Could reduced bone mineral densities in HIV be caused by nanobacteria?

Tetracycline attenuates calcifying nanoparticles-induced renal epithelial injury through suppression of inflammation, oxidative stress, and apoptosis in rat models

Background

Calcifying nanoparticles (CNPs) has been associated with the occurrence and development of kidney stones, but the exact mechanism is not clear. This study aimed to establish a rat model of CNP-induced renal epithelial injury and assess the efficacy of tetracycline in preventing this injury.

Methods

Kidney stones from patients after percutaneous nephrolithotomy (PCNL) were collected to isolate and culture CNPs. Thirty Sprague-Dawley rats were divided into three groups: the sham group (G1), the CNP group (G2), and the CNP + tetracycline group (G3). Rats in G2 and G3 were given an intravenous injection of CNPs via the tail vein, while rats in G1 were given saline. Meanwhile, rats in G3 were given tetracycline by gavage twice a day at a dose of 25 mg/kg. After 8 weeks, the 24-h urine of all rats was collected, and all rats were sacrificed to obtain blood and kidneys.

Results

The results revealed that in G2, activities of antioxidant enzymes such as superoxide dismutase and catalase were significantly lower than those in G1, while malondialdehyde activity in G2 was significantly higher than that in G1 and both of them were inhibited by tetracycline co-treatment in G3. CNPs significantly increased expression of inflammatory cytokines, including monocyte chemotactic protein 1 and interleukin 6, which were largely alleviated in G3. CNPs significantly increased TUNEL-positive cells and the apoptosis activity of Bcl2-associated X protein but decreased B-cell lymphoma-2 level compared with that in G1, and was limited by tetracycline co-treatment in G3. Furthermore, CNPs led to notable renal tubular epithelial cell damage, hyaline cast formation, desquamation, swelling, vacuolization in histology, all of which were alleviated by tetracycline.

Conclusions

Tetracycline can attenuate CNP-induced renal epithelial injury through suppression of inflammation, oxidative stress, and apoptosis.

Pathological calcification and replicating calcifying-nanoparticles: general approach and correlation

Calcification, a phenomenon often regarded by pathologists little more than evidence of cell death, is becoming recognized to be important in the dynamics of a variety of diseases from which millions of beings suffer in all ages. In calcification, all that is needed for crystal formation to start is nidi (nuclei) and an environment of available dissolved components at or near saturation concentrations, along with the absence of inhibitors for crystal formation. Calcifying nanoparticles (CNP) are the first calcium phosphate mineral containing particles isolated from human blood and were detected in numerous pathologic calcification related diseases. Controversy and critical role of CNP as nidi and triggering factor in human pathologic calcification are discussed.

Antiinfectives and low-level light: a new chapter in photomedicine

OBJECTIVE

The purpose of this study was to identify synergistic effects in the interaction of light with biosystems in the presence of chemical agents. Their systematic analysis promises therapeutic strategies.

BACKGROUND DATA

Light intensities around 1000 Wm(2) potentially induce density variations in nanoscopic water layers adhering to surfaces in air or subaquatically. In permeable nanoscopic compartments in the interior of biosystems, this could result in powerful flow processes and bidirectional flows for repetitive applications of light. Consequently, external stimulation with light will force microorganisms and cells to incorporate a suitable antiinfective. Nanoscale biosystems, which respond to both light stimulation and antibiotics, are nanobacteria. Responses include growth, inhibition, and slime secretion. Slime secretion was provoked in vitro by gentamycin, an agent proposed for in vivo eradication, and blocked by light. Depending on the field of action, co-operative effects between light and an antiinfective can be exploited by considering two properties of the drug: transmission of light and resorption by the tissue. Antiinfectives can be administered in an active form or via drug delivery systems. In the latter case, a double action of the light could be exploited: stimulated release from the carrier and subsequent uptake by the targeted biosystem.

METHODS

The attenuation of laser light (670 nm) by antiinfectives was measured in films of different thickness of a vaginal suppository. The effect of 670-nm laser light - not absorbed by water - on nanoscopic water layers was examined by comparing the evaporation time of irradiated drops of water-based nanosuspensions with non-irradiated controls.

RESULTS

The 6-microm-thick suppository films were virtually transparent to the laser light, and the 1-mm-thick films totally attenuated it. Nanosuspension drops irradiated with 670-nm light needed more time to evaporate than controls.

CONCLUSION

Low-level light (LLL) therapy is compatible with antiinfectives, and even capable of boosting effects of superficially applied and/or absorbed antiinfectives. Temporal coordination between light treatment and drug administration maximizes drug effects and minimizes possible adverse effects. Irradiation should start when the drug concentration has reached its maximum in the desired field of action. Light-induced flow in nanoscale cavities could represent one mechanism of LLL therapy.

Search for microbial signatures within human and microbial calcifications using soft x-ray spectromicroscopy

BACKGROUND

The origin of advanced arterial and renal calcification remains poorly understood. Self-replicating, calcifying entities have been detected and isolated from calcified human tissues, including blood vessels and kidney stones, and are referred to as nanobacteria. However, the microbiologic nature of putative nanobacteria continues to be debated, in part because of the difficulty in discriminating biomineralized microbes from minerals nucleated on anything else (eg, macromolecules, cell membranes). To address this controversy, the use of techniques capable of characterizing the organic and mineral content of these self-replicated structures at the submicrometer scale would be beneficial.

METHODS

Calcifying gram-negative bacteria (Caulobacter crescentus, Ramlibacter tataouinensis) used as references and self-replicating calcified nanoparticles cultured from human samples of calcified aneurysms were examined using a scanning transmission x-ray microscope (STXM) at the Advanced Light Source at Lawrence Berkeley National Laboratory. This microscope uses a monochromated and focused synchrotron x-ray beam (80-2,200 eV) to yield microscopic and spectroscopic information on both organic compounds and minerals at the 25 nm scale.

RESULTS

High-spatial and energy resolution near-edge x-ray absorption fine structure (NEXAFS) spectra indicative of elemental speciation acquired at the C K-edge, N K-edge, and Ca L(2,3)-edge on a single-cell scale from calcified C. crescentus and R. tataouinensis displayed unique spectral signatures different from that of nonbiologic hydroxyapatite (Ca(10)(PO(4))(6)(OH)(2)). Further, preliminary NEXAFS measurements of calcium, carbon, and nitrogen functional groups of cultured calcified nanoparticles from humans revealed evidence of organics, likely peptides or proteins, specifically associated with hydroxyapatite minerals.

CONCLUSION

Using NEXAFS at the 25 nm spatial scale, it is possible to define a biochemical signature for cultured calcified bacteria, including proteins, polysaccharides, nucleic acids, and hydroxyapatite. These preliminary studies suggest that nanoparticles isolated from human samples share spectroscopic characteristics with calcified proteins.

Nanobioaerosols--reconsidering agricultural irrigation in a warming world

Nanobacteria are best described as 60-300 nm nanovesicles. In the body they collect calcium and phosphate to form apatite, adhere to cells, or invade them--processes regulated by a slime based on proteins (primordial proteins). A versatile functionality realized with a minimum of properties equips nanobacteria with a unique survival potential. They were identified in humans, animals, wastewater and the stratosphere. In South Africa they were detected in people infected with HIV. Models indicate that they boost the genetic diversity of the HIV-1 virus. Experiments showed that they are excreted via urine, explaining their presence in the environment. Eradication would be virtually impossible if they had an extraterrestrial origin, implying a permanent bombardment from space. Whereas the biological status of nanobacteria is still not clarified, we postulate here that the native habitat of nanobacteria are mammals, suggesting that at least modern species have their origin on Earth. The thesis results from mapping functions and properties of the slime, and could facilitate the localisation of nanobacterial reservoirs, identification of local distribution routes and tracking of global transport cycles. Agricultural irrigation with water containing excreta from humans infected with nanobacteria could be a central disseminator of the nanobioaerosols.

Primordial proteins and HIV-Part II

Nanobacteria are suspected to be responsible for a number of diseases, i.e., kidney stones, heart disease, ovarian cancer, peripheral neuropathy, and reduced bone mineral density. Being protected by a mineral shell consisting of apatite, the nanovesicles can enter eukaryotic cells. Depending on the host's stress level, nanobacteria may carry a substantial layer of a protein based slime, instrumental in collecting calcium phosphate from the environment. Calcium phosphate is known to mediate the uptake of nucleic acids by eukaryotic cells. Surprisingly, a pathogenic effect of nanobacteria in HIV can be derived primarily from the trafficking of calcium phosphate in HIV infected cells, performed by primordial proteins. The inescapable conclusion is that nanobacteria could promote genetic diversity in HIV.

Primordial proteins and HIV

Primordial proteins regulate the response of nanobacteria to variations in their environment and reinforce existing pathogenic potentials. By analyzing specific response patterns, we predicted the prevalence of nanobacteria in HIV--and in the atmosphere. A current clinical study indicates the identification of a possibly giant nanobacterial reservoir in Africa: a significant fraction of a test group (40 HIV-infected mothers and 13 babies) was infected with nanobacteria. Concurrently, a multitude of 80-300 nm nanovesicles, apparently nanobacteria, were detected in the atmosphere of the Earth. Nanobacterial infections in HIV are possibly comparable to the twin epidemics HIV and tuberculosis. Models inspired by proteomics recommend methods to inactivate nanobacteria (and other slime-producing bacteria) in the body.

Keeping nanobacterial infections at bay during space travel

In January 2004, President George W. Bush unveiled plans to send astronauts to the Moon in 2015 and shortly thereafter to Mars. With the prospect of manned exploration of the planets drawing ever closer, the new discipline of Space Medicine is destined to come to the fore. Moreover, investigations of how human beings function under space conditions could provide important new insights into fundamental questions of human physiology and disease. We draw attention here to one such instance of a disease process that can be provoked by extended periods of exposure to low gravity.

Functions and Possible Provenance of Primordial Proteins

Nanobacteria or living nanovesicles are of great interest to the scientific community because of their dual nature: on the one hand, they appear as primal biosystems originating life; on the other hand, they can cause severe diseases. Their survival as well as their pathogenic potential is apparently linked to a self-synthesized protein-based slime, rich in calcium and phosphate (when available). Here, we provide challenging evidence for the occurrence of nanobacteria in the stratosphere, reflecting a possibly primordial provenance of the slime. An analysis of the slime's biological functions may lead to novel strategies suitable to block adhesion modalities in modern bacterial populations.