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1.
J Acupunct Meridian Stud ; 15(1): 12-24, 2022 Feb 28.
Article in English | MEDLINE | ID: mdl-35770570

ABSTRACT

Background: Intra-organic bone marrow node is predicted to be a part of the primo vascular system that plays a critical role in hematopoiesis and generation and regeneration of other cells. Two models of cell regeneration were suggested, one involving DNA synthesis and the other pertaining to DNA recycling. Objectives: The aim of this work is to extract a primo node from bone marrow, characterize its structure, understand its biochemistry and cell composition, and suggest a cell regeneration mechanism. Methods: Primo nodes were sampled from segmented halves of the rat femur. We used immunohistochemistry and high-resolution fluorescent microscopy to analyze 1200 samples obtained from 42 rats and 190 primo nodes. Results: Primo nodes in the bone marrow have an oval or round structure of about one millimeter in diameter, which is encompassed by a fine capsule, having incoming and outgoing vessels filled with the extracellular matrix and hematopoietic, mesenchymal, endothelial stem cells, as well as cells of the megakaryocyte family found in other primo nodes. Conclusion: Our findings imply that bone marrow nodes are intra-organic primo vascular nodes, and they provide ways and approaches for further investigation. Bone marrow nodes are simple to examine ex vivo in a variety of environments to assess cell regeneration mechanisms, wound healing, and organism rejuvenation and lifespan. Further research into these and other intra-organic nodes in animals and humans could lead to new regenerative medicine and longevity strategies that have yet to be discovered.


Subject(s)
Bone Marrow , Longevity , Animals , Rats , Rats, Sprague-Dawley
2.
Sci Rep ; 10(1): 18435, 2020 10 28.
Article in English | MEDLINE | ID: mdl-33116197

ABSTRACT

The role of zinc in neurobiology is rapidly expanding. Zinc is especially essential in olfactory neurobiology. Naturally occurring zinc nanoparticles were detected in olfactory and nasal respiratory epithelia and cilia in animals. The addition of these nanoparticles to a mixture of odorants, including ethyl butyrate, eugenol, and carvone, considerably increased the electrical responses of the olfactory sensory receptors. Studies of these nanoparticles by ransmission electron microscopy (TEM) and selected area electron diffraction revealed metal elemental crystalline zinc nanoparticles 2-4 nm in diameter. These particles did not contain oxidized zinc. The enhancement of the odorant responses induced by the endogenous zinc nanoparticles appears to be similar to the amplification produced by engineered zinc nanoparticles. Zinc nanoparticles produce no odor response but increase odor response if mixed with an odorant. These effects are dose-dependent and reversible. Some other metal nanoparticles, such as copper, silver, gold, and platinum, do not have the effects observed in the case of zinc nanoparticles. The olfactory enhancement was observed in young and mature mouse olfactory epithelium cultures, in the dissected olfactory epithelium of rodents, and in live conscious dogs. The physiological significance of the detected endogenous metal nanoparticles in an animal tissue has been demonstrated for the first time. Overall, our results may advance the understanding of the initial events in olfaction.


Subject(s)
Cilia/chemistry , Olfactory Mucosa/chemistry , Smell/physiology , Zinc/physiology , Animals , Male , Nanoparticles/analysis , Rats, Sprague-Dawley , Zinc/analysis
3.
Int J Mol Sci ; 21(2)2020 Jan 14.
Article in English | MEDLINE | ID: mdl-31947705

ABSTRACT

Stem cells are nurtured and regulated by a specialized microenvironment known as stem cell niche. While the functions of the niches are well defined, their structure and location remain unclear. We have identified, in rat bone marrow, the seat of hematopoietic stem cells-extensively vascularized node-like compartments that fit the requirements for stem cell niche and that we called hemmules. Hemmules are round or oval structures of about one millimeter in diameter that are surrounded by a fine capsule, have afferent and efferent vessels, are filled with the extracellular matrix and mesenchymal, hematopoietic, endothelial stem cells, and contain cells of the megakaryocyte family, which are known for homeostatic quiescence and contribution to the bone marrow environment. We propose that hemmules are the long sought hematopoietic stem cell niches and that they are prototypical of stem cell niches in other organs.


Subject(s)
Stem Cell Niche , Stem Cells/cytology , Stem Cells/metabolism , Animals , Blood Vessels , Bone Marrow/blood supply , Bone Marrow/metabolism , Bone Marrow Cells , Cell Differentiation , Cell Proliferation , Humans , Lymphatic Vessels , Lymphoid Tissue/blood supply , Lymphoid Tissue/cytology , Lymphoid Tissue/metabolism , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/metabolism
4.
Adv Exp Med Biol ; 1072: 413-418, 2018.
Article in English | MEDLINE | ID: mdl-30178380

ABSTRACT

The Primo Vascular System (PVS) is new to most scientists despite that it was discovered in the 1960s by Bonghan Kim. Out of the many physiological functions reported, one of the most important PVS functions appears to be its role in the regeneration via a small (~1 µm) subcellular body called 'sanal.' According to Kim, a cell generates multiple sanals and the sanals arriving at the primo nodes (PNs) via primo vessels (PV) eventually produce new cells, by way of the 'Sanal-Cell Cycle.' Sanals express stem cell biomarkers. Appropriately differentiated sanals have been shown to perform non-marrow hematopoiesis and repair damaged tissues. However, many questions on sanals still remain: e.g., how sanals reside in the PN; whether sanals are a new type of stem cells; and how exactly sanals produce cells and/or tissue. Our preliminary studies show that sanals reside inside the sinus formed by sub-PVs in the PNs; and in the PNs, there are more than one form of sanal-originated bodies of various sizes.


Subject(s)
Blood Vessels/cytology , Cardiovascular System/cytology , Stem Cells/cytology , Animals , Rats , Rats, Sprague-Dawley
5.
PLoS One ; 12(12): e0189273, 2017.
Article in English | MEDLINE | ID: mdl-29261701

ABSTRACT

Olfactory responses are intensely enhanced with the addition of endogenous and engineered primarily-elemental small zinc nanoparticles (NPs). With aging, oxidation of these Zn nanoparticles eliminated the observed enhancement. The design of a polyethylene glycol coating to meet storage requirements of engineered zinc nanoparticles is evaluated to achieve maximal olfactory benefit. The zinc nanoparticles were covered with 1000 g/mol or 400 g/mol molecular weight polyethylene glycol (PEG). Non-PEGylated and PEGylated zinc nanoparticles were tested by electroolfactogram with isolated rat olfactory epithelium and odorant responses evoked by the mixture of eugenol, ethyl butyrate and (±) carvone after storage at 278 K (5 oC), 303 K (30 oC) and 323 K (50 oC). The particles were analyzed by atomic force microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and laser Doppler velocimetry. Our data indicate that stored ZnPEG400 nanoparticles maintain physiologically-consistent olfactory enhancement for over 300 days. These engineered Nanoparticles support future applications in olfactory research, sensitive detection, and medicine.


Subject(s)
Metal Nanoparticles/chemistry , Odorants , Olfactory Mucosa/drug effects , Polyethylene Glycols/chemistry , Zinc/chemistry , Microscopy, Atomic Force , Microscopy, Electron, Transmission , Photoelectron Spectroscopy
6.
Biometals ; 29(6): 1005-1018, 2016 12.
Article in English | MEDLINE | ID: mdl-27649965

ABSTRACT

Electrical responses of olfactory sensory neurons to odorants were examined in the presence of zinc nanoparticles of various sizes and degrees of oxidation. The zinc nanoparticles were prepared by the underwater electrical discharge method and analyzed by atomic force microscopy and X-ray photoelectron spectroscopy. Small (1.2 ± 0.3 nm) zinc nanoparticles significantly enhanced electrical responses of olfactory neurons to odorants. After oxidation, however, these small zinc nanoparticles were no longer capable of enhancing olfactory responses. Larger zinc oxide nanoparticles (15 nm and 70 nm) also did not modulate responses to odorants. Neither zinc nor zinc oxide nanoparticles produced olfactory responses when added without odorants. The enhancement of odorant responses by small zinc nanoparticles was explained by the creation of olfactory receptor dimers initiated by small zinc nanoparticles. The results of this work will clarify the mechanisms for the initial events in olfaction, as well as to provide new ways to alleviate anosmia related to the loss of olfactory receptors.


Subject(s)
Metal Nanoparticles/chemistry , Odorants , Olfactory Receptor Neurons/drug effects , Zinc/chemistry , Zinc/pharmacology , Animals , Electrophysiology/methods , Male , Microscopy, Atomic Force , Microscopy, Electron, Transmission , Olfactory Receptor Neurons/physiology , Photoelectron Spectroscopy , Rats, Sprague-Dawley , Receptors, Odorant/chemistry , Zinc Oxide/chemistry , Zinc Oxide/pharmacology
7.
J Vis Exp ; (113)2016 07 11.
Article in English | MEDLINE | ID: mdl-27500362

ABSTRACT

This study was designed to evaluate the protective effect of the Bacillus subtilis strain against complications related to heat stress. Thirty-two Sprague-Dawley rats were used in this study. Animals were orally treated twice a day for two days with B. subtilis BSB3 strain or PBS. The next day after the last treatment, each group was divided and two experimental groups (one treated with PBS and one treated with B. subtilis) were placed at 45 (o)C for 25 min. Two control groups stayed for 25 min at room temperature. All rats were euthanized and different parameters were analyzed in all groups. Adverse effects of heat stress are registered by the decrease of villi height and total mucosal thickness in the intestinal epithelium; translocation of bacteria from the lumen; increased vesiculation of erythrocytes and elevation of the lipopolysaccharides (LPS) level in the blood. The protective efficacy of treatment is evaluated by prevention of these side effects. The protocol was set up for the oral treatment of rats with bacteria for prevention of heat stress complications, but this protocol can be modified and used for other routes of administration and for analysis of different compounds.


Subject(s)
Bacillus subtilis , Heat-Shock Response , Intestinal Mucosa/pathology , Intestine, Small/pathology , Animals , Bacterial Translocation , Hot Temperature , Rats , Rats, Sprague-Dawley
8.
J Therm Biol ; 60: 26-32, 2016 Aug.
Article in English | MEDLINE | ID: mdl-27503713

ABSTRACT

Heat stress results in a multitude of biological and physiological responses which can become lethal if not properly managed. It has been shown that heat stress causes significant adverse effects in both human and animals. Different approaches have been proposed to mitigate the adverse effects caused by heat stress, among which are special diet and probiotics. We characterized the effect of the yeast fermentate EpiCor (EH) on the prevention of heat stress-related complications in rats. We found that increasing the body temperature of animals from 37.1±0.2 to 40.6±0.2°C by exposure to heat (45°C for 25min) resulted in significant morphological changes in the intestine. Villi height and total mucosal thickness decreased in heat-stressed rats pre-treated with PBS in comparison with control animals not exposed to the heat. Oral treatment of rats with EH before heat stress prevented the traumatic effects of heat on the intestine. Changes in intestinal morphology of heat-stressed rats, pre-treated with PBS resulted in significant elevation of lipopolysaccharides (LPS) level in the serum of these animals. Pre-treatment with EH was effective in the prevention of LPS release into the bloodstream of heat-stressed rats. Our study revealed that elevation of body temperature also resulted in a significant increase of the concentration of vesicles released by erythrocytes in rats, pre-treated with PBS. This is an indication of a pathological impact of heat on the erythrocyte structure. Treatment of rats with EH completely protected their erythrocytes from this heat-induced pathology. Finally, exposure to heat stress conditions resulted in a significant increase of white blood cells in rats. In the group of animals pre-treated with EH before heat stress, the white blood cell count remained the same as in non-heated controls. These results showed the protective effect of the EH product in the prevention of complications, caused by heat stress.


Subject(s)
Dietary Supplements , Heat Stress Disorders/prevention & control , Probiotics , Saccharomyces cerevisiae , Animals , Body Temperature , Dietary Supplements/analysis , Erythrocytes/pathology , Fermentation , Heat Stress Disorders/blood , Heat Stress Disorders/pathology , Heat-Shock Response , Humans , Intestines/pathology , Lipopolysaccharides/blood , Male , Probiotics/analysis , Rats , Rats, Sprague-Dawley , Saccharomyces cerevisiae/chemistry , Saccharomyces cerevisiae/metabolism
9.
Article in English | MEDLINE | ID: mdl-26379743

ABSTRACT

In the 1960s Bong Han Kim discovered and characterized a new vascular system. He was able to differentiate it clearly from vascular blood and lymph systems by the use of a variety of methods, which were available to him in the mid-20th century. He gave detailed characterization of the system and created comprehensive diagrams and photographs in his publications. He demonstrated that this system is composed of nodes and vessels, and it was responsible for tissue regeneration. However, he did not disclose in detail his methods. Consequently, his results are relatively obscure from the vantage point of contemporary scientists. The stains that Kim used had been perfected and had been in use for more than 100 years. Therefore, the names of the stains were directed to the explicit protocols for the usage with the particular cells or molecules. Traditionally, it was not normally necessary to describe the method used unless it is significantly deviated from the original method. In this present work, we have been able to disclose staining methods used by Kim.

10.
Microsc Res Tech ; 76(11): 1163-70, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23964014

ABSTRACT

The images of human erythrocytes and vesicles were analyzed by a light microscopy system with spatial resolution of better than 90 nm. The samples were observed in an aqueous environment and required no freezing, dehydration, staining, shadowing, marking, or any other manipulation. Temperature elevation resulted in significant concentration increase of structurally transformed erythrocytes (echinocytes) and vesicles in the blood. The process of vesicle separation from spiculated erythrocytes was video recorded in real time. At a temperature of 37°C, mean vesicle concentrations and diameters were found to be 1.50 ± 0.35 × 10(6) vesicles per microliter and 0.365 ± 0.065 µm, respectively. The vesicle concentration increased approximately threefold as the temperature increased from 37 to 40°C. It was estimated that 80% of all vesicles found in the blood are smaller than 0.4 µm. Accurate account of vesicle numbers and dimensions suggest that 86% of the lost erythrocyte material is lost not by vesiculation but by another, as yet, unknown mechanism.


Subject(s)
Erythrocytes/radiation effects , Exosomes/radiation effects , Healthy Volunteers , Humans , Microscopy, Video/methods , Temperature
11.
J Vis Exp ; (75): e50474, 2013 May 08.
Article in English | MEDLINE | ID: mdl-23685833

ABSTRACT

A structurally transformed lytic bacteriophage having a broad host range of Staphylococcus aureus strains and a penicillin-binding protein (PBP 2a) antibody conjugated latex beads have been utilized to create a biosensor designed for discrimination of methicillin resistant (MRSA) and sensitive (MSSA) S. aureus species (1,2). The lytic phages have been converted into phage spheroids by contact with water-chloroform interface. Phage spheroid monolayers have been moved onto a biosensor surface by Langmuir-Blodgett (LB) technique (3). The created biosensors have been examined by a quartz crystal microbalance with dissipation tracking (QCM-D) to evaluate bacteria-phage interactions. Bacteria-spheroid interactions led to reduced resonance frequency and a rise in dissipation energy for both MRSA and MSSA strains. After the bacterial binding, these sensors have been further exposed to the penicillin-binding protein antibody latex beads. Sensors analyzed with MRSA responded to PBP 2a antibody beads; although sensors inspected with MSSA gave no response. This experimental distinction determines an unambiguous discrimination between methicillin resistant and sensitive S. aureus strains. Equally bound and unbound bacteriophages suppress bacterial growth on surfaces and in water suspensions. Once lytic phages are changed into spheroids, they retain their strong lytic activity and show high bacterial capture capability. The phage and phage spheroids can be utilized for testing and sterilization of antibiotic resistant microorganisms. Other applications may include use in bacteriophage therapy and antimicrobial surfaces.


Subject(s)
Bacteriophages/physiology , Biosensing Techniques/methods , Methicillin-Resistant Staphylococcus aureus/classification , Staphylococcus aureus/classification , Immunoconjugates/chemistry , Methicillin-Resistant Staphylococcus aureus/virology , Microspheres , Penicillin-Binding Proteins/chemistry , Peptide Synthases/chemistry , Quartz Crystal Microbalance Techniques/instrumentation , Quartz Crystal Microbalance Techniques/methods , Staphylococcus aureus/virology
12.
J Microbiol Methods ; 90(3): 182-91, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22587932

ABSTRACT

Discrimination of methicillin resistant (MRSA) and sensitive (MSSA) strains of Staphylococcus aureus, was achieved by the specially selected lytic bacteriophage with a wide host range of S. aureus strains and a penicillin-binding protein (PBP 2a) specific antibody. A quartz crystal microbalance with dissipation monitoring (QCM-D) was employed to analyze bacteria-phage interactions. The lytic phages were transformed into phage spheroids by exposure to water-chloroform interface. Phage spheroid monolayers were transferred onto QCM-D sensors by Langmuir-Blodgett (LB) technique. Biosensors were tested in the flow mode with bacterial water suspensions, while collecting frequency and energy dissipation changes. Bacteria-spheroid interactions resulted in decreased resonance frequency and an increase in dissipation energy for both MRSA and MSSA strains. Following the bacterial binding, these sensors were further exposed to a flow of the penicillin-binding protein (PBP 2a) specific antibody conjugated latex beads. Sensors tested with MRSA responded to PBP 2a antibody beads; while sensors examined with MSSA gave no response. This experimental difference establishes an unambiguous discrimination between methicillin resistant and sensitive S. aureus strains. Both free and immobilized bacteriophages strongly inhibit bacterial growth on solid/air interfaces and in water suspensions. After lytic phages are transformed into spheroids, they retain their strong lytic activity and demonstrate high bacterial capture efficiency. The phage and phage spheroids can be used for screening and disinfection of antibiotic resistant bacteria. Other applications may include use on biosensors, bacteriophage therapy, and antimicrobial surfaces.


Subject(s)
Methicillin-Resistant Staphylococcus aureus/drug effects , Methicillin-Resistant Staphylococcus aureus/virology , Antibodies, Bacterial/chemistry , Bacterial Typing Techniques , Bacteriolysis , Bacteriophages/physiology , Bacteriophages/ultrastructure , Host Specificity , Methicillin-Resistant Staphylococcus aureus/classification , Methicillin-Resistant Staphylococcus aureus/enzymology , Penicillin-Binding Proteins/immunology , Quartz Crystal Microbalance Techniques
13.
J Microbiol Methods ; 88(1): 140-6, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22093998

ABSTRACT

Stability of microbial cultures during sampling and storage is a vital issue in various fields of medicine, biotechnology, food science, and forensics. We have developed a unique bacterial preservation process involving a non-toxic, water-soluble acacia gum polymer that eliminates the need for refrigerated storage of samples. The main goal of this study is to characterize the efficacy of acacia gum polymer for preservation of pathogenic bacteria (Bacillus anthracis and methicillin-resistant Staphylococcus aureus-MRSA) on different materials, used for swabbing and filtration: cotton, wool, polyester, rayon, charcoal cloth, and Whatman paper. Acacia gum polymer used for preservation of two pathogens has been shown to significantly protect bacteria during dehydration and storage in all tested samples at the range of temperatures (5-45°C for MRSA and 40-90°C for B. anthracis). Our results showed higher recovery as well as higher viability during the storage of both bacteria in all materials with acacia gum. Addition of acacia gum polymer to swabbing materials or filters will increase efficacy of sample collection and identification of pathogenic bacteria from locations such as hospitals or the environment. Proposed approach can also be used for long-term storage of culture collections, since acacia gum contributes to viability and stability of bacterial cultures.


Subject(s)
Bacillus anthracis/chemistry , Biopolymers/chemistry , Gum Arabic/chemistry , Methicillin-Resistant Staphylococcus aureus/chemistry , Preservation, Biological/methods , Bacillus anthracis/growth & development , Methicillin-Resistant Staphylococcus aureus/growth & development , Preservation, Biological/instrumentation , Specimen Handling , Temperature
14.
J Microbiol Methods ; 78(2): 189-94, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19490929

ABSTRACT

A new inexpensive and simple method for preserving microorganisms has been developed. Natural polymers of acacia gum and pullulan were used to preserve model bacteria Escherichia coli and Bacillus subtilis via immobilization and storage under various conditions. Formulation of E. coli and B. subtilis in acacia gum significantly increased the viability of both cultures during desiccation at 40 degrees C as well as during the storage at various temperatures and relative humidity. In the ranges of temperatures and humidity used in experiments, the high humidity affected the viability of E. coli more than high temperature. Thermodynamic parameters for E. coli thermal degradation were used for quantification of results and characterization of the preservation process. Viability of B. subtilis in acacia gum polymer was not significantly changed during the storage in the temperature and humidity experiments. The number of viable B. subtilis recovered after storage in pullulan, and in PBS under various humidity conditions was 1-2 logs less in comparison with the number of cells before storage. It was found that acacia gum provides better protection than pullulan for both bacteria during the preservation process.


Subject(s)
Bacillus subtilis/physiology , Escherichia coli/physiology , Glucans , Gum Arabic , Microbial Viability , Polymers , Preservation, Biological/methods , Desiccation , Humidity , Temperature , Time Factors
15.
Chem Senses ; 34(7): 547-57, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19525316

ABSTRACT

Zinc metal nanoparticles in picomolar concentrations strongly enhance odorant responses of olfactory sensory neurons. One- to 2-nm metallic particles contain 40-300 zinc metal atoms, which are not in an ionic state. We exposed rat olfactory epithelium to metal nanoparticles and measured odorant responses by electroolfactogram and whole-cell patch clamp. A small amount of zinc nanoparticles added to an odorant or an extracellular/intracellular particle perfusion strongly increases the odorant response in a dose-dependent manner. Zinc nanoparticles alone produce no odor effects. Copper, gold, or silver nanoparticles do not produce effects similar to those of zinc. If zinc nanoparticles are replaced by Zn(+2) ions in the same concentration range, we observed a reduction of the olfactory receptor neuron odorant response. Based on these observations, we hypothesize that zinc nanoparticles are closely located to the interface between the guanine nucleotide-binding protein and the receptor proteins and are involved in transferring signals in the initial events of olfaction. Our results suggest that zinc metal nanoparticles can be used to enhance and sustain the initial olfactory events.


Subject(s)
Nanoparticles , Odorants , Olfactory Mucosa/metabolism , Olfactory Receptor Neurons/metabolism , Zinc/metabolism , Animals , Olfactory Mucosa/cytology , Rats
16.
J Ind Microbiol Biotechnol ; 36(8): 1123-6, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19471983

ABSTRACT

Two bacterial cultures were isolated and tested for degradation of shrimp shell waste. According to morphological examination, physiological tests, and applied molecular techniques, isolates were identified as Bacillus cereus and Exiguobacterium acetylicum. Both strains were cultivated separately in flasks with 100 mL of shrimp shell waste broth (3% of washed, dried and ground shrimp shell waste in tap water, pH 7.0) at 37 degrees C. At determined periods of time, deproteinization and demineralization of residuals were measured. Fermentation of 3% shell waste with B. cereus indicated 97.1% deproteinization and 95% demineralization. For E. acetylicum, the level of deproteinization and demineralization was 92.8 and 92%, respectively. Protein content was reduced from 18.7 to 5.3% with B. cereus and to 7.3% with E. acetylicum. No additional supplements were used during the fermentation of shell waste. B. cereus strain showed higher efficacy in decomposition of shell waste and was used for large-scale fermentation in 12 L of 10% shrimp shell waste broth. Incubation of bacteria with shell waste during 14 days at 37 degrees C resulted in 78.6% deproteinization and 73% demineralization. High activity of isolated cultures in decomposition of shrimp shell waste suggests broad potential for application of these bacteria in environmentally friendly approaches to chitin extraction from chitin-rich wastes.


Subject(s)
Food-Processing Industry/methods , Gram-Positive Bacteria/metabolism , Industrial Microbiology/methods , Industrial Waste , Penaeidae , Animals , Bacillus cereus/metabolism , Minerals/metabolism , Proteins/metabolism , Temperature , Time Factors
17.
Cells Tissues Organs ; 179(3): 115-24, 2005.
Article in English | MEDLINE | ID: mdl-15947462

ABSTRACT

Unfolding and subsequent aggregation of proteins is a common phenomenon that is linked to many human disorders. Misfolded hemoglobin is generally manifested in various autoimmune, infectious and inherited diseases. We isolated micrometer and submicrometer particles, termed proteons, from human and animal blood. Proteons lack nucleic acids but contain two major polypeptide populations with homology to the hemoglobin alpha-chain. Proteons form by reversible seeded aggregation of proteins around proteon nucleating centers (PNCs). PNCs are comprised of 1- to 2-nm metallic nanoclusters containing 40-300 atoms. Each milliliter of human blood contained approximately 7 x 10(13) PNCs and approximately 3 x 10(8) proteons. Exposure of isolated blood plasma to elevated temperatures increased the number of proteons. When an aliquot of this heated plasma was introduced into untreated plasma that was subsequently heated, the number of proteons further increased, reaching a maximum after a total of three such iterations. Small concentrations of PNCs were lethal to cultured cancer cells, whereas noncancerous cells were much less affected.


Subject(s)
Cell Death/physiology , Cell Proliferation , Metals/blood , Neoplasms/metabolism , Neoplasms/pathology , Animals , Cell Death/drug effects , Cell Line, Tumor , Dogs , Glioma/chemistry , Glioma/metabolism , Glioma/pathology , Glioma/ultrastructure , Hemoglobins/metabolism , Humans , Male , Metals/isolation & purification , Microscopy, Electron, Scanning , Nanostructures , Neoplasms/chemistry , Neoplasms/ultrastructure , Rabbits , Rats
18.
Biotechniques ; 37(2): 254-60, 2004 Aug.
Article in English | MEDLINE | ID: mdl-15335217

ABSTRACT

Cell-binding ligands for RG2 rat glioma were identified in our recent study from a library of peptides that are displayed as fusion molecules on phage particles. Here, one of the phage clones was used to affinity purify those cell membrane components to which the displayed peptides bind. This phage clone, displaying the ELRGDSLP peptide, was shown to recognize glioma cells specifically in comparison to control phage-expressing peptides of either similar or irrelevant sequences. Blocking experiments with synthetic RGDS peptide demonstrated that the phage-glioma cell recognition occurs via the RGD motif known to be present in many integrin-binding proteins. To form an affinity matrix that would bind to glioma cell membrane molecules, ELRGDSLP phage particles were cross-linked using dextran polymer. Whole cell lysate from RG2 rat glioma cells was passed through the matrix, resulting in the isolation of cell membrane components having strong affinity to the peptides on phage and molecules associated with those components. One of the isolated proteins was found to be CD44s, a cell surface adhesion molecule involved in glioma cell invasion and migration, which likely formed a complex with an RGD-binding integrin. Cell membrane proteins isolated with this innovative approach could be used for the design of cell-specific anticancer treatments.


Subject(s)
Chromatography, Affinity/methods , Glioma/metabolism , Membrane Proteins/isolation & purification , Neoplasm Proteins/isolation & purification , Peptide Library , Animals , Cell Line, Tumor , Feasibility Studies , Oligopeptides , Rats
19.
Mol Cancer Ther ; 2(11): 1129-37, 2003 Nov.
Article in English | MEDLINE | ID: mdl-14617786

ABSTRACT

Early diagnosis and effective treatment of malignant gliomas, which are heterogeneous brain tumors with variable expression of cell surface markers, are inhibited by the lack of means to characterize and target tumor-selective molecules. To create molecular profiles for RG2 rat glioma cells, we used phage display technology, an approach capable of producing valuable ligands to unknown cell surface targets. The ligands were selected from libraries of peptides displayed as fusion molecules on phage particles. Modifications of the selection conditions resulted in identification of three distinctive families of peptide ligands for malignant glioma cells. The first family with V (D)/(G) L P (E)/(T) H(3) binding motif appeared to target a marker that is common for glioma cells, normal brain cells, and cells of non-brain origin. The second group of peptide-presented phage displayed D (T)/S/(L) T K consensus sequence and contained peptides with pronounced glioma-selective properties. Phage clones expressing peptides with E (L)/V/(S) R G D S motif were found in cell lysates and represented the third family of glioma-specific ligands. All peptides within this family contain the RGD amino acid sequence, which is known to bind to a number of integrins. Phage clones that belong to this family were internalized by RG2 glioma cells about 63-fold more efficiently than by astrocytes. The approach described could be applicable for accurate detection of glioma expression patterns in individual tumors. Such patterns could be beneficial in the design of effective combinations of drugs for anti-glioma treatments.


Subject(s)
Bacteriophages/genetics , Glioma/diagnosis , Neuroglia/pathology , Peptide Library , Amino Acid Motifs , Amino Acid Sequence , Animals , Cell Line, Tumor , Gene Expression Profiling , Gene Expression Regulation, Neoplastic , Glioma/genetics , Glioma/pathology , Ligands , Neuroglia/metabolism , Rats
20.
J Mol Recognit ; 15(4): 197-203, 2002.
Article in English | MEDLINE | ID: mdl-12382237

ABSTRACT

Biosensors based on phage display-derived peptides as biorecognition molecules were used for the detection of cell surface cross-species markers in tissue homogenates. The peptide selected for murine myofibers was immobilized onto the surface of an acoustic wave sensor by biotin-streptavidin coupling. To detect peptide-receptor interaction, the sensors were exposed to muscle and control (kidney, liver, brain) tissue homogenates. The sensor showed a strong response to murine muscle. The amplitudes of the responses to the feline muscle homogenates were lower compared to those of the murine muscle, while the same K(d) indicated that the peptide has cross-species affinity. In contrast, murine kidney, liver and brain homogenates produced insignificant responses. Specificity of the sensor was shown in a blocking experiment, as reduced signal was detected when muscle preparations were preincubated with free peptide. Additionally, when muscle-specific peptide was replaced with two different random control peptides, the sensors produced no response to murine muscle. Suitability of peptide ligands for a variety of species can be evaluated using this technology.


Subject(s)
Muscle, Skeletal/metabolism , Acoustics/instrumentation , Animals , Binding Sites , Biosensing Techniques , Brain/metabolism , Calibration , Cats , Combinatorial Chemistry Techniques , In Vitro Techniques , Kidney/metabolism , Liver/metabolism , Mice , Peptide Library , Peptides/analysis , Peptides/genetics , Peptides/metabolism , Stearic Acids/metabolism
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