Number Of Lysosomes Research Articles

Sustained activation of sphingomyelin synthase by 2-hydroxyoleic acid induces sphingolipidosis in tumor cells

The mechanism of action of 2-hydroxyoleic acid (2OHOA), a potent antitumor drug, involves the rapid and specific activation of sphingomyelin synthase (SMS), leading to a 4-fold increase in SM mass in tumor cells. In the present study, we investigated the source of the ceramides required to sustain this dramatic increase in SM. Through radioactive and fluorescent labeling, we demonstrated that sphingolipid metabolism was altered by a 24 h exposure to 2OHOA, and we observed a consistent increase in the number of lysosomes and the presence of unidentified storage materials in treated cells. Mass spectroscopy revealed that different sphingolipid classes accumulated in human glioma U118 cells after exposure to 2OHOA, demonstrating a specific effect on C16-, C20-, and C22-containing sphingolipids. Based on these findings, we propose that the demand for ceramides required to sustain the SMS activation (ca. 200-fold higher than the basal level) profoundly modifies both sphingolipid and phospholipid metabolism. As the treatment is prolonged, tumor cells fail to adequately metabolize sphingolipids, leading to a situation resembling sphingolipidosis, whereby cell viability is compromised.

Ultrastructural responses and oxidative stress induced by cypermethrin in the liver of Labeo rohita

The present study was conducted to establish the relationship between selected oxidative stress parameters and ultrastructural responses in liver tissue of Labeo rohita fingerlings exposed to cypermethrin. Fish were exposed to lethal (4.0 μg L−1) and sublethal (0.4 μg L−1) concentrations of cypermethrin for a period of 24, 48, 72 and 96 h for acute studies and 1, 5, 10 and 15 days for subacute studies, respectively. Results showed increased catalase (CAT) and protease activity, hydrogen peroxide (H2O2), malondialdehyde (MDA), protein carbonyls and free amino acid (FAA) levels at both concentrations. This suggests participation of free-radical-induced oxidative cell injury in mediating the hepatotoxicity of cypermethrin. In corroboration of this, ultrastructural lesions witnessed a reduction in the number of cell organelles, swollen, vacuolated and condensed mitochondria, dilated rough endoplasmic reticulum, and reduced numbers of smooth enodplasmic reticulum, peroxisomes and lysosomes at the lethal (4.0 μg L−1) concentration. At the sublethal (0.4 μg L−1) concentration, cytoplasmic vacuolation, condensed, vacuolated and swollen mitochondria, dilated rough endoplasmic reticulum and an absence of hepatocyte microvilli were prominent. Ultrastructural changes were exhibited as subcellular responses due to the imbalance in cellular oxidative status by means of oxidative damage.

The Role of Autophagy Dysregulation in Manganese-Induced Dopaminergic Neurodegeneration

The etiological role of dysregulated autophagy in neurodegenerative diseases has been a subject of intense investigation. While manganese (Mn) is known to cause dopaminergic (DAergic) neurodegeneration, it has yet to be determined whether the dysregulation of autophagy plays a role in Mn-induced neuronal injury. In this study, we investigated the effect of Mn on autophagy in a rat model of manganism, a neurodegenerative disease associated with excessive exposure to Mn. After a single intrastriatal injection of Mn, the short- (4–12 h) and long-term (1–28 days) effect of Mn on DAergic neurons and autophagy were examined. Marked reduction in the number of TH-immunoreactive neurons in the substantia nigra pars compacta (SNpc) as well as TH protein expression, and a significant increase of apomorphine-induced rotations were observed in rats after Mn injection. Manganese also induced the down-regulation of dopamine levels and D1 dopamine receptor expression. In addition, autophagy was dysregulated and inhibited, as evidenced by increased number of abnormal lysosomes, decreased protein expression of Beclin1, and decreased ratio of microtubule-associated protein 1 light chain 3 (LC3) II over LC3 I, concomitant with activated mammalian target of rapamycin (mTOR)/p70 ribosomal protein S6 kinase (p70s6k) signaling. In contrast, in the early phase of Mn exposure, the level of autophagy was not be suppressed but compensatorily activated. Although the morphology of the DAergic neuron was intact in the early phase, Mn caused a significant decrease in TH-immunoreactivity and a significant increase in apomorphine-induced rotations in the presence of wortmannin, an inhibitor of autophagy. Taken together, these results demonstrate, for the first time, that autophagy may play a protective role against Mn-induced neuronal damage, whilst dysregulation of autophagy at later phases may mediate DAergic neurodegeneration.

A RANKL–PKCβ–TFEB signaling cascade is necessary for lysosomal biogenesis in osteoclasts

Bone resorption by osteoclasts requires a large number of lysosomes that release proteases in the resorption lacuna. Whether lysosomal biogenesis is a consequence of the action of transcriptional regulators of osteoclast differentiation or is under the control of a different and specific transcriptional pathway remains unknown. We show here, through cell-based assays and cell-specific gene deletion experiments in mice, that the osteoclast differentiation factor RANKL promotes lysosomal biogenesis once osteoclasts are differentiated through the selective activation of TFEB, a member of the MITF/TFE family of transcription factors. This occurs following PKCβ phosphorylation of TFEB on three serine residues located in its last 15 amino acids. This post-translational modification stabilizes and increases the activity of this transcription factor. Supporting these biochemical observations, mice lacking in osteoclasts--either TFEB or PKCβ--show decreased lysosomal gene expression and increased bone mass. Altogether, these results uncover a RANKL-dependent signaling pathway taking place in differentiated osteoclasts and culminating in the activation of TFEB to enhance lysosomal biogenesis-a necessary step for proper bone resorption.

ZKSCAN3 Is a Master Transcriptional Repressor of Autophagy

Autophagy constitutes a major cell-protective mechanism that eliminates damaged components and maintains energy homeostasis via recycling nutrients under normal/stressed conditions. Although the core components of autophagy have been well studied, regulation of autophagy at the transcriptional level is poorly understood. Herein, we establish ZKSCAN3, a zinc finger family DNA-binding protein, as a transcriptional repressor of autophagy. Silencing of ZKSCAN3 induced autophagy and increased lysosome biogenesis. Importantly, we show that ZKSCAN3 represses transcription of a large gene set (>60) integral to, or regulatory for, autophagy and lysosome biogenesis/function and that a subset of these genes, including Map1lC3b and Wipi2, represent direct targets. Interestingly, ZKSCAN3 and TFEB are oppositely regulated by starvation and in turn oppositely regulate lysosomal biogenesis and autophagy, suggesting that they act in conjunction. Altogether, our study uncovers an autophagy master switch regulating the expression of a transcriptional network of genes integral to autophagy and lysosome biogenesis/function.

Enhancement of chondrocyte autophagy is an early response in the degenerative cartilage of the temporomandibular joint to biomechanical dental stimulation

Autophagy is a cell protective mechanism for maintaining cellular homeostasis. The present study aimed to investigate whether autophagy is enhanced in the biomechanically induced degenerative cartilage of the temporomandibular joint (TMJ) and the potential role of mitogen-activated protein kinase kinase kinase kinase 3 (MAP4K3) and mammalian Target of rapamycin (mTOR) in this observation. To induce degenerative changes in the TMJs, rats were subjected to biomechanical dental stimulation by moving 4 molars away from their original position as we previously reported. The ultrastructure of autophagosome was observed by transmission electron microscopy. The number of lysosomes was analyzed by flow cytometry. The expression levels of Beclin1 and LC3 and the involvement of MAP4K3 activity were detected by immunohistochemistry, real-time PCR and western blot. The activity of the mTOR pathway indicated by p-mTOR and p-p70S6K was assayed by western blot. TMJ degeneration, characterized by irregular cell arrangement and cell-free area, was induced in the experimental groups. Under transmission electron microscopy, we observed the presence of autophagosomes, small patches of condensed chromatin, abundant rough endoplasmic reticulum and Golgi apparatus. The number of lysosomes and the expression levels of Beclin1 and LC3 increased, while the activity of mTOR and the expression level of MAP4K3 decreased in the experimental groups. Cartilage in TMJ which was induced to be degenerative biomechanically exhibited autophagy accompanied by reduced mTOR and MAP4K3 activity.

Abnormal Processing of Autophagosomes in Transformed B Lymphocytes from SCARB2-Deficient Subjects

Mutations of the intrinsic lysosomal membrane protein SCARB2 cause action myoclonus-renal failure syndrome (AMRF syndrome), a rare disease characterized by renal and neurological manifestations. In this study, examination of Cos7 cells transfected with SCARB2 cDNA derived from two patients with AMRF syndrome showed that the resultant protein was truncated and was not incorporated into vesicular structures, as occurred with full-length SCARB2 cDNA. Mutant SCARB2 protein failed to colocalize with lysosomes and was found in the endoplasmic reticulum or the cytosol indicating a loss of function. Cultured skin fibroblast and Epstein–Barr virus–transformed lymphoblastoid B cell lines (LCLs) were created from these two patients. Despite the loss of SCARB2 function, studies with lysosomal-associated membrane protein (LAMP) 1 and LAMP2 demonstrated normal lysosomal numbers in fibroblasts and LCLs. Immunofluorescence microscopy using anti-LAMP1 and anti-LAMP2 antibodies also showed normal lysosomal structures in fibroblasts. There was no change in the morphology of fibroblasts examined by electron microscopy compared with cells from unaffected individuals. By contrast, LCLs from individuals bearing SCARB2 mutations had large intracellular vesicles that resembled autophagosomes and contained heterogeneous cellular debris. Some of the autophagosomes were seen to be extruding cellular contents into the media. Furthermore, LCLs had elevated levels of microtubule-associated protein light chain 3-II, consistent with increased autophagy. These data demonstrate that SCARB2 mutations are associated with an inability to process autophagosomes in B lymphocytes, suggesting a novel function for SCARB2 in immune function.

Large Gradient High Magnetic Fields Affect Osteoblast Ultrastructure and Function by Disrupting Collagen I or Fibronectin/αβ1 Integrin

The superconducting magnet generates a field and field gradient product that can levitate diamagnetic materials. In this study a specially designed superconducting magnet with a large gradient high magnetic field (LG-HMF), which can provide three apparent gravity levels (μ-g, 1-g, and 2-g), was used to simulate a space-like gravity environment. The effects of LG-HMF on the ultrastructure and function of osteoblast-like cells (MG-63 and MC3T3-E1) and the underlying mechanism were investigated by transmission electromicroscopy (TEM), MTT, and cell western (ICW) assays. Under LG-HMF significant morphologic changes in osteoblast-like cells occurred, including expansion of endoplasmic reticulum and mitochondria, an increased number of lysosomes, distorted microvilli, and aggregates of actin filaments. Compared to controls, cell viability and alkaline phosphatase (ALP) secretion were significantly increased, and collagen I (col I), fibronectin (FN), vinculin, integrin α3, αv, and β1 expression were changed under LG-HMF conditions. In conclusion, LG-HMF affects osteoblast ultrastructure, cell viability, and ALP secretion, and the changes caused by LG-HMF may be related to disrupting col I or FN/αβ1 integrin.

18F-FDG Labeling of Mesenchymal Stem Cells and Multipotent Adult Progenitor Cells for PET Imaging: Effects on Ultrastructure and Differentiation Capacity

Because of their extended differentiation capacity, stem cells have gained great interest in the field of regenerative medicine. For the development of therapeutic strategies, more knowledge on the in vivo fate of these cells has to be acquired. Therefore, stem cells can be labeled with radioactive tracer molecules such as (18)F-FDG, a positron-emitting glucose analog that is taken up and metabolically trapped by the cells. The aim of this study was to optimize the radioactive labeling of mesenchymal stem cells (MSCs) and multipotent adult progenitor cells (MAPCs) in vitro with (18)F-FDG and to investigate the potential radiotoxic effects of this labeling procedure with a range of techniques, including transmission electron microscopy (TEM). Mouse MSCs and rat MAPCs were used for (18)F-FDG uptake kinetics and tracer retention studies. Cell metabolic activity, proliferation, differentiation and ultrastructural changes after labeling were evaluated using an Alamar Blue reagent, doubling time calculations and quantitative TEM, respectively. Additionally, mice were injected with MSCs and MAPCs prelabeled with (18)F-FDG, and stem cell biodistribution was investigated using small-animal PET. The optimal incubation period for (18)F-FDG uptake was 60 min. Significant early tracer washout was observed, with approximately 30%-40% of the tracer being retained inside the cells 3 h after labeling. Cell viability, proliferation, and differentiation capacity were not severely affected by (18)F-FDG labeling. No major changes at the ultrastructural level, considering mitochondrial length, lysosome size, the number of lysosomes, the number of vacuoles, and the average rough endoplasmic reticulum width, were observed with TEM. Small-animal PET experiments with radiolabeled MAPCs and MSCs injected intravenously in mice showed a predominant accumulation in the lungs and a substantial elution of (18)F-FDG from the cells. MSCs and MAPCs can be successfully labeled with (18)F-FDG for molecular imaging purposes. The main cellular properties are not rigorously affected. TEM confirmed that the cells' ultrastructural properties are not influenced by (18)F-FDG labeling. Small-animal PET studies confirmed the intracellular location of the tracer and the possibility of imaging injected prelabeled stem cell types in vivo. Therefore, direct labeling of MSCs and MAPCs with (18)F-FDG is a suitable technique to noninvasively assess cell delivery and early retention with PET.

In vitro changes in mitochondrial potential, aggresome formation and caspase activity by a novel 17‐β‐estradiol analogue in breast adenocarcinoma cells

2-Methoxyestradiol, a natural metabolite of estradiol, exerts antiproliferative and antitumour properties in vitro and in vivo. Because of its low oral bioavailability, several promising analogues of 2-methoxyestradiol have been developed. In this study, the in vitro influence of the compound, 2-ethyl-3-O-sulphamoyl-estra-1,3,5(10)16-tetraene (C19), a non-commercially available 17-β-estradiol analogue, was tested on the breast adenocarcinoma MCF-7 cell line. The in vitro influence of 24 h exposure to 0.18 μM of C19 on MCF-7 cells was evaluated on cell morphology, cell cycle progression and possible induction of apoptosis and autophagy. Polarization-optical transmitted light differential interference contrast and fluorescence microscopy revealed the presence of cells blocked in metaphase, occurrence of apoptotic bodies and compromised cell density in C19-treated cells. Hallmarks of autophagy, namely an increase in the number of acidic vacuoles and lysosomes, were also observed in C19-treated samples. An increase in the number of cells present in the sub-G1 fraction, as well as a reduction in mitochondrial membrane potential was observed. No significant alterations in caspase 8 activity were observed. A twofold increase in aggresome formation was observed in C19-treated cells. C19 induced both apoptosis and autophagy in MCF-7 cells.

The Probable Protective Role of Vitamin C against Cyclosporine an Induced Pulmonary Changes in Mice

 Abstract—Cyclosporine A (Cs-A) is a frequently used immunosuppressive agent in transplant medicine to prevent rejection and in the treatment of autoimmune diseases . Vitamin c is a potent antioxidant that has the ability to scavenge factors causing free radical formation in animals receiving Cs-A . It play a major role in disease prevention. Cs-A induced histological and ultrastructural alterations in the pulmonary tissue. These included congestion and hemorrhage of most blood capillaries, increased number of lymphocytes within the thickened interalveolar septa and destruction of the inner border of the respiratory bronchioles and increase of collagen fibers. Changes were seen in type I& II alveolar cells in the form of vacuolation, increase in the number of lysosomes, shortening of the apical microvilli and irregularity and swollen of the nuclei . Also, an increase in number of macrophages and fragmentation of the rough endoplasmic reticulum. Most of the main cell types in the alveolar tissue had restored their normal histological and ultrastructural appearance by VC. Conclusion: Antioxidant nutrients (VC) can improve lung histological and ultrastructural damage produced by Cs-A administration.

Effect of erythropoietin on mesenchymal stem cell differentiation and secretion in vitro in an acute kidney injury microenvironment

We investigated the effect of erythropoietin (EPO) on differentiation and secretion of bone marrow-derived mesenchymal stem cells in an acute kidney injury microenvironment. Acute kidney injury mouse models were prepared. Both renal cortices were then immediately collected to produce the ischemia/reperfusion kidney homogenate supernatant. The morphological and ultrastructural changes in the cells were observed using an inverted microscope and a transmission electron microscope. Cytokeratin-18 was detected using flow cytometry. Bone morphogenetic protein-7 levels, hepatocyte growth factor, and vascular endothelial growth factor in the culture medium were detected using an enzyme-linked immunosorbent assay. The cells had high CD29 and CD44 expression, as well as low CD34 and CD45 expression. More round and oval cells with cobble-like appearances were observed after EPO treatment. In addition, an increase in the number of rough endoplasmic reticula, lysosomes, and mitochondria was observed in the cytoplasm; the intercellular junction peculiar to epithelial cells was also seen on the cell surface. After treatment with ischemia/reperfusion kidney homogenate supernatant, cytokeratin-18 expression increased significantly and EPO could magnify its expression. Bone morphogenetic protein-7 levels, hepatocyte growth factor, and vascular endothelial growth factor levels after treatment with ischemia/reperfusion kidney homogenate supernatant significantly decreased, whereas EPO increased the cytokine secretion. The acute kidney injury microenvironment can induce the bone marrow-derived mesenchymal stem cells to partially differentiate into renal tubular epithelium-shaped cells, but weaken their secretion function. EPO intervention can boost up their differentiation function and reverse their low secretion effect.

Senescence as A Consequence of Ginsenoside Rg1Response on K562 Human Leukemia Cell Line

Traditional chemotherapy strategies for human leukemia commonly use drugs based on cytotoxicity to eradicate cancer cells. One predicament is that substantial damage to normal tissues is likely to occur in the course of standard treatments. Obviously, it is urgent to explore therapies that can effectively eliminate malignant cells without affecting normal cells. Our previous studies indicated that ginsenoside Rg1 (Rg1), a major active pharmacological ingredient of ginseng, could delay normal hematopoietic stem cell senescence. However, whether Rg1 can induce cancer cell senescence is still unclear. In the current study, human leukemia K562 cells were subjected to Rg1 exposure. The optimal drug concentration and duration with K562 cells was obtained by MTT colorimetric test. Effects of Rg1 on cell cycle were analyzed using flow cytometry and by SA-β-Gal staining. Colony-forming ability was measured by colony-assay. Telomere lengths were assessed by Southern blotting and expression of senescence-associated proteins P21, P16 and RB by Western blotting. Ultrastructural morphology changes were observed by transmission electron microscopy. K562 cells demonstrated a maximum proliferation inhibition rate with an Rg1 concentration of 20 μ molL-1 for 48h, the cells exhibiting dramatic morphological alterations including an enlarged and flat cellular morphology, larger mitochondria and increased number of lysosomes. Senescence associated-β-galactosidase (SA-β-Gal) activity was increased. K562 cells also had decreased ability for colony formation, and shortened telomere length as well as reduction of proliferating potential and arrestin G2/M phase after Rg1 interaction. The senescence associated proteins P21, P16 and RB were significantly up-regulated. Ginsenoside Rg1 can induce a state of senescence in human leukemia K562 cells, which is associated with p21-Rb and p16-Rb pathways.

Autophagy in endothelial progenitor cells is cytoprotective in hypoxic conditions

Endothelial progenitor cells (EPCs) may be incorporated into local vessels to enhance angiogenesis within ischemic tissue. Recently, EPC transplantation has become a potential therapy for improving tissue function in cardiovascular disease. However, the mechanisms of proliferation, differentiation, and survival of EPCs in a hypoxic microenvironment remain unclear. In this study, CD34(+)VEGFR-2(+) EPCs were isolated from mononuclear cells of human umbilical cord blood, and differentiation to endothelial cells was induced with VEGF. When EPC autophagy was inhibited with 3-methyladenine (3-MA) under normoxic conditions, proliferation and viability of the cells were decreased, and the cells failed to differentiate into endothelial cells. Under hypoxic conditions (1% O(2)), Beclin-1 expression of the cells was upregulated and both MDC-labeled and LC3-positive puncta and autophagic ultrastructures in the cells increased significantly. The number of lysosomes also increased in hypoxia-exposed cells. When autophagy was inhibited with 3-MA under hypoxic conditions, the number of apoptotic cells increased, and the number and size of lysosomes decreased. Conversely, apoptosis of the hypoxic EPCs was reduced when autophagy was induced by pretreatment with rapamycin. These results demonstrate that autophagy is involved in proliferation and differentiation of EPCs. Furthermore, hypoxia activates autophagy, promoting EPC survival by inhibiting apoptosis. Enhancing autophagy with hypoxic preconditioning may be beneficial for survival of the transplanted EPCs in a local hypoxic environment.

The HOPS Proteins hVps41 and hVps39 Are Required for Homotypic and Heterotypic Late Endosome Fusion

The homotypic fusion and protein sorting (HOPS) complex is a multisubunit tethering complex that in yeast regulates membrane fusion events with the vacuole, the yeast lysosome. Mammalian homologs of all HOPS components have been found, but little is known about their function. Here, we studied the role of hVps41 and hVps39, two components of the putative human HOPS complex, in the endo-lysosomal pathway of human cells. By expressing hemagglutinin (HA)-tagged constructs, we show by immunoelectron microscopy (immunoEM) that both hVps41 and hVps39 associate with the limiting membrane of late endosomes as well as lysosomes. Small interference RNA (siRNA)-mediated knockdown of hVps41 or hVps39 resulted in an accumulation of late endosomes, a depletion in the number of lysosomes and a block in the degradation of endocytosed cargo. Lysosomal pH and cathepsin B activity remained unaltered in these conditions. By immunoEM we found that hVps41 or hVps39 knockdown impairs homotypic fusion between late endosomes as well as heterotypic fusion between late endosomes and lysosomes. Thus, our data show that both hVps41 and hVps39 are required for late endosomal-lysosomal fusion events and the delivery of endocytic cargo to lysosomes in human cells.

Glycogen Synthase Kinase 3 Inhibition Promotes Lysosomal Biogenesis and Autophagic Degradation of the Amyloid-β Precursor Protein

Alzheimer's disease (AD) has been associated with altered activity of glycogen synthase kinase 3 (GSK3) isozymes, which are proposed to contribute to both neurofibrillary tangles and amyloid plaque formation. However, the molecular basis by which GSK3 affects the formation of Aβ remains unknown. Our aim was to identify the underlying mechanisms of GSK3-dependent effects on the processing of amyloid precursor protein (APP). For this purpose, N2a cells stably expressing APP carrying the Swedish mutation were treated with specific GSK3 inhibitors or transfected with GSK3α/β short interfering RNA. We show that inhibition of GSK3 leads to decreased expression of APP by enhancing its degradation via an increase in the number of lysosomes. This induction of the lysosomal/autophagy pathway was associated with nuclear translocation of transcription factor EB (TFEB), a master regulator of lysosomal biogenesis. Our data indicate that GSK3 inhibition reduces Aβ through an increase of the degradation of APP and its carboxy-terminal fragment (CTF) by activation of the lysosomal/autophagy pathway. These results suggest that an increased propensity toward autophagic/lysosomal alterations in AD patients could have consequences for neuronal function.

Functional Analysis of Lysosomes During Mouse Preimplantation Embryo Development

Lysosomes are acidic and highly dynamic organelles that are essential for macromolecule degradation and many other cellular functions. However, little is known about lysosomal function during early embryogenesis. Here, we found that the number of lysosomes increased after fertilization. Lysosomes were abundant during mouse preimplantation development until the morula stage, but their numbers decreased slightly in blastocysts. Consistently, the protein expression level of mature cathepsins B and D was high from the one-cell to morula stages but low in the blastocyst stage. One-cell embryos injected with siRNAs targeted to both lysosome-associated membrane protein 1 and 2 (LAMP1 and LAMP2) were developmentally arrested at the two-cell stage. Pharmacological inhibition of lysosomes also caused developmental retardation, resulting in accumulation of lipofuscin. Our findings highlight the functional changes in lysosomes in mouse preimplantation embryos.

Inhibition of Glioma Cell Lysosome Exocytosis Inhibits Glioma Invasion

Cancer cells invade by secreting enzymes that degrade the extracellular matrix and these are sequestered in lysosomal vesicles. In this study, the effects of the selective lysosome lysing drug GPN and the lysosome exocytosis inhibitor vacuolin-1 on lysosome exocytosis were studied to determine their effect on glioma cell migration and invasion. Both GPN and vacuolin-1 evidently inhibited migration and invasion in transwell experiments and scratch experiments. There are more lysosomes located on the cell membrane of glioma cells than of astrocytes. GPN decreased the lysosome number on the cell membrane. We found that rab27A was expressed in glioma cells, and colocalized with cathepsin D in lysosome. RNAi-Rab27A inhibited lysosome cathepsin D exocytosis and glioma cell invasion in an in vitro assay. Inhibition of cathepsin D inhibited glioma cell migration. The data suggest that the inhibition of lysosome exocytosis from glioma cells plays an important modulatory role in their migration and invasion.

Protective effect of lycopene on deltamethrin-induced histological and ultrastructural changes in kidney tissue of rats

Deltamethrin is globally used in crop protection and control of malaria and other vector-borne diseases. It has a potent insecticidal activity with an appreciable safety margin. However, a number of studies have demonstrated nephrotoxicity of deltamethrin in mammalian and nonmammalian species. Lycopene, a carotenoid occurring naturally in tomatoes, has attracted considerable attention as an antioxidant. This study was focused on investigating the possible protective effect of coadministration of lycopene on deltamethrin toxicity. In this study, male albino rats were divided into four groups of 10 animals each: group I served as control, which received standard diet; group II received oral administration of deltamethrin (1.28mg/kg per day) for 30days; group III received both deltamethrin and lycopene (1mg/kg per day); group IV received lycopene (1mg/kg per day). After the experiment, the animals were anesthetized and the cytokine, tumor necrosis factor-α (TNF-α), in the serum was measured; the kidney was taken for histological and ultrastructural studies. Deltamethrin significantly increased the TNF-α. The histopathological examination of kidney showed mild necrotic changes. Ultrastructural changes in renal proximal tubules of deltamethrin-treated group included an increased number and irregular shape of mitochondria with sparse fragmented cristae, serious ultrastructural lesions in renal proximal tubular lining cells, vacuolar degeneration in the epithelial cells, increased number of lysosomes and loss of apical microvilli. In addition, focal segmental thickening and the duplication of glomerular basement membrane and podocyte changes were observed. Histopathological and ultrastructural study showed some protective effect of lycopene on kidney tissues.

Aerosol delivery of beclin1 enhanced the anti-tumor effect of radiation in the lungs of K-rasLA1 mice

Radiotherapy alone has several limitations for treating lung cancer. Inhalation, a non-invasive approach for direct delivery of therapeutic agents to the lung, may help to enhance the therapeutic efficacy of radiation. Up-regulating beclin1, known as a tumor suppressor gene that plays a major role in autophagy, may sensitize tumors and lead to tumor regression in lungs of K-rasLA1 lung cancer model mice. To minimize the side-effects of radiotherapy, fractionated exposures (five times, 24-h interval) with low dose (2 Gy) of radiation to the restricted area (thorax, 2 cm) were conducted. After sensitizing the lungs with radiation, beclin1, complexed with a nano-sized biodegradable poly(ester amine), was prepared and delivered into the murine lung via aerosol three times/week for four weeks. In a histopathological analysis, animals treated with beclin1 and radiation showed highly significant tumor regression and low progression to adenocarcinoma. An increase in the number of autophagic vacuoles and secondary lysosomes was detected. Dissociation of beclin1-bcl2 stimulated autophagy activation and showed a synergistic anti-tumor effect by inhibiting the Akt-mTOR pathway, cell proliferation and angiogenesis. The combination of radiation with non-invasive aerosol delivery of beclin1 may provide a prospect for developing novel therapy regimens applicable in clinics.