Stimulation of TRPV1 by green laser light

Low-level laser irradiation of visible light had been introduced as a medical treatment already more than 40 years ago, but its medical application still remains controversial. Laser stimulation of acupuncture points has also been introduced, and mast-cells degranulation has been suggested. Activation of TRPV ion channels may be involved in the degranulation. Here, we investigated whether TRPV1 could serve as candidate for laser-induced mast cell activation. Activation of TRPV1 by capsaicin resulted in degranulation. To investigate the effect of laser irradiation on TRPV1, we used the Xenopus oocyte as expression and model system. We show that TRPV1 can functionally be expressed in the oocyte by (a) activation by capsaicin (K 1/2 = 1.1 μM), (b) activation by temperatures exceeding 42°C, (c) activation by reduced pH (from 7.4 to 6.2), and (d) inhibition by ruthenium red. Red (637 nm) as well as blue (406 nm) light neither affected membrane currents in oocytes nor did it modulate capsaicin-induced current. In contrast, green laser light (532 nm) produced power-dependent activation of TRPV1. In conclusion, we could show that green light is effective at the cellular level to activate TRPV1. To which extend green light is of medical relevance needs further investigation

Viral-bacterial interactions in the pathogenesis of human endodontic disease

In this study, we hypothesized that herpes viruses, EBV and/or HCMV contribute to endodontic disease via herpes virus-bacterium-host response interactions. In our in vitro study, we investigated potential pathogenic interactions between Epstein-Barr virus (EBV) and the Gram-positive bacterium, Enterococcus faecalis. In our in vivo study, we hypothesized that individuals with symptomatic endodontic disease would have elevated bacterial/viral replication and inflammation compared to that of asymptomatic individuals. In our in vitro study, EBV reactivation within latently infected cells was assessed following exposure to E. faecalis metabolic end products and cell wall by quantitative PCR of media for EBV virions and of cellular mRNA for viral gene expression. To determine potential mechanisms of EBV reactivation, the effect of E. faecalis mediated activation of latent EBV was evaluated when the cells were simultaneously exposed to bacterial products and specific pharmacologic inhibitors of signal transduction pathways. The growth and virulent gene expression of E. faecalis when exposed to lymphoid cells with and without latent EBV infection were evaluated using real-time PCR. To assess the role of viral and bacterial interaction on the host response, transcription of cellular inflammatory genes was determined using real-time RT-PCR. In our in vivo study, twenty pulp tissue samples were collected from patients diagnosed with irreversible pulpits, 10 with symptoms of self-reported severe pain (>7 on 10-point pain scale, Symptomatic) and 10 without self-reported pain (Asymptomatic), respectively. As controls, ten pulp tissue samples were collected from extracted healthy 3rd molars, which had no fracture, caries, or periodontal disease. Additionally, two periapical tissue samples were collected during apicoectomy from patients with persistent periapical infection after root canal treatment. Total DNA and RNA were extracted from pulp tissue using DNeasy and RNeasy kit (Qiagen), respectively. Quantification of total bacteria, Streptococcus sp., Lactobacillus sp., Fusobacterium sp., Actinomyces sp., E. faecalis, EBV and Human Cytomegalovirus (HCMV) were assessed using quantitative PCR (qPCR) for consensus or organism specific DNA. Total bacterial RNA was used to indicate transcriptional activity and was evaluated using quantitative reverse-transcriptase PCR (RT-PCR). The expression of inflammatory genes including IL-6, IL-10, TNF-[alpha], TNF-[beta] and IFN-[beta] was evaluated using quantitative reverse-transcriptase PCR. The result from our in vitro study showed that lipoteichoic acid (LTA), a cell wall component of E. faecalis, can re-activate latent EBV. E. faecalis LTA -mediated induction of lytic EBV infection was significantly reduced by both a TLR2 antagonist and an inhibitor of the NF-kB/Ikb pathway. Interestingly, the growth of E. faecalis increased 5-fold with presence of EBV. The expression of E. faecalis virulence genes were significantly increased in presence of EBV. Proinflammatory cytokine expression was also significantly higher in the presence of EBV. The result from our in vivo study showed that a greater than 5-fold increase was detected in bacterial DNA levels from pulp tissue of symptomatic patients compared to controls (P=0.004). These differences were not detected between asymptomatic patients and the control (P= 0.275). Likewise, total bacterial activity (RNA) was 5-fold higher in symptomatic patients than the asymptomatic (P=0.027). Lactobacillus sp., Fusobacterium sp. and Actinomyces sp. were present in inflamed pulp tissue, but not in healthy pulp tissue. Among the samples with Streptococcus sp., asymptomatic pulp tissues had 30 fold higher levels, and symptomatic pulp tissues had 5 folds higher levels detected compared to controls (P=0.001, P=0.003 respectively). Interestingly, while EBV was widely detected, CMV was detected only in periapical tissues. Greater than a 30-fold increase in EBV DNA was detected in pulp tissue from symptomatic individuals compared to controls (P<0.001). Further, a 30-fold difference was shown in EBV detection in pulp tissue from symptomatic compared to asymptomatic (P=0.028) patients. The quantity of EBV in the pulp tissue from asymptomatic patients was comparable to the control (P=0.403). Real-time RT-PCR analysis of inflammatory gene expression in pulp tissues detected expression in disease but not within healthy controls. The IL-6 gene was expressed at levels 11-fold higher in symptomatic pulp than in asymptomatic pulp (P=0.026). Regression analysis indicated that inflammatory gene expression levels were associated with bacterial transcription and with EBV viral load. Collectively, our in vitro results show that E. faecalis and EBV may have synergistic effect during inflammatory process. Our in vivo results suggest a significant association between bacteria, EBV and inflammation in symptomatic disease within the pulp tissue. CMV is more tightly associated with chronic infection than acute infection. These results support a paradigm shift in which elevated bacterial/viral replication and inflammation are associated with endodontic infection

Data-driven model construction for anisotropic dynamics of active matter

The dynamics of cellular pattern formation is crucial for understanding embryonic development and tissue morphogenesis. Recent studies have shown that human dermal fibroblasts cultured on liquid crystal elastomers can exhibit an increase in orientational alignment over time, accompanied by cell proliferation, under the influence of the weak guidance of a molecularly aligned substrate. However, a comprehensive understanding of how this order arises remains largely unknown. This knowledge gap may be attributed, in part, to a scarcity of mechanistic models that can capture the temporal progression of the complex nonequilibrium dynamics during the cellular alignment process. The orientational alignment occurs primarily when cells reach a high density near confluence. Therefore, for accurate modeling, it is crucial to take into account both the cell-cell interaction term and the influence from the substrate, acting as a one-body external potential term. To fill in this gap, we develop a hybrid procedure that utilizes statistical learning approaches to extend the state-of-the-art physics models for quantifying both effects. We develop a more efficient way to perform feature selection that avoids testing all feature combinations through simulation. The maximum likelihood estimator of the model was derived and implemented in computationally scalable algorithms for model calibration and simulation. By including these features, such as the non-Gaussian, anisotropic fluctuations, and limiting alignment interaction only to neighboring cells with the same velocity direction, this model quantitatively reproduce the key system-level parameters--the temporal progression of the velocity orientational order parameters and the variability of velocity vectors, whereas models missing any of the features fail to capture these temporally dependent parameters.Comment: 20 pages, 14 figure

Applications of Magnetic Microbubbles for Theranostics

Compared with other diagnostic methods, ultrasound is proven to be a safe, simple, non-invasive and cost-effective imaging technique, but the resolution is not comparable to that of magnetic resonance imaging (MRI). Contrast-enhanced ultrasound employing microbubbles can gain a better resolution and is now widely used to diagnose a number of diseases in the clinic. For the last decade, microbubbles have been widely used as ultrasound contrast agents, drug delivery systems and nucleic acid transfection tools. However, microbubbles are not fairly stable enough in some conditions and are not well administrated distributed in the circulation system. On the other hand, magnetic nanoparticles, as MRI contrast agents, can non-specifically penetrate into normal tissues because of their relatively small sizes. By taking advantage of these two kinds of agents, the magnetic microbubbles which couple magnetic iron oxides nanoparticles in the microbubble structure have been explored. The stability of microbubbles can be raised by encapsulating magnetic nanoparticles into the bubble shells and with the guidance of magnetic field, magnetic microbubbles can be delivered to regions of interest, and after appropriate ultrasound exposure, the nanoparticles can be released to the desired area while the magnetic microbubbles collapse. In this review, we summarize magnetic microbubbles used in diagnostic and therapeutic fields, and predict the potential applications of magnetic microbubbles in the future