ABSTRACTHuman placenta-derived mononuclear cells (MNC) were isolated by a Percoll density gradient and cultured in mesen-chymal stem cell (MSC) maintenance medium. The homogenous layer of adherent cells exhibited a ty...ABSTRACTHuman placenta-derived mononuclear cells (MNC) were isolated by a Percoll density gradient and cultured in mesen-chymal stem cell (MSC) maintenance medium. The homogenous layer of adherent cells exhibited a typical fibroblast-like morphology, a large expansive potential, and cell cycle characteristics including a subset of quiescent cells. In vitrodifferentiation assays showed the tripotential differentiation capacity of these cells toward adipogenic, osteogenic andchondrogenic lineages. Flow cytometry analyses and immunocytochemistry stain showed that placental MSC was ahomogeneous cell population devoid of hematopoietic cells, which uniformly expressed CD29, CD44, CD73, CD105,CD166, laminin, fibronectin and vimentin while being negative for expression of CD31, CD34, CD45 and α-smoothmuscle actin. Most importantly, immuno-phenotypic analyses demonstrated that these cells expressed class I majorhistocompatibility complex (MHC-I), but they did not express MHC-II molecules. Additionally these cells could sup-press umbilical cord blood (UCB) lymphocytes proliferation induced by cellular or nonspecific mitogenic stimuli. Thisstrongly implies that they may have potential application in allograft transplantation. Since placenta and UCB arehomogeneous, the MSC derived from human placenta can be transplanted combined with hematopoietic stem cells(HSC) from UCB to reduce the potential graft -versus-host disease (GVHD) in recipients.展开更多
Some of the most common human cancers, including breast cancer, prostate cancer, and lung cancer, metastasize with avidity to bone. What is the basis for their preferential growth within the bone microenvironment? Bid...Some of the most common human cancers, including breast cancer, prostate cancer, and lung cancer, metastasize with avidity to bone. What is the basis for their preferential growth within the bone microenvironment? Bidirectional interactions between tumor cells and cells that make up bone result in a selective advantage for tumor growth and can lead to bone destruction or new bone matrix deposition. This review discusses our current understanding of the molecu- lar components and mechanisms that are responsible for those interactions.展开更多
Spontaneous Ca2+ oscillations in vascular smooth muscle cells have been modeled using a single Ca2+ pool. This report describes spontaneous Ca2+ oscillations dependent on two separate Ca2+ sources for the nuclear vers...Spontaneous Ca2+ oscillations in vascular smooth muscle cells have been modeled using a single Ca2+ pool. This report describes spontaneous Ca2+ oscillations dependent on two separate Ca2+ sources for the nuclear versus cytoplas- mic compartments. Changes in free intracellular Ca2+ were monitored with ratiometric Ca2+- fluorophores using confo- cal microscopy. On average, spontaneous oscillations developed in 79% of rat aortic smooth muscle cells that were synchronous between the cytoplasm and nucleus. Reduction of extracellular Ca2+ (< 1 μM) decreased the frequency and amplitude of the cytoplasmic oscillations with 48% of the oscillations asynchronous between the nuclear and cytoplasmic compartments. Similar results were obtained with the Ca2+ channel blockers, nimodipine and diltiazem. Arg-vasopressin (AVP) induced a rapid release of intracellular Ca2+ stores that was greater in the nuclear compartment (4.20 ± 0.23 ratio units, n = 56) than cytoplasm (2.54 ± 0.28) in cells that had spontaneously developed prior oscillations. Conversely, cells in the same conditions lacking oscillations had a greater AVP-induced Ca2+ transient in the cytoplasm (4.99 ± 0.66, n = 17) than in the nucleus (2.67 ± 0.29). Pre-treatment with Ca2+ channel blockers depressed the AVP responses in both compartments with the cytoplasmic Ca2+ most diminished. Depletion of internal Ca2+ stores prior to AVP exposure blunted the nuclear response, mimicking the response of cells that lacked prior oscillations. Spontaneous oscillating cells had a greater sarcoplasmic reticulum network than cells that did not oscillate. We propose that sponta- neous nuclear oscillations rely on perinuclear sarcoplasmic reticulum stores, while the cytoplasmic oscillations rely on Ca2+ influx.展开更多
Kinetics of thymocyte development in vivo during embryogenesis was pursued. The early development of thymocytes in the fetal and neonatal BALB/c mice was discontinuous, with four waves of cell proliferation occurring ...Kinetics of thymocyte development in vivo during embryogenesis was pursued. The early development of thymocytes in the fetal and neonatal BALB/c mice was discontinuous, with four waves of cell proliferation occurring at fetal day (Fd) 14 to 17, Fd 18 to day (D) 1 after birth, D 2 to D 5 and D6 thereafter. The first three proliferation waves coincided with the generation of CD4hiCD8hi (DP), TCR+CD4hiCD8-/lo (CD4 SP), and TCR+CD4-/loCD8int/hi(CD8 SP) thymocytes, respectively. The transition from DN to DP cells was further investigated and it was found out that there were two differential pathways via immature single positive (ISP) cells in the BALB/c mice, each functioning at different fetal ages. One is via TCR-CD4-CD8+ cells, occurring between Fd 15 and Fd 17 and the other is via TCR-CD4+CD8- ceils,occurring from Fd 17 until birth. In contrast, the TCR-CD4-CD8+ pathway dominated overwhelmingly in the C57BL/6 mice. These findings shed new light on the hypothesis that the differential pathway preference varies with mouse strains. With respect to the shift in the intensity of CD4 and CD8 expression on thymocytes from fetal to adult mice, the TCR+CD4hiCD8-/lo, and TCR+CD4-/loCD8int/hi subsets might be equivalent to the medullary type TCR+CD4/CD8 SP cells.展开更多
The Chinese Medical Journal(CMJ)is published monthly in English by the Chinese Medical Association,and is a peer reviewed general medical Journal for all doctors,researchers,and health workers regardlessof their medic...The Chinese Medical Journal(CMJ)is published monthly in English by the Chinese Medical Association,and is a peer reviewed general medical Journal for all doctors,researchers,and health workers regardlessof their medical specialty or type of employment.Established in 1887,it is the oldest medical展开更多
This is the First Symposium on Frontiers of Biomedical Science organized by Cell Research, a peerreviewed journal supported by the Chinese Academy of Sciences. In recent years, epigenetics have shown its growing impor...This is the First Symposium on Frontiers of Biomedical Science organized by Cell Research, a peerreviewed journal supported by the Chinese Academy of Sciences. In recent years, epigenetics have shown its growing importance for the understanding of life processes and the control of human diseases in the genome era. I do hope that this timely symposium展开更多
Apoptosis is a form of genetically programmed cell death, which plays a key role in regulation of cellularity in a variety of tissue and cell types including the cardiovascular tissues. Under both physiological and pa...Apoptosis is a form of genetically programmed cell death, which plays a key role in regulation of cellularity in a variety of tissue and cell types including the cardiovascular tissues. Under both physiological and pathophysiological conditions, various biophysiological and biochemical factors, including mechanical forces, reactive oxygen and nitrogen species, cytokines, growth factors, oxidized lipoproteins, etc., ma influence apoptosis of vascular cells. The Fas/Fas ligand/caspase death-signaling pathway, Bcl-2 protein family/mitochondria, the tumor suppressive gene p53, and the proto-oncogene c-myc may be activated in atherosclerotic lesions, and mediates vascular apoptosis during the development of atherosclerosis. Abnormal expression and dysfunction of these apoptosis-regulating genes may attenuate or accelerate vascular cell apoptosis and affect the integrity and stability of atherosclerotic plaques. Clarification of the molecular mechanism that regulates apoptosis may help design a new strategy for treatment of atherosclerosis and ii major complication, the acute vascular syndromes.展开更多
GABA transporter 1(GAT1) takes important roles in multiple physiological processes through the uptake and release of GABA, but the regulation of GAT1 gene expression in different tissues is rarely known. To address th...GABA transporter 1(GAT1) takes important roles in multiple physiological processes through the uptake and release of GABA, but the regulation of GAT1 gene expression in different tissues is rarely known. To address the question, first, 5’ Rapid amplification of cDNA end (RACE) was used to determine GAT1 transcriptional starting sites in neonatal mouse cerebral cortex and intestine, adult mouse brain and adult rat testis. The products of 5’RACE were confirmed by DNA sequencing. We found that the transcript of GAT1 in neonatal mouse cerebral cortex and adult mouse brain starts at the same site (inside of exon 1), while in mouse intestine, GAT1 starts transcription in intron 1, and in rat testis, the transcript of GAT1 has an additional untranslation exon to the 5’ direction.展开更多
Human μ-opioid receptor （HμOR） with a tag of six consecutive histidines at its carboxyl terminus had been expressed in recombinant baculovirus infected Sf9 insect cells.The maximal binding capacity for the [3H] di...Human μ-opioid receptor （HμOR） with a tag of six consecutive histidines at its carboxyl terminus had been expressed in recombinant baculovirus infected Sf9 insect cells.The maximal binding capacity for the [3H] diprenorphine and [3H]ohmefentanyl （Ohm） were 9.1± 0.7 and 6.52±0.23 nmol/g protein, respectively. The [3H] diprenorphine or [3H] Ohm binding to the receptor expressed in Sf9 cells was strongly inhibited by μ-selective agonists [D-Ala2], N-methylPhe4, glyol5]enkephalin （DAGO）, Ohm, and morphine, but neither by δ nor by K selective agonist. Na+ （100 mM） and GTP （50 μM） could reduce HμOR agonists etorphine and Ohm affinity binding to the overexpressed HμOR. μ-selective agonists DAGO and Ohm effectively stimulated [35S]GTPγS binding (EC50 = 2.7nM and 6.9 nM) and inhibited forskolin- stimulated cAMP accumulation (IC50 = 0.9 nM and 0.3 nM). The agonist-dependent effects could be blocked by opioid antagonist naloxone or by pretreatment of cells with pertussis toxin （PTX）. These results demonstrated that HμOR overexpressed in Sf9 insect cells functionally coupled to endogenous Gi/o proteins.展开更多
FT Ⅰ (AAAAGGGGAAGCAGAG), a poly purine ele-ment within the myloid-lineage specific enhancer (En 1) of the mouse myeloperoxidase gene [1, 2] has been fur-ther characterised. 1, FT Ⅰ functions as a myeloid-lineage spe...FT Ⅰ (AAAAGGGGAAGCAGAG), a poly purine ele-ment within the myloid-lineage specific enhancer (En 1) of the mouse myeloperoxidase gene [1, 2] has been fur-ther characterised. 1, FT Ⅰ functions as a myeloid-lineage specific transcription regulatory element; 2, WEHI 3BD+ cells have higher binding activity to FT Ⅰ and express the proteins which could form the unique DNA-protein com-plex(es) of FT Ⅰ;. 3, The essential sequence for the specific DNA-protein interactions of FT Ⅰ is AAAAGGGGAAGC; 4, South-western analysis in conjunction with the compe-tition assay of the proteins binding to FT Ⅰ, has revealed a 28 kd protein in WEHI 3BD+ cells that displays the properties of the putative transcription factor which acts through FT Ⅰ. These new findings have demonstrated both the functional myeloid-lineage specificity and the novelty of FT Ⅰ.展开更多
The distribution of acetylcholinesterase(AChE)-positive structures in the developing rat spinal cord was studied with AChE-histochemistry.AChE-positive perikarya were first seen on embryonic day 14(E14) in the ventrol...The distribution of acetylcholinesterase(AChE)-positive structures in the developing rat spinal cord was studied with AChE-histochemistry.AChE-positive perikarya were first seen on embryonic day 14(E14) in the ventrolateral portion of the spinal cord.From that time onward.AChE=containing cells appeared gradually in the intermediate gray,dorsal horn and lateral spinal nucleus of the spinal cord in a ventral-to-dorsal,and lateral-to-medial order.No obvious rostral-to-caudal sequence was found.At birth,the distribution pattern of AChE-positive perikarya was basically similar to that in adults.After birth a dramatic increase in the AChE staining intensity extended from postnatal day 5(P5) to postnatal day 21(P21),In addition,two phases of transient AChE staining were observed in the external surface of the dorsal horn from embryonic day 15(E15) to embryonic day 21(E21) and in the marginal layer from embryonic day 21(E21) to postnatal day 14(P14),respectively.展开更多
基金This study was supported by a grant from National Natural Science Foundation of China(No.30271245)Hi-Tech Research and Development Program of China(863 Program)(No.2003AA205170)+1 种基金National Basic Research Program of China(973 Program)(No.G 1999054302)a grant from Bejing Gynecology and Obstetrics Hospital Affiliate of Capital University of Medical Sciences.
文摘ABSTRACTHuman placenta-derived mononuclear cells (MNC) were isolated by a Percoll density gradient and cultured in mesen-chymal stem cell (MSC) maintenance medium. The homogenous layer of adherent cells exhibited a typical fibroblast-like morphology, a large expansive potential, and cell cycle characteristics including a subset of quiescent cells. In vitrodifferentiation assays showed the tripotential differentiation capacity of these cells toward adipogenic, osteogenic andchondrogenic lineages. Flow cytometry analyses and immunocytochemistry stain showed that placental MSC was ahomogeneous cell population devoid of hematopoietic cells, which uniformly expressed CD29, CD44, CD73, CD105,CD166, laminin, fibronectin and vimentin while being negative for expression of CD31, CD34, CD45 and α-smoothmuscle actin. Most importantly, immuno-phenotypic analyses demonstrated that these cells expressed class I majorhistocompatibility complex (MHC-I), but they did not express MHC-II molecules. Additionally these cells could sup-press umbilical cord blood (UCB) lymphocytes proliferation induced by cellular or nonspecific mitogenic stimuli. Thisstrongly implies that they may have potential application in allograft transplantation. Since placenta and UCB arehomogeneous, the MSC derived from human placenta can be transplanted combined with hematopoietic stem cells(HSC) from UCB to reduce the potential graft -versus-host disease (GVHD) in recipients.
文摘Some of the most common human cancers, including breast cancer, prostate cancer, and lung cancer, metastasize with avidity to bone. What is the basis for their preferential growth within the bone microenvironment? Bidirectional interactions between tumor cells and cells that make up bone result in a selective advantage for tumor growth and can lead to bone destruction or new bone matrix deposition. This review discusses our current understanding of the molecu- lar components and mechanisms that are responsible for those interactions.
文摘Spontaneous Ca2+ oscillations in vascular smooth muscle cells have been modeled using a single Ca2+ pool. This report describes spontaneous Ca2+ oscillations dependent on two separate Ca2+ sources for the nuclear versus cytoplas- mic compartments. Changes in free intracellular Ca2+ were monitored with ratiometric Ca2+- fluorophores using confo- cal microscopy. On average, spontaneous oscillations developed in 79% of rat aortic smooth muscle cells that were synchronous between the cytoplasm and nucleus. Reduction of extracellular Ca2+ (< 1 μM) decreased the frequency and amplitude of the cytoplasmic oscillations with 48% of the oscillations asynchronous between the nuclear and cytoplasmic compartments. Similar results were obtained with the Ca2+ channel blockers, nimodipine and diltiazem. Arg-vasopressin (AVP) induced a rapid release of intracellular Ca2+ stores that was greater in the nuclear compartment (4.20 ± 0.23 ratio units, n = 56) than cytoplasm (2.54 ± 0.28) in cells that had spontaneously developed prior oscillations. Conversely, cells in the same conditions lacking oscillations had a greater AVP-induced Ca2+ transient in the cytoplasm (4.99 ± 0.66, n = 17) than in the nucleus (2.67 ± 0.29). Pre-treatment with Ca2+ channel blockers depressed the AVP responses in both compartments with the cytoplasmic Ca2+ most diminished. Depletion of internal Ca2+ stores prior to AVP exposure blunted the nuclear response, mimicking the response of cells that lacked prior oscillations. Spontaneous oscillating cells had a greater sarcoplasmic reticulum network than cells that did not oscillate. We propose that sponta- neous nuclear oscillations rely on perinuclear sarcoplasmic reticulum stores, while the cytoplasmic oscillations rely on Ca2+ influx.
基金supported by grants from National 973 Program in China(No.G1999053904)National Natural Sciences Foundation of China(No.39730410)
文摘Kinetics of thymocyte development in vivo during embryogenesis was pursued. The early development of thymocytes in the fetal and neonatal BALB/c mice was discontinuous, with four waves of cell proliferation occurring at fetal day (Fd) 14 to 17, Fd 18 to day (D) 1 after birth, D 2 to D 5 and D6 thereafter. The first three proliferation waves coincided with the generation of CD4hiCD8hi (DP), TCR+CD4hiCD8-/lo (CD4 SP), and TCR+CD4-/loCD8int/hi(CD8 SP) thymocytes, respectively. The transition from DN to DP cells was further investigated and it was found out that there were two differential pathways via immature single positive (ISP) cells in the BALB/c mice, each functioning at different fetal ages. One is via TCR-CD4-CD8+ cells, occurring between Fd 15 and Fd 17 and the other is via TCR-CD4+CD8- ceils,occurring from Fd 17 until birth. In contrast, the TCR-CD4-CD8+ pathway dominated overwhelmingly in the C57BL/6 mice. These findings shed new light on the hypothesis that the differential pathway preference varies with mouse strains. With respect to the shift in the intensity of CD4 and CD8 expression on thymocytes from fetal to adult mice, the TCR+CD4hiCD8-/lo, and TCR+CD4-/loCD8int/hi subsets might be equivalent to the medullary type TCR+CD4/CD8 SP cells.
文摘The Chinese Medical Journal(CMJ)is published monthly in English by the Chinese Medical Association,and is a peer reviewed general medical Journal for all doctors,researchers,and health workers regardlessof their medical specialty or type of employment.Established in 1887,it is the oldest medical
文摘This is the First Symposium on Frontiers of Biomedical Science organized by Cell Research, a peerreviewed journal supported by the Chinese Academy of Sciences. In recent years, epigenetics have shown its growing importance for the understanding of life processes and the control of human diseases in the genome era. I do hope that this timely symposium
文摘Apoptosis is a form of genetically programmed cell death, which plays a key role in regulation of cellularity in a variety of tissue and cell types including the cardiovascular tissues. Under both physiological and pathophysiological conditions, various biophysiological and biochemical factors, including mechanical forces, reactive oxygen and nitrogen species, cytokines, growth factors, oxidized lipoproteins, etc., ma influence apoptosis of vascular cells. The Fas/Fas ligand/caspase death-signaling pathway, Bcl-2 protein family/mitochondria, the tumor suppressive gene p53, and the proto-oncogene c-myc may be activated in atherosclerotic lesions, and mediates vascular apoptosis during the development of atherosclerosis. Abnormal expression and dysfunction of these apoptosis-regulating genes may attenuate or accelerate vascular cell apoptosis and affect the integrity and stability of atherosclerotic plaques. Clarification of the molecular mechanism that regulates apoptosis may help design a new strategy for treatment of atherosclerosis and ii major complication, the acute vascular syndromes.
基金foundations from Chinese Academy of Sciences and Special Funds for Major State Basic reseaxch of China (G1999053903).
文摘GABA transporter 1(GAT1) takes important roles in multiple physiological processes through the uptake and release of GABA, but the regulation of GAT1 gene expression in different tissues is rarely known. To address the question, first, 5’ Rapid amplification of cDNA end (RACE) was used to determine GAT1 transcriptional starting sites in neonatal mouse cerebral cortex and intestine, adult mouse brain and adult rat testis. The products of 5’RACE were confirmed by DNA sequencing. We found that the transcript of GAT1 in neonatal mouse cerebral cortex and adult mouse brain starts at the same site (inside of exon 1), while in mouse intestine, GAT1 starts transcription in intron 1, and in rat testis, the transcript of GAT1 has an additional untranslation exon to the 5’ direction.
文摘Human μ-opioid receptor （HμOR） with a tag of six consecutive histidines at its carboxyl terminus had been expressed in recombinant baculovirus infected Sf9 insect cells.The maximal binding capacity for the [3H] diprenorphine and [3H]ohmefentanyl （Ohm） were 9.1± 0.7 and 6.52±0.23 nmol/g protein, respectively. The [3H] diprenorphine or [3H] Ohm binding to the receptor expressed in Sf9 cells was strongly inhibited by μ-selective agonists [D-Ala2], N-methylPhe4, glyol5]enkephalin （DAGO）, Ohm, and morphine, but neither by δ nor by K selective agonist. Na+ （100 mM） and GTP （50 μM） could reduce HμOR agonists etorphine and Ohm affinity binding to the overexpressed HμOR. μ-selective agonists DAGO and Ohm effectively stimulated [35S]GTPγS binding (EC50 = 2.7nM and 6.9 nM) and inhibited forskolin- stimulated cAMP accumulation (IC50 = 0.9 nM and 0.3 nM). The agonist-dependent effects could be blocked by opioid antagonist naloxone or by pretreatment of cells with pertussis toxin （PTX）. These results demonstrated that HμOR overexpressed in Sf9 insect cells functionally coupled to endogenous Gi/o proteins.
文摘FT Ⅰ (AAAAGGGGAAGCAGAG), a poly purine ele-ment within the myloid-lineage specific enhancer (En 1) of the mouse myeloperoxidase gene [1, 2] has been fur-ther characterised. 1, FT Ⅰ functions as a myeloid-lineage specific transcription regulatory element; 2, WEHI 3BD+ cells have higher binding activity to FT Ⅰ and express the proteins which could form the unique DNA-protein com-plex(es) of FT Ⅰ;. 3, The essential sequence for the specific DNA-protein interactions of FT Ⅰ is AAAAGGGGAAGC; 4, South-western analysis in conjunction with the compe-tition assay of the proteins binding to FT Ⅰ, has revealed a 28 kd protein in WEHI 3BD+ cells that displays the properties of the putative transcription factor which acts through FT Ⅰ. These new findings have demonstrated both the functional myeloid-lineage specificity and the novelty of FT Ⅰ.
文摘The distribution of acetylcholinesterase(AChE)-positive structures in the developing rat spinal cord was studied with AChE-histochemistry.AChE-positive perikarya were first seen on embryonic day 14(E14) in the ventrolateral portion of the spinal cord.From that time onward.AChE=containing cells appeared gradually in the intermediate gray,dorsal horn and lateral spinal nucleus of the spinal cord in a ventral-to-dorsal,and lateral-to-medial order.No obvious rostral-to-caudal sequence was found.At birth,the distribution pattern of AChE-positive perikarya was basically similar to that in adults.After birth a dramatic increase in the AChE staining intensity extended from postnatal day 5(P5) to postnatal day 21(P21),In addition,two phases of transient AChE staining were observed in the external surface of the dorsal horn from embryonic day 15(E15) to embryonic day 21(E21) and in the marginal layer from embryonic day 21(E21) to postnatal day 14(P14),respectively.
