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Biomedical subjects

J H Yang

Publications and source records attributed to J H Yang.

At least 19 recordsLinked to original sources

ADAR1 is involved in the development of microvascular lung injury.

Deamination of adenosine on pre-mRNA to inosine is a recently discovered process of posttranscription modification of pre-mRNA, termed A-to-I RNA editing, which results in the production of proteins not inherent in the genome. The present study aimed to identify a role for A-to-I RNA editing in the development of microvascular lung injury. To that end, the pulmonary expression and activity of the RNA editase ADAR1 were evaluated in a mouse model of endotoxin (15 mg/kg IP)-induced microvascular lung injury (n=5) as well as in cultured alveolar macrophages stimulated with endotoxin, live bacteria, or interferon. ADAR1 expression and activity were identified in sham lungs that were upregulated in lungs from endotoxin-treated mice (at 2 hours). Expression was localized to polymorphonuclear and monocytic cells. These events preceded the development of pulmonary edema and leukocyte accumulation in lung tissue and followed the local production of interferon-gamma, a known inducer of ADAR1 in other cell systems. ADAR1 was found to be upregulated in alveolar macrophages (MH-S cells) stimulated with endotoxin (1 to 100 microg/mL), live Escherichia coli (5x10(7) colony-forming units), or interferon-gamma (1000 U/mL). Taken together, these data suggest that ADAR1 may play a role in the pathogenesis of microvascular lung injury possibly through induction by interferon.

Adenosine↗

Interleukin 12 gene therapy of cancer by peritumoral injection of transduced autologous fibroblasts: outcome of a phase I study.

A phase I dose-escalation clinical trial of peritumoral injections of interleukin 12 (IL-12)-transduced autologous fibroblasts was performed in patients with disseminated cancer for whom effective treatment does not exist. The goals of this study were to assess the safety and toxicities as well as the efficacy, and ancillarily the immunomodulatory effects, of peritumoral IL-12 gene transfer. Primary dermal fibroblasts cultured from the patients were transduced with retroviral vector carrying human IL-12 genes (p35 and p40) as well as the neomycin phosphotransferase gene (TFG-hIL-12-Neo). Patients received four injections at intervals of 7 days. Nine patients were enrolled in this dose-escalation study, with secreted IL-12 doses ranging from 300 ng/24 hr for the first three patients to 1000, 3000, and 5000 ng/24 hr for two patients in each subsequent dosage level. Although a definite statement cannot be made, there appears to be perturbation of systemic immunity. Also, the locoregional effects mediated by tumor necrosis factor alpha (TNF-alpha) and CD8+ T cells were observed with tumor regression. Treatment-related adverse events were limited to mild to moderate pain at the injection site; clinically significant toxicities were not encountered. Transient but clear reductions of tumor sizes were observed at the injected sites in four of nine cases, and at noninjected distant sites in one melanoma patient. Hemorrhagic necrosis of tumors was observed in two melanoma patients. These data indicate that gene therapy by peritumoral injection of IL-12-producing autologous fibroblasts is feasible, and promising in patients with advanced cancer.

Adult↗

Possible molecular targets of halogenated aromatic hydrocarbons in neuronal cells.

Halogenated aromatic hydrocarbon including polychlorinated biphenyls (PCBs) are persistent and bioaccumulative environmental toxicants. Although health effects associated with exposure to these chemicals, including motor dysfunction and impairment in memory and learning, have been identified, their molecular site of action is unknown. Previous study from this laboratory demonstrated that, while ortho PCBs perturbed intracellular signaling mechanisms including Ca2+ homeostasis, receptor-mediated inositol phosphate production and translocation of PKC, non-ortho PCBs did not. Since PKC signaling pathway is implicated in the modulation of motor behavior, as well as learning and memory, and the roles of PKC are isoform-specific, we have now studied the effects of two structurally distinct PCBs on isoforms of PKC in cerebellar granule cell culture model. Cells were exposed to 2,2'-dichlorobiphenyl (ortho PCB; 2,2'-DCB) or 4,4'-dichlorobiphenyl (non-ortho PCB; 4,4'-DCB) for 15 min, respectively, and subsequently fractionated and immunoblotted against the selected PKC monoclonal antibodies (alpha, gamma, delta, epsilon, lambda, iota). While 2,2'-DCB induced a translocation of PKC-alpha [cytosol (% control): 54 +/- 12 at 25 microM and 66 +/- 10 at 50 microM; membrane (% control): 186 +/- 37 at 25 microM and 200 +/- 48 at 50 microM] and -epsilon [cytosol (% control): 92 +/- 12 at 25 microM and 97 +/- 15 at 50 microM; membrane (% control): 143 +/- 23 at 25 microM and 192 +/- 24 at 50 microM] from cytosol to membrane fraction in a concentration-dependent manner, 4,4'-DCB had no effects. 2,2'-DCB induced translocation of PKC-alpha was blocked by pretreatment with sphingosine, suggesting a possible role of sphingolipid pathway. Although reports on implication of PKC-gamma with learning and memory are relatively extensive, the expression of this particular isoform in the primary cerebellar granule cells was below the detectable level. PKC-delta, -lambda and -iota were present in these cells, but were not altered by PCB exposure. These results suggest that the effects of 2,2'-DCB on PKC is isoform-dependent and PKC-alpha as well as PKC-epsilon may be target molecules for ortho-PCBs in neuronal cells.

Animals↗

Changes in myometrial thickness during hysteroscopic resection of deeply invasive submucous myomas.

STUDY OBJECTIVE: To evaluate the efficacy of hysteroscopy in resecting submucous myomas with deep intramural invasion. DESIGN: Prospective, observational study (Canadian Task Force classification II-2). SETTING: Department of gynecology at a general hospital. PATIENTS: Sixteen women with a solitary submucous myoma, in which myometrial thickness between the outer edge of the myoma and inner edge of the serosa was between 5 and 10 mm. INTERVENTION: One-step hysteroscopic myomectomy. MEASUREMENTS AND MAIN RESULTS: Median myoma diameter and weight were 3.3 cm and 30 g, respectively. Myometrial thickness between the myoma and serosa increased gradually and significantly from 6.7 mm before, to 8.9 mm during, to 16.1 mm immediately after hysteroscopic myomectomy (p <0.001). The thickness of the opposite uterine wall increased from 10.1 mm before, to 11.4 mm during, to 18.8 mm after operation (p <0.001). CONCLUSION: One-step hysteroscopic myomectomy may be performed to remove deeply infiltrating submucous myomas when myometrial thickness at the implantation site is as thin as 5 mm.

Adult↗

Fracture strength of copy-milled and conventional In-Ceram crowns.

The purpose of this study was to compare the fracture resistance of copy-milled and conventional In-Ceram crowns. Four groups of 10 uniform sized all-ceramic anterior crowns were fabricated for this test: (1) In-Ceram Spinell (2) In-Ceram Alumina (3) Celay In-Ceram Spinell, and (4) Celay In-Ceram Alumina crowns. All specimens were cemented on stainless steel master die with resin cement and stored in 37 degrees C water for one day prior to loading into a universal testing machine. Using a steel ball at a crosshead speed of 0.5 mm min-1, the crowns were loaded at 30 degrees C angle until catastrophic failure occurred. Mean fracture strength was analysed and compared. Under the conditions of this study and the materials used, the following conclusions were drawn: 1. The strength of Celay In-Ceram anterior crowns had a slightly higher fracture strength than conventional In-Ceram crowns. 2. In-Ceram Alumina crowns had a significantly higher fracture strength than In-Ceram Spinell crowns in both conventional and copy milling methods.

Aluminum Oxide↗

Expression of p21Waf1, p27Kip1 and cyclin D1 proteins in breast ductal carcinoma in situ: Relation with clinicopathologic characteristics and with p53 expression and estrogen receptor status.

p21Waf1 (p21), p27Kip1 (p27) and cyclin D1 have recently been reported as useful prognostic markers for patients with breast carcinoma. However, studies on these cell cycle regulators in ductal carcinoma in situ (DCIS) have been extremely limited. Therefore, we studied the immunohistochemical expression of p21, p27 and cyclin D1 proteins in 49 DCIS cases and compared the findings with the clinicopathologic parameters (age, tumor size, gross type, histologic type, histologic grade, necrosis and mitotic index), p53 and estrogen receptor (ER) status. A significant correlation was found between positive p21 immunoreactivity (67.3% of the cases) and well-differentiated histologic grade, non-comedo type, ER-positive and p53-negative (p53-) status. DCIS with p21+/p53- is likely to be the non-comedo type. The overexpression of cyclin D1 (59.2% of the cases) correlated positively with the ER expression (P = 0.001). The p27 protein expression (46.9% of the cases) correlated with the cyclin D1 immunopositivity (P = 0.0003) and ER expression (P = 0.005). No significant associations were seen in the p27 or cyclin D1 expression and other clinicopathologic parameters. Our results suggest that p21 might be more related to the useful biologic markers in DCIS than p27 or cyclin D1. The significant positive association between p21, p27 or cyclin D1 and ER status, and close association of p27 and cyclin D1 expression might be implicated in the tumor biology of DCIS.

Adult↗

Routine measurement of serum calcitonin is useful for early detection of medullary thyroid carcinoma in patients with nodular thyroid diseases.

BACKGROUND: Medullary thyroid carcinoma (MTC) is characterized by a high concentration of serum calcitonin. Routine measurement of serum calcitonin concentration has been advocated for detection of MTC among patients with nodular thyroid diseases. However, a minimal to moderate increase of serum calcitonin concentration has been frequently observed in diseases other than MTC. Fine-needle aspiration cytology (FNAC) is not a reliable method for detection of MTC. Therefore, we evaluated the usefulness of routine measurement of serum calcitonin concentration in patients with nodular thyroid diseases, and studied the validity of pentagastrin stimulation test and FNAC in these patients. SUBJECTS AND METHODS: We performed routine measurement of serum calcitonin concentrations in 1,448 patients (male, 285, female, 1,163) with nodular thyroid diseases. The average age was 46 years (range, 14-86 years). Initial examination included thyroid examination, thyroid scan or ultrasonography, measurements of serum free triiodothyronine) (T3), free thyroxine (T4), thyrotropin (TSH) levels, and antithyroid autoantibodies. FNAC was performed in all patients who had palpable or visible thyroid nodule by ultrasonography, and pentagastrin stimulation test was performed in 39 patients who consented. Serum calcitonin concentration was measured with a two-site immunoradiometric assay using commercial kits. We also measured the serum calcitonin concentration in 407 healthy subjects without thyroid or nonthyroid diseases. RESULTS: Serum calcitonin concentration was 10 pg/mL or less in 403 normal subjects (99.0 percentile), and 11-13 pg/mL in the remaining 4 subjects. We found that 56 (3.87%) of 1,448 patients with nodular thyroid diseases had serum calcitonin level above 10 pg/mL. Ten patients (0.69%) with histologically confirmed MTC were detected by the routine measurement of serum calcitonin. The prevalence of MTC was 5.2% in 194 patients with thyroid carcinoma. Five of 10 patients with MTC had basal serum calcitonin level above 100 pg/mL. The remaining 5 patients had minimal or moderate elevation of basal serum calcitonin (range, 12-86 pg/mL). Serum calcitonin concentration increased to more than 100 pg/mL by pentagastrin in all patients with MTC (2.4- to 37.7-fold increase). FNAC suggested MTC in only 2 patients (22.2%), and failed to diagnose MTC in 7 patients. FNAC was not performed in 1 patient with MTC, because he had no visible mass by ultrasonography. CONCLUSION: These results suggested that routine measurement of serum calcitonin is useful in the early detection of MTC among patients with nodular thyroid diseases. Pentagastrin stimulation test may also be a reliable way for evaluating thyroid nodular patients with mild or moderate elevation of serum calcitonin concentrations. However, FNAC was not sensitive in detecting MTC. We recommend routine measurement of serum calcitonin concentration in patients with nodular thyroid diseases.

Adolescent↗

Comparison of intraoperative frozen section analysis of sentinel node with preoperative positron emission tomography in the diagnosis of axillary lymph node status in breast cancer patients.

BACKGROUND: Although axillary lymph node status is an important prognostic factor and axillary dissection is regarded as the gold standard for staging, it requires radical surgery which is accompanied by considerable postoperative problems such as lymphedema. This study was carried out to evaluate the diagnostic accuracy of preoperative positron emission tomography (PET) and intraoperative frozen biopsy of sentinel lymphadenectomy (SLND) in detecting axillary lymph node metastasis. METHODS: We studied 18 patients who had preoperative PET and SLND for breast cancer in the Department of Surgery at Samsung Medical Center. They all had preoperative PET with a radiolabeled glucose analogue ([18F]FDG) to visualize primary tumors and metastatic nodes. Isosulphan blue dye was used for intraoperative SLND. Frozen and permanent biopsies were then compared after full axillary dissection. RESULTS: In 18 cases, six had positive metastatic nodes in the permanent biopsy of full axillary dissection but were negative in three cases by preoperative PET. There was one false negative result by frozen biopsy of SLND which was later shown to be positive by permanent biopsy. The sensitivity and specificity of SLND and PET for detecting axillary node metastasis were 83, 100% and 50, 100%, respectively. CONCLUSION: Although both methods are good for axillary nodal status, the intraoperative frozen biopsy result of SLND was superior to preoperative PET in our preliminary study.

Adult↗

Apoptotic cell death of cultured salamander photoreceptors induced by cccp: CsA-insensitive mitochondrial permeability transition.

Photoreceptor degeneration is mediated by apoptosis in several animal models, although the underlying mechanisms are yet to be elucidated. We present here an apoptotic model based on a primary cell culture of tiger salamander photoreceptors, in which treatment with carbonyl cyanide m-chlorophenylhydrazone (cccp), a protonophore, induced apoptosis. Cells exposed to cccp showed condensed nuclei and displayed positive TdT-dUTP terminal nick-end labeling (TUNEL). In addition, 10-100 microM cccp rapidly induced a reduction of Delta psi(m) and > or = 30 microM cccp induced a significant leakage of calcein from mitochondria to cytosol and nucleus, indicating a change in mitochondrial inner membrane permeability. Cyclosporin A (CsA), a transition pore blocker, did not prevent the cccp-induced MPT or the cccp-evoked apoptotic cell death, suggesting that cccp-induced apoptotic process was mediated by a CsA-insensitive pathway. This cell model provides an in vitro tool for studying mechanisms of photoreceptor apoptosis in isolated photoreceptors and may provide clues to the etiology of retinal degeneration.

Animals↗

Library search of mass spectra with a new matching algorithm based on substructure similarity.

A new matching algorithm for library searches of mass spectra is presented in this paper. The algorithm is based on the substructure similarity of substances. It emphasizes m/z positions rather than abundance values. 32 spectra, whose corresponding molecular weights are less than 200, were randomly selected from a mass library of 61,993 spectra and taken as targets of library search to illustrate the availability of this algorithm. The results show that the algorithm is better than the one built in a commercial instrument when there is no spectrum of the unknown in the library but there are similar ones.

Journal Article↗

Frequencies of fetal chromosomal abnormalities at prenatal diagnosis: 10 years experiences in a single institution.

We present frequencies of fetal chromosomal abnormalities in 4,907 prenatal cytogenetic examinations at Samsung Cheil Hospital from 1988 to 1997 for 10 yr duration. Prenatal karyotypes were undertaken in 3,913 amniotic fluid samples, 800 chorionic villi samples, and 194 percutaneous umbilical blood samples. The frequency of fetal abnormal karyotypes was 3.1% (150 cases). Numerical chromosome abnormalities were 87 cases (1.8%) and structural aberrations of chromosomes were 63 cases (1.3%). In the numerical chromosomal abnormalities, the frequency of trisomy 21 was by far the highest (36 cases), followed by trisomy 18 in 22 cases and sex chromosome aneuploidies in 19 cases. In the structural chromosomal aberrations, 5 cases had the inversions in chromosome 2, 7, 17, and Y. Chromosomal deletions in 6 cases and additions in 4 cases were analysed. Of the remaining 47 translocation in abnormal fetuses, reciprocal translocation was in 26 cases and Robertsonian translocation in 21 cases. Among them, 41 cases were balanced translocation and 6 were unbalanced. Thirty five cases of translocation were inherited from one of the parents. Four had de novo chromosome rearrangements, and 8 cases were unknown.

Chromosome Aberrations↗

Elevated E2: oocyte ratio in women undergoing IVF and tubal ET. Correlation with a decrease in the implantation rate.

OBJECTIVE: To investigate the influence of various estradiol (E2): oocyte ratios on reproductive outcome in women undergoing in vitro fertilization and tubal embryo transfer (IVF-TET). STUDY DESIGN: Two hundred seven women undergoing 251 IVF-TET cycles were recruited in this retrospective study. All the women received a flare-up gonadotropin releasing hormone agonist (GnRHa) protocol to achieve ovarian hyperstimulation. Oocyte retrieval was performed 34-36 hours after human chorionic gonadotropin (hCG) injection, followed by TET two days later. RESULTS: An E2: oocyte ratio > or = 350 pg/mL had a higher E2 level (2,213 +/- 2,258 vs. 1,553 +/- 972 pg/mL, P < .05) and fertilization rate (77 +/- 23 vs. 64 +/- 23%, P < .001) but a lower oocyte number (4.8 +/- 4.7 vs. 7.6 +/- 4.8, P < .001) than in those with a ratio < 350 pg/mL. The pregnancy (17.9% vs. 32.8%, P = .03) and implantation (5.3% vs. 12.9%, P = .008) rates were significantly decreased in cycles with an E2: oocyte ratio > or = 350 pg/mL as compared to those with a ratio < 350 pg/mL. CONCLUSION: IVF-TET cycles with an elevated E2: oocyte ratio correlated with lower pregnancy and implantation rates. The poor reproductive outcome possibly was due to the relatively high E2 concentration, which might have a detrimental effect on endometrial receptivity.

Buserelin↗

Collection of buccal cell DNA in seventh-grade children using water and a toothbrush.

We developed a simple and effective method for collecting a large quantity of buccal cell DNA in school-based studies of seventh-grade and older children. Seventh-grade students at schools in Wuhan, China brushed each buccal surface with a soft toothbrush and then rinsed with 10 ml of water. We added 5 ml of 99% ethanol to preserve the sample. Among 1563 samples transported at room temperature over 1 week and then stored for 13-14 months at -70 degrees C before extraction, using a modified Gentra Puregene protocol, the median total DNA yield was 108 microg, range of 14 to 416 microg. We assayed every 20th sample (n = 77) for NAT2 by the PCR, and all samples gave a 1093-bp product. From the 1563 samples, we obtained a result for single nucleotide polymorphisms in the interleukin-13 gene (at +2044) by RFLP-PCR on 98.8% and in the promoter of the myeloperoxidase gene (at -463) by real-time PCR on 99.7%. A water-rinse method, that we used among 12th-grade students in Southern California, gave a lower total DNA yield than the toothbrush rinse (median of 17 microg) and a slightly reduced ability to generate a PCR product. However, 26 of 27 water-rinse samples gave a result for two genes, albumin and CYP1A1, using real-time PCR methods. We did not quantify human, versus bacterial, DNA in our samples. However, given the amounts of total DNA required for genotyping, a sample with the median yield of 108 microg should suffice for approximately 2160 genotypes by RFLP-PCR methods or five times as many by real-time PCR. We recommend the toothbrush-rinse method, combined with a modified Gentra Puregene DNA extraction protocol, for large-scale, in-person collections of buccal cell DNA in children. The method requires only inexpensive, readily available materials and produces a large quantity of high-quality DNA for PCR analyses.

Albumins↗

Caveolin-1 associates with TRAF2 to form a complex that is recruited to tumor necrosis factor receptors.

Tumor necrosis factor (TNF) receptor-associated factor (TRAF) 2 is an intracellular adapter protein, which, upon TNF stimulation, is directly recruited to the intracellular region of TNF receptor 2 (TNFR2) or indirectly, via TRADD, to the intracellular region of TNF receptor 1 (TNFR1). In cultured human umbilical vein endothelial cells, endogenous TRAF2 colocalizes with the membrane-organizing protein caveolin-1 at regions of enrichment subjacent to the plasma membrane as detected by confocal fluorescence microscopy. Both endogenous and transfected TRAF2 protein coimmunoprecipitate with caveolin-1 in the absence of ligand. Upon TNF treatment, the TRAF2-caveolin-1 complex transiently associates with TRADD, and upon overexpression of TNFR2, the TRAF2-caveolin-1 complex stably associates with and causes redistribution of this receptor as detected by confocal fluorescence microscopy. In human embryonic kidney 293 cells, which have minimal endogenous expression of caveolin-1, cotransfection of TRAF2 and caveolin-1 results in spontaneous association of these proteins which can further associate with and redistribute transfected TNFR2 molecules. The association of caveolin-1 with TNFR2 depends upon TRAF2. Cotransfection of caveolin-1 protein increases TRAF2 protein expression levels in HEK 293 cells, which correlates with enhancement of TNF and TRAF2 signaling, measured as transcription of a NF-kappaB promoter-reporter gene, although the caveolin-enhanced response to TNF is attenuated at higher caveolin levels. These findings suggest that intracellular distribution of activated TNF receptors may be regulated by caveolin-1 via its interaction with TRAF2.

Antigens, CD↗

Overexpression of eotaxin and the CCR3 receptor in human atherosclerosis: using genomic technology to identify a potential novel pathway of vascular inflammation.

BACKGROUND: Unstable atherosclerotic lesions typically have an abundant inflammatory cell infiltrate, including activated T cells, macrophages, and mast cells, which may decrease plaque stability. The pathophysiology of inflammatory cell recruitment and activation in the human atheroma is incompletely described. METHODS AND RESULTS: We hypothesized that differential gene expression with DNA microarray technology would identify new genes that may participate in vascular inflammation. RNA isolated from cultured human aortic smooth muscle cells treated with tumor necrosis factor-alpha (TNF-alpha) was examined with a DNA microarray with 8600 genes. This experiment and subsequent Northern analyses demonstrated marked increases in steady-state eotaxin mRNA (>20 fold), a chemokine initially described as a chemotactic factor for eosinophils. Because eosinophils are rarely present in human atherosclerosis, we then studied tissue samples from 7 normal and 14 atherosclerotic arteries. Immunohistochemical analysis demonstrated overexpression of eotaxin protein and its receptor, CCR3, in the human atheroma, with negligible expression in normal vessels. Eotaxin was predominantly located in smooth muscle cells. The CCR3 receptor was localized primarily to macrophage-rich regions as defined by immunopositivity for CD 68; a minority of mast cells also demonstrated immunopositivity for the CCR3 receptor. CONCLUSIONS: Eotaxin and its receptor, CCR3, are overexpressed in human atherosclerosis, suggesting that eotaxin participates in vascular inflammation. These data demonstrate how genomic differential expression technology can identify novel genes that may participate in the stability of atherosclerotic lesions.

Actins↗

Synthesis and biological activity of conformationally controlled 2-PAM derivatives.

A series of conformationally controlled 2-PAM derivatives were prepared from 2-acetylpyridine and 2,3-pyrido[b]cycloalkenones in two steps and their reactivities towards parathion poisoned AChE were evaluated. The most planar 2,3-pyrido[b]cyclohexanone oxime methiodide showed an activity comparable to 2-PAM implying E-syn is that the most active conformation of 2-PAM in the biological system.

Acetylcholinesterase↗

Up-regulation and co-expression of fibroblast growth factor receptors in human gastric cancer.

Fibroblast growth factor (FGF), a key regulatory factor of cell growth and differentiation, is involved in embryonic development, angiogenesis, and tumorigenesis. To date, four different FGF receptors (FGFRs) have been cloned and characterized. We examined the expression of four FGFRs in human gastric cancer tissues and cell lines using Northern analysis, ribonuclease protection assay, and immunohistochemistry. The mRNAs of FGFR-1 (10/14), FGFR-2 (9/14), and FGFR-4 (9/14) were up-regulated in cancer compared with normal tissues. FGFR-3 mRNAs were barely detectable in both normal and cancer tissues. These FGFR mRNAs were co-expressed in various combinations of two or three in the same tissue. Immunohistochemistry confirmed specific staining of multiple FGFRs, except FGFR-3, in the cancer specimens. To investigate the functional significance of FGFR co-expression we examined the invasive property of SNU-16 cells, which exhibited gene amplification of FGFR-2, -3, and -4 as well as over-expression of keratinocyte growth factor receptor (KGFR), a splice variant of FGFR-2, and FGFR-4 mRNA. KGF plus acidic FGF (aFGF), KGF, and aFGF treatment enhanced the invasive potential of SNU-16 cells over the control by 100%, 107%, and 47%, respectively, indicating that neither additive nor synergistic effect was induced by stimulation with aFGF plus KGF. These results suggest that co-expression of FGFRs in various combinations may cause subtle changes in the progression of gastric cancer.

Alternative Splicing↗

Biomechanical regulation of human monocyte/macrophage molecular function.

When the monocyte infiltrates a tissue, adhesion to the extracellular matrix provides structural anchors, and the cell may be deformed through these attachments. To test the hypothesis that human monocytes/macrophages are mechanically responsive, we studied the effects of small cyclic mechanical deformations on cultured human monocytes/macrophages. When monocytes/macrophages were subjected to 4% strain at 1 Hz for 24 hours, neither matrix metalloproteinase (MMP)-1 nor MMP-3 was induced; however, in the presence of phorbol myristate acetate, strain augmented MMP-1 expression by 5.1 +/- 0.7-fold (P < 0.05) and MMP-3 expression by 1. 6 +/- 0.1-fold (P < 0.05). In contrast, MMP-9 expression was not changed by mechanical strain in the presence or absence of phorbol myristate acetate. Deformation rapidly induced the immediate early response genes c-fos and c-jun. In addition, mechanical deformation induced the transcription factor PU.1, an ets family member that is essential in monocyte differentiation, as well as mRNA for the M-CSF receptor. These studies demonstrate that human monocytes/macrophages respond to mechanical deformation with selective augmentation of MMPs, induction of immediate early genes, and induction of the M-CSF receptor. In addition to enhancing the proteolytic activity of macrophages within repairing tissues, cellular deformation within tissues may play a role in monocyte differentiation.

Acetylcysteine↗