Toluidine blue O and porphyrin-mediated photodynamic therapy on three main pathogenic bacteria of periodontitis using portable LED phototherapy device

Photodynamic therapy(PDT)has been commonly used in treating many diseases,such as cancer and infectious diseases.We investigated the different effects of PDT on three main pathogenic bacteria of periodontitis-Prevotella melaninogenica(P.m.),Porphyromonas gingitvalis(P.g.)and Aggregatibacter actinomycetercomitans(A.a-).The portable red light-ermitting diode(LED)phototherapy device was used to assess the exogenous PDT effects with different light doses and photosensitizer concentrations(Toluidine blue O,TBO).The portable blue LED phototherapy device was used to assess the endogenous PDT effects with the use of endogenous photosensit izers(porphyrin)under dfferent light doses.We found out that both exogenous and endogenous PDT were able to restrict the growth of all the three bacteria significantly.Moreover,the optimal PDT conditions for these bacteria were obtained through this in vitro screening and could guide the clinical PDT on periodontitis.

ICAM-1 depletion in the center of immunological synapses is important for calcium releasing in T-cells

T-cell activation requires the formation of the immunological sy napse(IS)bet ween a T-cll and anantigen-presenting cell(AP C)to control the development of the adaptive immune response.How-ever,calcium release,an initial signal of T-cell activation,has been found to occur before IS for-mation.The mechanism for triggering the calcium signaling and relationship bet ween calciumrelease and IS format ion remains unclear.Herein,using live-cell imaging,we found that int ercellularadhesion molecule 1(ICAM-1),an essential mdlecule for IS formation,accumulated and then wasdepleted at the center of the synapse before complete IS formation.During the proces of ICAM1depletion,calcium was released.if ICAM-1 failed to be depleted from the center of the synapse,thesustained calcium signaling could not be induced.Moreover,depletion of ICAM-1 in ISs preferen-tially ccurred with the contact of antigen-specific T-cels and dendritic clls(DCs).Blocking thebinding ofICA M-1 and lymphocy te finction-associated antigen 1(LFA-1),ICAM-1 failed to depleteat the center of the synapse,and calcium release in T-clls decreased.In studying the mechanism ofhow the depletion ofiCA M1 could influence calcium release in T-clls,we found that the movementof ICAM-1 was associat ed with the localization of LFA-1 in the IS,which afected the localization ofcalcium microdomains,ORAIl and mitochondria in IS.Therefore,the depletion of ICAM-1 in the center of the synapse is an important factor for an initial sust ained calcium release in T-cells.

Cell counting for in vivo flow cytometry signals with baseline drift

In biomedical research fields,the in vio Aow cytometry(IVFC)is a widely used technology which is able to monitor target cells dynamically in living animals.Although the setup of IVFC system has been well established,baseline drift is still a challenge in the process of quantifying circulating cells.Previous methods,i.e.,the dynamic peak picking method,counted cells by setting a static threshold without considering the baseline drift,leading to an inaccurate cell quantification.Here,we developed a method of cell counting for IVFC data with baseline drift by interpolation fitting,automatic segmentation and wavelet-based denoising.We demonstrated its performance for IVFC signals with three types of representative baseline drift.Compared with non-baseline correction methods,this method showed a higher sensitivity and specificity,as well as a better result in the Pearson's correlation coefficient and the mean-squared error(MSE).

Microglia modulation with 1070-nm light attenuates Aβ burden and cognitive impairment in Alzheimer’s disease mouse model

Photobiomodulation,by utilizing low-power light in the visible and near-infrared spectra to trigger biological responses in cells and tissues,has been considered as a possible therapeutic strategy for Alzheimer’s disease(AD),while its specific mechanisms have remained elusive.Here,we demonstrate that cognitive and memory impairment in an AD mouse model can be ameliorated by 1070-nm light via reducing cerebralβ-amyloid(Aβ)burden,the hallmark of AD.The glial cells,including microglia and astrocytes,play important roles in Aβclearance.Our results show that 1070-nm light pulsed at 10 Hz triggers microglia rather than astrocyte responses in AD mice.The 1070-nm lightinduced microglia responses with alteration in morphology and increased colocalization with Aβare sufficient to reduce Aβload in AD mice.Moreover,1070-nm light pulsed at 10 Hz can reduce perivascular microglia and promote angiogenesis to further enhance Aβclearance.Our study confirms the important roles of microglia and cerebral vessels in the use of 1070-nm light for the treatment of AD mice and provides a framework for developing a novel therapeutic approach for AD.

In vivo flow cytometry reveals a circadian rhythm of circulating tumor cells

Circulating tumor cells(CTCs)is an established biomarker of cancer metastasis.The circulation dynamics of CTCs are important for understanding the mechanisms underlying tumor cell dissemination.Although studies have revealed that the circadian rhythm may disrupt the growth of tumors,it is generally unclear whether the circadian rhythm controls the release of CTCs.In clinical examinations,the current in vitro methods for detecting CTCs in blood samples are based on a fundamental assumption that CTC counts in the peripheral blood do not change significantly over time,which is being challenged by recent studies.Since it is not practical to draw blood from patients repeatedly,a feasible strategy to investigate the circadian rhythm of CTCs is to monitor them by in vivo detection methods.Fluoresce nee in vivo flow cytometry(IVFC)is a powerful optical technique that is able to detect fluoresce nt circulating cells directly in living animals in a noninvasive manner over a long period of time.In this study,we applied fluorescence IVFC to monitor CTCs noninvasively in an orthotopic mouse model of human prostate cancer.We observed that CTCs exhibited stochastic bursts over cancer progression.The probability of the bursting activity was higher at early stages than at late stages.We longitudinally monitored CTCs over a 24-h period,and our results revealed striking daily oscillations in CTC counts that peaked at the onset of the night(active phase for rodents),suggesting that the release of CTCs might be regulated by the circadian rhythm.

Reply to Comment on “In vivo flow cytometry reveals a circadian rhythm of circulating tumor cells”

Dear Editor,We thank Niedre et al.for their correspondence regarding our recent paper1.They proposed a point that the temporal distribution of circulating tumor cells(CTCs)monitored by diffuse in vivo flow cytometry in a multiple myeloma mouse model in their previous work2 might be different from our results.Niedre et al.claimed that CTC detection statistics deviated from Poisson but did not found circadian variations in CTC numbers in a multiple myeloma mouse model.They also cite another literature by Juratli.et al.3,in which the authors reported that CTC numbers did not always correlate with tumor size during cancer progression.However,by establishing an orthotopic mouse model of prostate cancer and utilizing the technology in vivo flow cytometry(IVFC),we found CTCs exhibited bursting activity and daily oscillation in an orthotopic model of prostate cancer.