Mutant VPS35-D620N induces motor dysfunction and impairs DAT-mediated dopamine recycling pathway.

The D620N mutation in vacuolar protein sorting protein 35 (VPS35) gene has been identified to be linked to late onset familial Parkinson disease (PD). However, the pathophysiological roles of VPS35-D620N in PD remain unclear. Here, we generated the transgenic Caenorhabditis elegans overexpressing either human wild type or PD-linked mutant VPS35-D620N in neurons. C. elegans expressing VPS35-D620N, compared with non-transgenic controls, showed movement disorders and dopaminergic neuron loss. VPS35-D620N worms displayed more swimming induced paralysis but showed no defects in BSR assays, thus indicating the disruption of dopamine (DA) recycling back inside neurons. Moreover, VPS35 formed a protein interaction complex with DA transporter (DAT), RAB5, RAB11 and FAM21. In contrast, the VPS35-D620N mutant destabilized these interactions, thus disrupting DAT transport from early endosomes to recycling endosomes, and decreasing DAT at the cell surface. These effects together increased DA in synaptic clefts, and led to dopaminergic neuron degeneration and motor dysfunction. Treatment with reserpine significantly decreased the swimming induced paralysis in VPS35-D620N worms, as compared with vehicle treated VPS35-D620N worms. Our studies not only provide novel insights into the mechanisms of VPS35-D620N-induced dopaminergic neuron degeneration and motor dysfunction via disruption of DAT function and the DA signaling pathway but also indicate a potential strategy to treat VPS35-D620N-related PD and other disorders.

The role of bile acid receptor TGR5 in regulating inflammatory signalling.

Takeda G protein-coupled receptor 5 (TGR5) is a bile acid receptor, and its role in regulating metabolism after binding with bile acids has been established. Since the immune response depends on metabolism to provide biomolecules and energy to cope with challenging conditions, emerging evidence reveals the regulatory effects of TGR5 on the immune response. An in-depth understanding of the effect of TGR5 on immune regulation can help us disentangle the interaction of metabolism and immune response, accelerating the development of TGR5 as a therapeutic target. Herein, we reviewed more than 200 articles published in the last 20 years in PubMed, to discuss the roles of TGR5 in regulating inflammatory response, the molecular mechanism, as well as existing problems. Particularly, its anti-inflammation effect is emphasized.

Profiling the human protein-DNA interactome reveals ERK2 as a transcriptional repressor of interferon signaling.

Protein-DNA interactions (PDIs) mediate a broad range of functions essential for cellular differentiation, function, and survival. However, it is still a daunting task to comprehensively identify and profile sequence-specific PDIs in complex genomes. Here, we have used a combined bioinformatics and protein microarray-based strategy to systematically characterize the human protein-DNA interactome. We identified 17,718 PDIs between 460 DNA motifs predicted to regulate transcription and 4,191 human proteins of various functional classes. Among them, we recovered many known PDIs for transcription factors (TFs). We identified a large number of unanticipated PDIs for known TFs, as well as for previously uncharacterized TFs. We also found that over three hundred unconventional DNA-binding proteins (uDBPs)--which include RNA-binding proteins, mitochondrial proteins, and protein kinases--showed sequence-specific PDIs. One such uDBP, ERK2, acts as a transcriptional repressor for interferon gamma-induced genes, suggesting important biological roles for such proteins.

TREM2 mediates physical exercise-promoted neural functional recovery in rats with ischemic stroke via microglia-promoted white matter repair.

BACKGROUND: The repair of white matter injury is of significant importance for functional recovery after ischemic stroke, and the up-regulation of triggering receptors expressed on myeloid cells 2 (TREM2) after ischemic stroke is neuroprotective and implicated in remyelination. However, the lack of effective therapies calls for the need to investigate the regenerative process of remyelination and the role of rehabilitation therapy. This study sought to investigate whether and how moderate physical exercise (PE) promotes oligodendrogenesis and remyelination in rats with transient middle cerebral artery occlusion (tMCAO). METHODS: Male Sprague-Dawley rats (weighing 250-280 g) were subjected to tMCAO. AAV-shRNA was injected into the lateral ventricle to silence the Trem2 gene before the operation. The rats in the physical exercise group started electric running cage training at 48 h after the operation. The Morris water maze and novel object recognition test were used to evaluate cognitive function. Luxol fast blue staining, diffusion tensor imaging, and electron microscopy were used to observe myelin injury and repair. Immunofluorescence staining was applied to observe the proliferation and differentiation of oligodendrocyte precursor cells (OPCs). Expression of key molecules were detected using immunofluorescence staining, quantitative real-time polymerase chain reaction, Western blotting, and Enzyme-linked immunosorbent assay, respectively. RESULTS: PE exerted neuroprotective efects by modulating microglial state, promoting remyelination and recovery of neurological function of rats over 35 d after stroke, while silencing Trem2 expression in rats suppressed the aforementioned effects promoted by PE. In addition, by leveraging the activin-A neutralizing antibody, we found a direct beneficial effect of PE on microglia-derived activin-A and its subsequent role on oligodendrocyte differentiation and remyelination mediated by the activin-A/Acvr axis. CONCLUSIONS: The present study reveals a novel regenerative role of PE in white matter injury after stroke, which is mediated by upregulation of TREM2 and microglia-derived factor for oligodendrocytes regeneration. PE is an effective therapeutic approach for improving white matter integrity and alleviating neurological function deficits after ischemic stroke.

G2019S-LRRK2 mutation enhances MPTP-linked Parkinsonism in mice.

Parkinson's disease (PD) is a common neurodegenerative disease with a heterogeneous etiology that involves genetic and environmental factors or exogenous. Current LRRK2 PD animal models only partly reproduce the characteristics of the disease with very subtle dopaminergic neuron degeneration. We developed a new model of PD that combines a sub-toxic MPTP insult to the G2019S-LRRK2 mutation. Our newly generated mice, overexpressing mutant G2019S-LRRK2 protein in the brain, displayed a mild, age-dependent progressive motor impairment, but no reduction of lifespan. Cortical neurons from G2019S-LRRK2 mice showed an increased vulnerability to stress insults, compared with neurons overexpressing wild-type WT-LRRK2, or non-transgenic (nTg) neurons. The exposure of LRRK2 transgenic mice to a sub-toxic dose of MPTP resulted in severe motor impairment, selective loss of dopamine neurons and increased astrocyte activation, whereas nTg mice with MPTP exposure showed no deficits. Interestingly, mice overexpressing WT-LRRK2 showed a significant impairment that was milder than for the mutant G2019S-LRRK2 mice. L-DOPA treatments could partially improve the movement impairments but did not protect the dopamine neuron loss. In contrast, treatments with an LRRK2 kinase inhibitor significantly reduced the dopaminergic neuron degeneration in this interaction model. Our studies provide a novel LRRK2 gene-MPTP interaction PD mouse model, and a useful tool for future studies of PD pathogenesis and therapeutic intervention.

Specific detection of fusion transcripts based on a duplex-specific nuclease and isothermal exponential amplification reaction.

Fusion genes are mostly found in tumor tissues, but are in low expression levels in healthy tissues, making them good candidate biomarkers for tumor diagnosis and therapy. Here, we propose a duplex-specific nuclease-isothermal exponential amplification reaction (DSN-IEXPAR) method for the detection of fusion transcripts. A DNA probe is specifically designed for fusion transcript recognition and hybridization, and DSN cleavages the DNA probe in the DNA/RNA duplex. Through controlling the recognition and cleavage temperature, DSN can only cut the DNA probe fully matched with the target fusion transcript rather than other transcripts containing partial the same sequence, endowing the proposed method with high specificity to the fusion transcript in the presence of homologous sequences. The truncated DNA probe after cutting can subsequently trigger IEXPAR as a probe, so as low as 100 fM fusion transcript can be detected with the proposed DSN-IEXPAR. The evaluation of the analytical performance of DSN-IEXPAR demonstrates that it can provide an effective platform for fusion transcript detection in the ordinary laboratory and clinical diagnosis.

Sensitive detection of fusion transcripts with padlock probe-based continuous cascade amplification (P-CCA).

Gene fusion, resulting from chromosomal rearrangements, is the juxtaposition of two or more original genes into the same set to form a functional gene. The significant specificity of fusion genes for tumor cells makes them promising candidates for diagnostic biomarkers and therapeutic targets. The sensitive detection of fusion transcripts is of great significance in biological research and disease diagnosis. Here, we propose a method for the sensitive detection of PML-RARα gene fusion transcripts by the direct ligation of the padlock probe at the junction site, and the cyclized DNA then triggers a continuous cascade amplification of two subsequent amplification reactions: rolling circle amplification (RCA) and loop-mediated isothermal amplification (LAMP). Due to the ability of the ligation reaction to differentiate mismatched sequences and the high amplification efficiency of continuous cascade amplification reactions, the proposed method can detect as low as 1 fM targets with high specificity, and has been successfully applied to real samples. Through a facile design of the triggering sequence in padlock probes, the cascade RCA and LAMP can be integrated into one-tube isothermal reactions with a simple one-step operation. Therefore, this work provides a convenient padlock probe-based continuous cascade amplification (P-CCA) method for the detection of fusion transcripts, and offers a fast and reliable platform for the early clinical diagnosis of gene fusion-related cancers.

CT-based radiomics to predict development of macrovascular invasion in hepatocellular carcinoma: A multicenter study.

BACKGROUND: Macrovascular invasion (MaVI) occurs in nearly half of hepatocellular carcinoma (HCC) patients at diagnosis or during follow-up, which causes severe disease deterioration, and limits the possibility of surgical approaches. This study aimed to investigate whether computed tomography (CT)-based radiomics analysis could help predict development of MaVI in HCC. METHODS: A cohort of 226 patients diagnosed with HCC was enrolled from 5 hospitals with complete MaVI and prognosis follow-ups. CT-based radiomics signature was built via multi-strategy machine learning methods. Afterwards, MaVI-related clinical factors and radiomics signature were integrated to construct the final prediction model (CRIM, clinical-radiomics integrated model) via random forest modeling. Cox-regression analysis was used to select independent risk factors to predict the time of MaVI development. Kaplan-Meier analysis was conducted to stratify patients according to the time of MaVI development, progression-free survival (PFS), and overall survival (OS) based on the selected risk factors. RESULTS: The radiomics signature showed significant improvement for MaVI prediction compared with conventional clinical/radiological predictors (P < 0.001). CRIM could predict MaVI with satisfactory areas under the curve (AUC) of 0.986 and 0.979 in the training (n = 154) and external validation (n = 72) datasets, respectively. CRIM presented with excellent generalization with AUC of 0.956, 1.000, and 1.000 in each external cohort that accepted disparate CT scanning protocol/manufactory. Peel9_fos_InterquartileRange [hazard ratio (HR) = 1.98; P < 0.001] was selected as the independent risk factor. The cox-regression model successfully stratified patients into the high-risk and low-risk groups regarding the time of MaVI development (P < 0.001), PFS (P < 0.001) and OS (P = 0.002). CONCLUSIONS: The CT-based quantitative radiomics analysis could enable high accuracy prediction of subsequent MaVI development in HCC with prognostic implications.

Chronic colitis exacerbates NLRP3-dependent neuroinflammation and cognitive impairment in middle-aged brain.

BACKGROUND: Neuroinflammation is a major driver of age-related brain degeneration and concomitant functional impairment. In patients with Alzheimer's disease, the most common form of age-related dementia, factors that enhance neuroinflammation may exacerbate disease progression, in part by impairing the glymphatic system responsible for clearance of pathogenic beta-amyloid. Inflammatory bowel diseases (IBDs) induce neuroinflammation and exacerbate cognitive impairment in the elderly. The NACHT-LRR and pyrin (PYD) domain-containing protein 3 (NLRP3) inflammasome has been implicated in neuroinflammation. Therefore, we examined if the NLRP3 inflammasome contributes to glymphatic dysfunction and cognitive impairment in an aging mouse model of IBD. METHODS: Sixteen-month-old C57BL/6J and NLRP3 knockout (KO) mice received 1% wt/vol dextran sodium sulfate (DSS) in drinking water to model IBD. Colitis induction was confirmed by histopathology. Exploratory behavior was examined in the open field, associative memory by the novel-object recognition and Morris water maze tests, glymphatic clearance by in vivo two-photon imaging, and neuroinflammation by immunofluorescence and western blotting detection of inflammatory markers. RESULTS: Administration of DSS induced colitis, impaired spatial and recognition memory, activated microglia, and increased A1-like astrocyte numbers. In addition, DSS treatment impaired glymphatic clearance, aggravated amyloid plaque accumulation, and induced neuronal loss in the cortex and hippocampus. These neurodegenerative responses were associated with increased NLRP3 inflammasome expression and accumulation of gut-derived T lymphocytes along meningeal lymphatic vessels. Conversely, NLRP3 depletion protected against cognitive dysfunction, neuroinflammation, and neurological damage induced by DSS. CONCLUSIONS: Colitis can exacerbate age-related neuropathology, while suppression of NLRP3 inflammasome activity may protect against these deleterious effects of colitis.

Fish consumption and awareness of fish advisories among Burmese refugees: A respondent-driven sampling study in Milwaukee, Wisconsin.

BACKGROUND: Since 2000, more than 6000 Burmese refugees were resettled in Wisconsin. The Burmese diet is traditionally rich in fish and fish products, and studies show that Burmese refugees continue to rely on local waterbodies for food. Given that Wisconsin has five Areas of Concern (AOC) that are severely affected by pollution, long-term exposure to contaminants in sport-caught fish is a health concern. To better understand fish consumption among Burmese refugees, we conducted a biomonitoring study in Milwaukee. The present study examined Burmese refugees' fish consumption habits and awareness of fish advisories. METHODS: We used respondent-driven sampling (RDS) methodology to recruit Burmese refugees in Milwaukee. RDS Analysis Tool 7.1 was used to obtain adjusted population estimates for demographic characteristics, fish consumption habits, and awareness of fish advisories. Homophily and equilibrium were investigated to evaluate the effectiveness of RDS in recruitment. RESULTS: Initiated by five active seeds, we recruited 103 respondents to participate in the study. Respondents had a strong preference to recruit those with the same ethnicity (Homophily-score: 0.614 to 0.699) and a relatively weak preference to recruit those with the same sex (Homophily-score: 0.188 to 0.222) to participate in our study. The majority (72.5%) of respondents were women of childbearing age (WCBA). Most (68.5%) had 8th grade or less education. Regarding sportfish consumption per month in the last year, 30.6% reported eating 1-3 meals and 21.2% reported eating more than 3 meals. When asked about purchased fish consumption per month, 26.3% reported eating 1-3 meals. The overwhelming majority were not aware of safe-eating sportfish guidelines for Wisconsin (88.3%) or Milwaukee waterbodies (96.6%). CONCLUSIONS: RDS is an effective methodology to recruit hard-to-reach populations, such as the Burmese surveyed in this study. High percentages of WCBA eating potentially contaminated sportfish meals, low awareness of consumption advisories, and limited economic resources make the Burmese population more likely to be exposed to contaminants. Health education efforts should be focused in this vulnerable population, particularly among Burmese WCBA.

The improved antiviral activities of amino-modified chitosan derivatives on Newcastle virus.

Chitosan is widely used as a medical material because of its excellent biological activities. However, the low solubility of natural chitosan limited its medicinal activity to some extent. The solubility can be improved by introducing more active groups and lowering molecular weight. Therefore, 6-amine chitosan derivatives were synthesized in this paper since more active groups were introduced to increase the medicinal activity. Those derivatives were characterized by elemental analysis, HPLC, and FT-IR and the antiviral activity was tested by hemagglutination tests. Finally, 6-amine chitosan derivatives improved the antiviral activity, especially after the introduction of bromine ion. When 6-deoxy-6-bromo-N-phthaloyl chitosan was 1 g/L, they reduced the hemagglutination titer of virus to zero. The RT-PCR result showed that the expression level of TNF-α and IFN-ß increased significantly, which indicated that the antiviral activity of amino-modified chitosan worked through the stimulation of immune response.

The Biomonitoring of Great Lakes Populations-III Program: The Milwaukee Angler Project.

As part of our continued effort to highlight innovative approaches to improve the health and environment of communities, the Journal is pleased to publish regular columns from the Agency for Toxic Substances and Disease Registry (ATSDR) at the Centers for Disease Control and Prevention (CDC). ATSDR serves the public by using the best science, taking responsive public health actions, and providing trusted health information to prevent harmful exposures and diseases related to toxic substances. The purpose of this column is to inform readers of ATSDR's activities and initiatives to better understand the relationship between exposure to hazardous substances in the environment, its impact on human health, and how to protect public health. The conclusions of this column are those of the author(s) and do not necessarily represent the official position of ATSDR or CDC.

Mutant G2019S-LRRK2 Induces Abnormalities in Arteriolar Cerebral Blood Volume in Mouse Brains: An MRI Study.

BACKGROUND: Parkinson's disease (PD) is the second most common neurodegenerative disease and the most common movement disorder characterized by motor impairments resulting from midbrain dopamine neuron loss. Abnormalities in small pial arteries and arterioles, which are the primary pathways of local delivery of nutrients and oxygen in brain tissue, have been reported in many neurodegenerative diseases including PD. Mutations in LRRK2 cause genetic PD and contribute to sporadic PD. The most common PD-linked mutation LRRK2 G2019S contributes 20-47% of genetic forms of PD in Caucasian populations. The human LRRK2 G2019S transgenic mouse model displays PD-like movement impairment and was used to identify novel LRRK2 inhibitors, which provides a useful model for studying microvascular abnormalities in PD. OBJECTIVES: To investigate abnormalities in arteriolar cerebral blood volume (CBVa) in various brain regions using the inflow-based vascular-space occupancy (iVASO) MRI technique in LRRK2 mouse models of PD. METHODS: Anatomical and iVASO MRI scans were performed in 5 female and 7 male nontransgenic (nTg), 3 female and 4 male wild-type (WT) LRRK2, and 5 female and 7 male G2019S-LRRK2 mice of 9 months of age. CBVa was calculated and compared in the substantia nigra (SN), olfactory cortex, and prefrontal cortex. RESULTS: Compared to nTg mice, G2019S-LRRK2 mice showed decreased CBVa in the SN, but increased CBVa in the olfactory and prefrontal cortex in both male and female groups, whereas WT-LRRK2 mice showed no change in CBVa in the SN (male and female), the olfactory (female), and prefrontal (female) cortex, but a slight increase in CBVa in the olfactory and prefrontal cortex in the male group only. CONCLUSIONS: Alterations in the blood volume of small arteries and arterioles (CBVa) were detected in the G2019S-LRRK2 mouse model of PD. The opposite changes in CBVa in the SN and the cortex indicate that PD pathology may have differential effects in different brain regions. Our results suggest the potential value of CBVa as a marker for clinical PD studies.

Blockade of IL-17A/IL-17R Pathway Protected Mice from Sepsis-Associated Encephalopathy by Inhibition of Microglia Activation.

Sepsis-associated encephalopathy (SAE) is a poorly understood condition that leads to long-term cognitive impairment and increased mortality in survivors. Recent research revealed that IL-17A/IL-17R might serve as a checkpoint in microglia-mediated neuroinflammation. The present study was designed to determine the specific role of IL-17A-mediated microglia activation in the development of SAE. A mouse model of SAE was induced by cecal ligation and puncture (CLP), and behavior performance was evaluated by the inhibitory avoidance test and the open field test. Cytokine expression and microglia activation in brain tissue were determined at 6 h, 12 h, 24 h, 48 h, and day 7 post surgery. Further, septic mice were intracerebral ventricle- (i.c.v.-) injected with recombinant IL-17A, anti-IL-17A ab, anti-IL-17R ab, or isotype controls to evaluate the potential effects of IL-17A/IL-17R blockade in the prevention of SAE. Septic peritonitis induced significant impairment of learning memory and exploratory activity, which was associated with a higher expression of IL-17A, IL-1ß, and TNF-α in the brain homogenate. Fluorescence intensity of Iba-1 and IL-17R in the hippocampus was significantly increased following CLP. Treatment with recombinant IL-17A enhanced the neuroinflammation and microglia activation in CLP mice. On the contrary, neutralizing anti-IL-17A or anti-IL-17R antibodies mitigated the CNS inflammation and microglia activation, thus alleviating the cognitive dysfunction. Furthermore, as compared to the sham control, microglia cultured from CLP mice produced significantly higher levels of cytokines and expressed with higher fluorescence intensity of Iba-1 in response to IL-17A or LPS. Pretreatment with anti-IL-17R ab suppressed the Iba-1 expression and cytokine production in microglia stimulated by IL-17A. In conclusion, blockade of the IL-17A/IL-17R pathway inhibited microglia activation and neuroinflammation, thereby partially reversing sepsis-induced cognitive impairment. The present study suggested that the IL-17A/IL-17R signaling pathway had an important, nonredundant role in the development of SAE.

How Do Women View Risk-Based Mammography Screening? A Qualitative Study.

BACKGROUND: Decades of persuasive messages have reinforced the importance of traditional screening mammography at regular intervals. A potential new paradigm, risk-based screening, adjusts mammography frequency based on a woman's estimated breast cancer risk in order to maximize mortality reduction while minimizing false positives and overdiagnosis. Women's views of risk-based screening are unknown. OBJECTIVE: To explore women's views and personal acceptability of a potential risk-based mammography screening paradigm. DESIGN: Four semi-structured focus group discussions about screening mammography and surveys before provision of information about risk-based screening. We analyzed coded focus group transcripts using a mixed deductive (content analysis) and inductive (grounded theory) approach. PARTICIPANTS: Convenience sample of 29 women (40-74 years old) with no personal history of breast cancer recruited by print and online media in New Hampshire and Vermont. RESULTS: Twenty-seven out of 29 women reported having undergone mammography screening. All participants were white and most were highly educated. Some women accepted the idea that early cancer detection with traditional screening was beneficial-although many also reported hearing inconsistent recommendations from clinicians and mixed messages from media reports about mammography. Some women were familiar with a risk-based screening paradigm (primarily related to cervical cancer, n = 8) and thought matching screening mammography frequency to personal risk made sense (n = 8). Personal acceptability of risk-based screening was mixed. Some believed risk-based screening could reduce the harms of false positives and overdiagnosis (n = 7). Others thought screening less often might result in missing a dangerous diagnosis (n = 14). Many (n = 18) expressed concerns about the feasibility of risk-based screening and questioned whether breast cancer risk estimates could be accurate. Some suspected that risk-based mammography was motivated by a desire to save money (n = 6). CONCLUSION: Some women thought risk-based screening made sense. Willingness to abandon traditional screening for the new paradigm was mixed. Broad acceptability of risk-based screening will require clearer communication about its rationale and feasibility and consistent messages from the health care team.

Towards an Iterated Game Model with Multiple Adversaries in Smart-World Systems.

Diverse and varied cyber-attacks challenge the operation of the smart-world system that is supported by Internet-of-Things (IoT) (smart cities, smart grid, smart transportation, etc.) and must be carefully and thoughtfully addressed before widespread adoption of the smart-world system can be fully realized. Although a number of research efforts have been devoted to defending against these threats, a majority of existing schemes focus on the development of a specific defensive strategy to deal with specific, often singular threats. In this paper, we address the issue of coalitional attacks, which can be launched by multiple adversaries cooperatively against the smart-world system such as smart cities. Particularly, we propose a game-theory based model to capture the interaction among multiple adversaries, and quantify the capacity of the defender based on the extended Iterated Public Goods Game (IPGG) model. In the formalized game model, in each round of the attack, a participant can either cooperate by participating in the coalitional attack, or defect by standing aside. In our work, we consider the generic defensive strategy that has a probability to detect the coalitional attack. When the coalitional attack is detected, all participating adversaries are penalized. The expected payoff of each participant is derived through the equalizer strategy that provides participants with competitive benefits. The multiple adversaries with the collusive strategy are also considered. Via a combination of theoretical analysis and experimentation, our results show that no matter which strategies the adversaries choose (random strategy, win-stay-lose-shift strategy, or even the adaptive equalizer strategy), our formalized game model is capable of enabling the defender to greatly reduce the maximum value of the expected average payoff to the adversaries via provisioning sufficient defensive resources, which is reflected by setting a proper penalty factor against the adversaries. In addition, we extend our game model and analyze the extortion strategy, which can enable one participant to obtain more payoff by extorting his/her opponents. The evaluation results show that the defender can combat this strategy by encouraging competition among the adversaries, and significantly suppress the total payoff of the adversaries via setting the proper penalty factor.

Deferoxamine inhibits microglial activation, attenuates blood-brain barrier disruption, rescues dendritic damage, and improves spatial memory in a mouse model of microhemorrhages.

Cerebral microbleeds are strongly linked to cognitive dysfunction in the elderly. Iron accumulation plays an important role in the pathogenesis of intracranial hemorrhage. Deferoxamine (DFX), a metal chelator, removes iron overload and protects against brain damage in intracranial hemorrhage. In this study, the protective effects of DFX against microhemorrhage were examined in mice. C57BL6 and Thy-1 green fluorescent protein transgenic mice were subjected to perforating artery microhemorrhages on the right posterior parietal cortex using two-photon laser irradiation. DFX (100 mg/kg) was administered 6 h after microhemorrhage induction, followed by every 12 h for three consecutive days. The water maze task was conducted 7 days after induction of microhemorrhages, followed by measurement of blood-brain barrier permeability, iron deposition, microglial activation, and dendritic damage. Laser-induced multiple microbleeds in the right parietal cortex clearly led to spatial memory disruption, iron deposits, microglial activation, and dendritic damage, which were significantly attenuated by DFX, supporting the targeting of iron overload as a therapeutic option and the significant potential of DFX in microhemorrhage treatment. Irons accumulation after intracranial hemorrhage induced a serious secondary damage to the brain. We proposed that irons accumulation after parietal microhemorrhages impaired spatial cognition. After parietal multiple microhemorrhages, increased irons and ferritin contents induced blood-brain barrier disruption, microglial activation, and further induced dendrites loss, eventually impaired the water maze, deferoxamine treatment protected from these damages.

Antidiabetic activity of differently regioselective chitosan sulfates in alloxan-induced diabetic rats.

The present study investigated and compared the hypoglycemic activity of differently regioselective chitosan sulfates in alloxan-induced diabetic rats. Compared with the normal control rats, significantly higher blood glucose levels were observed in the alloxan-induced diabetic rats. The differently regioselective chitosan sulfates exhibited hypoglycemic activities at different doses and intervals, especially 3-O-sulfochitosan (3-S). The major results are as follows. First, 3,6-di-O-sulfochitosan and 3-O-sulfochitosan exhibited more significant hypoglycemic activities than 2-N-3, 6-di-O-sulfochitosan and 6-O-sulfochitosan. Moreover, 3-S-treated rats showed a more significant reduction of blood glucose levels than those treated by 3,6-di-O-sulfochitosan. These results indicated that -OSO3- at the C3-position of chitosan is a key active site. Second, 3-S significantly reduced the blood glucose levels and regulated the glucose tolerance effect in the experimental rats. Third, treatment with 3-S significantly increased the plasma insulin levels in the experimental diabetic rats. A noticeable hypoglycemic activity of 3-S in the alloxan-induced diabetic rats was shown. Clinical trials are required in the future to confirm the utility of 3-S.