Characterization of cerebrovascular changes in Alzheimer's disease mice by photoacoustic imaging

The cerebral vasculature plays a significant role in the development of Alzheimer's disease(AD),however,the specific association between them remains unclear.In this paper,based on the benefits of photoacoustic imaging(PAI),including label-free,high-resolution,in vivo imaging of vessels,we investigated the structural changes of cerebral vascular in wild-type(WT)mice and AD mice at different ages,analyzed the characteristics of the vascular in different brain regions,and correlated vascular characteristics with cognitive behaviors.The results showed that vascular density and vascular branching index in the cortical and frontal regions of both WT and AD mice decreased with age.Meanwhile,vascular lacunarity increased with age,and the changes in vascular structure were more pronounced in AD mice.The trend of vascular dysfunction aligns with the worsening cognitive dysfunction as the disease progresses.Here,we utilized in vivo PAI to analyze the changes in vascular structure during the progression of AD,elucidating the spatial and temporal correlation with cognitive impairment,which will provide more intuitive data for the study of the correlation between cerebrovascular and the development of AD.

Runx1 is a key regulator of articular cartilage homeostasis by orchestrating YAP,TGFβ,and Wnt signaling in articular cartilage formation and osteoarthritis

Runt-related transcription factor 1(Runx1)plays a key role in cartilage formation,but its function in articular cartilage formation is unclear.We generated non-inducible and inducible Runx1-deficient mice(Runx1^(f/f)Col2α1-Cre and Runx1^(f/f)Col2α1-CreER mice)and found that chondrocyte-specific Runx1-deficient mice developed a spontaneous osteoarthritis(OA)-like phenotype and showed exacerbated articular cartilage destruction under OA,characterized by articular cartilage degradation and cartilage ossification,with decreased Col2α1 expression and increased Mmp13 and Adamts5 expression.RNA-sequencing analysis of hip articular cartilage from the Runx1^(f/f)Col2α1-Cre mice compared to that from wild-type mice and subsequent validation analyses demonstrated that Runx1 is a central regulator in multiple signaling pathways,converging signals of the Hippo/Yap,TGFβ/Smad,and Wnt/β-catenin pathways into a complex network to regulate the expression of downstream genes,thereby controlling a series of osteoarthritic pathological processes.RNA-sequencing analysis of mutant knee joints showed that Runx1’s role in signaling pathways in articular cartilage is different from that in whole knee joints,indicating that Runx1 regulation is tissue-specific.Histopathologic analysis confirmed that Runx1 deficiency decreased the levels of YAP and p-Smad2/3 and increased the levels of activeβ-catenin.Overexpression of Runx1 dramatically increased YAP expression in chondrocytes.Adeno-associated virus-mediated Runx1 overexpression in the knee joints of osteoarthritic mice showed the protective effect of Runx1 on articular cartilage damaged in OA.Our results notably showed that Runx1 is a central regulator of articular cartilage homeostasis by orchestrating the YAP,TGFβ,and Wnt signaling pathways in the formation of articular cartilage and OA,and targeting Runx1 and its downstream genes may facilitate the design of novel therapeutic approaches for OA.

Strategies of polyhydroxyalkanoates modification for the medical application in neural regeneration/nerve tissue engineering

Neural regeneration was once considered to be impossible, especially in the central nervous system where neural regeneration comprise the generation of new neurons, glia, axons, myelin, and synapses. Until recently, neural stem cells/neural progenitor cells (NSCs/NPCs) were identified from various areas of brain and brought hopes to the neural repair and regeneration. Tissue engineering has revolutionized the current neural regeneration technology and it has become a pioneering interdisciplinary field in the areas of biomedical research. Polyhydoxyalkanoate (PHA) as one of biodegradable material has been successfully used as tissue engineering materials. It has also been applied in nerve tissue engineering due to the high biocompatibility and low cytotoxicity. Over the past 10 years, different kinds of modification strategies have been undertaken to improve the properties of PHA to fit the requirements from various fields. Several members of PHA family have been attempted for neural regeneration. This article reviewed the recent modification strategies for improving the properties of PHA and highlighted the pioneer applications in neural regeneration.

Three-dimensional printing of β-tricalcium phosphate/calcium silicate composite scaffolds for bone tissue engineering

Bioactive scaffolds with interconnected porous structures are essential for guiding cell growth and new bone formation. In this work, we successfully fabricated three-dimensional （3D） porous β-tricalcium phosphate （β-TCP）/calcium silicate （CS） composite scaffolds with different ratios by 3D printing technique and further investigated the physiochemical properties, in vitro apatite mineralization properties and degradability of porous β-TCP/CS scaffolds. Moreover, a series of in vitro cell experiments including the attachment, proliferation and osteogenic differentiation of mouse bone marrow stromal cells were conducted to testify their biological performances. The results showed that 3D printed β-TCP/CS scaffolds possessed of controllable internal porous structures and external shape. Furthermore, the introduction of CS decreased the shrinkage of scaffolds and improved the in vitro apatite formation activity and degradation rate. Meanwhile, compared with pure β- TCP scaffold, the β-TCP/CS composite scaffolds were more conducive to promote cell adhesion, spread and osteogenesis differentiation. However, when the content of CS was increased to 45%, the ions dissolution rate of the composite scaffolds was so high that leaded to the increase in pH value, which inhibited the proliferation of cells. Our results suggested that the introduction of appropriate CS into β-TCP bioceramic is an effective strategy to prepare bioactive 3D printed bioceramic scaffolds for hard tissue regeneration.

Development of water-soluble AIE-based wash-free Aβprobes superior to commercial ThT

Alzheimer's disease(AD)is a typical neurodegenerative disease.β-amyloid(AβÞplaque is the most prominent pathological biomarker associated with the progression of AD.Conventional Aβprobes,including commercial probe ThT,usually suffer from tedious washing procedures.Herein,novel AIE-active Aβprobes with excellent water solubility,named DE-V1-PYC3 and DE-V1-PYOH,were developed for the detection and image of Aβwithout tedious washing procedures.Compared with commercial probe ThT,the AIE-active Aβprobes exhibited better sensitivity and a±nity to Aβaggregates.Moreover,for ThT,the washing procedures are essential to obtain high signal-to-noise ratio(SNR)images of Aβplaques in AD brain tissue slices.DE-V1-PYC3 and DE-V1-PYOH can label Aβplaques in AD brain tissue slices with high SNR even without tedious washing procedures.

Engineering of Cell Spatiotemporal Mechanical Microenvironment

Cells in vivo are in a three-dimensional(3D)complicated microenvironment composed of various biological,physical and chemical cues.Although it is well accepted that biological and chemical cues can significantly influence cell functions,more and more evidence has also shown that physical cues are also vital.Using today’s micro and nanoscale technologies,creating synthetic but native-like conditions are the prerequisites for understanding cell behaviors.Most research has been carried out on artificial two-dimensional(2D)substrates.However,recent studies showed that cells respond and behave differently in these 2D settings compared to in 3D intricate microenvironment.Therefore,innovative 3D in vitro cellular models with precisely patterned multiple types of cells are needed for re-creating distinct niches and in vitro cell modeling under well-defined and reproducible conditions.In this talk,I will present the 3D nano and microscale tissue engineering methods we are developing for engineering cell spatiotemporal mechanical microenvironment.

A novel model of drug cue-induced behaviours in rhesus macaque subjected to chronic ketamine exposure

To the Editor,Non-human primate(NHP)models are advantageous for mimicking human addiction with high behavioural validity.1 However,current NHP drug addiction models(eg,self-administration)often require a comprehensive behavioural training paradigm,relatively expensive apparatus and invasive surgical procedures.

Reduced information transmission in the internal segment of the globus pallidus of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced rhesus monkey models of Parkinson's disease

Rhesus monkey models of Parkinson＇s disease were induced by injection of N-methyl-4-phenyl- 1,2,3,6-tetrahydropyridine. Neural firings were recorded using microelectrodes placed in the interna segment of the globus pallidus. The wavelets and power spectra show gradual power reduction during the disease process along with increased firing rates in the Parkinson＇s disease state. Singular values of coefficients decreased considerably during tremor-related activity as well as in the Parkinson＇s disease state compared with normal signals, revealing that higher-frequency components weaken when Parkinson＇s disease occurs. We speculate that the death of neurons could be reflected by irregular frequency spike trains, and that wavelet packet decomposition can effectively detect the degradation of neurons and the loss of information transmission in the neural circuitry.

Three-dimensional structure of liver vessels and spatial distribution of hepatic immune cells

As the largest internal organ of the human body,the liver has an extremely complex vascularnetwork and multiple types of immune cells.It plays an important role in blood circulation,material metabolism,and immune response.Optical imaging is an effective tool for studying finevascular structure and immunocyte distribution of the liver.Here,we provide an overview of thestructure and composition of liver vessels,the threedimensional(3D)imaging of the liver,andthe spatial distribution and immune function of various cell components of the liver.Especially,we emphasize the 3D imaging methods for visualizing fine structure in the liver.Finally,wesummarize and prospect the development of 3D imaging of liver vesels and immune cells.

Circuit-specific gene therapy is knocking on the door of Parkinson's disease

Parkinson's disease(PD)is a prevalent neurodegenerative disorder that affects millions of individuals worldwide.Symptoms of PD typically manifest as movement impairments,including bradykinesia,rigidity,tremors,and postural instability,as well as non-motor symptoms,such as cognitive decline,pain,and depression(Bloem et al.,2021).

MMAE-loaded PLGA nanomedicine with improved biosafety to achieve efficient antitumor treatment

Monomethyl auristatin E(MMAE)is a derivative of the marine peptide Dolastatin 10,which has therapeutic effects against various cancers according to its antimitotic activity in multiple clinical trials.The antibody drug conjugate(ADC)of MMAE is currently used in clinical practice.However,the safety issues of MMAE-based ADC,such as high drug toxicity and poor bioavailability,still exist when using it for anticancer therapy.A sustained release of drug delivery approach should be used to reduce toxicity and achieve sufficient anticancer effects.Herein,PLGA-b-PEG 2000 with excellent biocompatibility and slow degradation ability was adopted to construct MMAE-loaded nanoparticles for safe and effective chemotherapy.The sustained release effect and the immunogenic cell death(ICD)effect of PLGA-MMAE nanoparticles were assessed by in vitro experiments.The PLGA-MMAE nanoparticles effectively accumulated in the tumor through the enhanced permeability and retention(EPR)effect,inducing cell apoptosis and causing a certain degree of immune response.The sustained drug release of PLGA-MMAE improved the bioavailability and effectively reduced the toxicity and development of the tumor compared to the effect of free MMAE or ADC.Overall,this study provides a safe and effective chemotherapeutic approach,as well as a simple and effective synthetic process for MMAE-based nanoparticles,improving their therapeutic efficacy and safety.

Structural Characterization of Volatile Components of Rosa Banksiae Ait for Estimation and Prediction of Their Linear Retention Indices and Retention Times

The molecular electronegativity-distance vector （MEDV） was used to describe the molecular structure of volatile components of Rosa banksiae Ait, and QSRR model was built up by use of multiple linear regression （MLR）. Furthermore, in virtue of variable screening by the stepwise multiple regression technique, the QSRR models of 10 and 6 variables and linear retention index （LRI） 10, 7 and 6 varieables were built up by combinating MEDV with the Ultra2 column GC retention time （tR） of 53 volatile components of Rosa Banksiae Air. The multiple correlation coefficients （R） of modeling calculation values of QSRR model were 0.906, 0.906, 0.949, 0.943 and 0.949, respectively. The cross-verification multiple correlation coefficients （RCV） were 0.903, 0.904, 0.867, 0.901 and 0.904, respectively. The results show that the models constructed could provide estimation stability and favorable predictive ability.

Synergistic anticancer properties of docosahexaenoic acid and 5-fluorouracil through interference with energy metabolism and cell cycle arrest in human gastric cancer cell line AGS cells

AIM: To explore the synergistic effect of docosahexaenoic acid(DHA)/5-fluorouracil(5-FU) on the human gastric cancer cell line AGS and examine the underlying mechanism.METHODS: AGS cells were cultured and treated with a series of concentrations of DHA and 5-FU alone or in combination for 24 and 48 h. To investigate the synergistic effect of DHA and 5-FU on AGS cells, the inhibition of cell proliferation was determined by MTT assay and cell morphology. Flow cytometric analysis was also used to assess cell cycle distribution, and the expression of mitochondrial electron transfer chain complexes(METCs)?Ⅰ, Ⅱ and Ⅴ in AGS cells was further determined by Western blot analysis. RESULTS: DHA and 5-FU alone or in combination could markedly suppress the proliferation of AGS cells in a significant time and dose-dependent manner. DHA markedly strengthened the antiproliferative effect of 5-FU, decreasing the IC50 by 3.56-2.15-fold in an apparent synergy. The morphological changes of the cells were characterized by shrinkage, cell membrane blebbing and decreased adherence. Cell cycle analysis showed a shift of cells into the G0/G1 phase from the S phase following treatment with DHA or 5-FU(G0/G1 phase: 30.04% ± 1.54% vs 49.05% ± 6.41% and 63.39% ± 6.83%, respectively, P < 0.05; S phase: 56.76% ± 3.14% vs 34.75% ± 2.35% and 25.63% ± 2.21%, respectively, P < 0.05). Combination treatment of DHA and 5-FU resulted in a significantly larger shift toward the G0/G1 phase and subsequent reduction in S phase(G0/G1 phase: 69.06% ± 2.63% vs 49.05% ± 6.41% and 63.39% ± 6.83%, respectively, P < 0.05; S phase: 19.80% ± 4.30% vs 34.75% ± 2.35% and 25.63% ± 2.21%, respectively, P < 0.05). This synergy was also reflected in the significant downregulation of the expression of METCs in AGS cells.CONCLUSION: Synergistic anticancer properties of DHA and 5-FU may involve interference with energy production of AGS cells via downregulation of METCs and cell cycle arrest.

A Modified Monte Carlo Model of Speckle Tracking of Shear Wave Induced by Acoustic Radiation Force for Acousto-Optic Elasticity Imaging

A modified Monte Carlo model of speckle tracking of shear wave propagation in scattering media is proposed. The established Monte Carlo model mainly concerns the variations of optical electric field and speckle. The two- dimensional intensity distribution and the time evolution of speckles in different probe locations are obtained. The fluctuation of speckle intensity tracks the acoustic-radiation-force shear wave propagation, and especially the reduction of speckle intensity implies attenuation of shear wave. Then, the shear wave velocity is estimated quantitatively on the basis of the time-to-peak algorithm and linear regression processing. The results reveal that a smaller sampling interval yields higher estimation precision and the shear wave velocity is estimated more efficiently by using speckle intensity difference than by using speckle contrast difference according to the estimation error. Hence, the shear wave velocity is estimated to be 2.25 m/s with relatively high accuracy for the estimation error reaches the minimum （0.071）.

Inhibition of proliferation of prostate cancer cell line, PC-3, in vitro and in vivo using （-）-gossypol

We investigated the antiproliferative activity of （-）-gossypol on the human prostate cancer cell line PC3 in vitro and in vivo to elucidate its potential molecular mechanisms. Cell growth and viability were evaluated using the 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） assay, and cell apoptosis was detected by flow cytometry, terminal deoxynucleotidyl transferase dUTP nick end labelling （TUNEL） and electron microscopy. Expression of proliferating cell nuclear antigen （PCNA）, Bcl-2, CD31, caspase-3 and caspase-8 in tumour tissue was determined by immunohistochemistry. The drug concentration that yielded 50% cell inhibition （IC50 value） was 4.74 μg mL-1. In the PC-3 tumour xenograft study, （-）-gossypol （〉 5 mg kg-1） given once a day for 7 days significantly inhibited tumour growth in a dose-dependent manner. Immunohistochemical analysis revealed that （-）-gossypol enhanced caspase-3 and caspase-8 expression and decreased the expression of PCNA, Bcl-2 and CD31 in tumour tissues. It suggested that cell apoptosis and inhibition of angiogenesis might contribute to the anticancer action of （-）-gossypol.

A General Overview of the Typical 18 Frontal-VentralTransverse Cirri Oxytrichidae s. l. Genera(Ciliophora, Hypotrichia)

Oxytrichidae s. l. ciliates usually have 18 frontal-ventral-transverse cirri which are clustered to six distinct groups usu- ally originating from six longitudinal primordia segregating 1, 3, 3, 3, 4, 4 cirri. During morphogenesis, three dorsal kinetics anlagen are primarily formed. Fragmentation of kinety 3 usually present, while sometimes secondarily lost. Dorsomarginal kineties are formed, while sometimes lost. Oxytrichids tend to have overlapping characters, e.g. cell shape and size, infraciliature, pellicle fea- tures. This makes a great problem for genera separation. In the present work, all typical 18 frontal-ventral-transverse-cirri Oxytrichi- dae s. 1. genera were revised systematically based on their living morphology, ciliature patterns and dorsal morphogenetic features. The outline of the genera, the schematic illustrations, and the key to typical 18 frontal-ventral-transverse-cirri genera of Oxytrichidae s. l. were clarified. Additionally, some morphological and morphogenetic patterns were summarized and compared.

Apogossypolone, a novel inhibitor of anfiapoptotic Bcl-2 family proteins, induces autophagy of PC-3 and LNCaP prostate cancer cells in vitro

Limited treatment options are available for aggressive prostate cancer. Gossypol has been reported to have a potent anticancer activity in many types of cancer. It can increase the sensitivity of cancer cells to alkylating agents, diminish multidrug resistance and decrease metastasis. Whether or not it can induce autophagy in cancer cells has not yet been determined. Here we investigated the antiproliferative activity of apogossypolone （ApoG2） and （-）-gossypol on the human prostate cancer cell line PC3 and LNCaP in vitro. Exposure of PC-3 and LNCaP cells to ApoG2 resulted in several specific features characteristic of autophagy, including the appearance of membranous vacuoles in the cytoplasm and formation of acidic vesicular organelles. Expression of autophagy-associated LC3-Ⅱ and beclin-1 increased in both cell lines after treatment. Inhibition of autophagy with 3-methyladenine promoted apoptosis of both cell types. Taken together, these data demonstrated that induction of autophagy could represent a defense mechanism against apoptosis in human prostate cancer cells.

On QSAR Study of Stereoselectivity for Wittig Reaction

Molecular structures of reactants were characterized by molecular electronegativity distance vector （VHMED） considering hydrogen association. A reasonable molecular modeling equation with 4-parameters was achieved for quantitative structure-property/activity relationship （QSPR/QSAR） by stepwise multiple regression （SMR） that the variable was introduced item by item in significant level order. A high correlation coefficient （R = 0.980） demonstrates that the model is able to well express a quantitative relation between stereoselectivity and the reactant structures as quantitative structure-reactivity/stereoselectivity relationship （QSRR/QSSR）. The multiple correlation coefficient （Rcv= 0.964） was tested through cross-validation with the leave-one-out （LOO） procedure. The above results show that the model possesses high estimation stability and good prediction ability between the amount of both cis and trans isomers in products and reactants.

Effects of rhubarb extracts on hyperexcitability of hippocampal CA1 neurons after fluid percussion injury

Objective To investigate the effects of rhubarb extracts,i.e.rhein and emodin,on the neuronal hyperexcitability and synaptic transmission,and to further reveal the mechanism of the secondary brain damage.Methods The fluid percussion injury(FPI) rat model and extracellular recording method were used.The evoked field potentials by stimulating Schaffer collaterals were collected from the ipsilateral(impact side) and the contralateral hippocampal CA1 areas of rat in vitro.And the field potentials,including the field excitatory postsynaptic potential and the population spike,were analyzed.Results After the impact was performed on the rat parietal cortex,the evoked field potentials in the ipsilateral hippocampus CA1 area were enhanced obviously.Rhubarb extracts reduced the slope of the field excitatory postsynaptic potential and the number of the population spike significantly while rhein and emodin increased the latency of the population spike obviously.Conclusion Rhubarb extracts,i.e. rhein and emodin,can depress the neuronal hyperexcitability,which suggests that rhein and emodin play an important role in protecting the central nervous system from neuronal damage after traumatic brain injury.FPI produces hyperexcitability of hippocampal CA1 neurons,probably by enhancing excitatory synaptic transmission.

The Matrix Stiffness and Physical Confinement of Hydrogel Microchannel Jointly Induce the Mesenchymal-Amoeboid Transition for Cancer Cell Migration

The migration mode transition of cancer cell enhances its invasive capability and the drug resistance,where physical confinement of cell microenvironment has been revealed to induce the mesenchymal-amoeboid transition(MAT).However,most existing studies are performed in PDMS microchannels,of which the stiffness is much higher than that of most mammalian tissues.Therefore,the amoeboid migration transition observed in these studies is actually induced by the synergistic effect of matrix stiffness and confinement.Since the stiffness of cell microenvironment has been reported to influence the cell migration in 2D substrate,the decoupling of stiffness and confinement effects is thus in need for elucidating the underlying mechanism of MAT.However,it is technically challenging to construct microchannels with physiologically relevant stiffness and channel size,where existing microchannel platforms with physiological relevance stiffness are all with>10μm channel width.Such size is too wide to mimic the physical confinement that migrating cancer cells confront in vivo,and also larger than the width of PDMS channel,in which the MAT of cancer cell was observed.Therefore,an in vitro cell migration platform,which could mimic both stiffness and confinement of the native physical microenvironment during cancer metastasis,could profoundly contribute to researches on cancer cell migration and cellular mechanotransduction.In this paper,we overcome the limitations of engineering soft materials in microscale by combining the collagen-alginate hydrogel with photolithography.This enables us to improve the accuracy of molded microchannel,and thus successfully construct a 3D microchannel platform,which matches the stiffness and width ranges of native environmental confinement that migrating cancer cells confront in vivo.The stiffness(0.3~20 kPa),confinement(channel width:3.5~14μm)and the adhesion ligand density of the microchannel can be tuned independently.Interestingly,using this platform,we observed that the migration speed of cancer cell is influenced by the synergistic effect of channel stiffness and width,and the increasing stiffness reverses the effect of channel width on the migration speed of cancer cells.In addition,MAT has a strong correlation with the channel stiffness.These findings make us reconsider the widely accepted hypothesis:physical confinement can induce MAT.Actually,this transition can only occur in stiff confined microenvironment not in soft one.For soft microchannels,the compliance of the channel walls could cause little cell/nucleus deformation,and the MAT could not be induced.To further investigate the mechanism of MAT,we developed a computational model to simulate the effect of nucleus deformation on MAT.With the model,we found that deforming the cell nuclear by decreasing the nucleus stiffness will reduce the cellmigration speed.This implies that nuclear stiffness plays an important role in the regulation of cancer migration speed and thus MAT in microchannels.The effect of channel stiffness on MAT and migration speed as observed in our experiment could partially explain previous findings reported in the literature,where the increasing matrix stiffness of tumor microenvironment promotes cancer metastasis.Our observations thus highlight the critical role of cell nuclear deformation not only in MAT,but also in regulating cellular mechanotransduction and cell-ECM interactions.This developed platform is capable of mimicking the native physical microenvironment during metastasis,providing a powerful tool for high-throughput screening applications and investigating the interaction between cancer migration and biophysical microenvironment.