Biomedical subjects

Lei Cui

Publications and source records attributed to Lei Cui.

At least 19 recordsLinked to original sources

PubMed2026

Insights Into the Structural Features, Codon Usage Patterns, and Phylogenetic Analysis in Neoniphon argenteus (Teleostei: Holocentriformes) Based on Complete Mitochondrial Genome.

Neoniphon argenteus, a widely distributed nocturnal coral reef fish in the family Holocentridae, plays an important role in maintaining coral reef ecosystem health, yet its phylogenetic position remains poorly resolved. To bridge this gap, we sequenced and analyzed the complete mitochondrial genome of a specimen from the South China Sea to characterize its structural features, codon usage patterns, and phylogenetic relationships. The 16,569 bp mitogenome (GenBank: PP190474.1) encodes 13 protein-coding genes (PCGs), 22 tRNAs, two rRNAs, and two non-coding regions, exhibiting a distinct A + T bias. All tRNAs fold into typical cloverleaf secondary structures except tRNA-Ser (AGN), which lacks the dihydrouridine (DHU) arm. The control region contains palindromic motifs (TACAT/ATGTA) capable of forming hairpin structures and five conserved sequence blocks, whereas the OL region harbors a conserved 5'-GCCGG-3' motif. RSCU analysis revealed 31 frequently used codons (RSCU > 1) with a pronounced preference for A/C-ending codons. The ΔRSCU method identified 10 candidate optimal codons (GCA, CAA, GAA, GGA, AUU, CUA, CCA, CGA, ACA, and GUC). Selection pressure analysis using EasyCodeML and site-specific models indicated that all PCGs are predominantly under purifying selection, with no significant evidence of pervasive positive selection. ND6 exhibited elevated pairwise Ka/Ks ratios (mean = 1.209 ± 0.047), consistent with reduced selective constraint rather than adaptive evolution. Phylogenetic analysis of 19 Holocentriformes species using maximum likelihood and Bayesian inference with partitioned models based on 13 PCGs and two rRNA genes (12S and 16S) assigned all taxa to two well-supported subfamilies (Holocentrinae and Myripristinae). Within Holocentrinae, Neoniphon species form a monophyletic clade nested within a paraphyletic Sargocentron, suggesting that the genus Sargocentron as currently defined is not monophyletic. This study provides useful baseline molecular data for further exploration of the evolutionary history of N. argenteus and other members of Holocentriformes.

Holocentridae↗

PubMed2025

Cytogenetics and genomics analysis of cold-hardy perennial wheatgrass: insights into agronomic performance, chromosome composition, and gene expression.

Intermedium wheatgrass (Thinopyrum intermedium), a perennial species with extensive root systems and high tolerance to cold, drought, and salinity, is a valuable genetic resource for the development of perennial crops. Over a decade-long selection process, two cold-hardy perennial wheatgrass lines were developed by crossing wheat-Thinopyrum partial amphiploids with Th. intermedium. These lines inherited key traits from Th. intermedium, including plant stature, spike morphology, and postharvest regrowth. Transcriptome-based single-nucleotide polymorphism tracing and sequential multicolor genomic in situ hybridization analyses revealed variations in the chromosome compositions of the perennial wheatgrass lines. The introgression of wheat chromosomes enhanced grain weight and size, while preserving the cold-hardy, perennial characteristics of the wheatgrass lines compared to Th. intermedium. Genome-wide gene expression was generally suppressed in the wheatgrass lines relative to Th. intermedium, particularly in conserved genes. This suppression was especially pronounced in genes involved in cell division and DNA repair pathways. In contrast, genes associated with cold tolerance and the water stress response were upregulated. We identified eight cold-tolerance genes in the Th. intermedium chromosomes and validated three of them, Thint.J05G452200, Thint.J05G452300, and Thint.V05G408900, using qRT-PCR. These genes encode proteins associated with cold tolerance and are potential candidates for further functional validation. Additionally, three chromosomes from homoeologous group 6 were introgressed, carrying six genes potentially associated with superior grain traits. Among them, TraesCS6D02G287800, which encodes a specific protein, exhibited high expression levels in both wheatgrass lines, suggesting its critical role in enhancing grain traits. Our results indicate that the suppression of grass gene expression, likely due to the introgression of wheat chromosomes and the upregulation of pathways related to cold tolerance and overwintering ability, contributes to the adaptive features of the wheatgrass lines. This study provides a genomic foundation for understanding gene expression regulation in distant hybrid progeny and offers valuable insights for designing new breeding strategies for perennial wheat or wheatgrass.

Chromosomes, Plant↗

PubMed2006

Essential role of insulin and insulin-like growth factor 1 receptor signaling in cardiac development and function.

Cardiovascular disease is the leading cause of death in people with type 2 diabetes and is linked to insulin resistance even in the absence of diabetes. Here we show that mice with combined deficiency of the insulin receptor and insulin-like growth factor 1 (IGF-1) receptor in cardiac and skeletal muscle develop early-onset dilated cardiomyopathy and die from heart failure within the first month of life despite having a normal glucose homeostasis. Mice lacking the insulin receptor show impaired cardiac performance at 6 months, and mice lacking the insulin receptor plus one Igf1r allele have slightly increased mortality. By contrast, mice lacking the IGF-1 receptor or the IGF-1 receptor plus one Ir allele appear normal. Morphological characterization and oligonucleotide array analysis of gene expression demonstrate that prior to development of these physiological defects, mice with combined deficiency of both insulin and IGF-1 receptors have a coordinated down-regulation of genes encoding components of the electron transport chain and mitochondrial fatty acid beta-oxidation pathways and altered expression of contractile proteins. Thus, while neither the insulin receptor nor IGF-1 receptor in muscle is critical for glucose homeostasis during the first month of life, signaling from these receptors, particularly the insulin receptor, is required for normal cardiac metabolism and function.

Animals↗

PubMed2006

Repair of canine mandibular bone defects with bone marrow stromal cells and porous beta-tricalcium phosphate.

Tissue engineering has become a new approach for repairing bone defects. Previous studies have been limited to the use of slow-degradable scaffolds with bone marrow stromal cells (BMSCs) in mandibular reconstruction. In this study, a 30 mm long mandibular segmental defect was repaired by engineered bone graft using osteogenically induced autologous BMSCs seeded on porous beta-tricalcium phosphate (beta-TCP, n=5). The repair of defects was compared with those treated with beta-TCP alone (n=6) or with autologous mandibular segment (n=4). In the BMSCs/beta-TCP group, new bone formation was observed from 4 weeks post-operation, and bony-union was achieved after 32 weeks, which was detected by radiographic and histological examination. In contrast, minimal bone formation with almost fibrous connection was observed in the group treated with beta-TCP alone. More importantly, the engineered bone with BMSCs/beta-TCP achieved a satisfactory biomechanical property in terms of bending load strength, bending displacement, bending stress and Young's modulus at 32 weeks post-operation, which was very close to those of contralateral edentulous mandible and autograft bone (p>0.05). Based on these results, we conclude that engineered bone from osteogenically induced BMSCs and biodegradable beta-TCP can well repair the critical-sized segmental mandibular defects in canines.

Animals↗

PubMed2006

PICOT inhibits cardiac hypertrophy and enhances ventricular function and cardiomyocyte contractility.

Multiple signaling pathways involving protein kinase C (PKC) have been implicated in the development of cardiac hypertrophy. We observed that a putative PKC inhibitor, PICOT (PKC-Interacting Cousin Of Thioredoxin) was upregulated in response to hypertrophic stimuli both in vitro and in vivo. This suggested that PICOT may act as an endogenous negative feedback regulator of cardiac hypertrophy through its ability to inhibit PKC activity, which is elevated during cardiac hypertrophy. Adenovirus-mediated gene transfer of PICOT completely blocked the hypertrophic response of neonatal rat cardiomyocytes to enthothelin-1 and phenylephrine, as demonstrated by cell size, sarcomere rearrangement, atrial natriuretic factor expression, and rates of protein synthesis. Transgenic mice with cardiac-specific overexpression of PICOT showed that PICOT is a potent inhibitor of cardiac hypertrophy induced by pressure overload. In addition, PICOT overexpression dramatically increased the ventricular function and cardiomyocyte contractility as measured by ejection fraction and end-systolic pressure of transgenic hearts and peak shortening of isolated cardiomyocytes, respectively. Intracellular Ca(2+) handing analysis revealed that increases in myofilament Ca(2+) responsiveness, together with increased rate of sarcoplasmic reticulum Ca(2+) reuptake, are associated with the enhanced contractility in PICOT-overexpressing cardiomyocytes. The inhibition of cardiac remodeling by of PICOT with a concomitant increase in ventricular function and cardiomyocyte contractility suggests that PICOT may provide an efficient modality for treatment of cardiac hypertrophy and heart failure.

Animals↗

PubMed2006

Bone reconstruction with bone marrow stromal cells.

Bone marrow stromal/stem cells (BMSCs) are multipotent adult stem cells and have become the important cell source for cell therapy and engineered tissue repair. Their osteogenic differentiation potential has been well characterized in many in vitro studies. In addition, small animal model-based studies also reveal their capability of bone formation in vivo when implanted with biodegradable scaffold, indicating the great potential for therapeutic application. Bone defect is a common clinical problem that deserves an optimal therapy. Unlike traditional surgical repair that needs to sacrifice donor site tissue, the tissue-engineering approach can achieve the goal of bone regeneration and repair without the necessity of donor site morbidity. To safely translate experimental study into a clinical trial of engineered bone repair, in vivo study using large animal models has become the key issue. Our in vivo study in this aspect and the published results indicate that bone regeneration and repair by BMSCs and biodegradable scaffold is a realistic goal that can be achieved.

Animals↗

PubMed2006

In vitro tendon engineering with avian tenocytes and polyglycolic acids: a preliminary report.

Although there are many reports of in vivo tendon engineering using different animal models, only a few studies involve the short-term investigation of in vitro tendon engineering. Our previous study demonstrated that functional tendon tissue could be engineered in vivo in a hen model using tenocytes and polyglycolic acid (PGA) fibers. This current study explored the feasibility of in vitro tendon engineering using the same type of cells and scaffold material. Tenocytes were extracted from the tendons of a hen's foot with enzyme digestion and cultured in DMEM plus 10% FBS. Unwoven PGA fibers were arranged into a cord-like construct and fixed on a U-shape spring, and tenocytes were then seeded on PGA fibers to generate a cell-PGA construct. In experimental group 1, 22 cell-scaffold constructs were fixed on the spring with no tension and collected at weeks 4 (n = 7), 6 (n = 7) and 10 (n = 8); in experimental group 2, five cell-scaffold constructs were fixed on the spring with a constant strain and collected after 6 weeks of culture. In the control group, three cell-free scaffolds were fixed on the spring without tension. The collected engineered tendons were subjected to gross and histological examinations and biomechanical analysis. The results showed that tendon tissue could be generated during in vitro culture. In addition, the tissue structure and mechanical property became more mature and stronger with the increase of culture time. Furthermore, application of constant strain could enhance tissue maturation and improve mechanical property of the in vitro engineered tendon (1.302 +/- 0.404 Mpa with tension vs 0.406 +/- 0.030 Mpa without tension at 6 weeks). Nevertheless, tendon engineered with constant strain appeared much thinner in its diameter than tendon engineered without mechanical loading. Additionally, its collagen fibers were highly compacted when compared to natural tendon structure, suggesting that constant strain may not be the optimal means of mechanical load. Thus, application of dynamic mechanical load with a bioreactor to the construction of tendon tissue will be our next goal in this series of in vitro tendon engineering study.

Animals↗

PubMed2006

Repair of experimental alveolar bone defects by tissue-engineered bone.

Alveolar bone resorption caused by periodontal diseases remains a difficult clinical problem to treat. Our purpose here was to develop protocols for repairing experimental horizontal alveolar bone defects. The procedure entailed isolating bone marrow stromal cells (BMSC). They were expanded and induced in vitro into osteogenic cells in a defined medium. Induced BMSCs were mixed with calcium alginate to form a gel form of cell-scaffold construct for developing engineered bone. A horizontal alveolar bone defect was created in 15 mongrel dogs, which was 5 mm high on each of two buccal sides at the location of mandibular premolar 3, 4, and molar 1. Without bias, the animals were separated into the following groups: (1) cell-scaffold construct as the experimental group; (2) calcium alginate alone as the control group A; (3) untreated as the control group B. Block sections of the defects were collected at 4, 12, and 24 weeks postsurgery, respectively, and processed for gross and histological observation as well as x-ray examination. The results showed that in vitro induced BMSCs exhibited an osteogenic phenotype. Histologically, bone nodule structure was observed in the tissue of the experimental group at 4 weeks postsurgery and the engineered bone became more mature after 12 weeks, which was similar to normal bone. At 12 weeks postsurgery, the height of repaired alveolar bone reached 2.43 +/- 0.93 mm, 0.98 +/- 0.87 mm, 0.78 +/- 0.75 mm for the experimental group, control groups A and B, respectively, with a significant difference between the experimental and control groups (p < 0.01). The average level of buccal alveolar ridge in experimental group, control groups A and B reached 48.59%, 19.74%, and 15.76% of the height of normal alveolus, respectively, with a significant difference between the experimental group and two control groups (p < 0.01). We thus conclude that BMSCs can be induced to become osteogenic and can be used as seed cells to engineer bone tissue and repair experimental alveolar bone defects.

Alginates↗

PubMed2006

Tissue-engineered bone repair of goat-femur defects with osteogenically induced bone marrow stromal cells.

Tissue engineering can generate bone tissue and has been shown to provide a better means of repairing weight-bearing bone defect. Previous studies, however, have heretofore been limited to the use of nonosteogenically induced bone marrow stromal cells (BMSCs) or the application of slow-degradation scaffolds. In this study, weight-bearing bone was engineered using osteogenically induced BMSCs. In addition, coral was used as a scaffold material, due to its proper degradation rate for the engineering and repair of a goat femur defect. A 25 mm long defect was created at the middle of the right femur in each of 10 goats. The rates of defect repair were compared in an experimental group of ten goats receiving implants containing osteogenically induced BMSCs and in the control group of goats (n = 10) receiving just coral cylinders. In the experimental group, bony union was observed by radiographic and gross view at 4 months, and engineered bone was further remodeled into newly formed cortexed bone at 8 months. There was increased gray density of radiographic rays in the repaired area, which was significantly different (p < 0.05) from that of the control group. H&E staining demonstrated that trabecular bone was formed at 4 months. Moreover, irregular osteon was observed at 8 months. Most importantly, the tissue-engineered bone segment revealed a similarity to the left-side normal femur in terms of bend load strength and bend rigidity, showing no significant difference (p > 0.05). In contrast, the coral cylinders of the control group showed no bone formation. Furthermore, almost complete resorption of the carrier had occurred, being evident at 2 months in the control group. H&E staining demonstrated that a small amount of residual coral particle was surrounded by fibrous tissue at 4 months whereas the residues disappeared at 8 months. Based on these results, we conclude that engineered bone from osteogenically induced BMSCs and coral can ideally heal critical-sized segmental bone defects in the weight-bearing area of goats.

Animals↗

PubMed2006

Repair of tendon defect with dermal fibroblast engineered tendon in a porcine model.

Harvesting autologous tenocytes for tendon engineering may cause secondary tendon defect at the donor site. Dermal fibroblasts are an easily accessible cell source and do not cause major donor site defect. This study aims to explore the possibility of tendon engineering using dermal fibroblasts. A total of 45 hybrid pigs were randomly divided into three groups: experimental group (n = 15)--repair of tendon defect with a dermal fibroblast engineered tendon; control group 1 (n = 15)--repair of defect with a tenocyte engineered tendon; and control group 2 (n = 15)-repair of defect with a scaffold alone. Both autologous dermal fibroblasts and tenocytes were seeded on polyglycolic acid (PGA) unwoven fibers to form a cell-scaffold construct and cultured in vitro for 7 days before in vivo implantation to repair a defect of flexor digital superficial tendon. Specimens were harvested at weeks 6, 14, and 26 for gross, histological, and mechanical analyses. Microscopy revealed good attachment of both dermal fibroblasts and tenocytes on PGA fibers and matrix production. In vivo results showed that fibroblast and tenocyte engineered tendons were similar to each other in their gross view, histology, and tensile strength. At 6 weeks, parallel collagen alignment was observed at both ends, but not in the middle in histology, with more cellular components than natural tendons. At weeks 14 and 26, both engineered tendons exhibited histology similar to that of natural tendon. Collagens became parallel throughout the tendon structure, and PGA fibers were completely degraded. Interestingly, dermal fibroblast and tenocyte engineered tendons did not express type III collagen at 26 weeks, which remained observable in normal pig skin and control group 2 tissue using polarized microscopy, suggesting a possible phenotype change of implanted dermal fibroblasts. Furthermore, both fibroblast and tenocyte engineered tendons shared similar tensile strength, about 75% of natural tendon strength. At 6 weeks in control group 2, neo-tissue was formed only at the peripheral area by host cells. A cord-like tissue was formed at weeks 14 and 26. However, the formed tissue was histologically disorganized and mechanically weaker than both cell-engineered tendons (p < 0.05). These results suggest that dermal fibroblasts may have the potential as seed cells for tendon engineering.

Absorbable Implants↗

PubMed2006

The beta-catenin/T-cell factor/lymphocyte enhancer factor signaling pathway is required for normal and stress-induced cardiac hypertrophy.

In cells capable of entering the cell cycle, including cancer cells, beta-catenin has been termed a master switch, driving proliferation over differentiation. However, its role as a transcriptional activator in terminally differentiated cells is relatively unknown. Herein we utilize conditional, cardiac-specific deletion of the beta-catenin gene and cardiac-specific expression of a dominant inhibitory mutant of Lef-1 (Lef-1Delta20), one of the members of the T-cell factor/lymphocyte enhancer factor (Tcf/Lef) family of transcription factors that functions as a coactivator with beta-catenin, to demonstrate that beta-catenin/Tcf/Lef-dependent gene expression regulates both physiologic and pathological growth (hypertrophy) of the heart. Indeed, the profound nature of the growth impairment of the heart in the Lef-1Delta20 mouse, which leads to very early development of heart failure and premature death, suggests beta-catenin/Tcf/Lef targets are dominant regulators of cardiomyocyte growth. Thus, our studies, employing complementary models in vivo, implicate beta-catenin/Tcf/Lef signaling as an essential growth-regulatory pathway in terminally differentiated cells.

Animals↗

PubMed2006

Transcription factor CHF1/Hey2 suppresses cardiac hypertrophy through an inhibitory interaction with GATA4.

Pathological cardiac hypertrophy is considered a precursor to clinical heart failure. Understanding the transcriptional regulators that suppress the hypertrophic response may have profound implications for the treatment of heart disease. We report the generation of transgenic mice that overexpress the transcription factor CHF1/Hey2 in the myocardium. In response to the alpha-adrenergic agonist phenylephrine, they show marked attenuation in the hypertrophic response compared with wild-type controls, even though blood pressure is similar in both groups. Isolated myocytes from transgenic mice demonstrate a similar resistance to phenylephrine-induced hypertrophy in vitro, providing further evidence that the protective effect of CHF1/Hey2 is mediated at the myocyte level. Induction of the hypertrophy marker genes ANF, BNP, and beta-MHC in the transgenic cells is concurrently suppressed in vivo and in vitro, demonstrating that the induction of hypertrophy-associated genes is repressed by CHF1/Hey2. Transfection of CHF1/Hey2 into neonatal cardiomyocytes suppresses activation of an ANF reporter plasmid by the transcription factor GATA4, which has previously been shown to activate a hypertrophic transcriptional program. Furthermore, CHF1/Hey2 binds GATA4 directly in coimmunoprecipitation assays and inhibits the binding of GATA4 to its recognition sequence within the ANF promoter. Our findings demonstrate that CHF1/Hey2 functions as an antihypertrophic gene, possibly through inhibition of a GATA4-dependent hypertrophic program.

Animals↗

PubMed2006

[Effect of adeno-BMP7 transfection on osteogenesis of BMSCs].

OBJECTIVE: To study the effect of adeno-BMP7 transfection on the biology of bone marrow stromal cells (BMSCs). METHODS: Bone marrow was obtained from the goat. The BMSCs were isolated and cultured at the second passage. Once the cells attached and formed a monolayer with 70%-80% confluency, adeno-BMP7 (M.O.I. = 100) was added to the cells. After three days, calcium node was examined with staining; cell-coral compound was replanted subcutaneously. RESULTS: With adeno-BMP7 transfection, BMP7 expression was detected with Western-blot; big calcium nodes were observed with staining. New bone formation was enhanced, which was evaluated by X-ray and histological examinations. CONCLUSIONS: BMSCs transfected with adeno-BMP7 show much stronger osteogenic ability.

Adenoviridae↗

PubMed2006

[Repair of canine segmental mandibular defects using autogenous bone marrow stromal cells and coralline hydroxyapatite].

OBJECTIVE: To repair segmental mandibular defects with autogenous bone marrow stromal cells (BMSCs) and coralline hydroxyapatite. METHODS: Isolated BMSCs were in vitro expanded and osteogenically induced. In 11 canines, a 3 cm segmental mandibular defect in right mandible was created. Five canine's defects were repaired with cell-scaffold constructs made from induced BMSCs and coralline hydroxyapatite (CHA); Others were repaired with CHA as control. The engineered bone was evaluated by X-ray, CT, gross and histological examination, biomechanical test 12, 26, 32 weeks post-operation respectively. RESULTS: BMSCs grew well on the CHA. X-ray and CT images showed better callus formation at connection sites in experimental group over time while worse formation at connection sites eventually in control group. At 32 weeks post-operation in experimental group, the defects were well repaired grossly. Histologically, there were bony healing and lamellar bone formation, in experimental group fibrous healing and woven bone formation in control group. Biomechanical test revealed no significant difference between experimental group and normal control group. CONCLUSIONS: Canine segmental mandibular defects can be ultimately repaired with the tissue-engineered bone generated by autogenous osteogenic BMSCs and CHA scaffold.

Animals↗

PubMed2006

[In vitro study on proliferation and multi-lineage differentiation potential of adipose-derived cells].

Adipose were obtained from patients underwent liposuction treatment (total 19 female donors, 31.5 +/- 5.8 years old). Liposuction tissues were digested with type I collagenase, cells were isolated and cultured up to passage 10. To evaluate the proliferation potential of ADCs, growth curve and cumulative population doubling were achieved by cell counting. CD29,CD105, CD106, CD166, CD49d, CD34, CD31, 3G5 were analyzed by flow cytometry and immunocytochemistry to characterize the cell population. The multi-lineage potential of ADCs was testified by differentiating cells with osteogenic,chondrogenic and adipogenic inducer. A total of 5x10(7) nucleared cells could be obtained from 300ml liposuction tissues. After in vitro cultivation,cumulative population doubling number reached 15.53 at passage 10 (average 1.59 +/- 0.224 /passage). Flow cytometry and immunocytochemistry showed that ADCs expressed high level (>60%) of stem cell-related antigen (CD29, CD105, CD106, CD166), while cells expressed hematopoiesis-related antigen CD34 and CD31 around 7.3% and 29.2% respectively. Collagen II (both in mRNA and protein level) was detected in chondrogenic differentiation. The calcified nodules were observed by von Kossa and Alizarn Red staining and the expressions of AKP and Osteonectin were detected by RT-PCR in osteogenic differentiation. PPARr2, GLU-4, and Leptin genes were detected in adipogenic differentiation and intracellular lipid droplets could be observed by Oil Red staining. ADCs can be abundantly harvested and have high proliferative and multi-lineage differentiation potential.

Adipocytes↗

PubMed2005

Selective loss of fine tuning of Gq/11 signaling by RGS2 protein exacerbates cardiomyocyte hypertrophy.

Alterations in cardiac G protein-mediated signaling, most prominently G(q/11) signaling, are centrally involved in hypertrophy and heart failure development. Several RGS proteins that can act as negative regulators of G protein signaling are expressed in the heart, but their functional roles are still poorly understood. RGS expression changes have been described in hypertrophic and failing hearts. In this study, we report a marked decrease in RGS2 (but not other major cardiac RGS proteins (RGS3-RGS5)) that occurs prior to hypertrophy development in different models with enhanced G(q/11) signaling (transgenic expression of activated Galpha(q)(*) and pressure overload due to aortic constriction). To assess functional consequences of selective down-regulation of endogenous RGS2, we identified targeting sequences for effective RGS2 RNA interference and used lipid-based transfection to achieve uptake of fluorescently labeled RGS2 small interfering RNA in >90% of neonatal and adult ventricular myocytes. Endogenous RGS2 expression was dose-dependently suppressed (up to 90%) with no major change in RGS3-RGS5. RGS2 knockdown increased phenylephrine- and endothelin-1-induced phospholipase Cbeta stimulation in both cell types and exacerbated the hypertrophic effect (increase in cell size and radiolabeled protein) in neonatal myocytes, with no major change in G(q/11)-mediated ERK1/2, p38, or JNK activation. Taken together, this study demonstrates that endogenous RGS2 exerts functionally important inhibitory restraint on G(q/11)-mediated phospholipase Cbeta activation and hypertrophy in ventricular myocytes. Our findings point toward a potential pathophysiological role of loss of fine tuning due to selective RGS2 down-regulation in G(q/11)-mediated remodeling. Furthermore, this study shows the feasibility of effective RNA interference in cardiomyocytes using lipid-based small interfering RNA transfection.

Animals↗

PubMed2005

[Cartilage-derived morphogenetic protein 1 initiates chondrogenic differentiation of human dermal fibroblasts in vitro].

OBJECTIVE: To explore the factors influencing the differentiation of fibroblasts into chondrocyte phenotype induced by a growth factor, cartilage-derived morphogenetic protein 1 (CDMP1). METHODS: Fibroblasts isolated from foreskin obtained during circumcision were cultured in the forms of micromass and monolayer culture. The culture fluid of the fibroblasts at the passage 2, 7, and 10 was added with CDMP1 of the concentrations at the concentrations of 10, 30, 100, and 300 ng/ml respectively and co-cultured for 7 days. RT-PCR was used to detect the expression of bone morphogenetic protein receptor (BMPR), activin receptor-like kinase (ALK) receptor, collagen types II, IV, and X before and after CDMP1 induction. Western blotting was used to detect the protein expression of collagen types II, a transcriptional factor Sox9, and aggrcan before and after the induction. Flow cytometry was used to detect the superficial markers CD29, CD105, CD106, and CD166, and the expression of collagen types I and II. RESULTS: Western blotting showed that the collagen type II positive cell rate in the passage 5 cells was 74.3% +/- 0.4%, not significantly different from that of the passage 2 cells (73.4% + 0.5%). When the concentrations of CDMP1 were 10 and 30 ng/ml no expression of aggrecan and collagen type II was detected, When the concentrations of CDMP1 was 100 and 300 ng/ml, the expression of aggrecan and collagen type II could be detected and without significant differences between these 2 concentrations. The expression of aggrcan and collagen type II mRNA disappeared in the monolayer cultured P2 and P5 fibroblasts induced by CDMP1 for 14 days, However, RT-PCR and Western blotting showed expression of collagen type II, aggrcan and SOX9 in the micromass cultured fibroblasts. RT-PCR showed that all fibroblasts cultured in vitro expressed ActR-I/ALK-2, BMPR-IA/ALK-3, and BMPR-IB/ALK-6 genes, and the expression of these genes significantly increased after CDMP1 for 7 days. CONCLUSION: CDMP1 stimulates the human dermal fibroblasts expanded in vitro to differentiate into chondrogenic phenotype in a dose dependent manner. Three-dimensional culture environments accelerate the chondrogenic differentiation. The expression of ALK receptors may involve the CDMP1 stimulated differentiation of fibroblasts.

Adolescent↗

PubMed2005

[Human adipose derived stem cells suppress lymphocyte proliferation induced by cellular or nonspecific mitogenic stimuli].

OBJECTIVE: To study immunological properties of adipose derived stem cells (ADSC) and their in vitro immunomodulatory effects on lymphocytes. METHODS: ADSC was isolated from fat tissue by liposuction and culture expanded. Cells at passage 2 were observed for the expression of HLAI, HLAII by FACs analysis. Peripheral blood lymphocytes (PBL) were cultured with allogeneic ADSCs at dose of 1 x 10(5). A third-party ADSCs at dose of 1 x 10(2), 1 x 10(3), 1 x 10(4), 1 x 10(5) were added to the ongoing two-way mixed lymphocyte reactions (MLR) for 6 days. Value of CPM (count per minute) was calculated with luminescence counter. RESULTS: Flow cytometry showed that undifferentiated ADSCs express HLA class I but not class II. Addition of interferon gamma (IFN-gamma) for 48 hours induced greater than 90% of cells to express HLA class II. No lymphocyte response was induced by allogeneic ADSCs as stimulators. Results were similar using ADSCs pretreated with IFN-gamma. ADSCs elicited inhibit function of mixed lymphocyte cultures in a dose dependent way. Even if ADSCs were pretreated with IFN-gamma, the suppression ability was maintained. CONCLUSION: Undifferentiated ADSCs do not elicit alloreactive lymphocyte proliferative responses and could modulate immune responses in vitro.

Adipocytes↗