The mitochondria-targeted small molecule SS31 delays progression of behavioral deficits by attenuating ß-amyloid plaque formation and mitochondrial/synaptic deterioration in APP/PS1 mice.

Alzheimer's disease (AD) is a common neurodegenerative disorder characterized by progressive cognitive dysfunction and an impaired ability to carry out daily life functions. Mitochondrial dysfunction and ß-amyloid (Aß) deposition are the most common causes of AD. Antioxidants have been shown to delay brain aging and AD development; however, it remains unknown whether the antioxidant peptide SS31 can protect mitochondrial and synaptic function and delay the progression of behavioral deficits in early-stage AD in vivo. Therefore, in this study we compared mitochondrial and synaptic changes, as well as the protective effects of SS31, in APP/PS1 transgenic mice and C57BL/6J control mice. The APP/PS1 transgenic mice exhibited elevated expression of Aß40/Aß42 and mitochondrial fission protein DLP1 and reduced expression of synaptophysin (SYN) and postsynaptic density protein 95 (PSD95) reductions, as well as increased levels of neuronal apoptosis and ROS in the hippocampus, and long-term treatment with SS31 reversed these effects. Furthermore, the cognitive impairments observed in APP/PS1 transgenic mice were reversed by SS31 treatment. Our findings show that SS31 lowers ROS and Aß levels, protecting mitochondrial homeostasis and synaptic integrity, and ultimately improving behavioral deficits in early-stage AD. This suggests that SS31 is a potential pharmacological agent for treating or slowing the progression of AD.

CB1 receptor antagonist rimonabant protects against chronic intermittent hypoxia-induced bone metabolism disorder and destruction in rats.

OBJECTIVE: The endocannabinoid system (ECS) regulates bone turn-over and remodeling. Chronic intermittent hypoxia (CIH) occurring during obstructive sleep apnea (OSA) may lead to disorders of the ECS and bone metabolism abnormalities. This study aimed to investigate whether or not the cannabinoid receptor 1 (CB1R) antagonist rimonabant (Ri) alleviates bone metabolism abnormalities and bone destruction induced by chronic intermittent hypoxia (CIH). METHODS: Healthy male Sprague Dawley (SD) rats (n=48) were randomly divided into 6 groups of 8 rats: 2 normal control (NC) groups, 2 intermittent hypoxia (IH) groups, and 2 IH + Ri groups. Rats in NC groups breathed room air for 4 weeks (4w NC group) and 6 weeks (6w NC group). Rats in IH groups experienced IH environment for 4 weeks (4w IH group) and 6 weeks (6w IH group). In addition to the same IH exposure, rats in IH + Ri group were given daily intraperitoneal injection of Ri at the dosage of 1.5 mg/kg/d for 4 weeks (4w IH + Ri group) and 6 weeks (6w IH + Ri group). Levels of serum tartrate-resistant acid phosphatase (TRAP, a marker of bone resorption) were determined by ELISA. Hematoxylin and eosin (HE) staining was performed on bone sections to observe the changes in bone microstructure. Expression of CB1R in bone tissue was determined by immunohistochemistry. RESULTS: TRAP levels were higher in the 4w IH and 6w IH groups than in the 4w NC and 6w NC groups; TRAP levels were lower in the 4w IH + Ri and 6w IH + Ri groups than in the 4w IH and 6w IH groups. HE staining showed that the morphology of bone cells in the NC group was normal, but the 4w IH group had mild edema of bone cells, reduction in trabecular bone, and destruction of bone microstructure. Changes were more severe in the 6w IH group than 4w IH. The 4w IH + Ri group was slightly improved compared with the 4w IH group. The 6w IH + Ri group was improved compared with the 4w IH + Ri group. The results of immunohistochemistry showed that the expression of CB1R in IH group was significantly higher than that in NC group. The expression of CB1R in the IH + Ri group was lower than that in the IH group. With the prolongation of hypoxia, the expression of CB1R in bone cells of IH group increased. The expression level of CB1R in IH + Ri group decreased with the prolongation of intervention time. Correlation analysis showed that the expression rate of CB1R in bone cells was positively correlated with the level of TRAP in serum. CONCLUSION: CIH increases serum TRAP levels and triggers metabolic bone disorder by activating bone CB1R. Intervention with CB1R antagonist (rimonabant) reduces the bone dysmetabolism in the CIH rat model.

Assessing executive function following the early stage of mild Ischemic stroke with three brief screening tests.

OBJECTIVE: Executive dysfunction following stroke is well documented, but less is known about whether it occurs in mild stroke patients. The purpose of the study was to investigate executive impairment in this population and explore the correlation between executive function tests and cognitive tests of other domains. METHODS: Cross-sectional study was undertaken to compare 139 mild ischemic stroke patients (National Institute of Health Stroke Scale (NIHSS) ≤ 7) aged 40-80 with 131 normal controls matched age, gender and levels of education. All participants were administered a neuropsychological test battery including three measures of executive functioning: Clock Drawing Test (CDT), Trial Making Test-A and B (TMT-A and B), and Stroop Color Word Test (SCWT). The CDT was evaluated using three quantitative scoring rubrics, with a total score of 3,10,18, respectively and a qualitative scoring method with six types of errors. Spearman's correlations were made to analyze the correlation between executive function tests and other neuropsychological tests. RESULTS: Control group performed better than stroke group on most executive function tests at a statistical significance. Qualitative CDT showed that errors of "graphic difficulties", "conceptual deficits" and "spatial and/or planning deficits" occurred frequently in the early stage of mild stroke. Correlation data clarified that among the executive function tests, time for TMT-B correlated with global cognition most. CONCLUSION: Executive dysfunction is common following even mild strokes, and that relatively brief measures such as CDT, TMT and SCWT can be employed for it before discharge as part of rehabilitation planning.

Trends in cognitive function assessed by a battery of neuropsychological tests after mild acute ischemic stroke.

OBJECTIVE: The aim of this study is to investigate the domain-specific trends of cognitive function up to 12 months after mild acute ischemic stroke. METHODS: Enrolment of consecutive cohort of patients with mild acute ischemic stroke with recorded clinical characteristics and extensive neuropsychological assessments, including five cognitive domains. The Montreal cognitive assessment of the Beijing version (MoCA-Bj) was used to assess overall cognition. All patients completed all domain-specific examinations were categorised into three groups according to the time between the stroke onset and neuropsychological profiling, the time duration including less than one month (n = 174), one month to six months (n = 65) and over six months (n = 39). RESULTS: The final cohort consisted of 278 patients. The executive (χ2 = 6.95, P<0.05) and memory dysfunctions (χ2 = 9.6, P<0.01) showed strong improvement, especially in executive function, which prevalence was 48.85% at <1- month group and 25.64% at >6 months group. The prevalence of attention and information processing also had a declining trend, the differences, however, were not statistically significant (χ2 = 0.23 and 2.25, respectively, P>0.05). There was no significant change in language function (χ2 = 0.46, P>0.05) and the MoCA (χ2 = 0.59, P>0.05) at 3-time point groups. In 195 first-ever stroke patients, the results of memory (χ2 = 6.94 P<0.05) and executive dysfunctions (χ2 = 6.25 P<0.05) also showed significant improvement. CONCLUSION: There is varying degree of improvement tendency in executive and memory dysfunctions after mild acute ischemic stroke. Early cognitive assessments after mild acute ischemic stroke do not reflect the cognitive level of stable period.

Serum S100A12 and Progression of Coronary Artery Calcification Over 4 Years in Hemodialysis Patients.

BACKGROUND/AIM: Vascular calcification is common and contributes to increased cardiovascular mortality in hemodialysis (HD) patients. In this prospective study, we aimed to investigate the associations of serum S100A12 in the presence of severe coronary artery calcification (CAC) and the progression of CAC in HD patients. METHODS: Sixty maintenance HD patients and 30 controls were enrolled. Serum S100A12 levels were measured using ELISA. CAC scores (CACs) were measured twice at a 4-year interval using multislice spiral CT. The HD patients were classified as rapid progressors or slow progressors according to the change in the CACs across these 2 measurements (x0394;CACs). RESULTS: The incidences of rapid progression of CAC in patients with baseline CACs ≤10, CACs >10 and CACs >400 were 12.5, 40.0 and 64.3%, respectively. Both baseline and 4-year serum S100A12 levels were significantly higher in the rapid progressors than in the slow progressors (medians of 45.6 vs. 30.2 ng/ml, p < 0.001 and 62.3 vs. 39.4 ng/ml, p = 0.002, respectively). The serum S100A12 levels were significantly correlated with baseline CACs (r = 0.466, p < 0.001), 4-year CACs (r = 0.440, p < 0.001) and x0394;CACs (r = 0.392, p < 0.001). Importantly, the x0394;CACs were significantly correlated with x0394;S100A12 levels (r = 0.396, p < 0.001). Logistic regression analysis revealed that the serum S100A12 level was as an independent determinant of the presence of severe CAC and that the increment in the serum S100A12 level was a factor that was significantly independently associated with the progression of CAC. CONCLUSIONS: Serum S100A12 levels were significantly associated with the presence of severe CAC, and the increment in serum S100A12 levels was an independent determinant of the progression of CAC.

Chinese version of the auditory verbal learning test: normative study and clinical applications in Chinese-speaking population in Shijiazhuang city.

OBJECTIVE: The purposes were to establish standardized values for the Auditory Verbal Learning Test (AVLT) in the communities of Shijiazhuang city (China), with particular focus on the influences of age, education and sex, and to detect the discriminant validity data of the AVLT in patients with acute ischemic stroke (AIS). METHODS: 406 Chinese-speaking subjects (age: 50-84 years old) from Shijiazhuang city, were brought into this study. Using linear regression analyses, standardized values were developed for three variables of interest, including scores on short-term memory (sum of AVLT trials 1-3), delayed recall (AVLT trial 4), and an index representing recognition memory corrected for false-positive identifications (AVLT trial 5). 177 patients with AIS were included to probe the discriminant validity of the AVLT. RESULTS: The linear regression analysis showed statistically significant effect of age and sex on all trials of the AVLT. Years of education contributed significantly to trial 1-3 and trial 4 but not trial 5. Based on the results obtained, trail 1-3 and trail 4 of AVLT norms were stratified by age (3 strata), education (2 strata), and sex (2 strata). Trail 5 norms were stratified by age (3 strata) and sex (2 strata). Moreover, AIS groups performed significantly worse on most AVLT trials than matched cognitively healthy controls. CONCLUSIONS: Normative data stratified by age, education and sex for the Chinese-speaking community-residents in Shijiazhuang was presented for use in research and clinical settings. The AVLT measures adequately differentiated between the cognitive performance (especially memory decline) of healthy adults and patients with AIS.

Autophagic and apoptotic mechanisms of curcumin-induced death in K562 cells.

Curcumin (1), a natural polyphenolic compound, has shown strong antioxidant and anticancer activities. Several molecular mechanisms have been attributed to its inhibitory effects on a wide range of tumor cells. In this study, the response of the chronic myeloid leukemia cell line K562 cells to 1 is investigated. Curcumin inhibited the viability of K562 cells in a dose- and time-dependent manner. Furthermore, curcumin-induced cell death was associated with the formation of the apoptosome complex, the collapse of the mitochondrial membrane potential, and caspase-3 activation. Curcumin treatment also induced Bid cleavage and downregulated the expression of Bcl-2 protein. Surprisingly, even with these molecular features of apoptosis, we showed that 1 stimulated autophagy, which was evidenced by microtubule-associated protein light chain 3 (LC3) immunoreactivty. Curcumin also increased the protein levels of beclin 1 and membrane form LC3 (LC3-II). Autophagy inhibitor bafilomycin A1 and the pan-caspase inhibitor Z-VAD-fmk suppressed curcumin-induced K562 cell death. Overall, these results suggest that curcumin induces autophagic and apoptotic death of K562 cells. These findings suggest that both apoptotic and autophagic mechanisms contribute to the curcumin-induced K562 cell death.

SS31, a Small Molecule Antioxidant Peptide, Attenuates ß-Amyloid Elevation, Mitochondrial/Synaptic Deterioration and Cognitive Deficit in SAMP8 Mice.

Mitochondrial dysfunction, oxidative stress and ß -amyloid (Aß) formation are thought to cause neuronal and synaptic degeneration underlying cognitive decline in Alzheimer's disease (AD). The senescence-accelerated mouse-prone 8 (SAMP8) mice have been used as an animal model for mechanistic and translational research for AD. In the present study we characterized mitochondrial and synaptic alterations in SAMP8 mice relative to SAMR1control mice and explored a protective effect of the small molecule peptide SS31, a cell membrane penetrant antioxidant, on mitochondrial and synaptic protein integrity as well as cognitive performance. Electron microscopic analysis revealed mitochondrial/synaptic deterioration in 10 months-old SAMP8 relative to SAMR1 mice, with the changes in the former rescued following 8 weeks treatment with SS31 (5 mg/kg/day, i.p.). Elevation of Aß42, mitochondrial fission protein (DLP1, Fis1) and matrix protein cyclophilin D (CypD), and reductions of mitochondrial fusion protein (Mfn2) and synaptic (i.e., synaptophysin, postsynaptic density protein 95 and growth associated protein 43) proteins, were detected in hippocampal lysates in SAMP8 mice relative to SAMR1. The above altered protein expressions in the SAMP8 mouse brain were restored with the SS31 treatment. Moreover, the SS31 treatment rescued learning and memory deficits detected in 10 month-old SAMP8 mice. Together, the findings suggest that this mitochondria-targeting antioxidant peptide may be of potential utility for AD therapy, with its pharmacological efficacy involves lowering of central Aß levels and protection of mitochondrial homeostasis and synaptic integrity, which may help slow down cognitive decline.

Retinoic acid retards fetal and hindlimb skeletal development asymmetrically in a retinoic acid-induced clubfoot model.

Retinoic acid (RA) has been shown to induce congenital clubfoot in animal models, but it is unknown whether the effect of RA on the formation of clubfoot in vivo results from generalized growth retardation or from the specific effects of hindlimb skeletal development. Our experimental research was based on a clubfoot model treated by maternal administration of RA (120, 130 or 140 mg/kg body weight) as an intragastric dose on embryonic day 10 (E10), and a control group was administered with an equivalent dose of solvent. Prenatal RA exposure reduced fetal body weight, length and skeletal ossification of the hindlimb compared with the control fetuses in a dose-dependent manner. The normal development curves indicated that the RA-exposed fetuses showed delayed increase in body weight and skeletal ossification development. However, there was no uniform effect on the skeletons of the hindlimb, not least retardation in ossification and induction malformation on the talus and calcaneus. Our results demonstrated that prenatal RA exposure had retardation effects on the developing hindlimb skeleton that was independent of those on the overall fetal growth. The normal skeletal ossification showed that the talus and calcaneus were poorly ossified and they were delayed by almost one day in the RA 120 mg/kg group. Therefore, during the susceptible stages, different regions of the limb bud responded differently to the teratogenic effects of RA.

Dynamic effects of autophagy on arsenic trioxide-induced death of human leukemia cell line HL60 cells.

AIM: To evaluate the contribution of an autophagic mechanism to the As2O3- induced death of human acute myeloid leukaemia cell line HL60 cells. METHODS: The growth inhibition of HL60 cells induced by As2O3 was assessed with 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide colorimetric assay. The activation of autophagy was determined with monodansylcadaverine labeling and transmission electron microscope. The role of autophagy in the As2O3-induced death of HL60 cells was assessed using autophagic and lysosomal inhibitors. Immunofluorescence, flow cytometry, and Western blot analysis were used to study the apoptotic and autophagic mechanisms. RESULTS: After treatment with As2O3, the proliferation of HL60 cells was significantly inhibited and the formation of autophagosomes increased. The blockade of autophagy maturation with the autophagy-specific inhibitor 3-methyladenine (3-MA) or the lysosome-neutralizing agent NH4Cl 1 h before As2O3 potentiated the As2O3-induced death of HL60 cells. In contrast, 3-MA attenuated As2O3-induced death when administered 30 min after As2O3. 3-MA and NH4Cl also inhibited As2O3-induced upregulation of microtubule-associated protein 1 light chain 3, the protein required for autophagy in mammalian cells. Following As2O3, lysosomes were activated as indicated by increased levels of cathepsins B and L. The apoptotic response of HL60 cells to As2O3 was suggested by the collapse of mitochondrial membrane potential, release of cytochrome c from mitochondria, and the activation of caspase-3. Pretreatment with 3-MA prior to As2O3 amplified these apoptotic signals, while posttreatment with 3-MA 30 min after As2O3 attenuated the apoptotic pathways. CONCLUSION: Autophagy plays complex roles in the As2O3-induced death of HL60 cells; it inhibits As2O3-induced apoptosis in the initiation stage, but amplifies the As2O3-mediated apoptotic program if it is persistently activated.