathogen that can cause acute infection,such as septicemia in pigs and streptococcal toxic shock-like syndrome(STSLS)in humans,indicating that SS2 can evade innate immun...Streptococcus suis serotype 2(SS2)is a zoonotic pathogen that can cause acute infection,such as septicemia in pigs and streptococcal toxic shock-like syndrome(STSLS)in humans,indicating that SS2 can evade innate immunity.Macrophages perform essential antimicrobial functions in the innate immune system by engulfing and killing pathogens.Previously,a dna K mutant strain that showed impaired phagocytosis resistance ability was screened from the transposon mutant library of SS2,but the specific mechanism is unclear.In this study,we further demonstrated that DnaK was required for SS2 to be antiphagocytosed by macrophages and survive in adverse environments.A mouse challenge experiment indicated that DnaK promoted bacteremia and systemic dissemination of SS2,enhancing bacterial pathogenicity.Western blot and immunofluorescence results indicated that DnaK could be secreted by SS2 and was able to enter RAW264.7 macrophages.Then,the endocytic receptor LRP1 regulated by DnaK was identified through RNA sequencing(RNA-Seq).We found that DnaK decreased both the mRNA and protein levels of LRP1.Knockdown of the LRP1β-chain(LRP1β)significantly decreased the phagocytosis rate of the SS2 strain ZY05719,suggesting that LRP1 is a phagocytic receptor of SS2.Furthermore,inhibitor treatment assays revealed that DnaK decreased LRP1 protein levels through the transcription factor PPARγand the ubiquitin-proteasome system.In summary,DnaK contributes to the phagocytosis resistance of SS2 by decreasing LRP1 protein levels in macrophages,providing new insights into the antiphagocytosis mechanisms of SS2 and helping to understand its pathogenesis.展开更多
Objective: To study the multidrug resistance (MDR) mechanism of lung resistance protein (LRP) gene in hepatocellular carcinoma (HCC), and the relations among the expression of the LRP gene and clinicopathologic featur...Objective: To study the multidrug resistance (MDR) mechanism of lung resistance protein (LRP) gene in hepatocellular carcinoma (HCC), and the relations among the expression of the LRP gene and clinicopathologic features, the influence of α-fetoprotein (AFP), and prognosis of patients who received adjuvant chemotherapy after resection of HCC. Methods: The expression of the LRP gene encoding LRP and mRNA LRP was detected in tissues from 54 untreated patients with HCC, adjacent tissues from 24 patients with HCC and archival paraffin-embedded tissues from 12 patients with posthepatitic cirrhosis. The relationship between the LRP gene expression and the change of AFP level was analyzed in the 24 postoperative HCC patients whose AFP was measured after 2 weeks. All of the HCC patients were followed up. Results: The percentage of positive expression of LRP and mRNA LRP in the 3 tissues was 61.1%, 33.3%, 16.7%, and 75.9%, 37.5%, 33.3% respectively. There was significant difference between the untreated HCC tissue and other tissues (P<0.05). No difference existed between the LRP gene expression and clinicopathologic findings, age, sex, and tumor size (P>0.05), but the expression was related to the degree of differentiation of HCC (P<0.05). The effective rate of AFP in the LRP gene positive expression group or in postoperative chemotherapeutic patients was very lower than that in the negative group (P<0.05). Although the mean survival time of postoperative HCC patients in negative LRP gene expression group was longer than that of positive group, there was no difference between them (P<0.05). Conclusion: LRP gene expression is related to MDR of HCC and initiates the intrinsic MDR. Detection of LRP gene expression is of great guiding significance in accessing chemotherapeutic resistance of HCC. As an index to chemotherapy of HCC, detection of LRP expression provides evidence for making individual chemotherapeutic treatment,and reversing MDR in HCC. Although LRP gene expression correlates with the tumor differential degree (P<0.05), it perhaps does not relate with the prognosis of HCC patients.展开更多
基金The Andor dragonfly Spinning Disk microscope in the CCI was funded by the BBSRC(BB/R01390X/1)This work was supported by the ministry of education of the Kingdom of Saudi Arabia(to M.Alhashmi)+6 种基金Libyan Ministry of Higher Education and Scientific Research and ECMage(to A.M.E.Gremida)Qatar National Research Fund(to N.A.Al-Maslamani)European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement(860635 to M.Antonaci and A.Kerr)BBSRC Grants(BB/T00715X/1 to S.K.Maharana and G.N.WheelerBB/X000907/1 to D.A.Turner)Versus Arthritis Career Development Fellowship(21447 to K.Yamamoto)Versus Arthritis Bridging Fellowship(23137 to K.Yamamoto).
文摘Low-density lipoprotein receptor-related protein 1(LRP1)is a multifunctional endocytic receptor whose dysfunction is linked to developmental dysplasia of the hip,osteoporosis and osteoarthritis.Our work addresses the critical question of how these skeletal pathologies emerge.Here,we show the abundant expression of LRP1 in skeletal progenitor cells at mouse embryonic stage E10.5 and onwards,especially in the perichondrium,the stem cell layer surrounding developing limbs essential for bone formation.Lrp1 deficiency in these stem cells causes joint fusion,malformation of cartilage/bone template and markedly delayed or lack of primary ossification.
文摘Loss-of-function variants of low-density lipoprotein receptor-related protein 5(LRP5)can lead to reduced bone formation,culminating in diminished bone mass.Our previous study reported transcription factor osterix(SP7)-binding sites on the LRP5 promoter and its pivotal role in upregulating LRP5 expression during implant osseointegration.However,the potential role of SP7 in ameliorating LRP5-dependent osteoporosis remained unknown.In this study,we used mice with a conditional knockout(c KO)of LRP5 in mature osteoblasts,which presented decreased osteogenesis.The in vitro experimental results showed that SP7 could promote LRP5 expression,thereby upregulating the osteogenic markers such as alkaline phosphatase(ALP),Runt-related transcription factor 2(Runx2),andβ-catenin(P<0.05).For the in vivo experiment,the SP7 overexpression virus was injected into a bone defect model of LRP5 c KO mice,resulting in increased bone mineral density(BMD)(P<0.001)and volumetric density(bone volume(BV)/total volume(TV))(P<0.001),and decreased trabecular separation(Tb.Sp)(P<0.05).These data suggested that SP7 could ameliorate bone defect healing in LRP5 c KO mice.Our study provides new insights into potential therapeutic opportunities for ameliorating LRP5-dependent osteoporosis.
基金funded by the National Key Research and Development Program of China(2021YFD1800400)the National Natural Science Foundation of China(32373018)+2 种基金Jiangsu Agriculture Science and Technology Innovation Fund,China(CX(23)1029)the Excellent Research Innovation Team in Universities in Anhui Province,China(2022AH010088)the Shennong Scholar Project of Anhui Agricultural University,China(rc392101)。
文摘Streptococcus suis serotype 2(SS2)is a zoonotic pathogen that can cause acute infection,such as septicemia in pigs and streptococcal toxic shock-like syndrome(STSLS)in humans,indicating that SS2 can evade innate immunity.Macrophages perform essential antimicrobial functions in the innate immune system by engulfing and killing pathogens.Previously,a dna K mutant strain that showed impaired phagocytosis resistance ability was screened from the transposon mutant library of SS2,but the specific mechanism is unclear.In this study,we further demonstrated that DnaK was required for SS2 to be antiphagocytosed by macrophages and survive in adverse environments.A mouse challenge experiment indicated that DnaK promoted bacteremia and systemic dissemination of SS2,enhancing bacterial pathogenicity.Western blot and immunofluorescence results indicated that DnaK could be secreted by SS2 and was able to enter RAW264.7 macrophages.Then,the endocytic receptor LRP1 regulated by DnaK was identified through RNA sequencing(RNA-Seq).We found that DnaK decreased both the mRNA and protein levels of LRP1.Knockdown of the LRP1β-chain(LRP1β)significantly decreased the phagocytosis rate of the SS2 strain ZY05719,suggesting that LRP1 is a phagocytic receptor of SS2.Furthermore,inhibitor treatment assays revealed that DnaK decreased LRP1 protein levels through the transcription factor PPARγand the ubiquitin-proteasome system.In summary,DnaK contributes to the phagocytosis resistance of SS2 by decreasing LRP1 protein levels in macrophages,providing new insights into the antiphagocytosis mechanisms of SS2 and helping to understand its pathogenesis.
文摘Objective: To study the multidrug resistance (MDR) mechanism of lung resistance protein (LRP) gene in hepatocellular carcinoma (HCC), and the relations among the expression of the LRP gene and clinicopathologic features, the influence of α-fetoprotein (AFP), and prognosis of patients who received adjuvant chemotherapy after resection of HCC. Methods: The expression of the LRP gene encoding LRP and mRNA LRP was detected in tissues from 54 untreated patients with HCC, adjacent tissues from 24 patients with HCC and archival paraffin-embedded tissues from 12 patients with posthepatitic cirrhosis. The relationship between the LRP gene expression and the change of AFP level was analyzed in the 24 postoperative HCC patients whose AFP was measured after 2 weeks. All of the HCC patients were followed up. Results: The percentage of positive expression of LRP and mRNA LRP in the 3 tissues was 61.1%, 33.3%, 16.7%, and 75.9%, 37.5%, 33.3% respectively. There was significant difference between the untreated HCC tissue and other tissues (P<0.05). No difference existed between the LRP gene expression and clinicopathologic findings, age, sex, and tumor size (P>0.05), but the expression was related to the degree of differentiation of HCC (P<0.05). The effective rate of AFP in the LRP gene positive expression group or in postoperative chemotherapeutic patients was very lower than that in the negative group (P<0.05). Although the mean survival time of postoperative HCC patients in negative LRP gene expression group was longer than that of positive group, there was no difference between them (P<0.05). Conclusion: LRP gene expression is related to MDR of HCC and initiates the intrinsic MDR. Detection of LRP gene expression is of great guiding significance in accessing chemotherapeutic resistance of HCC. As an index to chemotherapy of HCC, detection of LRP expression provides evidence for making individual chemotherapeutic treatment,and reversing MDR in HCC. Although LRP gene expression correlates with the tumor differential degree (P<0.05), it perhaps does not relate with the prognosis of HCC patients.
