Proliferation Of Rat Fibroblasts Research Articles

Wound healing in weaning, adult, and old rats with provoked incisional hernias. A comparative study

BackgroundIncisional hernias are more frequent in adults than in children. It is hypothesized that a more efficient healing process in pediatric patients could explain this difference in incidence. Certain elements of healing such as neovascularization, degree of inflammation, percentage of mature and immature collagen, the proliferation of fibroblasts, and expression of certain genes could explain why healing in children is more efficient when compared to the adult and elderly populations. Materials and methodsSeventy-one rats of 3 different age groups (weaning, adult, and old) underwent surgery with 3 different incisions (vertical, oblique, and horizontal). During the procedure, the skin and abdominal wall of the animal were sectioned and only the skin was sutured to mimic incisional hernia in the animals. Four weeks after surgery, the rats were euthanized, their skin was removed, and the extent of scar tissue formed in the muscle opening was measured. In addition, samples of the scar tissue were collected for histological, immunohistochemical, and molecular analyzes. Nine rats served as controls. ResultsShorter-length hernias were formed in weaning rats when compared to old ones when the surgical incision was horizontal (p = 0.03). There was a greater proliferation of fibroblasts in rats in the younger age groups, regardless of the type of incision. The Lox gene was more expressed in weaning rats with vertical and oblique incisions. ConclusionsThese differences could explain the better healing and lower incidence of hernias in the pediatric population, although this aspect requires further studies.

Comparation between cicatrization in weaning, adult and old rats with provoked incisional hernia

Background: Incisional hernias occur with some frequency in adult population, however they are rare in children. It is hypothesized that the most efficient process of healing in pediatric population is the answer to this important difference in incidence. Therefore, certain elements of healing such as neovascularization, degree of inflammation, percentage of mature and immature collagen, proliferation of fibroblasts and expression of certain genes can explain why healing in children is more efficient when compared to the adult and elderly population. Materials and methods: Seventy-one rats of 3 different age groups (weaning, adult and old) underwent surgery in 3 different incisions (vertical, oblique and horizontal). In the procedure, skin and abdominal wall of the animal were sectioned and only skin was sutured, in order to mimic incisional hernia in the animals. After 4 weeks of surgery, the rats were sacrificed, their skin removed, and the extent of scar tissue formed in the muscle opening was measured. In addition, samples of scar tissue were collected and histological, immunohistochemical and molecular analyzes were performed. Results: Shorter length hernias were formed in weaning rats when compared to old ones in surgery with horizontal incision (p=0.03). There was greater proliferation of fibroblasts in rats of the younger age groups, regardless of the type of incision made. The Lox gene was more expressed in weaning-aged rats in vertical and oblique incision surgeries. Conclusions: The contraction of scar tissue formed in wounds appears to be more intense in horizontal cuts than vertical ones. The greater proliferation of fibroblasts in scar tissue of weaning rats may explain the better healing and lower incidence of hernias in pediatric population. The Lox gene seems to be more expressed in weaning groups and may also explain better healing in children, but more studies need to be done.

The effect of suramin on inhibiting fibroblast proliferation and preventing epidural fibrosis after laminectomy in rats.

BackgroundEpidural fibrosis often causes serious complications in patients after lumbar laminectomy and discectomy and is associated with the proliferation of fibroblasts. Suramin is known to have an obvious inhibitory effect on the coactions of many growth factors and their receptors, but little was previously known about the effect of suramin on fibroblast proliferation and the progress of epidural fibrosis.MethodsWe illustrated the effect of suramin on cultured fibroblasts of rats with different concentrations (0, 200, 400, 600 mg/l). The proliferation of suramin-treated fibroblasts was evaluated by CCK-8 and western blot analysis. Additionally, in a rat model of laminectomy, different concentrations of suramin (100, 200, and 300 mg/ml) and saline were applied to the laminectomy sites locally. The effect of suramin on preventing epidural fibrosis was detected by the Rydell classification, hydroxyproline content, histological analysis, and collagen density analyses.ResultsThe results of CCK-8 shown that suramin could significantly inhibit fibroblasts proliferation in a dose-dependent manner. The western blotting shown that the expression levels of the cell proliferation markers such as cyclin D1, cyclin E, and PCNA were down-regulated. Moreover, in a rat model, we found that suramin could reduce epidural fibrosis as well as inhibit fibroblast proliferation, and 300 mg/ml suramin had better effect.ConclusionsTopical application of suramin could reduce epidural fibrosis after laminectomy, and the application of suramin could inhibit the proliferation of fibroblasts in rats. This study indicates that suramin is a potent antifibrotic agent that may have therapeutic potential for patients with epidural fibrosis.

Investigation on Molecular Mechanism of Fibroblast Regulation and the Treatment of Recurrent Oral Ulcer by Shuizhongcao Granule-Containing Serum.

The purpose is to study the intervention, proliferation, and differentiation on fibroblast by Shuizhongcao Granule during the treatment of ROU and investigate the action mechanism in inflammatory microenvironment. Proliferation of rat fibroblasts was detected using CCK8. Western blot was used to detect the effect of drug-containing serum on the expression of protein associated with NF-κB and ERK pathway in rat fibroblasts. Expression of IL-10 and IL-12 was detected by PCR. Shuizhongcao Granule group successfully inhibited proliferation of rat fibroblast. Western blot results revealed that p65 and IKKB were significantly less expressed in Chinese medicine group, while pIκBα and pIKKαβ expression were significantly increased. We have also found that in this group the expression of pAKT was evidently suppressed and expression of pERK significantly decreased. PCR results showed significantly decreased expression levels of IL-10 and 1IL-12b in Chinese medicine group, while the expression of IL-12a was increased. Our results suggest that Shuizhongcao Granule can suppress the proliferation of fibroblast and inhibit the activation of NF-κB and thus suppress inflammatory reactions, possibly involving the inhibited expression of phosphorylated AKT, rather than the canonical pathway. Furthermore, it can inhibit ERK pathway and reduce IL-10 and IL-12b gene expression while enhancing IL-12a expression.

In-vitro Response of Fibroblasts to Poly-L-lactide Composite Materials Containing Bovine Bone

This study aimed to investigate the interaction between fibroblastic cells and poly-L-lactide (PLLA) composite film containing bovine bone. The effects of PLLA/bovine bone on cell cytotoxicity, attachment, proliferation and differentiation of fibroblasts in-vitro were investigated. The results of cytotoxicity tests showed that cells cultured in extracts of PLLA/bovine bone and on the surface of composites showed normal growth and proliferation, and mineralization nodules were observed for fibroblasts cultured in PLLA/bovine bone extract at day 7 by using von Kossa staining and tetracycline staining. Compared with pure PLLA materials, bovine bone in the PLLA composites facilitated both adhesion and proliferation of rat fibroblasts on the PLLA/bovine bone composite film. In conclusion, these results suggest that the introduction of bovine bone may improve the cell response involved in the osteogenesis and thus may be beneficial to further modify poly-L-lactide as a better bone repairing material.

The Biological Evaluation of the PEG/PLA Amphiphilic Diblock Copolymer

To assess the biological properties of poly(ethylene glycol)/polylactic acid (PEG/PLA) amphiphilic diblock copolymer, cellular cultivation in-vitro and MTT assay were conducted for evaluating the material's influence on the morphology, growth and proliferation of cultured fibroblasts. In addition, hemolysis, pyrogen tests, acute systemic toxicity test and genetic toxicity test were also carried out according to the requirements of ISO10993 standards. The results indicated that cells attached to the culture plate when cultured in PEG/PLA leaching liquor, and the number of cells increased with increasing of cultured time. The diblock copolymer showed no acute systemic toxicity, genetic toxicity, and pyrogen reaction, and the hemolysis ratio was 0.398%. The introduction of amphiphilic PEG into PLA matrix facilitates both adhesion and proliferation of rat fibroblasts in the leaching liquor of PEG/PLA.

Evaluation of In-Vitro Cytotoxicity of Composite Materials Composed of Poly-L-lactic Acid and β-Tricalcium Phosphate

Composite material film composed of Poly-L-lactic acid (PLLA) and β-tricalcium phosphate (β-TCP) was prepared by a solvent evaporation technique. Cellular cultivation in vitro, Von Kossa staining and MTT assay were performed. The results of cytotoxicity test show that cells cultured in extracts of PLLA/β-TCP and on the surface of composite showed normal growth and proliferation, mineralization nodules were observed for fibroblasts cultured in PLLA/β-TCP extract at day 7. Compared with pure PLLA materials, β-TCP in the PLLA composite facilitate both adhesion and proliferation of rat fibroblasts on the PLLA/β-TCP composite film.

Preparation of poly-L-lactide/bioactive glass composite and evaluation of cytotoxicity in vitro

Bioactive and bioresorbable composite materials were fabricated from poly-L-lactide and bioactive glass (average particle size 6.8 μm) by a solvent evaporation technique. Cellular cultivation in vitro and MTT assay were conducted for evaluating the influence on morphology, growth and proliferation of cultured fibroblasts. The results of cytotoxicity testing show that cells cultured in extracts of PLLA/BG and on the surface of composites demonstrate normal growth and proliferation. The bioactive glass in PLLA composite facilitates both adhesion and proliferation of rat fibroblasts on PLLA/bioactive glass composite film.

Orange-red light attenuates inhibition of proliferation of rat fibroblasts induced by ultraviolet-A

Excessive UV radiation suppresses processes important for normal functioning of tissues [1, 2]. Therefore, a topical problem is studying the factors which protect cells from the negative effects of UV radiation. One of such factors may be illumination with light of orange-red range of the spectrum [2‐4]. The primary skin-muscular fibroblasts were isolated from 15-day-old embryos of SHR rats with the SPF status (the nursery of Shemyakin‐Ovchinnikov Institute of Bioorganic Chemistry (Pushchino Branch), Russian Academy of Sciences, Pushchino). The suspension of fibroblasts was placed in tissue culture flasks impermeable to UV-A and orange‐red light (ORL). After one day of incubation, the medium with unadhered cells was removed and the adhered fibroblasts were cultured untill formation of a monolayer in DMEM (ICN) supplemented with glutamine, HEPES, and fetal calf serum. The cells were kept in an incubator at 37°C in a 5% CO 2 atmosphere. The fibroblasts of the 4th to 8th passages were used in the experiments. The adhered cells were detached with the use of a mixture of trypsin and Versen (Pan Eko), counted, and placed in flasks for illumination with ORL (0.9‐3.6 J/cm 2 ) or UV-A (0.27‐1.08 J/cm 2 ) or their combinations. A matrix with light-emitting Luxeon Star diodes (Lumileds) with λ m = 625 nm and a light flux intensity of 5.5 mW/cm 2 was used as source of ORL. An MD-108 irradiator (Germany) with λ M = 365 nm and a light flux intensity of 2.5 mW/cm 2 was used as a UV-A source. The suspension of fibroblasts was distributed with the use of pipette in 96-well plates for analysis of the proliferation rate. Each well with culture medium contained 10 4 cells. The fibroblasts were stained with thiazolyl blue 48 and 72 h after illumination. The cells were additionally incubated for 1 h and, then, the medium in the wells was replaced with dimethylsulfoxide. The optical density of the cells was determined with the use of a Spectra Count spectrophotometer (Packard, Germany). Analysis of the fibroblast proliferation 48 h after illumination showed that ORL had a stimulatory effect at a dose of 0.9 J/cm 2 (Fig. 1), which is in agreement

Differences in cell division and thymidine incorporation with rat and primate fibroblasts in collagen lattices

Human and gorilla dermal fibroblasts, primate cells, suspended in a collagen lattice, do not divide for the first 3 days. In contrast, rat fibroblasts divide within 24 hr. In this study, the proliferation of rat fibroblasts were compared to primate fibroblasts. Rat fibroblasts in monolayer culture increase from 100,000 to 355,000 in 2 days, and human cells increase from 100,000 to 436,000 in the same period. An initial seeding of 100,000 rat fibroblasts suspended in collagen increased to 163,000 cells in 2 days. An initial 100,000 human fibroblasts seeded in collagen decreased to 80,000 cells in 2 days. Retarded proliferation of human and gorilla fibroblasts in collagen is unrelated to a defect in DNA synthesis. By autoradiography human fibroblasts suspended in collagen incorporate labelled thymidine. By flow cytometry analysis, the DNA concentrations of human fibroblasts suspended in collagen exhibited 41% in a 4N chromosome state, compared to 14% in monolayer culture. Nuclei of gorilla fibroblasts from collagen displayed 42% in a 4N state, compared to 19% in monolayer culture. With nuclei of rat fibroblasts from collagen, 14% were in a 4N state, compared to 9% in monolayer culture. Primate fibroblasts show a three-fold increase in the number of nuclei in a 4N state compared to rat fibroblasts suspended in collagen. After replating fibroblasts released from collagen in monolayer culture in the presence of 1 mM hydroxyurea (an inhibitor of DNA synthesis) primate fibroblasts doubled in 24 hr. Under identical conditions, rat fibroblasts showed no cell division. Primate cells suspended in collagen have completed DNA synthesis but show a delay in cell division, indicating fibroblasts are arrested in G 2 of the cell cycle. Polymerized collagen produces a physical constraint on primate fibroblasts which retards these cells from entering mitosis. In contrast rat fibroblasts show no constraint and readily enter mitosis upon completion of DNA synthesis.