Effects of bisphosphonates on different zones of the epiphyseal growth plate of rats

Bisphosphonates (BIS) are indicated for several clinical disorders (e.g., osteoporosis). However, BIS has been associated with osteonecrosis and alterations in osteoclastogenesis and skeletal development. This study aimed to evaluate the effects of BIS (zoledronic acid - ZA and alendronate sodium - AS) on zones of the growth plate of rat femur. Animals (Wistar rats, n = 19) were divided into groups: 1) AS Group: animals received alendronate sodium orally (3 mg/kg per day); 2) ZA Group: ZA was administered intraperitoneally (0.2 mg/kg per week); and 3) Control Group (CG): a vehicle was administered. Animals were euthanized 21 days after the treatment, and femurs were collected for histological analysis. The images of all zones (resting, proliferative, hypertrophic, and calcified) were processed by the Qcapture® software providing a 40 and 400-fold increase. ZA decreased epiphyseal growth plate cell zones (ZA Group vs. CG) in most cases. Likewise, AS diminished the proliferative zone (AS Group vs. CG). Furthermore, ZA increased the calcified zone (ZA Group vs. CG). Previous works demonstrated that BIS decrease the epiphyseal disc. This reduction is probably due to the shortening of the cellular zones that undergoes calcification/ossification. The present results suggest that BIS should be carefully indicated because these drugs might accelerate epiphyseal closure.

Application of Shape Context and Fourier Descriptor to Shape Description in Preparation of Nanowood Powder

The nanowood powder made from varying wood species has different properties. Therefore, while preparing nanowood powder, it is critical for us to accurately identify the wood species. By adopting the method of analyzing the wood species from the microstructure of the plate cell, we are able to ensure a high level of accuracy of the recognition. It is one of the commonly used parameters to identify sheet materials for further exploration of the microscopic cell shape. While applying the method of improved Fourier descriptor and the method of shape context, we have carried out the mathematical analysis of common soft wood plank cells in 5 slice images. In addition, we have conducted studies on the single cell graphics and quadrilateral, pentagon, round, oval similarity analysis respectively, and explored the use of benchmark cell model, thus providing statistical support for the subsequent material identification. Experiments have shown that this method is both efficient and robust in identifying sheet materials.

Muscle Progenitors Derived from Extraocular Muscles Express Higher Levels of Neurotrophins and their Receptors than other Cranial and Limb Muscles

Extraocular muscles (EOMs) show resistance to muscle dystrophies and sarcopenia. It has been recently demonstrated that they are endowed with different types of myogenic cells, all of which present an outstanding regenerative potential. Neurotrophins are important modulators of myogenic regeneration and act promoting myoblast proliferation, enhancing myogenic fusion rates and protecting myotubes from inflammatory stimuli. Here, we adapted the pre-plate cell isolation technique to obtain myogenic progenitors from the rat EOMs, and quantified their in vitro expression of neurotrophins and their receptors by RT–qPCR and immunohistochemistry, respectively. The results were compared with the expression on progenitors isolated from buccinator, tongue and limb muscles. Our quantitative analysis of brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF) and neurotrophin-3 (NT-3) transcripts showed, for the first time, that EOMs-derived cells express more of these factors and that they expressed TrkA, but not TrkB and TrkC receptors. On the contrary, the immunofluorescence analysis demonstrated high expression of p75NTR on all myogenic progenitors, with the EOMs-derived cells showing higher expression. Taken together, these results suggest that the intrinsic trophic differences between EOMs-derived myogenic progenitors and their counterparts from other muscles could explain why those cells show higher proliferative and fusion rates, as well as better regenerative properties.

Biodegradation of Organophosphorus Compounds Predicted by Enzymatic Process Using Molecular Modelling and Observed in Soil Samples Through Analytical Techniques and Microbiological Analysis: A Comparison

Organophosphorus compounds (OP) are chemicals widely used as pesticides in different applications such as agriculture and public health (vector control), and some of the highly toxic forms have been used as chemical weapons. After application of OPs in an environment, they persist for a period, suffering a degradation process where the biotic factors are considered the most relevant forms. However, to date, the biodegradation of OP compounds is not well understood. There are a plenty of structure-based biodegradation estimation methods, but none of them consider enzymatic interaction in predicting and better comprehending the differences in the fate of OPs in the environment. It is well known that enzymatic processes are the most relevant processes in biodegradation, and that hydrolysis is the main pathway in the natural elimination of OPs in soil samples. Due to this, we carried out theoretical studies in order to investigate the interactions of these OPs with a chosen enzyme—the phosphotriesterase. This one is characteristic of some soils’ microorganisms, and has been identified as a key player in many biodegradation processes, thanks to its capability for fast hydrolyzing of different OPs. In parallel, we conducted an experiment using native soil in two conditions, sterilized and not sterilized, spiked with specific amounts of two OPs with similar structure—paraoxon-ethyl (PXN) and O-(4-nitrophenyl) O-ethyl methylphosphonate (NEMP). The amount of OP present in the samples and the appearance of characteristic hydrolysis products were periodically monitored for 40 days using analytical techniques. Moreover, the number of microorganisms present was obtained with plate cell count. Our theoretical results were similar to what was achieved in experimental analysis. Parameters calculated by enzymatic hydrolysis were better for PXN than for NEMP. In soil, PXN suffered a faster hydrolysis than NEMP, and the cell count for PXN was higher than for NEMP, highlighting the higher microbiological toxicity of the latter. All these results pointed out that theoretical study can offer a better comprehension of the possible mechanisms involved in real biodegradation processes, showing potential in exploring how biodegradation of OPs relates with enzymatic interactions.

RNF152 Negatively Regulates mTOR Signalling and Blocks Cell Proliferation in the Floor Plate

The neural tube is composed of a number of neural progenitors and postmitotic neurons distributed in a quantitatively and spatially precise manner. The floor plate, located in the ventral-most region of the neural tube, has a lot of unique characteristics, including a low cell proliferation rate. The mechanisms by which this region-specific proliferation rate is regulated remain elusive.Here we show that the activity of the mTOR signalling pathway, which regulates the proliferation of the neural progenitor cells, is significantly lower in the floor plate than in other domains of the embryonic neural tube. We identified the forkhead-type transcription factor FoxA2 as a negative regulator of mTOR signalling in the floor plate. We demonstrate that FoxA2 transcriptionally induces the expression of the E3 ubiquitin ligase RNF152, which together with its substrate RagA, regulates cell proliferation via the mTOR pathway. Silencing of RNF152 led to the aberrant upregulation of the mTOR signal and aberrant cell division in the floor plate. Taken together, the present findings suggest that floor plate cell number is controlled by the negative regulation of mTOR signalling through the activity of FoxA2 and its downstream effector RNF152.

IL-6 As a Potential Cell Released Marker of Prostate Cancer Cell Death

Introduction: Interleukin 6 (IL-6) is proinflammatory cytokine which is produced by cell when Nod-like receptors (NLRs) are activated. Increased production of IL-6 was shown to promote tumor growth and metastasis.Therefore, it could be suggested that activation of NLRs could support malignancy. PC-3, prostate tumor derived cells, was shown to produce IL-6; however, little is known about the role of NLRs in regulation of cytokine secretion. Method: PC-3 cells were seeded in 48 well plate cell culture plates and culturd in presence of VX765, Nigericin or Camptothesin. After 24 hours incubation, cell death was determined using Annexin V test. Additionally, IL-6 level was assessed in culture medium using Bio-Plex Pro™ Human Chemokine Panel (Biorad). Data was analyzed using One Way Anova, Post Hoc Tukey test, SPSS 20. Results: Viability of PC3 cells was reduced when treated with Nigericin (37.74±0.33%) and Champtothesin (10.10±0.23%) as compared to untreated cells (P<0.01), while VX765 did not affect cell viability (4.78±0.28 %; P= 0.645). Nigerecin significatly increased IL-6 production in PC3 cells when compared to untreated cells. Interestingly, IL-6 levels in culture medium of PC3 cells treated with nigerecin was significantly higher than that in cells treated with VX765 and campthothesin (p< 0.001). Conclusion: It appears that IL-6 can be produced by PC3 cells upon stmulation of NLRs. Since NLRs activation was associated with reduced cell vitality, we suggest that increased IL-6 level in culture medium could be the result of the cytokine release from dead cells. This study was supported by RFBR Grant #18-34-01000 and Program of Competitive Growth of KFU. Disclosures No relevant conflicts of interest to declare.