Propidium iodide (PI) stains Nissl bodies and may serve as a quick marker for total neuronal cell count

Loss of neuronal activity facilitates surface accumulation of p75NTR and cell death in avian cochlear nucleus

Sensorineural hearing loss causes cell death in central auditory neurons, but molecular mechanisms of triggering this process are not fully understood. We report here that loss of afferent activity promotes cell death by facilitating proBDNF-p75NTR signals in cochlear nucleus of chicks around hatch. RNA-seq analyses revealed up-regulation of genes related to proBDNF-p75NTR-JNK signals as well as apoptosis at the nucleus within 24 h after unilateral cochlea deprivation. Western blotting confirmed a high level of proBDNF protein at the nucleus. Moreover, FLAG-tagged p75NTR accumulated at the plasma membrane of the neurons within 6 h after the deprivation, well before the upregulation of apoptotic genes. Cell viability assay using propidium iodide in organ culture showed that proBDNF increased the fraction of dying neurons in a dose-dependent manner. In addition, pharmacological blockades of synaptic and spike activities in the culture reproduced the surface accumulation of p75NTR in vivo and increased the fraction of dying neurons, while genetic inhibition of p75NTR signals occluded the cell death during the activity blockades. These results indicate that afferent activity is crucial for suppressing surface accumulation of p75NTR and hence proBDNF-p75NTR signals and that the loss of this suppression would contribute to triggering cell death after deafferentation in the developing brainstem auditory circuit.

The effect of tactile stimulation on spatial memory and hippocampal neuronal density in male rats with sensory deprivation during a critical period

It is well known that sensory information driven from whiskers serves as an example of tactile perception in rodents, and plays an important role in social behavior, environmental exploration, and decision-making processes, the influence of manipulations performed during the development of whiskers, on learning has been received little attention in the literature. This study aimed to evaluate the effect of tactile stimulation (TS) on spatial memory performance and neuronal density in the hippocampus during adulthood in early sensory-deprived rats. Wistar albino male rats were divided into four groups: control (CTL), bilateral whisker trimming (BWT), tactile stimulation (TS), and bilateral whisker trimming+tactile stimulation (BWT + TS). All whiskers were trimmed between P0-10, a critical period for whisker development. TS was applied from P3 to P21 using a soft brush. In this study, the 8-arm radial maze test was conducted from postnatal days 77 to 81 to assess spatial memory Animals sacrificed by intracardial perfusion and neuronal density in CA1, CA3, vDG, and dDG regions of the hippocampus were evaluated by Nissl staining. TS exposure negatively affected spatial memory performance and hippocampal neuronal density compared to BWT. We conclude that TS in healthy offspring can cause stress by interrupting maternal care, given the vulnerability of early development. On the contrary, the sensory deprivation protocol in this study was terminated at a time of high homeostatic plasticity and did not produce complete whisker deprivation, have triggered learning by inducing moderate stress early in development.

Short-term exposure of 2.4 GHz electromagnetic radiation on cellular ROS generation and apoptosis in SH-SY5Y cell line and impact on developing chick embryo brain tissue

BACKGROUND

Electromagnetic radiation (EMR) from wireless technology and mobile phones, operates at various frequencies. The present study analyses the major impact of short-term exposure to 2.4 GHz frequency EMR, using the two model systems chick embryos and SH-SY5Y cell lines. We hypothesized that exposure to this frequency would induce oxidative stress and apoptosis in neurons.

METHODS AND RESULTS

Chick embryos were exposed continuously to 2.4 GHz EMR for 4 h each day over a 5-day period, and comparisons were made with a control group. At the end of the exposure, brain tissues were dissected for histopathological analysis, antioxidant assays, and reactive oxygen species (ROS) detection. Additionally, SH-SY5Y cells were exposed to 2.4 GHz EMR to assess cell viability, DNA damage, and apoptosis. Our results showed that exposure to 2.4 GHz EMR induces oxidative stress in both chick embryos and the SH-SY5Y cells, though no significant tissue-level impact was observed. In SH-SY5Y cells, ROS production increased after 4 h of exposure, accompanied by moderate DNA damage and early markers of apoptosis, such as upregulation of the Bax gene. Furthermore, we observed that antioxidants, such as NAC and Mito-TEMPO, helped mitigate the cytotoxic effects of EMR in both the study models.

CONCLUSION

In conclusion, short-term exposure (4 h) to 2.4 GHz EMR induced moderate cellular and molecular changes, primarily oxidative stress. The oxidative stress was reduced by antioxidants, which suggests potential benefits in preventing EMR-induced cytotoxicity. Extended exposure to EMR beyond 4 h may pose adverse health risks to humans, endorsing further investigation.

Identification of 3-methyl-1-(3-methylpyridin-2-yl)-1H-pyrazol-5-ol as promising neuroprotective agent

Pyrazolol derivatives are gaining significant attention for their diverse pharmacological effects, such as analgesic, anti-inflammatory, antioxidant, and anticancer activities. In this study, 20 pyrazolol derivatives were designed and synthesized to develop an anti-ischemic stroke formulation with free radical scavenging activity. Most of these synthesized compounds demonstrated antioxidant capabilities in DPPH, ABTS radical scavenging, and ORACFL assays. The methyl-substituted compound Y12, in particular, showed exceptional antioxidant capacity. Additionally, these compounds showed excellent neurocytoprotective effects in the SH-SY5Y cell injury model subjected to oxygen-glucose deprivation/reoxygenation (OGD/R). Notably, Y12 exhibited significant metal chelating activity with Cu2+. In vivo studies confirmed that compound Y12 has neuroprotective effects and can significantly reduce the infarct area in a mouse model of focal cerebral ischemia induced by transient middle cerebral artery occlusion (tMCAO).

A Potential Neurotoxic Mechanism: Bisphenol S-Induced Inhibition of Glucose Transporter 1 Leads to ATP Excitotoxicity in the Zebrafish Brain

Many environmental pollutants have neurotoxic effects, but the initial molecular events involved in these effects are unclear. Here, zebrafish were exposed to the neurotoxicant bisphenol S (BPS, 1, 10, or 100 μg/L) from the embryonic stage to the larval stage to explore the ability of BPS to interfere with energy metabolism in the brain. BPS, which is similar to a glucose transporter 1 (GLUT1) inhibitor, inhibited GLUT1 function but increased mitochondrial activity in the brains of larval zebrafish. Interestingly, GLUT1 inhibitor treatment and BPS exposure did not reduce energy production in the brain; instead, they increased ATP production by inducing the preferential use of ketone bodies. Moreover, BPS promoted the protein expression of the purinergic 2X receptor but inhibited the purinergic 2Y-mediated phosphatidylinositol signaling pathway, indicating that excess ATP acts as a neurotransmitter to activate the purinergic 2X receptor under the BPS-induced restriction of GLUT1 function. BPS-induced inhibition of GLUT1 increased the number of neurons but promoted apoptosis by activating ATP-purinergic 2X receptors in the brain, causing ATP excitatory neurotoxicity. Our data reveal a potential neurotoxic mechanism induced by BPS that may represent a new adverse outcome pathway.

The cytoarchitectonic landscape revealed by deep learning method facilitated precise positioning in mouse neocortex

Neocortex is a complex structure with different cortical sublayers and regions. However, the precise positioning of cortical regions can be challenging due to the absence of distinct landmarks without special preparation. To address this challenge, we developed a cytoarchitectonic landmark identification pipeline. The fluorescence micro-optical sectioning tomography method was employed to image the whole mouse brain stained by general fluorescent nucleotide dye. A fast 3D convolution network was subsequently utilized to segment neuronal somas in entire neocortex. By approach, the cortical cytoarchitectonic profile and the neuronal morphology were analyzed in 3D, eliminating the influence of section angle. And the distribution maps were generated that visualized the number of neurons across diverse morphological types, revealing the cytoarchitectonic landscape which characterizes the landmarks of cortical regions, especially the typical signal pattern of barrel cortex. Furthermore, the cortical regions of various ages were aligned using the generated cytoarchitectonic landmarks suggesting the structural changes of barrel cortex during the aging process. Moreover, we observed the spatiotemporally gradient distributions of spindly neurons, concentrated in the deep layer of primary visual area, with their proportion decreased over time. These findings could improve structural understanding of neocortex, paving the way for further exploration with this method.

Isobavachalcone alleviates ischemic stroke by suppressing HDAC1 expression and improving M2 polarization

Ischemic stroke is a serious cerebrovascular condition. Isobavachalcone (ISO) has been documented to exhibit an anti-inflammatory effect across a variety of diseases; however, its protective impact on ischemic stroke remains unexplored. In this study, we evaluated the influence of ISO in both transient middle cerebral artery occlusion/reperfusion (tMCAO/R) rat models and oxygen-glucose deprivation/reperfusion (OGD/R) cell models. We observed that pretreatment with 50 mg/kg ISO diminished the volume of brain infarction, reduced brain edema, and ameliorated neurological deficits in rats. A reduction in Nissl bodies was noted in the tMCAO/R group, which was reversed following treatment with 50 mg/kg ISO. TUNEL/NeuN double staining revealed a decrease in TUNEL-positive cells in tMCAO/R rats treated with ISO. Furthermore, ISO treatment suppressed the expression of cleaved caspase-3 and BAX, while elevating the expression of BCL-2 in tMCAO/R rats. The levels of CD86 and iNOS were elevated in tMCAO/R rats; conversely, ISO treatment enhanced the expression of CD206 and Arg-1. Additionally, the expression of TNF-α, IL-6, and IL-1β was elevated in tMCAO/R rats, whereas ISO treatment counteracted this effect. ISO treatment also increased the expression of TGF-β and IL-10 in the ischemic penumbra of tMCAO/R rats. It was found that ISO treatment hindered microglial M1 polarization and favored M2 polarization. Histone Deacetylase 1 (HDAC1) is the downstream target protein of ISO, with ISO treatment resulting in decreased HDAC1 expression in both tMCAO/R rats and OGD/R-induced cells. Overexpression of HDAC1 was shown to promote microglial M1 polarization and inhibit M2 polarization in OGD/R+ISO cells. Overall, ISO treatment mitigated brain damage following ischemic stroke by promoting M2 polarization and attenuated ischemic injury by repressing HDAC1 expression.

Open-top Bessel beam two-photon light sheet microscopy for three-dimensional pathology

Nondestructive pathology based on three-dimensional (3D) optical microscopy holds promise as a complement to traditional destructive hematoxylin and eosin (H&E) stained slide-based pathology by providing cellular information in high throughput manner. However, conventional techniques provided superficial information only due to shallow imaging depths. Herein, we developed open-top two-photon light sheet microscopy (OT-TP-LSM) for intraoperative 3D pathology. An extended depth of field two-photon excitation light sheet was generated by scanning a nondiffractive Bessel beam, and selective planar imaging was conducted with cameras at 400 frames/s max during the lateral translation of tissue specimens. Intrinsic second harmonic generation was collected for additional extracellular matrix (ECM) visualization. OT-TP-LSM was tested in various human cancer specimens including skin, pancreas, and prostate. High imaging depths were achieved owing to long excitation wavelengths and long wavelength fluorophores. 3D visualization of both cells and ECM enhanced the ability of cancer detection. Furthermore, an unsupervised deep learning network was employed for the style transfer of OT-TP-LSM images to virtual H&E images. The virtual H&E images exhibited comparable histological characteristics to real ones. OT-TP-LSM may have the potential for histopathological examination in surgical and biopsy applications by rapidly providing 3D information.

Regioselective Synthesis of Phenanthridines via Pd(II)-Catalyzed Annulative C(sp2)-H Activation

A robust synthesis of phenanthridines has been described via Pd(II)-catalyzed domino C(sp2)-H activation/N-arylation using oxime esters with aryl acyl peroxides in a highly regioselective manner. This protocol is compatible with acetophenone as well as benzophenone-derived oxime esters and allows modular construction of functionalized phenanthridines with wide tolerance of electronic functionality. Further transformations were conducted to synthesize key building blocks, and control experiments were performed to understand the plausible reaction mechanism.

Nissl Granules, Axonal Regeneration, and Regenerative Therapeutics: A Comprehensive Review

Nissl granules, traditionally recognized for their pivotal role in protein synthesis within neuronal cell bodies, are emerging as intriguing components with far-reaching implications in the realm of regenerative therapeutics. This abstract encapsulates the essence of a comprehensive review, exploring the nexus between Nissl granules, axonal regeneration, and their transformative applications in regenerative medicine. The molecular intricacies of Nissl granules form the foundation of this exploration, unraveling their dynamic role in orchestrating cellular responses, particularly in the context of axonal regeneration. As we delve into the interplay between Nissl granules and regenerative processes, this review highlights the diverse mechanisms through which these granules contribute to neuronal repair and recovery. Beyond their conventional association with neurobiology, recent advancements underscore the translational potential of Nissl granules as therapeutic agents. Insights into their involvement in enhancing axonal regeneration prompt a reconsideration of these granules as key players in the broader field of regenerative medicine. The abstract encapsulates evidence suggesting that modulating Nissl granule-related pathways holds promise for augmenting tissue regeneration, extending their applicability beyond the confines of the nervous system. This review aims to serve as a valuable resource for medical professionals, researchers, and clinicians seeking to comprehend the multifaceted role of Nissl granules in regenerative therapeutics. By illuminating the intricate connections between Nissl granules, axonal regeneration, and therapeutic applications, this work aspires to catalyze further research and innovation, ultimately contributing to the evolution of regenerative strategies that harness the innate reparative capacities within cellular constituents.

Deep ultraviolet fluorescence microscopy of three-dimensional structures in the mouse brain

Three-dimensional (3D) imaging at cellular resolution improves our understanding of the brain architecture and is crucial for structural and functional integration as well as for the understanding of normal and pathological conditions in the brain. We developed a wide-field fluorescent microscope for 3D imaging of the brain structures using deep ultraviolet (DUV) light. This microscope allowed fluorescence imaging with optical sectioning due to the large absorption at the surface of the tissue and hence low tissue penetration of DUV light. Multiple channels of fluorophore signals were detected using single or a combination of dyes emitting fluorescence in the visible range of spectrum upon DUV excitation. Combination of this DUV microscope with microcontroller-based motorized stage enabled wide-field imaging of a coronal section of the cerebral hemisphere in mouse for deciphering cytoarchitecture of each substructure in detail. We extended this by integrating vibrating microtome which allowed serial block-face imaging of the brain structure such as the habenula in mouse. Acquired images were with resolution high enough for quantification of the cell numbers and density in the mouse habenula. Upon block-face imaging of the tissues covering entire extent of the cerebral hemisphere of the mouse brain, acquired data were registered and segmented for quantification of cell number in each brain regions. Results in the current analysis indicated that this novel microscope could be a convenient tool for large-scale 3D analysis of the brain in mice.

Protective effect of bone morphogenetic protein-7 induced differentiation of bone marrow mesenchymal stem cells in rat with acute spinal cord injury

The principal aim of present study was to assess the therapeutic efficacy of bone morphogenetic protein-7 (BMP-7) induced differentiation of bone marrow mesenchymal stem cells (BMSCs) in a rat acute spinal cord injury (SCI) model. BMSCs were isolated from rats, and then divided into a control and a BMP-7 induction groups. The proliferation ability of BMSCs and glial cell markers were determined. Forty Sprague-Dawley (SD) rats were randomly divided into sham, SCI, BMSC, and BMP7 + BMSC groups (n = 10). Among these rats, the recovery of hind limb motor function, the pathological related markers, and motor evoked potentials (MEP) were identified. BMSCs differentiated into neuron-like cells after the introduction of exogenous BMP-7. Interestingly, the expression levels of MAP-2 and Nestin increased, whereas the expression level of GFAP decreased after the treatment with exogenous BMP-7. Furthermore, the Basso, Beattie, and Bresnahan (BBB) score reached 19.33 ± 0.58 in the BMP-7 + BMSC group at day 42. Nissl bodies in the model group were reduced compared to the sham group. After 42 days, in both the BMSC and BMP-7 + BMSC groups, the number of Nissl bodies increased. This is especially so for the number of Nissl bodies in the BMP-7 + BMSC group, which was more than that in the BMSC group. The expression of Tuj-1 and MBP in BMP-7 + BMSC group increased, whereas the expression of GFAP decreased. Moreover, the MEP waveform decreased significantly after surgery. Furthermore, the waveform was wider and the amplitude was higher in BMP-7 + BMSC group than that in BMSC group. BMP-7 promotes BMSC proliferation, induces the differentiation of BMSCsinto neuron-like cells, and inhibits the formation of glial scar. BMP-7 plays a confident role in the recovery of SCI rats.

Unveiling the therapeutic potential of cabozantinib-loaded poly D,L-lactic-co-glycolic acid and polysarcosine nanoparticles in inducing apoptosis and cytotoxicity in human HepG2 hepatocellular carcinoma cell lines and in vivo anti-tumor activity in SCID female mice

Introduction

The study aimed to develop a nano-based drug delivery system for the treatment of hepatocellular carcinoma (HCC), a type of liver cancer that accounts for 90% of all liver malignancies. The study focused on the use of cabozantinib (CNB), a potent multikinase inhibitor that targets the VEGF receptor 2, as the chemotherapeutic drug. We developed CNB-loaded nanoparticles made from Poly D, L-lactic-co-glycolic acid, and Polysarcosine (CNB-PLGA-PSar-NPs) for use in human HepG2 cell lines.

Methods

By O/W solvent evaporation method, the polymeric nanoparticles were prepared. The various techniques, such as photon correlation spectroscopy, scanning electron microscopy, and transmission electron microscopy were used, to determine the formulation's particle size, zeta potential, and morphology. SYBR Green/ROX qPCR Master Mix and RT-PCR equipment used to measure liver cancer cell line and tissue mRNA expression and MTT assay to test HepG2 cell cytotoxicity. Cell cycle arrest analysis, annexin V assay, and ZE5 Cell Analyzer apoptosis assay were also performed.

Results

The results of the study showed that the particle diameters were 192.0 ± 3.67 nm with 0.128 PDI and -24.18 ± 3.34 mV zeta potential. The antiproliferative and proapoptotic effects of CNB-PLGA-PSar-NPs were evaluated using MTT and flow cytometry (FCM). The IC50 value of CNB-PLGA-PSar-NPs was 45.67 µg/mL, 34.73 µg/mL, and 21.56 µg/mL for 24, 48, and 72 h, respectively. The study also found that 11.20% and 36.77% of CNB-PLGA-PSar-NPs-treated cells were apoptotic at 60 µg/mL and 80 µg/mL, respectively, suggesting that the nanoparticles were effective in inducing apoptosis in the cancer cells. It can also conclude that, CNB-PLGA-PSar-NPs inhibit human HepG2 hepatocellular carcinoma cells and kill them by upregulating the tumour suppressor genes MT1F, MT1X, and downregulating MTTP, APOA4. Further in vivo antitumor activity was well reported in SCID female mice.

Discussion

Overall, this study suggests that the CNB-PLGA-PSar-NPs are a promising drug delivery system for the treatment of HCC, and further research is needed to investigate their potential in clinical treatment.

Cytotoxicity, apoptosis inducing activity and Western blot analysis of tanshinone derivatives from Stachys parviflora on prostate and breast cancer cells

Cytotoxic activities of methanolic crude extract of Stachys parviflora (Lamiaceae family) and its sub-fractions were primarily evaluated against human breast adenocarcinoma (MCF-7 and MDA-MB-231) and prostate (PC3) cell lines. The methanolic extract exhibited the highest activity, and was chosen for the isolation procedure. Four diterpenoid quinones, namely miltirone [1], tanshinone IIA [2], 1-hydroxy-tanshinone IIA [3], and cryptotanshinone [4] were isolated. Notably, this is the first report on the isolation and/or characterization of the mentioned diterpenoids from the Stachys genus. In this study, 1-hydroxy-tanshinone IIA [3] displayed the highest cytotoxicity among the isolated compounds. The mechanism of the cytotoxicity of methanolic extract and isolated compounds was further investigated by the utilization of propidium iodide staining (PI) assay. The results showed that the methanolic extract and 1-hydroxy-tanshinone IIA [3] enhanced DNA fragmentation in PC3 and MCF-7 cells. Moreover, the western blotting analysis demonstrated increasing and decreasing protein levels of Bax and Bcl2, respectively, and cleaved poly ADP-ribose polymerase (PARP). Further bioassay-guided phytochemical assessments of S. parviflora can be suggested as a promising approach for discovering potent bioactive secondary metabolites.

Total flavonoids of hawthorn leaves protect spinal motor neurons via promotion of autophagy after spinal cord injury

The death of spinal motor neurons (SMNs) after spinal cord injury (SCI) is a crucial cause, contributing to a permanent neurological deficit. Total flavonoids of hawthorn leaves (TFHL) have been confirmed to have potentially therapeutic for SCI. Nonetheless, the roles and mechanisms of TFHL in recovering neuromotor function and regenerating axons of SMNs have not been fully elucidated. In this study, TFHL was applied to treat rats with SCI and injured SMNs for 7 days. In vivo experiment, rats with SCI were evaluated by a BBB (Basso-Beattie-Bresnahan) score to assess their motor functional recovery. The morphology, microstructure, apoptosis, Nissl bodies, and autophagy of SMNs in spinal cord tissue were detected by Hematoxylin-eosin (HE) staining, transmission electron microscopy, TUNEL staining, Nissl staining, and immunohistochemistry respectively. In vitro experiment, the co-culture model of SMNs and astrocytes was constructed to simulate the internal environment around SMNs in the spinal cord tissue. The cell morphology, microstructure, axonal regeneration, and autophagy were observed via optical microscope, transmission electron microscopy, and immunofluorescence. The content of neurotrophic factors in the cell culture medium of the co-culture model was detected by ELISA. Moreover, the expression of axon-related and autophagy-related proteins in the spinal cord tissue and SMNs was measured by Western Blot. We demonstrated that TFHL improved the neuromotor function recovery in rats after SCI. We then found that TFHL significantly promoted injured spinal cord tissue repair, reduced apoptosis, and improved the functional status of neurons in spinal cord tissue in vivo. Meanwhile, the cell morphology, microstructure, and axonal regeneration of damaged SMNs also obviously were improved, and the secretion of neurotrophic factors was facilitated after treatment with TFHL in vitro. Further, we revealed that TFHL promoted autophagy and related protein expression in vivo and vitro. Taken together, our study suggested that TFHL might facilitate autophagy and have neuroprotective properties in SMNs to enhance the recovery of neuromotor function of rats with SCI.

Nanosheets Based Approach to Elevate the Proliferative and Differentiation Efficacy of Human Wharton's Jelly Mesenchymal Stem Cells

Mesenchymal stem cell (MSC)-based therapy and tissue repair necessitate the use of an ideal clinical biomaterial capable of increasing cell proliferation and differentiation. Recently, MXenes 2D nanomaterials have shown remarkable potential for improving the functional properties of MSCs. In the present study, we elucidated the potential of Ti2CTx MXene as a biomaterial through its primary biological response to human Wharton's Jelly MSCs (hWJ-MSCs). A Ti2CTx nanosheet was synthesized and thoroughly characterized using various microscopic and spectroscopic tools. Our findings suggest that Ti2CTx MXene nanosheet exposure does not alter the morphology of the hWJ-MSCs; however, it causes a dose-dependent (10-200 µg/mL) increase in cell proliferation, and upon using it with conditional media, it also enhanced its tri-lineage differentiation potential, which is a novel finding of our study. A two-fold increase in cell viability was also noticed at the highest tested dose of the nanosheet. The treated hWJ-MSCs showed no sign of cellular stress or toxicity. Taken together, these findings suggest that the Ti2CTx MXene nanosheet is capable of augmenting the proliferation and differentiation potential of the cells.

Sialic Acid Ameliorates Cognitive Deficits by Reducing Amyloid Deposition, Nerve Fiber Production, and Neuronal Apoptosis in a Mice Model of Alzheimer's Disease

(1) Background: As a natural carbohydrate, sialic acid (SA) is helpful for brain development, cognitive ability, and the nervous system, but there are few reports about the effect of SA on Alzheimer's disease (AD). (2) Method: The present study evaluated the effect of SA on cognitive ability, neuronal activity, Aβ formation, and tau hyperphosphorylation in a double transgenic AD (2×Tg-AD) mice model. The 2×Tg-AD mice were randomly divided into four groups: the AD control group, 17 mg/kg SA-treated AD group, 84 mg/kg SA-treated AD group, and 420 mg/kg SA-treated AD group. Mice from all four groups were fed to 7 months of age for the behavioral test and to 9 months of age for the pathological factors investigation. (3) Results: In the Morris water maze, the escape latency significantly decreased on the fifth day in the SA-treated groups. The number of rearing and crossing times in the open field test also increased significantly, compared with the control group. SA treatment significantly reduced amyloid β-peptide (Aβ) and nerve fibers and increased the number of Nissl bodies in the brain of AD mice. (4) Conclusions: SA reduced the neuron damage by reducing Aβ and inhibited tau protein hyperphosphorylation, which improved the cognitive ability and mobility of AD mice.

Ki20227 aggravates apoptosis, inflammatory response, and oxidative stress after focal cerebral ischemia injury

The survival of microglia depends on the colony-stimulating factor-1 receptor (CSF1R) signaling pathway under physiological conditions. Ki20227 is a highly selective CSF1R inhibitor that has been shown to change the morphology of microglia. However, the effects of Ki20227 on the progression of ischemic stroke are unclear. In this study, male C57BL/6 mouse models of focal cerebral ischemic injury were established through the occlusion of the middle cerebral artery and then administered 3 mg/g Ki20227 for 3 successive days. The results revealed that the number of ionized calcium-binding adaptor molecule 1/bromodeoxyuridine double positive cells in the infarct tissue was reduced, the degree of edema was increased, neurological deficits were aggravated, infarct volume was increased, and the number of peri-infarct Nissl bodies was reduced. The number of terminal deoxynucleotidyl transferase dUTP nick-end labeling-positive cells in the peri-infarct tissue was increased. The expression levels of Bax and Cleaved caspase-3 were up-regulated. Bcl-2 expression was downregulated. The expression levels of inflammatory factors and oxidative stress-associated factors were increased. These findings suggested that Ki20227 blocked microglial proliferation and aggravated the pathological progression of ischemia/reperfusion injury in a transient middle cerebral artery occlusion model. This study was approved by the Animal Ethics Committee of Lanzhou University Second Hospital (approval No. D2020-68) on March 6, 2020.

Apoptosis of hepatocellular carcinoma HepG2 cells induced by seleno-ovalbumin (Se-OVA) via mitochondrial pathway

Seleno-ovalbumin (Se-OVA) was a selenium conjugating protein synthesized by the combination of ovalbumin (OVA) and inorganic selenium. In this paper, the structure of Se-OVA was characterized, and the anticancer effect of Se-OVA on hepatocellular carcinoma HepG2 cells was investigated. Through FT-IR, UV, endogenous fluorescence and XRD assays, it was found that the structural characterization of Se-OVA changed after seleno-modification. In addition, the cell assays showed that Se-OVA could induce apoptosis of HepG2 cells by arresting cell cycle in S phase, generating intracellular reactive oxygen species, reducing the mitochondrial transmembrane potential, and triggering the Bax- and Bcl-2-mediated mitochondria apoptosis pathway. These findings revealed that Se-OVA might serve as a novel anticancer drug for cancer adjuvant therapy.

Fluorescent tagging of endogenous Heme oxygenase-1 in human induced pluripotent stem cells for high content imaging of oxidative stress in various differentiated lineages

Tagging of endogenous stress response genes can provide valuable in vitro models for chemical safety assessment. Here, we present the generation and application of a fluorescent human induced pluripotent stem cell (hiPSC) reporter line for Heme oxygenase-1 (HMOX1), which is considered a sensitive and reliable biomarker for the oxidative stress response. CRISPR/Cas9 technology was used to insert an enhanced green fluorescent protein (eGFP) at the C-terminal end of the endogenous HMOX1 gene. Individual clones were selected and extensively characterized to confirm precise editing and retained stem cell properties. Bardoxolone-methyl (CDDO-Me) induced oxidative stress caused similarly increased expression of both the wild-type and eGFP-tagged HMOX1 at the mRNA and protein level. Fluorescently tagged hiPSC-derived proximal tubule-like, hepatocyte-like, cardiomyocyte-like and neuron-like progenies were treated with CDDO-Me (5.62–1000 nM) or diethyl maleate (5.62–1000 µM) for 24 h and 72 h. Multi-lineage oxidative stress responses were assessed through transcriptomics analysis, and HMOX1-eGFP reporter expression was carefully monitored using live-cell confocal imaging. We found that eGFP intensity increased in a dose-dependent manner with dynamics varying amongst lineages and stressors. Point of departure modelling further captured the specific lineage sensitivities towards oxidative stress. We anticipate that the newly developed HMOX1 hiPSC reporter will become a valuable tool in understanding and quantifying critical target organ cell-specific oxidative stress responses induced by (newly developed) chemical entities.

Structural Characterization of an Alkali-Soluble Polysaccharide from Angelica sinensis and Its Antitumor Activity in Vivo

A novel alkali-soluble polysaccharide (AASP) was isolated from Angelica sinensis (Oliv.) Diels under aqueous alkali treatment, and its structural characterization and antitumor activity in Vivo were evaluated in present study. Results of HPGPC and IC revealed that AASP was a neutral polysaccharide containing Ara, Gal and Glc in the mole ratio of 1.00 : 2.26 : 24.43, with the average molecular weight of 4.7 kDa. Periodate oxidation, Smith degradation, methylation, FT-IR, and NMR analyses further demonstrated that a preliminary structure of AASP was proposed as follows: (1→3)-linked arabinose, (1→6)-linked galactose, and (1→), (1→4), (1→6), (1→3,6)-linked glucose with α- and β-configuration. In Vivo antitumor assays, AASP exhibited prominent antitumor effects on H22 hepatoma cells with an inhibitory ratio of 48.57 % and effectively protected thymuses and spleens of tumor-bearing mice. Besides, AASP displayed a proliferation stimulating activity of immunocytes (splenocytes, peritoneal macrophages and natural killer cells), and an auxo-action for cytokines release (TNF-α, IL-2 and IFN-γ), leading to the apoptosis of H22 solid tumors cells via G0/G1 phase arrested. The above data demonstrated that AASP holds great application potential to be a safe and effective antitumor supplement in the future.

Purification, Structural Characteristics, and Biological Activities of Exopolysaccharide Isolated From Leuconostoc mesenteroides SN-8

In this study, a novel exopolysaccharide (EPS) was extracted from Leuconostoc mesenteroides Shen Nong's (SN)-8 which can be obtained from Dajiang. After the purification step, EPS-8-2 was obtained with molecular weights of 1.46 × 105 Da. The structural characterization of EPS indicated that the EPS belonged to the class polysaccharide, mainly composed of glucan and also contained certain mannose residues that were found to be connected by α-1,6 glycosidic bonds. Moreover, the results demonstrated that EPS displayed a significant capacity to scavenge free radical to some extent, and this anti-oxidant potential was found to be concentration dependent. The results further revealed that EPS displayed a significant inhibitory potential on the growth of HepG2 cells by promoting apoptosis and induced cell cycle arrest in G1 and G2 phases. Overall, these results suggested that EPS can be explored as a possible anti-cancer agent.

Synthesis of Double Interfering Biodegradable Nano-MgO Micelle Composites and Their Effect on Parkinson's Disease

Although gene therapy targeting the α-synuclein gene (SNCA) has achieved outstanding results in the treatment of Parkinson's disease (PD), the lack of a suitable gene delivery system and inadequate therapeutic effects remains a tremendous obstacle for RNAi therapy. Here, a degradable nano-MgO micelle composite (MgO(pDNA)-INS-Plu-mRNA-NGF) with double interference (mediated by RNAi and α-synuclein (α-syn)-targeted mRNA) was constructed. Binding mRNA treatment significantly increased the inhibitory effect compared to the reduction of α-syn expression by RNAi alone. Moreover, the cell experiments demonstrated that the viability of the PD cell model can be significantly improved by nano-MgO micelle composite treatment. More importantly, the composite has the ability to penetrate the blood brain barrier and deliver genes and mRNA to neurons through endocytosis mediated by the nerve growth factor and its receptors, thus significantly downregulating the expression of α-syn in the PD mice model without causing damage to other major organs. Overall, this work provides a novel insight into the design of biomaterials for gene therapy for PD.

Propagation of Mitochondria-Derived Reactive Oxygen Species within the Dipodascus magnusii Cells

Mitochondria are considered to be the main source of reactive oxygen species (ROS) in the cell. It was shown that in cardiac myocytes exposed to excessive oxidative stress, ROS-induced ROS release is triggered. However, cardiac myocytes have a network of densely packed organelles that do not move, which is not typical for the majority of eukaryotic cells. The purpose of this study was to trace the spatiotemporal development (propagation) of prooxidant-induced oxidative stress and its interplay with mitochondrial dynamics. We used Dipodascus magnusii yeast cells as a model, as they have advantages over other models, including a uniquely large size, mitochondria that are easy to visualize and freely moving, an ability to vigorously grow on well-defined low-cost substrates, and high responsibility. It was shown that prooxidant-induced oxidative stress was initiated in mitochondria, far preceding the appearance of generalized oxidative stress in the whole cell. For yeasts, these findings were obtained for the first time. Preincubation of yeast cells with SkQ1, a mitochondria-addressed antioxidant, substantially diminished production of mitochondrial ROS, while only slightly alleviating the generalized oxidative stress. This was expected, but had not yet been shown. Importantly, mitochondrial fragmentation was found to be primarily induced by mitochondrial ROS preceding the generalized oxidative stress development.

4,5-Seco-5,10-friedo-abietane-type diterpenoids with anticancer activity from Salvia atropatana Bunge

The purpose of this study is cytotoxicity-guided isolation of the petroleum ether fraction from the roots of Salvia atropatana for the first time, which has shown to growth inhibition and apoptosis induction in MCF-7 and PC3 cells. Bioassay-guided isolation method was conducted for finding compounds with highest cytotoxicity. Different extracts were prepared from the roots of Salvia atropatana. All extracts were tested for their cytotoxic activity against three cancer cell lines (PC3, MCF-7, and MDA-MB-231). The most cytotoxic extract was chosen for further isolation by column chromatography and HPLC. The chemical structures were determined by spectroscopic methods including 1D and 2D NMR. From the petroleum ether extract, four abietane-type diterpenoids, including a new abietane-type diterpenoid, named atropatanene (1), together with three known diterpenoids, 7α-acetoxyroyleanone (2), and a mixture of two isomers, saprorthoquinone and aethiopinone (3+4), were isolated. The latter exhibited substantial cytotoxicity with IC₅₀ value of 8.73 μg/ml against PC3 cells and led to an increasing number of cells in the subG1 region and an increase in the amount of Bax and cleavage of PARP protein, indicating apoptotic cell death. Owing to its numerous biological activities, Salvia species could be represented as a natural potential source against several cancer cell lines.

The Expression of E2F1, p53, and Caspase 3 in the Rat Dorsal Root Ganglia After Sciatic Nerve Transection

Neurotrauma is among the main causes of human disability and mortality. Nerve injury impairs not only neurons but also causes death of satellite glial cells remote from the injury site. We studied the dynamics of expression of different proapoptotic proteins (E2F1, p53, caspase 3) in the dorsal root ganglia (DRG) of a rat after sciatic nerve transection. TUNEL staining and immunoblotting were used for analysis of cell apoptosis and axotomy-induced biochemical changes. Apoptosis of glial cells was observed at 24 h after sciatic nerve transection and increased on day 7, when apoptosis of some neurons only started. The earliest proapoptotic event in the injured DRG was overexpression of transcription factor E2F1 at 4 h after sciatic nerve transection. This preceded the induction of p53 and cleavage of caspase 3 at 24-h post-axotomy. The nerve injury marker amyloid precursor protein and the nerve regeneration marker GAP-43 were overexpressed in DRG on day 7 after sciatic nerve transection. We also developed a novel fluorescence method for differential visualization of the rat DRG and nerves by means of double staining with propidium iodide and Hoechst 33342 that impart red and blue-green fluorescence, respectively. The present experiments showed that glial cells remote from the nerve transection site were more vulnerable to axotomy than DRG neurons. E2F1 and p53 may be considered promising molecular targets for development of potential neuroprotective agents.

Mapping the Architecture of Ferret Brains at Single-Cell Resolution

Mapping the cytoarchitecture of the whole brain can reveal the organizational logic of neural systems. However, this remains a significant challenge, especially for gyrencephalic brains with a large volume. Here we propose an integrated pipeline for generating a cytoarchitectonic atlas with single-cell resolution of the whole brain. To analyze a large-volume brain, we used a modified en-bloc Nissl staining protocol to achieve uniform staining of large-scale brain specimens from ferret (Mustela putorius furo). By combining whole-brain imaging and big data processing, we established strategies for parsing cytoarchitectural information at a voxel resolution of 0.33 μm × 0.33 μm × 1 μm and terabyte-scale data analysis. Using the cytoarchitectonic datasets for adult ferret brain, we identified giant pyramidal neurons in ferret brains and provide the first report of their morphological diversity, neurochemical phenotype, and distribution patterns in the whole brain in three dimensions. This pipeline will facilitate studies on the organization and development of the mammalian brains, from that of rodents to the gyrencephalic brains of ferret and even primates.

Integrated proteomics and metabolomics analysis reveals the antifungal mechanism of the C-coordinated O-carboxymethyl chitosan Cu(II) complex

With wide application in agriculture, copper fungicides have undergone three stages of development: inorganic copper, synthetic organic copper, and natural organic copper. Using chitin/chitosan (CS) as a substrate, the natural organic copper fungicide C-coordinated O-carboxymethyl chitosan Cu(II) complex (O-CSLn-Cu) was developed in the laboratory. Taking Phytophthora capsici Leonian as an example, we explored the antifungal mechanism of O-CSLn-Cu by combining tandem mass tag (TMT)-based proteomics with non-targeted liquid chromatography-mass spectrometry (LC-MS)-based metabolomics. A total of 1172 differentially expressed proteins were identified by proteomics analysis. According to the metabolomics analysis, 93 differentially metabolites were identified. Acetyl-CoA-related and membrane localized proteins showed significant differences in the proteomics analysis. Most of the differential expressed metabolites were distributed in the cytoplasm, followed by mitochondria. The integrated analysis revealed that O-CSLn-Cu could induce the "Warburg effect", with increased glycolysis in the cytoplasm and decreased metabolism in the mitochondria. Therefore, P. capsici Leonian had to compensate for ATP loss in the TCA cycle by increasing the glycolysis rate. However, this metabolic shift could not prevent the death of P. capsici Leonian. To verify this hypothesis, a series of biological experiments, such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), and enzyme activity measurements were carried out. The results suggest that O-CSLn-Cu causes mitochondrial injury, which consequently leads to excessive ROS levels and insufficient ATP levels, thereby killing P. capsici Leonian.

Mechanisms of Neuronal Death in the Cerebral Cortex during Aging and Development of Alzheimer's Disease-Like Pathology in Rats

Alzheimer's disease (AD) is the commonest type of late-life dementia and damages the cerebral cortex, a vulnerable brain region implicated in memory, emotion, cognition, and decision-making behavior. AD is characterized by progressive neuronal loss, but the mechanisms of cell death at different stages of the disease remain unknown. Here, by means of OXYS rats as an appropriate model of the most common (sporadic) AD form, we studied the main pathways of cell death during development of AD-like pathology, including the preclinical stage. We found that apoptosis is activated at the pre-symptomatic stage (age 20 days) correlating with the retardation of brain development in the OXYS strain early in life. Progression of the AD-like pathology was accompanied by activation of apoptosis and necroptosis resulting from a decline of autophagy-mediated proteostasis. Our results are consistent with the idea that the nature of changes in the pathways of apoptosis, autophagy, and necrosis depends on the stage of AD.

Dcf1 Affects Memory and Anxiety by Regulating NMDA and AMPA Receptors

The hippocampus is critical for memory and emotion and both N-methyl-D-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl- 4-isoxazolepropionic acid (AMPA) receptors are known to contribute for those processes. However, the underlying molecular mechanisms remain poorly understood. We have previously found that mice undergo memory decline upon dcf1 deletion through ES gene knockout. In the present study, a nervous system-specific dcf1 knockout (NKO) mouse was constructed, which was found to present severely damaged neuronal morphology. The damaged neurons caused structural abnormalities in dendritic spines and decreased synaptic density. Decreases in hippocampal NMDA and AMPA receptors of NKO mice lead to abnormal long term potentiation (LTP) at DG, with significantly decreased performance in the water maze, elevated- plus maze, open field and light and dark test. Investigation into the underlying molecular mechanisms revealed that dendritic cell factor 1 (Dcf1) contributes for memory and emotion by regulating NMDA and AMPA receptors. Our results broaden the understanding of synaptic plasticity's role in cognitive function, thereby expanding its known list of functions.

Seleno-short-chain chitosan induces apoptosis in human breast cancer cells through mitochondrial apoptosis pathway in vitro

Seleno-short-chain chitosan (SSCC) was a synthesized chitosan derivative with the molecular weight of 4826.986 Da. The study is aimed to investigate cytotoxicity of SSCC on human breast cancer MCF-7 and BT-20 cells and explore apoptosis-related mechanism in vitro. The MTT (3- [4,5-Dimethylthiazol-2-yl]-2, 5-diphenylterazolium bromide) assay showed that SSCC exhibited significantly cytotoxic effects on MCF-7 and BT-20 cells in a dose- and time-dependent manner, and the effective inhibitory concentration was 100 μg/ml and 200 μg/ml, respectively. Apoptosis assay of these two kinds of cells was determined by Hoechst 33,342/PI and Annexin V-FITC/PI double staining. The cell cycle assay showed that SSCC triggered S and G2/M phase cell cycle arrest in MCF-7 cells and S phase cell cycle arrest in BT-20 cells in a time-dependent manner. Further studies demonstrated that SSCC led to the generation of reactive oxygen species (ROS) and the disruption of mitochondrial membrane potential (MMP) in these two kinds of cells. N- acetyl-L cysteine (NAC), as a radical scavenger, significantly inhibited the generation of ROS and decreased the apoptosis of MCF-7 and BT-20 cells. Moreover, the expression of mitochondrial apoptosis-related proteins was detected by western blot assay. SSCC up-regulated the expression of Bax, down-regulated the expression of Bcl-2, subsequently increased the release of cytochrome c from mitochondria to cytoplasm, and activated the cleavage of caspase-9 and -3, which finally induced apoptosis in MCF-7 and BT-20 cells in vitro. Consequently, these data indicated that SSCC could induce apoptosis of MCF-7and BT-20 cells in vitro by mitochondrial pathway.

Alcohol-soluble polysaccharide from Astragalus membranaceus: Preparation, characteristics and antitumor activity

The alcohol-soluble polysaccharide (ASP) was extracted from Astragalus membranaceus, and their preliminary structural characteristics and in vivo antitumor activity were investigated in this study. The contents of total sugar, protein and uronic acid in ASP was 92.04%, 0.51% and 1.42%, respectively. FTIR and IC results indicated that ASP (about 2.1 × 10³ Da) was a neutral polysaccharide composed of arabinose, galactose, glucose and mannose (molar ratio: 1.00:0.98:3.01:1.52) with pyranose ring and α-type glycosidic linkages. Besides, ASP could significantly inhibit the growth of H22 heptoma cells in vivo via improving the levels of serum cytokines (TNF-α, IL-2 and IFN-γ) and activities of immune cells (macrophages, lymphocytes and NK cells), thereby inducing tumor cell apoptosis and attenuating their accessional damages. These results suggested that ASP may serve as a novel potential antitumor agent in the future.

Lipidated α/α-AA heterogeneous peptides as antimicrobial agents

With an increase of resistance in bacteria there is an urgent need for alternative treatment methods that could complement conventional antibiotics. In the past two decades, focus has been drawn to Host Defense Peptides (HDPs) as potential antibiotic agents. Herein we reported our studies on the development of lipidated α/α-AA heterogeneous peptides as a new class of HDP mimetics. These compounds showed potent antimicrobial activity toward both Gram-positive and Gram-negative bacteria, and they also displayed excellent selectivity as they only exhibited limited hemolytic activity. The fluorescence microscopy suggested that the mechanism of action of these heterogeneous peptides is bacterial membrane disruption, which is believed to be the major reason why it is difficult for bacteria to develop resistance. The subsequent time kill studies suggested that these compounds could rapidly eradicate bacteria. Moreover, this class of compounds could also effectively clear biofilms formed by both Gram-positive and Gram-negative bacteria. These findings suggested that lipidated α/α-AA heterogeneous peptides, as a new class of peptidomimetics, are promising antibiotic agents combating antibiotic resistance.

Triple-Gene Therapy for Stroke: A Proof-of-Concept in Vivo Study in Rats

Natural brain repair after stroke is extremely limited, and current therapeutic options are even more scarce with no clinical break-through in sight. Despite restricted regeneration in the central nervous system, we have previously proved that human umbilical cord blood mono-nuclear cells (UCB-MC) transduced with adenoviral vectors carrying genes encoding vascular endothelial growth factor (VEGF), glial cell-derived neurotrophic factor (GDNF), and neural cell adhesion molecule (NCAM) successfully rescued neurons in amyotrophic lateral sclerosis and spinal cord injury. This proof-of-principle project was aimed at evaluating the beneficial effects of the same triple-gene approach in stroke. Rats subjected to distal occlusion of the middle cerebral artery were treated intrathecally with a combination of these genes either directly or using our cell-based (UCB-MC) approach. Various techniques and markers were employed to evaluate brain injury and subsequent recovery after treatment. Brain repair was most prominent when therapeutic genes were delivered via adenoviral vector- or UCB-MC-mediated approach. Remodeling of brain cortex in the stroke area was confirmed by reduction of infarct volume and attenuated neural cell death, depletion of astrocytes and microglial cells, and increase in the number of oligodendroglial cells and synaptic proteins expression. These results imply that intrathecal injection of genetically engineered UCB-MC over-expressing therapeutic molecules (VEGF, GDNF, and NCAM) following cerebral blood vessel occlusion might represent a novel avenue for future research into treating stroke.

Spinal Cord Molecular and Cellular Changes Induced by Adenoviral Vector- and Cell-Mediated Triple Gene Therapy after Severe Contusion

The gene therapy has been successful in treatment of spinal cord injury (SCI) in several animal models, although it still remains unavailable for clinical practice. Surprisingly, regardless the fact that multiple reports showed motor recovery with gene therapy, little is known about molecular and cellular changes in the post-traumatic spinal cord following viral vector- or cell-mediated gene therapy. In this study we evaluated the therapeutic efficacy and changes in spinal cord after treatment with the genes encoding vascular endothelial growth factor (VEGF), glial cell-derived neurotrophic factor (GDNF), angiogenin (ANG), and neuronal cell adhesion molecule (NCAM) applied using both approaches. Therapeutic genes were used for viral vector- and cell-mediated gene therapy in two combinations: (1) VEGF+GDNF+NCAM and (2) VEGF+ANG+NCAM. For direct gene therapy adenoviral vectors based on serotype 5 (Ad5) were injected intrathecally and for cell-mediated gene delivery human umbilical cord blood mononuclear cells (UCB-MC) were simultaneously transduced with three Ad5 vectors and injected intrathecally 4 h after the SCI. The efficacy of both treatments was confirmed by improvement in behavioral (BBB) test. Molecular and cellular changes following post-traumatic recovery were evaluated with immunofluorescent staining using antibodies against the functional markers of motorneurons (Hsp27, synaptophysin, PSD95), astrocytes (GFAP, vimentin), oligodendrocytes (Olig2, NG2, Cx47) and microglial cells (Iba1). Our results suggest that both approaches with intrathecal delivery of therapeutic genes may support functional recovery of post-traumatic spinal cord via lowering the stress (down regulation of Hsp25) and enhancing the synaptic plasticity (up regulation of PSD95 and synaptophysin), supporting oligodendrocyte proliferation (up regulation of NG2) and myelination (up regulation of Olig2 and Cx47), modulating astrogliosis by reducing number of astrocytes (down regulation of GFAP and vimetin) and microglial cells (down regulation of Iba1).

Enhancing Photodynamic Therapy through Resonance Energy Transfer Constructed Near-Infrared Photosensitized Nanoparticles

Photodynamic therapy (PDT) is an important cancer treatment modality due to its minimally invasive nature. However, the efficiency of existing PDT drug molecules in the deep-tissue-penetrable near-infrared (NIR) region has been the major hurdle that has hindered further development and clinical usage of PDT. Thus, herein a strategy is presented to utilize a resonance energy transfer (RET) mechanism to construct a novel dyad photosensitizer which is able to dramatically boost NIR photon utility and enhance singlet oxygen generation. In this work, the energy donor moiety (distyryl-BODIPY) is connected to a photosensitizer (i.e., diiodo-distyryl-BODIPY) to form a dyad molecule (RET-BDP). The resulting RET-BDP shows significantly enhanced absorption and singlet oxygen efficiency relative to that of the acceptor moiety of the photosensitizer alone in the NIR range. After being encapsulated with biodegradable copolymer pluronic F-127-folic acid (F-127-FA), RET-BDP molecules can form uniform and small organic nanoparticles that are water soluble and tumor targetable. Used in conjunction with an exceptionally low-power NIR LED light irradiation (10 mW cm-2 ), these nanoparticles show superior tumor-targeted therapeutic PDT effects against cancer cells both in vitro and in vivo relative to unmodified photosensitizers. This study offers a new method to expand the options for designing NIR-absorbing photosensitizers for future clinical cancer treatments.

Toxic effect of acrylamide on the development of hippocampal neurons of weaning rats

Although numerous studies have examined the neurotoxicity of acrylamide in adult animals, the effects on neuronal development in the embryonic and lactational periods are largely unknown. Thus, we examined the toxicity of acrylamide on neuronal development in the hippocampus of fetal rats during pregnancy. Sprague-Dawley rats were mated with male rats at a 1:1 ratio. Rats were administered 0, 5, 10 or 20 mg/kg acrylamide intragastrically from embryonic days 6–21. The gait scores were examined in pregnant rats in each group to analyze maternal toxicity. Eight weaning rats from each group were also euthanized on postnatal day 21 for follow-up studies. Nissl staining was used to observe histological change in the hippocampus. Immunohistochemistry was conducted to observe the condition of neurites, including dendrites and axons. Western blot assay was used to measure the expression levels of the specific nerve axon membrane protein, growth associated protein 43, and the presynaptic vesicle membrane specific protein, synaptophysin. The gait scores of gravid rats significantly increased, suggesting that acrylamide induced maternal motor dysfunction. The number of neurons, as well as expression of growth associated protein 43 and synaptophysin, was reduced with increasing acrylamide dose in postnatal day 21 weaning rats. These data suggest that acrylamide exerts dose-dependent toxic effects on the growth and development of hippocampal neurons of weaning rats.