Proliferating cell nuclear antigen (PCNA) immunolocalization in paraffin sections: an index of cell proliferation with evidence of deregulated expression in some neoplasms

Differentiation-inducing and anti-proliferative activities of lupeol on canine melanoma cells

Canine melanoma is the most common oral malignant tumor reported in the field of veterinary medicine. We found that lupeol, a lupine triterpene, inhibited mouse melanoma cell growth in vitro and in vivo by inducing cell differentiation. In the present study, we examined the differentiation-inducing activities of lupeol on 4 canine melanoma cells in vitro and in vivo.

The induction of canine melanoma cell differentiation by lupeol was confirmed by evaluating some differentiation markers such as tyrosinase with real-time RT-PCR. Furthermore, we transplanted canine melanoma cells into a severe combined immunodeficiency mouse, and studied the anti-progressive effects of lupeol on tumor tissue.

The gene expression of microphthalmia-associated transcription factor, tyrosinase, and tyrosinase-related protein-2, which are markers of pigment cell differentiation, was induced in 4 canine oral malignant melanoma cells by lupeol, and the agent markedly inhibited tumor progression in canine melanoma-bearing mice.

Effect of prolactin-induced protein on human skin: new insight into the digestive action of this aspartic peptidase on the stratum corneum and its induction of keratinocyte proliferation

Human prolactin-induced protein (PIP) is a major protein found in exocrine fluids such as saliva and sweat. Intriguingly, PIP possesses residues (human PIP (hPIP): PIP (29-63)) that display similarity to the aspartic peptidase candidapepsin. Here, we aimed to determine the effect of PIP as a protease on normal skin structure. Using an adhesive tape-stripping technique, we applied hPIP peptide on the corneocytes of normal-appearing facial skin from infants with eczema and healthy infants and then analyzed the morphological structure of corneocytes with Nile Red fluorescence. We also repeatedly applied the hPIP peptide onto the surface of a three-dimensional (3-D) human skin model and then analyzed any changes to the stratum corneum and epidermis using light microscopy and scanning electron microscopy. In both infant groups, a decrease in hydrophobic lipids from the cornified envelope was observed after treatment with hPIP. The peptide hPIP appeared to digest the fine structure of the stratum corneum and induce a proliferation of epidermal keratinocytes within the 3-D human skin model. Our results suggest that aspartic peptidase of PIP found in sweat or saliva deteriorates the skin barrier in a de novo manner, which potentially leads directly to the proliferation of epidermal keratinocytes without any external antigenic factors.

No evidence for neo-oogenesis may link to ovarian senescence in adult monkey

Female germline or oogonial stem cells transiently residing in fetal ovaries are analogous to the spermatogonial stem cells or germline stem cells (GSCs) in adult testes where GSCs and meiosis continuously renew. Oocytes can be generated in vitro from embryonic stem cells and induced pluripotent stem cells, but the existence of GSCs and neo-oogenesis in adult mammalian ovaries is less clear. Preliminary findings of GSCs and neo-oogenesis in mice and humans have not been consistently reproducible. Monkeys provide the most relevant model of human ovarian biology. We searched for GSCs and neo-meiosis in ovaries of adult monkeys at various ages, and compared them with GSCs from adult monkey testis, which are characterized by cytoplasmic staining for the germ cell marker DAZL and nuclear expression of the proliferative markers PCNA and KI67, and pluripotency-associated genes LIN28 and SOX2, and lack of nuclear LAMIN A, a marker for cell differentiation. Early meiocytes undergo homologous pairing at prophase I distinguished by synaptonemal complex lateral filaments with telomere perinuclear distribution. By exhaustive searching using comprehensive experimental approaches, we show that proliferative GSCs and neo-meiocytes by these specific criteria were undetectable in adult mouse and monkey ovaries. However, we found proliferative nongermline somatic stem cells that do not express LAMIN A and germ cell markers in the adult ovaries, notably in the cortex and granulosa cells of growing follicles. These data support the paradigm that adult ovaries do not undergo germ cell renewal, which may contribute significantly to ovarian senescence that occurs with age.

Non-Structural protein 1 (NS1) gene of Canine Parvovirus-2 regresses chemically induced skin tumors in Wistar rats

The Non-Structural protein 1 of Canine Parvovirus-2 (CPV2.NS1) plays a major role in viral cytotoxicity and pathogenicity. CPV2.NS1 has been proven to cause apoptosis in HeLa cells in vitro in our laboratory. Here we report that CPV2.NS1 has no toxic side effects on healthy cells but regresses skin tumors in Wistar rats. Histopathological examination of tumor tissue from CPV2.NS1 treated group revealed infiltration of mononuclear and polymorphonuclear cells with increased extra cellular matrix, indicating signs of regression. Tumor regression was also evidenced by significant decrease in mitotic index, AgNOR count and PCNA index, and increase in TUNEL positive apoptotic cells in CPV2.NS1 treated group. Further, CPV2.NS1 induced anti-tumor immune response through significant increase in CD8(+) and NK cell population in CPV2.NS1 treated group. These findings suggest that CPV2.NS1 can be a possible therapeutic candidate as an alternative to chemotherapy for the treatment of cancer.

Decreased parathyroid Klotho expression is associated with persistent hyperparathyroidism after kidney transplantation

Although successful kidney transplantation usually corrects hyperparathyroidism, the condition persists in some patients. The present study was designed to determine whether Klotho or fibroblast growth factor 23, the key regulator of parathyroid hormone, is involved in persistent hyperparathyroidism in kidney transplant recipients (KTRs). Nineteen hyperplastic parathyroid glands were obtained from end-stage renal disease (ESRD) patients and KTRs; 6 normal parathyroid glands were used as controls. We compared the expression of Klotho, fibroblast growth factor receptor 1 (FGFR1) and calcium-sensing receptor (CaSR) in the KTRs and ESRD patients. Expressions of Klotho, FGFR1, CaSR and vitamin D receptor, as evaluated by immunohistochemistry, were quantified as the number of positive cells per unit area. The Klotho, FGFR1 and CaSR expressions in parathyroid glands of the post-kidney transplantation (PSKT) and the ESRD groups were significantly decreased compared with normal controls. In the ESRD group, Klotho expression and number of proliferating cell nuclear antigen-positive cells in the parathyroid gland were significantly decreased in parathyroid adenomas as compared with parathyroid hyperplasia. The expression of FGFR1 and CaSR in the parathyroid glands was significantly increased in the PSKT compared with the ESRD group. There was no significant difference in Klotho expression between the PSKT and ESRD groups. Incomplete recovery of Klotho levels in the parathyroid gland may play a role in the pathogenesis of tertiary hyperparathyroidism after kidney transplantation.

IKVAV regulates ERK1/2 and Akt signalling pathways in BMMSC population growth and proliferation

Objectives

The molecular mechanism of bone marrow mesenchymal stem cell (BMMSC) population growth and proliferation, induced by Isoleucyl‐lysyl‐valyl‐alanyl‐valine (IKVAV), was explored in this study.

Materials and methods

IKVAV peptides were synthesized by the solid‐phase method. Influence of IKVAV on BMMSC population growth and proliferation were investigated by assays of CCK‐8, flow cytometry, real‐time PCR and western blotting.

Results

IKVAV peptide was found to induce proliferation and proliferating cell nuclear antigen (PCNA) synthesis of BMMSC in a dose‐ and time‐dependent manner. Cell cycle analysis showed that the proportion of IKVAV‐treated BMMSC in S phase in was higher than controls. Western blot results suggested that mitogen‐activated protein kinase/extracellular signal‐regulated kinase (MAPK/ERK) and phosphatidylinositol 3‐kinase/protein kinase B (PI3K/Akt) signalling pathways were activated by IKVAV by enhancing phosphorylation levels of ERK1/2 and Akt in the BMMSCs. Meanwhile, phosphorylation levels of ERK1/2 and Akt were partially blocked by ERK1/2 inhibitor (PD98059) and Akt inhibitor (wortmannin), respectively.

Conclusions

Our results demonstrated that IKVAV stimulated BMMSC population growth and proliferation by activating MAPK/ERK1/2 and PI3K/Akt signalling pathways. This study is the first to reveal an enhancement effect of IKVAV peptide on BMMSC at the signal transduction level, and the outcome could provide experimental evidence for application of IKVAV‐grafted scaffolds in the field of BMMSC‐based tissue engineering.

Role of monochromatic light on development of cecal tonsil in young broilers

Previously, the different monochromatic lights have been demonstrated to affect splenocyte proliferation and melatonin (MEL) secretion in broilers. The present study was designed to evaluate the effects of different monochromatic lights on the development and immune function of broiler cecal tonsils, and to disclose the mechanisms underlying these phenomena. A total of 185 broilers (P0) including intact, sham-operated, and pinealectomized groups were exposed to blue light (BL), green light (GL), red light (RL), and white light (WL) by a light-emitting diode system for 14 days. Compared with RL groups, the GL in the intact and sham-operated groups showed larger follicle areas (66.70%), higher percentages of proliferating cell nuclear antigen (PCNA)-positive cells (33.33%), increased numbers of IgA(+) cells (48.60%), and increased antioxidase activity (33.33%-61.37%), whereas, the density of iNOS and MDA content in GL were lower (43.63%-54.43%) than that of RL. In contrast, after pinealectomy, the area of follicles, the percentage of PCNA-positive cells, the number of IgA(+) cells, and the antioxidase activity decreased in the different light treatments, but the density of iNOS and MDA content increased substantially. There was no significant difference in these parameters between broilers exposed to GL and other lights (P = 0.085-1.000). The results suggested that the enhanced effects of GL on the development and immune function of cecal tonsils in young broilers were mediated by elevated antioxidative status via up-regulation of MEL.

Timelines in the insect brain: fates of identified neural stem cells generating the central complex in the grasshopper Schistocerca gregaria

This study employs labels for cell proliferation and cell death, as well as classical histology to examine the fates of all eight neural stem cells (neuroblasts) whose progeny generate the central complex of the grasshopper brain during embryogenesis. These neuroblasts delaminate from the neuroectoderm between 25 and 30 % of embryogenesis and form a linear array running from ventral (neuroblasts Z, Y, X, and W) to dorsal (neuroblasts 1-2, 1-3, 1-4, and 1-5) along the medial border of each protocerebral hemisphere. Their stereotypic location within the array, characteristic size, and nuclear morphologies, identify these neuroblasts up to about 70 % of embryogenesis after which cell shrinkage and shape changes render progressively more cells histologically unrecognizable. Molecular labels show all neuroblasts in the array are proliferative up to 70 % of embryogenesis, but subsequently first the more ventral cells (72-75 %), and then the dorsal ones (77-80 %), cease proliferation. By contrast, neuroblasts elsewhere in the brain and optic lobe remain proliferative. Apoptosis markers label the more ventral neuroblasts first (70-72 %), then the dorsal cells (77 %), and the absence of any labeling thereafter confirms that central complex neuroblasts have exited the cell cycle via programmed cell death. Our data reveal appearance, proliferation, and cell death proceeding as successive waves from ventral to dorsal along the array of neuroblasts. The resulting timelines offer a temporal blueprint for building the neuroarchitecture of the various modules of the central complex.

Ventromedial hypothalamic lesions enhance small intestinal cell proliferation in mice

SUMMARY

BACKGROUND

We have found previously that ventromedial hypothalamic lesions (VMH) enhance cell proliferation in the visceral organs through vagal hyperactivity in rats. The goal of the current study was to determine the characteristics and nature of cell proliferation in the small intestine in VMH-lesioned mice.

METHODS

The weight and length of the small intestine, thickness of the mucosal and muscle layers, number of proliferating cell nuclear antigen (PCNA)-positive cells, and mitotic cell count in the mucosal layer in VMH-lesioned and Sham VMH-lesioned mice were determined at 7 days after the operation.

RESULTS

The weight and length of the small intestine in VMH-lesioned mice were significantly greater than those in Sham VMH-lesioned mice, by 11.6% and 15.0%, respectively. The thicknesses of the mucosal and muscle layers of the small intestine in VMH-lesioned mice were also significantly greater than those in Sham VMH-lesioned mice, by 12.7% and 12.5%, respectively. PCNA-positive cells and mitotic cells in the mucosal layer were densely present in crypts in VMH-lesioned mice, and were significantly increased by 31.9% and 71.7%, respectively, compared to Sham VMH-lesioned mice.

CONCLUSIONS

These results demonstrate that VMH lesions in mice enhance cell proliferation in the mucosal layers and cause cell hypertrophy or cell proliferation in the muscle layers of the small intestine, which increases the weight and length of the small intestine. VMH lesions in mice may be a new tool for identifying growth factors and related genes involved in enlarging the small intestine mainly through cell proliferation.

Knockdown of RAGE inhibits growth and invasion of gastric cancer cells

The receptor for advanced glycation endproducts (RAGE) is an oncogenic trans-membranous receptor, which is overexpressed in multiple human cancers. However, the role of RAGE in gastric cancer is still elusive. In this study, we investigated the expression and molecular mechanisms of RAGE in gastric cancer cells. Forty cases of gastric cancer and corresponding adjacent non-cancerous tissues (ANCT) were collected, and the expression of RAGE was assessed using immunohistochemistry (IHC) in biopsy samples. Furthermore, RAGE signaling was blocked by constructed recombinant small hairpin RNA lentiviral vector (Lv-shRAGE) used to transfect into human gastric cancer SGC-7901 cells. The expression of AKT, proliferating cell nuclear antigen (PCNA) and matrix metallopeptidase-2 (MMP-2) was detected by Real-time PCR and Western blot assays. Cell proliferative activities and invasive capability were respectively determined by MTT and Transwell assays. Cell apoptosis and cycle distribution were analyzed by flow cytometry. As a consequence, RAGE was found highly expressed in cancer tissues compared with the ANCT (70.0% vs 45.0%, P=0.039), and correlated with lymph node metastases (P=0.026). Knockdown of RAGE reduced cell proliferation and invasion of gastric cancer with decreased expression of AKT, PCNA and MMP-2, and induced cell apoptosis and cycle arrest. Altogether, upregulation of RAGE expression is associated with lymph node metastases of gastric cancer, and blockade of RAGE signaling suppresses growth and invasion of gastric cancer cells through AKT pathway, suggesting that RAGE may represent a potential therapeutic target for this aggressive malignancy.

UV-B-induced DNA damage and repair in the mouse lens

PURPOSE

Epidemiologic studies have linked UV-B exposure to development of cortical cataracts, but the underlying molecular mechanism(s) is unresolved. Here, we used a mouse model to examine the nature and distribution of DNA photolesions produced by ocular UV-B irradiation.

METHODS

Anesthetized mice, eye globes, or isolated lenses were exposed to UV-B. Antibodies specific for 6-4 photoproducts (6-4 PPs) or cyclobutane pyrimidine dimers (CPDs) were used to visualize DNA adducts.

RESULTS

Illumination of intact globes with UV-B-induced 6-4 PP and CPD formation in cells of the cornea, anterior iris, and central lens epithelium. Photolesions were not detected in retina or lens cells situated in the shadow of the iris. Photolesions in lens epithelial cells were produced with radiant exposures significantly below the minimal erythemal dose. Lens epithelial cells rapidly repaired 6-4 PPs, but CPD levels did not markedly diminish, even over extended postirradiation recovery periods in vitro or in vivo. The repair of 6-4 PPs did not depend on the proliferative activity of the epithelial cells, since the repair rate in the mitotically-active germinative zone (GZ) was indistinguishable from that of quiescent cells in the central epithelium.

CONCLUSIONS

Even relatively modest exposures to UV-B produced 6-4 PP and CPD photolesions in lens epithelial cells. Cyclobutane pyrimidine dimer lesions were particularly prevalent and were repaired slowly if at all. Studies on sun-exposed skin have established a causal connection between photolesions and so-called UV-signature mutations. If similar mechanisms apply in the lens, it suggests that somatic mutations in lens epithelial cells may contribute to the development of cortical cataracts.

Differential action of glycoprotein hormones: significance in cancer progression

Growth of multicellular organisms depends on maintenance of proper balance between proliferation and differentiation. Any disturbance in this balance in animal cells can lead to cancer. Experimental evidence is provided to conclude with special reference to the action of follicle-stimulating hormone (FSH) on Sertoli cells, and luteinizing hormone (LH) on Leydig cells that these hormones exert a differential action on their target cells, i.e., stimulate proliferation when the cells are in an undifferentiated state which is the situation with cancer cells and promote only functional parameters when the cell are fully differentiated. Hormones and growth factors play a key role in cell proliferation, differentiation, and apoptosis. There is a growing body of evidence that various tumors express some hormones at high levels as well as their cognate receptors indicating the possibility of a role in progression of cancer. Hormones such as LH, FSH, and thyroid-stimulating hormone have been reported to stimulate cell proliferation and act as tumor promoter in a variety of hormone-dependent cancers including gonads, lung, thyroid, uterus, breast, prostate, etc. This review summarizes evidence to conclude that these hormones are produced by some cancer tissues to promote their own growth. Also an attempt is made to explain the significance of the differential action of hormones in progression of cancer with special reference to prostate cancer.

Pipoxolan ameliorates cerebral ischemia via inhibition of neuronal apoptosis and intimal hyperplasia through attenuation of VSMC migration and modulation of matrix metalloproteinase-2/9 and Ras/MEK/ERK signaling pathways

Pipoxolan (PIPO) has anti-spasmodic effects, and it is used clinically to relieve smooth muscle spasms. Cerebrovascular disease is one of the leading causes of disability and death worldwide. The main aim of this study was to investigate the effects of PIPO on cerebral ischemia and vascular smooth muscle cell (VSMC) migration in vivo and in vitro. Cerebral infarction area, ratio of intima to media area (I/M ratio) and PCNA antibody staining of the carotid artery in vivo were measured. Cell viability of A7r5 cells, PDGF-BB-stimulated cell migration, and potential mechanisms of PIPO were evaluated by wound healing, transwell and Western blotting. PIPO (10 and 30 mg/kg p.o.) reduced: the cerebral infarction area; neurological deficit; TUNEL-positive cells; cleaved caspase 3-positive cells; intimal hyperplasia; and inhibited proliferating cell nuclear antigen (PCNA)-positive cells in rodents. PIPO (5, 10 and 15 µM) significantly inhibited PDGF-BB-stimulated VSMC migration and reduced Ras, MEK, and p-ERK levels. Moreover, PIPO decreased levels of matrix metalloproteinases -2 and -9 in PDGF-BB-stimulated A7r5 cells. In summary, PIPO is protective in models of ischemia/reperfusion-induced cerebral infarction, carotid artery ligation-induced intimal hyperplasia and VSMC migration both in vivo and in vitro. PIPO could be potentially efficacious in preventing cerebrovascular and vascular diseases.

Mesenchyme-specific knockout of ESET histone methyltransferase causes ectopic hypertrophy and terminal differentiation of articular chondrocytes

The exact molecular mechanisms governing articular chondrocytes remain unknown in skeletal biology. In this study, we have found that ESET (an ERG-associated protein with a SET domain, also called SETDB1) histone methyltransferase is expressed in articular cartilage. To test whether ESET regulates articular chondrocytes, we carried out mesenchyme-specific deletion of the ESET gene in mice. ESET knock-out did not affect generation of articular chondrocytes during embryonic development. Two weeks after birth, there was minimal qualitative difference at the knee joints between wild-type and ESET knock-out animals. At 1 month, ectopic hypertrophy, proliferation, and apoptosis of articular chondrocytes were seen in the articular cartilage of ESET-null animals. At 3 months, additional signs of terminal differentiation such as increased alkaline phosphatase activity and an elevated level of matrix metalloproteinase (MMP)-13 were found in ESET-null cartilage. Staining for type II collagen and proteoglycan revealed that cartilage degeneration became progressively worse from 2 weeks to 12 months at the knee joints of ESET knock-out mutants. Analysis of over 14 pairs of age- and sex-matched wild-type and knock-out mice indicated that the articular chondrocyte phenotype in ESET-null mutants is 100% penetrant. Our results demonstrate that expression of ESET plays an essential role in the maintenance of articular cartilage by preventing articular chondrocytes from terminal differentiation and may have implications in joint diseases such as osteoarthritis.

Prepubertal mouse testis growth and maturation and androgen production are acutely sensitive to di-n-butyl phthalate

Phthalates are plasticizers with widespread industrial, domestic, and medical applications. Epidemiological data indicating increased incidence of testicular dysgenesis in boys exposed to phthalates in utero are reinforced by studies demonstrating that phthalates impair fetal rodent testis development. Because humans are exposed to phthalates continuously from gestation through adulthood, it is imperative to understand what threat phthalates pose at other life stages. To determine the impact during prepuberty, we assessed the consequences of oral administration of 1 to 500 mg di-n-butyl phthalate (DBP)/kg/d in corn oil to wild-type (C57BL/6J) male mice from 4 to 14 days of age. Dose-dependent effects on testis growth correlated with reduced Sertoli cell proliferation. Histological and immunohistochemical analyses identified delayed spermatogenesis and impaired Sertoli cell maturation after exposure to 10 to 500 mg DBP/kg/d. Interference with the hypothalamic-pituitary-gonadal axis was indicated in mice fed 500 mg DBP/kg/d, which had elevated circulating inhibin but no change in serum FSH. Increased immunohistochemical staining for inhibin-α was apparent at doses of 10 to 500 mg DBP/kg/d. Serum testosterone and testicular androgen activity were lower in the 500 mg DBP/kg/d group; however, reduced anogenital distance in all DBP-treated mice suggested impaired androgen action at earlier time points. Long-term effects were evident, with smaller anogenital distance and indications of disrupted spermatogenesis in adult mice exposed prepubertally to doses from 1 mg DBP/kg/d. These data demonstrate the acute sensitivity of the prepubertal mouse testis to DBP at doses 50- to 500-fold lower than those used in rat and identify the upregulation of inhibin as a potential mechanism of DBP action.

The effects of chronic alcoholism on cell proliferation in the human brain

Neurogenesis continues in the human subventricular zone and to a lesser extent in the hippocampal subgranular zone throughout life. Subventricular zone-derived neuroblasts migrate to the olfactory bulb where survivors become integrated as interneurons and are postulated to contribute to odor discrimination. Adult neurogenesis is dysregulated in many neurological, neurovascular and neurodegenerative diseases. Alcohol abuse can result in a neurodegenerative condition called alcohol-related brain damage. Alcohol-related brain damage manifests clinically as cognitive dysfunction and the loss of smell sensation (hyposmia) and pathologically as generalized white matter atrophy and focal neuronal loss. The exact mechanism linking chronic alcohol intoxication with alcohol-related brain damage remains largely unknown but rodent models suggest that decreased neurogenesis is an important component. We investigated this idea by comparing proliferative events in the subventricular zone and olfactory bulb of a well-characterized cohort of 15 chronic alcoholics and 16 age-matched controls. In contrast to the findings in animal models there was no difference in the number of proliferative cell nuclear antigen-positive cells in the subventricular zone of alcoholics (mean±SD=28.7±20.0) and controls (27.6±18.9, p=1.0). There were also no differences in either the total (p=0.89) or proliferative cells (p=0.98) in the granular cell layer of the olfactory bulb. Our findings show that chronic alcohol consumption does not affect cell proliferation in the human SVZ or olfactory bulb. In fact only microglial proliferation could be demonstrated in the latter. Therefore neurogenic deficits are unlikely to contribute to hyposmia in chronic alcoholics.

Glia associated with central complex lineages in the embryonic brain of the grasshopper Schistocerca gregaria

We have investigated the pattern of glia associated with central complex lineages in the embryonic brain of the grasshopper Schistocerca gregaria. Using the glia-specific marker Repo, we identified glia associated externally with such lineages, termed lineage-extrinsic glia, and glia located internally within the lineages, termed lineage-intrinsic glia. Populations of both glial types increase up to 60 % of embryogenesis, and thereafter decrease. Extrinsic glia change their locations over time, while intrinsic ones are consistently found in the more apical part of a lineage. Apoptosis is not observed for either glial type, suggesting migration is a likely mechanism accounting for changes in glial number. Proliferative glia are present both within and without individual lineages and two glial clusters associated with the lineages, one apically and the other basally, may represent sources of glia.

Blockade of NF-κB nuclear translocation results in the inhibition of the invasiveness of human gastric cancer cells

The aim of the present study was to investigate the effect of the nuclear factor-κB (NF-κB) p65 inhibitor, SN50, on the invasiveness and mechanisms of SGC7901 human gastric carcinoma cell xenografts in nude mice. Nude mice were randomly divided into model control and SN50 treatment groups. On days 5, 10 and 15 following treatment, the tumor samples were observed and a selection of parameters were recorded, including the level of tumor growth inhibition, the pathological changes in the tumor specimens, the expression levels of matrix metalloproteinase-9 (MMP-9), proliferating cell nuclear antigen (PCNA), tissue inhibitor of metalloproteinases type-1 (TIMP-1) and vascular endothelial growth factor (VEGF) and the apoptosis indices in the tumor samples. The results demonstrated that treating the tumor with SN50 for 5, 10 and 15 days inhibited carcinoma growth in comparison with the control group. Hematoxylin and eosin (HE) staining indicated that the level of inhibition increased progressively, in correlation with apoptosis. The expression of the MMP-9, PCNA and VEGF proteins was observed to be downregulated, while that of the TIMP-1 protein was shown to be upregulated, using immunohistochemical staining. In conclusion, the NF-κB p65 inhibitor, SN50, inhibited the invasiveness of the gastric cancer cells by downregulating the protein expression of MMP-9, PCNA and VEGF and upregulating the protein expression of TIMP-1. It was further suggested that SN50 may be a molecular target of anti-invasion therapy for gastric cancer, and that the inhibition of the NF-κB p65 signaling pathway may be considered as a potential strategy for treating gastric cancer.

Paeonia lactiflora Extract Attenuating Cerebral Ischemia and Arterial Intimal Hyperplasia Is Mediated by Paeoniflorin via Modulation of VSMC Migration and Ras/MEK/ERK Signaling Pathway

Paeonia lactiflora is a well-known traditional Chinese medicine. Paeoniflorin is an active component found in Paeonia lactiflora, which is used to treat smooth muscle spasms and pain and to protect the cardiovascular system. The objective of this study was to determine if Paeonia lactiflora would be protective in rodent models of cerebral ischemia and arterial intimal hyperplasia. Paeonia lactiflora extract (PLex) and paeoniflorin (PF) significantly attenuated cerebral infarction in ischemia/reperfusion injury rats and the severity of intimal hyperplasia in mice where the carotid artery was ligated. PLex and PF reduced PDGF-stimulated VSMC proliferation and migration in a dose-dependent manner by MTT, wound healing, and transwell assays. PF significantly reduced protein levels of Ras, MEK, p-MEK and p-ERK, but not MMP-2 and MMP-9. In summary, Paeonia lactiflora reduced cerebral ischemia and arterial intimal hyperplasia which were mainly made via the intermediary of PF. The protective effect of PF was related to the modulation of the Ras/MEK/ERK signaling pathway.

Lithium induces follicular atresia in rat ovary through a GSK-3β/β-catenin dependent mechanism

Lithium chloride (LiCl) is a drug used to treat bipolar disorder, but has side effects in the female reproductive system. Although lithium is known to decrease folliculogenesis and induce follicular atresia in rodent ovaries, its cellular and molecular effects in the ovary have not yet been addressed. To investigate these effects, 23-day-old immature female rats were injected with 10 IU pregnant mare serum gonadotropin (PMSG), followed by injections of 250 mg/kg LiCl every 12 hr for four doses. Ovaries were removed 40 and 48 hr after PMSG administration and prepared for histology, immunohistochemistry, Western blotting, and DNA laddering analysis. Our results showed that in the ovaries of LiCl-treated rats, few antral but more atretic follicles were present compared to those of the control rats. The induction of atresia by LiCl was further confirmed by the presence of DNA fragmentation, accompanied by a reduced level of 17β-estradiol in the serum. At the cellular level, lithium significantly decreased the number of proliferating cell nuclear antigen (PCNA)-positive cells and conversely increased the number of TUNEL-positive cells in the granulosa layer of the antral follicles. At the molecular level, lithium increased the level of phosphorylated glycogen synthase kinase-3β, and unexpectedly decreased the expression of active (stabilized) β-catenin. Altogether, our results indicate that lithium disrupts the balance between proliferation and apoptosis in granulosa cells, leading to follicular atresia possibly through the reduction in both the stabilized β-catenin and 17β-estradiol synthesis.

Resveratrol is a potent inhibitor of vascularization and cell proliferation in experimental endometriosis

STUDY QUESTION

Does the phytochemical compound resveratrol inhibit vascularization of endometriotic lesions?

SUMMARY ANSWER

Resveratrol suppresses the development of new microvessels in endometriotic lesions by inhibiting endothelial cell proliferation.

WHAT IS KNOWN ALREADY

Establishment and progression of endometriosis is crucially dependent on angiogenesis. Resveratrol is a pleiotropic agent, which dose-dependently suppresses the development of new blood vessels.

STUDY DESIGN, SIZE, DURATION

This was a randomized study in a mouse model of endometriosis. Twenty female BALB/c mice with surgically induced endometriosis were treated with resveratrol (40 mg/kg/day, n = 10) or vehicle (n = 10) for 4 weeks.

MATERIAL, SETTING, METHODS

Peritoneal and mesenteric endometriotic lesions were surgically induced by uterine tissue transplantation into the abdominal cavity of BALB/c mice. The animals were daily treated with resveratrol (40 mg/kg) or vehicle by oral gavage. Lesion growth, vascularization, apoptosis and cell proliferation were subsequently analyzed by means of high-resolution ultrasound imaging, caliper measurements, histology and immunohistochemistry throughout an observation period of 4 weeks.

MAIN RESULTS AND THE ROLE OF CHANCE

Resveratrol inhibited angiogenesis in peritoneal and mesenteric endometriotic lesions, as indicated by a significantly reduced microvessel density when compared with controls. Additional immunohistochemical analyses revealed that this was caused by a decreased proliferating activity of CD31-positive endothelial cells in the newly developing microvasculature of the lesions. In line with these findings, lesions in resveratrol-treated mice exhibited a reduced growth rate and a smaller final size than controls. This was associated with lower numbers of proliferating cell nuclear antigen- and Ki67-positive stromal and glandular cells. Apoptotic cells were not detectable in either group. To limit the role of chance, the experiments were conducted under standardized laboratory conditions with appropriate controls. Statistical significance was accepted for a value of P < 0.05.

LIMITATIONS, REASONS FOR CAUTION

Endometriotic lesions were surgically induced by uterine tissue transplantation without the use of pathological endometriotic tissue of human origin. Therefore, the results obtained in this mouse model may not fully correlate to human patients with endometriosis.

WIDER IMPLICATIONS OF THE FINDINGS

Resveratrol is a potent inhibitor of vascularization in endometriotic lesions. This, most probably, causes the suppression of lesion growth. Accordingly, resveratrol represents a promising candidate therapy for future phytochemical treatment of endometriosis.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by a grant of the 'Freunde des Universitätsklinikums des Saarlandes'. The authors have no conflicts of interest to declare.

Hesperidin alleviates oxidative stress and downregulates the expressions of proliferative and inflammatory markers in azoxymethane-induced experimental colon carcinogenesis in mice

OBJECTIVE

Colon cancer is a common malignant neoplasm causing huge morbidity and mortality worldwide. Current therapeutic interventions are unsatisfying, which necessitates novel chemopreventive strategies. The present study was intended to elucidate the chemopreventive efficacy of hesperidin against azoxymethane (AOM)-induced mouse colon carcinogenesis.

MATERIALS AND METHODS

Swiss albino mice were subjected to intraperitoneal injections of AOM once a week for 3 consecutive weeks. Hesperidin treatments were provided in the initiation or post-initiation phases. The number and multiplicity of aberrant crypt foci (ACF), tumor incidence and antioxidant status were determined. Histopathological analyses, proliferating cell nuclear antigen (PCNA) index and modulations in the expression of inflammatory markers such as nuclear factor kappa B (NF-κB), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were studied.

RESULTS

Hesperidin treatments significantly inhibited the number and multiplicities of AOM-induced ACF and tumor incidence. Hesperidin reduced oxidative stress parameters and enhanced antioxidant status. A marked decrease in the PCNA index was evident on hesperidin administration. Hesperidin treatments caused a prominent downregulation of NF-κB and its target molecules iNOS and COX-2, thereby combating inflammation.

CONCLUSION

This study proves the chemopreventive efficacy of hesperidin against the deleterious traits of colon carcinogenesis including accelerated proliferation, inflammation and persistent oxidative stress.

In vitro and in vivo evaluation of electrospun PCL/PMMA fibrous scaffolds for bone regeneration

Scaffolds were fabricated by electrospinning using polycaprolactone (PCL) blended with poly(methyl methacrylate) (PMMA) in ratios of 10/0, 7/3, 5/5 and 3/7. The PCL/PMMA ratio affected the fiber diameter, contact angle, tensile strength and biological in vitro and in vivo properties of the scaffolds, and the 7/3 ratio resulted in a higher mechanical strength than 5/5 and 3/7. In vitro cytotoxicity and proliferation of MG-63 osteoblast cells on these blended scaffolds were examined by MTT assay, and it was found that PCL/PMMA blends are suitable for osteoblast cell proliferation. Confocal images and expression of proliferating cell nuclear antigen confirmed the good proliferation and expression of cells on the 7/3 PCL/PMMA fibrous scaffolds. In vivo bone formation was examined using rat models, and bone formation was observed on the 7/3 PCL/PMMA scaffold within 2 months. In vitro and in vivo results suggest that 7/3 PCL/PMMA scaffolds can be used for bone tissue regeneration.

Antioxidative, antiapoptotic, and proliferative effect of curcumin on liver regeneration after partial hepatectomy in rats

The aim of the present study was to assess the influence of curcumin on liver regeneration after partial hepatectomy (PH) in rats. A total of 24 male Sprague Dawley rats were divided into three groups: sham-operated (SH), PH, and PH + curcumin; each group contains eight animals. The rats in curcumin-treated groups were given curcumin (in a dose of 100 mg/kg body weight) once a day orally for 7 days, starting 3 days prior to hepatectomy operation. At 7 days after resection, liver samples were collected. The malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH) levels were estimated in liver homogenates. Moreover, histopathological examination, mitotic index (MI), proliferating cell nuclear antigen labeling, proliferation index (PI), transferase-mediated 2'-deoxyuridine, 5'-triphosphate nick end-labeling assay, and apoptotic index (AI) were evaluated at 7 days after hepatectomy. As a result, curcumin significantly increased MI and PI and significantly decreased AI in PH rats. Additionally, curcumin remarkably inhibited MDA elevation, restored impaired antioxidant SOD activity and GSH level and also attenuated hepatic vacuolar degeneration and sinusoidal congestion. These results suggested that curcumin treatment had a beneficial effect on liver regenerative capacity of the remnant liver tissue after hepatectomy, probably due to its antioxidative, antiapoptotic, and proliferative properties.

Orbital cavernous haemangiomas: immunohistochemical study of proliferative capacity, vascular differentiation and hormonal receptor status

BACKGROUND/AIMS

Immunohistochemical characterisation of orbital cavernous haemangiomas (CHs) with respect to proliferative capacity, hormone receptor status and vascular differentiation.

METHODS

Eleven cases of orbital CHs were reviewed. Immunohistochemical stains for Mib-1, proliferating cell nuclear antigen (PCNA), Bcl-2, estrogen and progesterone receptors (ER & PR), CD31, D2-40, and VEGF were investigated in 11 specimens.

RESULTS

Immunohistochemical staining revealed positivity for PCNA in ten of the 11 cases (91%). Bcl-2 was positive in 8 cases (73%). VEGF and PR were each weakly positive in 3 cases. All cases were negative for Mib-1, ER and D2-40. The staining was localized around the endothelium.

CONCLUSION

This is the first study to characterise in detail the immunohistochemical features of orbital CHs. The proliferative markers PCNA and Mib-1 show discordant expression in these lesions and the expression of PCNA and Bcl-2 in the absence of Mib-1 is indicative of low proliferative potential. Small subsets of these tumors express PR and VEGF, which may partly explain the proliferative capacity of some orbital CHs.

Chrysin suppresses renal carcinogenesis via amelioration of hyperproliferation, oxidative stress and inflammation: plausible role of NF-κB

Flavonoid family is a rich source of polyphenolic compounds and hence possess strong antioxidant and anti inflammatory properties. The aim of this study was to determine the efficacy of chrysin; a bio-active flavonoid as an anticancer agent. Renal cancer was initiated by single intraperitoneal (i.p.) injection of N-nitrosodiethylamine (DEN 200 mg/kg BW body weight) and promoted by twice weekly administration of ferric nitrilotriacetate (Fe-NTA) 9 mg Fe/kg BW for 16 wk. In the present study, we report the chemopreventive effects of chrysin against (Fe-NTA) induced renal oxidative stress, inflammation, hyperproliferative response, and two-stage renal carcinogenesis. To ascertain the molecular mechanism implicated in the antitumor promoting activity of chrysin, its effect was investigated on markers of tumor promotion and inflammation: ornithine decarboxylase (ODC) activity, proliferating cell nuclear antigen (PCNA), inducible nitric oxide synthase (iNOS) and cyclo-oxygenase-2 (COX-2) expression, and on levels of proinflammatory cytokines interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and prostaglandin E(2) (PGE(2)). Pretreatment of animals with chrysin at both doses (20 and 40 mg/kg body weight) markedly inhibited all. Further, Fe-NTA enhances renal lipid peroxidation, with concomitant reduction in reduced glutathione content (GSH), antioxidant enzymes, and phase II metabolizing enzymes. It induces serum toxicity markers, viz., blood urea nitrogen (BUN), creatinine and lactate dehydrogenase (LDH). Prophylactic treatment of animals with chrysin before the administration of Fe-NTA was effective in modulating oxidative and renal injury markers and resulted in the diminution of Fe-NTA mediated injury. These results suggest chrysin as an effective chemopreventive agent having the capability to obstruct DEN initiated and Fe-NTA promoted renal cancer in the rat model.

Dietary folate suppresses DMH-induced colon carcinogenesis in a rat model and affects DMH-induced expression of four DNA repair enzymes

This study investigated the potential role of folate in the dimethylhydrazine (DMH) colon cancer model in male Wistar rats. For induction of colon cancer, group 1 rats were injected subcutaneously with 30 mg DMH/kg body weight weekly for 30 wk. Group 2 received DMH vehicle. Group 3 rats received DMH as in Group 1 but their diet was supplemented with 8 mg folate/kg diet. Group 4 was fed diet supplemented with 8 mg folate/kg diet. Upregulation of DNA damage repair genes Apurinic/apyrimidinic endonuclease 1, X-ray repair complementing defective repair in Chinese hamster cells 5, 8-oxoguanine-DNA glycosylase, and proliferating cell nuclear antigen, associated with a reduction of folic acid level was observed in colons of DMH group. Reductions of these gene upregulations and a significant increase of colonic folic acid level occurred in the DMH group supplemented with folic acid and this group also had significant inhibition of tumor incidence, normal survival rate and histologically nearly normal colonic architecture. It can be concluded that folate supplementation exerts a potent protective effect on rat colon carcinogenesis via significant modulation of DNA repair, providing a mechanism by which it plays a role in the etiology of human cancer.

Antiproliferative efficacy of hesperetin (citrus flavanoid) in 1,2-dimethylhydrazine-induced colon cancer

Cancer is the second leading cause of death worldwide and is increasing at an alarming rate. The present study was to evaluate the antiproliferative effects of hesperetin, a flavonoid commonly found in many herbal medicines and foods, on aberrant crypt foci (ACF), argyrophylic nucleolar organizer regions (AgNORs) and proliferating cell nuclear antigen (PCNA) in 1,2-dimethylhydrazine (DMH)-induced colon carcinogenesis in rats. Rats were given subcutaneous injections of DMH (20 mg/kg body weight) weekly for 15 weeks to induce carcinogenesis, and hesperetin was administered orally at the dose of 20 mg/kg body weight. DMH exposure alone produced a high incidence of ACF and showed positive staining for PCNA and AgNORs in colonic tissues. Supplementation with hesperetin lowered the PCNA labeling index and suppressed the formation of ACF in the rats with colon cancer. These results clearly reveal that dietary hesperetin possesses antiproliferative ability against chemically induced colon tumourigenesis.

Expression patterns of Nurr1 in rat retina development

Nurr1 is a member of the nuclear receptor superfamily, and is involved in regulating the differentiation, migration and maturation of mesencephalic dopaminergic neurons. The present study was designed to observe Nurr1 protein expression patterns during rat retina development. Immunohistochemical double staining, fluorescence double staining and western blotting were used. The results revealed dramatic and dynamic changes in Nurr1 protein expression during retinal development. Nurr1-positive cells appeared in small quantities at embryonic day 18, and their number then increased markedly during development. The peak occurred at postnatal days 3-7. As maturation continued, the number of positive cells gradually decreased. Comparative observation of Nurr1 and PCNA showed that Nurr1 was confined to differentiated and migrating immature cells, and that it was not present in proliferating cells. Nurr1-positive cells, identified by comparative observation of Nurr1 and syntaxin-1, were amacrine cells. In addition, the Nurr1 and tyrosine hydroxylase coexisted in the same cells, but most cells with Nurr1 expression did not express tyrosine hydroxylase. These results suggest that Nurr1 may play a regulatory role in the differentiation and maturation of both dopaminergic and non-dopaminergic amacrine cells in the rat retina.

MFG-E8 activates proliferation of vascular smooth muscle cells via integrin signaling

An accumulation of milk fat globule EGF-8 protein (MFG-E8) occurs within the context of arterial wall inflammatory remodeling during aging, hypertension, diabetes mellitus, or atherosclerosis. MFG-E8 induces VSMC invasion, but whether it affects VSMC proliferation, a salient feature of arterial inflammation, is unknown. Here, we show that in the rat arterial wall in vivo, PCNA and Ki67, markers of cell cycle activation, increase with age between 8 and 30 months. In fresh and early passage VSMC isolated from old aortae, an increase in CDK4 and PCNA, an increase in the acceleration of cell cycle S and G2 phases, decrease in the G1/G0 phase, and an increase in PDGF and its receptors confer elevated proliferative capacity, compared to young VSMC. Increased coexpression and physical interaction of MFG-E8 and integrin αvβ5 occur with aging in both the rat aortic wall in vivo and in VSMC in vitro. In young VSMC in vitro, MFG-E8 added exogenously, or overexpressed endogenously, triggers phosphorylation of ERK1/2, augmented levels of PCNA and CDK4, increased BrdU incorporation, and promotes proliferation, via αvβ5 integrins. MFG-E8 silencing, or its receptor inhibition, or the blockade of ERK1/2 phosphorylation in these cells reduces PCNA and CDK4 levels and decelerates the cell cycle S phase, conferring a reduction in proliferative capacity. Collectively, these results indicate that MFG-E8 in a dose-dependent manner coordinates the expression of cell cycle molecules and facilitates VSMC proliferation via integrin/ERK1/2 signaling. Thus, an increase in MFG-E8 signaling is a mechanism of the age-associated increase in aortic VSMC proliferation.

Malignant transformation of rat kidney induced by environmental substances and estrogen

The use of organophosphorous insecticides in agricultural environments and in urban settings has increased significantly. The aim of the present study was to analyze morphological alterations induced by malathion and 17β-estradiol (estrogen) in rat kidney tissues. There were four groups of animals: control, malathion, estrogen and combination of both substances. The animals were injected for five days and sacrificed 30, 124 and 240 days after treatments. Kidney tissues were analyzed for histomorphological and immunocytochemical alterations. Morphometric analysis indicated that malathion plus estrogen-treated animals showed a significantly (p < 0.05) higher grade of glomerular hypertrophy, signs of tubular damage, atypical proliferation in cortical and hilium zone than malathion or estrogen alone-treated and control animals after 240 days. Results indicated that MFG, ER-α, ER-β, PgR, CYP1A1, Neu/ErbB2, PCNA, vimentin and Thrombospondin 1 (THB) protein expression was increased in convoluted tubules of animals treated with combination of malathion and estrogen after 240 days of 5 day treatment. Malignant proliferation was observed in the hilium zone. In summary, the combination of malathion and estrogen induced pathological lesions in glomeruli, convoluted tubules, atypical cell proliferation and malignant proliferation in hilium zone and immunocytochemical alterations in comparison to control animals or animals treated with either substance alone. It can be concluded that an increased risk of kidney malignant transformation can be induced by exposure to environmental and endogenous substances.

Chemopreventive efficacy of hesperetin (citrus flavonone) against 1,2-dimethylhydrazine-induced rat colon carcinogenesis

BACKGROUND

Colorectal carcinogenesis is one of the most common cancers/lethal diseases. Chronic inflammation is considered a risk factor for colorectal cancer. Hesperetin, a flavonone found in citrus fruits and oranges is shown to possess potent growth inhibitory effects against various human cancer cells. It possesses anti-inflammatory and antioxidant properties. AIM OF THE SCOPE: In the present study, we have evaluated the chemopreventive efficacy of hesperetin against rat colon carcinogenesis in male Wistar rats.

METHODS

Group 1 served as control, received modified pellet diet and group 2 rats received 20 mg/kg body weight of hesperetin p.o. every day. Groups 3-6 rats were given subcutaneous injections of 1,2-dimethylhydrazine (DMH, 20 mg/kg body weight) once a week for 15 consecutive weeks. In addition, rats in group 4 received hesperetin as in group 2 for the first 15 weeks (initiation), group 5 rats received hesperetin as in group 2 after the last injection of DMH and continued till the end of the experimental period (postinitiation). Group 6 rats received hesperetin as in group 2 throughout the entire experimental period of 32 weeks.

RESULTS

Detection of cell proliferation markers such as proliferating cell nuclear antigen (PCNA) (immunohistochemistry), argyrophilic nucleolar organizer regions (AgNORs) (silver staining); apoptosis (immunoblotting and immunohistochemistry); angiogenic growth factors (ELISA) indicated decreased cell proliferation and increased apoptotic markers in the colon. In addition, decreased angiogenic growth factors such as vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), and downregulation of mRNA Cyclooxygenase-2 (COX-2) expressions were observed in mucosal and fecal samples of hesperetin-supplemented rats.

CONCLUSIONS

Hesperetin supplementation showed an inhibition of cell proliferation markers, angiogenic growth factors, COX-2 mRNA expression and induction of apoptosis. Thus, hesperetin can be used as a potent chemopreventive agent against DMH-induced colon cancer.

Beneficial effects of splenectomy on liver regeneration in a rat model of massive hepatectomy

BACKGROUND

Small-for-size syndrome is a widely recognized clinical complication after living donor liver transplantation or extended hepatectomy due to inadequate liver mass. The purpose of this study was to investigate the role of splenectomy in rats after massive hepatectomy, a surrogate model of small-for-size graft.

METHODS

Rats were divided into eight groups, each with 20 animals: 50% hepatectomy (50% Hx), 50% hepatectomy+splenectomy (50% Hx+Sp), 60% Hx, 60% Hx+Sp, 70% Hx, 70% Hx+Sp, 90% Hx and 90% Hx+Sp. The following parameters were evaluated: liver function tests (ALT, AST and TBIL), liver regeneration ratio, DNA synthesis, proliferation cell nuclear antigen, hepatic oxygen delivery (HDO2) and hepatic oxygen consumption (HVO2).

RESULTS

The liver regeneration ratio was enhanced in the Hx+Sp groups (P<0.05). In addition, compared with the Hx groups, the Hx+Sp groups had better liver functions (P<0.05). DNA synthesis and proliferation cell nuclear antigen were also increased in the Hx+Sp groups compared with the Hx groups (P<0.05). Furthermore, in the Hx+Sp groups, HDO2 and HVO2 were increased over those in the Hx groups (P<0.05), and were positively correlated with the liver regeneration ratio.

CONCLUSIONS

Splenectomy significantly improved liver function, and enhanced DNA synthesis and proliferation cell nuclear antigen after massive hepatectomy in rats. This operation could be mediated through increased HDO2 and HVO2, which facilitate liver regeneration.

Antiapoptotic and proliferative activity of curcumin on ovarian follicles in mice exposed to whole body ionizing radiation

The aim of this study was to evaluate the antiapoptotic and proliferative activity of curcumin (Cur) on the ovarian follicles in mice exposed to whole body ionizing radiation (Rd). The mice were exposed to 8.3 gray whole body Rd, and Cur groups were given as a daily dose of 100 mg/kg of Cur for 10 days (10 days before Rd). The ovaries were collected 3 and 12 h after irradiation. To date, no such studies have been performed on antiapoptotic and proliferative activity of Cur on the ovarian follicles in mice exposed to whole body Rd. Analysis of mice ovary after exposure to Rd by terminal-deoxynucleotidyl-transferase-mediated dUTP nick end labeling showed that there were apoptotic cells both in the follicular wall and the antrum, and that the number of follicles showing early atresic features was high 3 h after Rd. On the other hand, analysis of mice ovary 12 h after exposure to Rd showed that the number of follicles containing apoptotic cells with advanced atresic features was significantly higher when compared to the 3-h Rd exposure group. The proliferating cell nuclear antigen -positive granulosa cells were decreased in association with follicular atresia. The groups given treatment were observed to have some benefit from Cur against the damage caused by Rd. The results of this study demonstrate that Cur prevents follicular atresia in Rd-induced apoptosis in ovarian follicles.

Mice lacking the Raf-1 kinase inhibitor protein exhibit exaggerated hypoxia-induced pulmonary hypertension

BACKGROUND AND PURPOSE

Increased pulmonary vascular remodelling, pulmonary arterial pressure and pulmonary vascular resistance characterize the development of pulmonary arterial hypertension (PAH). Activation of the Raf/mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK)1/2 is thought to play an important role in PAH and Raf-1 kinase inhibitor protein (RKIP), negatively regulates this pathway. This study investigated whether genetic deletion of RKIP (and hence ERK1/2 up-regulation) resulted in a pulmonary hypertensive phenotype in mice and investigated a role for RKIP in mitogen-regulated proliferative responses in lung fibroblasts.

EXPERIMENTAL APPROACH

Pulmonary vascular haemodynamics and remodelling were assessed in mice genetically deficient in RKIP (RKIP-/-) after 2 weeks of either normoxia or hypoxia. Immunoblotting and immunohistochemistry were used to examine phosphorylation of Raf-1, RKIP and ERK1/2 in mouse pulmonary arteries. In vitro, RKIP inhibition of mitogen signalling was analysed in CCL39 hamster lung fibroblasts.

KEY RESULTS

RKIP-/- mice demonstrated elevated indices of PAH and ERK1/2 phosphorylation compared with wild-type (WT) mice. Hypoxic RKIP-/- mice exhibited exaggerated PAH indices. Hypoxia increased phosphorylation of Raf-1, RKIP and ERK1/2 in WT mouse pulmonary arteries and Raf-1 phosphorylation in RKIP-/- mouse pulmonary arteries. In CCL39 cells, inhibition of RKIP potentiated mitogen-induced proliferation and phosphorylation of RKIP, and Raf-1.

CONCLUSIONS AND IMPLICATIONS

The lack of RKIP protein resulted in a pulmonary hypertensive phenotype, exaggerated in hypoxia. Hypoxia induced phosphorylation of RKIP signalling elements in WT pulmonary arteries. RKIP inhibition potentiated mitogen-induced proliferation in lung fibroblasts. These results provide evidence for the involvement of RKIP in suppressing the development of hypoxia-induced PAH in mice.

Efficacy of chitin-PAA-GTMAC gel in promoting wound healing: animal study

Acrylic grafted chitin (chitin-PAA) was modified with glycidyltrimethylammonium chloride (GTMAC) with the aim of promoting wound healing. The chitin-PAA-GTMAC gels with different GTMAC contents were compared with the original chitin-PAA gel and Intrasite gel for their efficacy in deep wound healing of Wistar rats. Four full-thickness wounds were made on the dorsal skin of rats and then each was treated with 4 materials; chitin-PAA, chitin-PAA-GTMAC(1:4), chitin-PAA-GTMAC(1:10) and Intrasite gel. During 18 days of treatment, the wounds were visually observed and calculated for wound size using image analysis program. Skin wound tissues of sacrificed rats were processed for routine histological observation and immunohistochemistry of proliferating cell nuclear antigen (PCNA). The wounds covered with the chitin derivatives either with or without GTMAC showed a significant reduction in wound size in day 9 in comparison with day 12 for those covered with Intrasite gel. The faster rate and the better pattern of epidermal development observed in histological study as well as the higher dermal cell proliferation (PCNA expression) also demonstrated the better efficiency in wound healing of the chitin derivatives than Intrasite. The earliest epidermal development of the wounds treated with chitin-PAA-GTMAC (1:4) among the tested materials suggested the most promising of this material for the treatment of full-thickness open wound.