The use of individual-based FDG-PET volume of interest in predicting conversion from mild cognitive impairment to dementia

BACKGROUND

Based on a longitudinal cohort design, the aim of this study was to investigate whether individual-based 18F fluorodeoxyglucose positron emission tomography (18F-FDG-PET) regional signals can predict dementia conversion in patients with mild cognitive impairment (MCI).

METHODS

We included 44 MCI converters (MCI-C), 38 non-converters (MCI-NC), 42 patients with Alzheimer's disease with dementia, and 40 cognitively normal controls. Data from annual cognitive measurements, 3D T1 magnetic resonance imaging (MRI) scans, and 18F-FDG-PET scans were used for outcome analysis. An individual-based FDG-PET approach was applied using seven volumes of interest (VOIs), Z transformed using a normal FDG-PET template. Hypometabolism was defined as a Z score < -2 of regional standard uptake value ratio. For the longitudinal cognitive test scores, generalized estimating equations were used. A linear mixed-effects model was used to compare the temporal impact of cortical hypometabolism and cortical thickness degeneration.

RESULTS

The clinical follow-up period was 6.6 ± 3.8 years (range 3.1 to 16.0 years). The trend of cognitive decline could differentiate MCI-C from MCI-NC after 3 years of follow-up. In the baseline 18F-FDG-PET scan of the patients with MCI, medial temporal lobe (MTL; 94.7% sensitivity, 80.5% specificity) and posterior cingulate cortex (PCC; 89.5% sensitivity, 73.1% specificity) hypometabolism predicted conversion with high accuracy. 18F-FDG-PET hypometabolism preceded dementia conversion at an interval of 3.70 ± 1.68 years and was earlier than volumetric changes, with the exception of the MTL.

CONCLUSIONS

Our finding supports the use of individual-based 18F-FDG-PET analysis to predict MCI conversion to dementia. Reduced FDG-PET metabolism in the MTL and PCC were strongly associated with future cognitive decline in the MCI-C group. Changes in 18F-FDG-PET occurred 1 to 8 years prior to conversion to dementia. Progressive hypometabolism in the PCC, precuneus and lateral temporal lobe, but not MTL, preceded MRI findings at the MCI stage.

Diet Pattern Analysis in Alzheimer's Disease Implicates Gender Differences in Folate-B12-Homocysteine Axis on Cognitive Outcomes

BACKGROUND & AIMS

Low plasma B12 and folate levels or hyperhomocysteinemia are related to cognitive impairment. This study explores the relationships among diet pattern, blood folate-B12-homocysteine levels, and cognition measurement in Alzheimer's disease (AD) while exploring whether a gender effect may exist.

METHODS

This cross-sectional study enrolled 592 AD patients (246 males, 346 females) and the demographic data, blood biochemical profiles, Mini-Mental State Examination (MMSE), and a Food Frequency Questionnaire (FFQ) for quantitative assessment of dietary frequency were collected. Structural Equation Modeling (SEM) was employed to explore the associations among dietary patterns, blood profiles, and cognition. A least absolute shrinkage and selection operator regression model, stratified by gender, was constructed to analyze the weighting of possible confounders.

RESULTS

Higher MMSE scores were related to higher frequencies of coffee/tea and higher educational levels, body mass index, and younger age. The SEM model revealed a direct influence of dietary frequencies (skimmed milk, thin pork, coffee/tea) and blood profiles (homocysteine, B12, and folate) on cognitive outcomes. At the same time, the influence of dietary pattern on cognition was not mediated by folate-B12-homocysteine levels. In males, a direct influence on the MMSE is attributed to B12, while in females, homocysteine is considered a more critical factor.

CONCLUSIONS

Dietary patterns and blood profiles are both associated with cognitive domains in AD, and there are gender differences in the associations of dietary patterns and the levels of B12 and homocysteine. To enhance the quality of dietary care and nutritional status for individuals with dementia, our study results still require future validations with multi-center and longitudinal studies.

Towards quantifying atmospheric dispersion of pesticide spray drift in Yuma County Arizona

While pesticide vapor and particles from agricultural spray drift have been reported to pose a risk to public health, limited baseline ambient measurements exist to warrant an accurate assessment of their impacts at community-to-county-wide scale. Here, we present an initial modeling investigation of the transport and deposition of applied pesticides in an agricultural county in Arizona (Yuma County), to provide initial estimates on the corresponding enhancements in ambient levels of these spray drifts downwind of application sites. With a 50 × 50 km domain, we use the dispersion model CALPUFF with meteorology from the Weather Research and Forecasting (WRF) to investigate the spatiotemporal distribution of pesticide abundance due to spray drift from a representative sample of nine application sites. Data records for nine application days in September and October 2011, which are the peak months of pesticide application, were retroactively simulated for 48-h for all nine application sites using an active ingredient lambda-cyhalothrin, which is a commonly-used pesticide in the county. Twenty-one WRF/CALPUFF simulations were conducted with varying emissions, chemical lifetime, deposition rate, application height, and meteorology inputs, allowing for an ensemble-based analysis on the possible ranges in modeled abundance. Our results show that dispersion of vapors released at time of application heavily depends on prevailing meteorology, particularly wind speed and direction. Dispersion is limited to thin plumes that are easily transported out of the domain. The ensemble-mean vapor concentrations of the 48-h average (> 90 percentile domain-wide) range from 0.2 nanograms (ng)/m3 to 200 ng/m3, and the peak can be as high as 1000 ng/m3 near the application sites. Pesticide particles are mainly deposited within 1-2 km from the application sites at an average rate of 106 ng/km2/h but vary with particle mean diameter and standard deviation. While these findings are generally consistent with reported ambient levels in the literature, the associated ensemble-spread on these estimates are in the same order of magnitude as their ensemble-mean. At the two nearby communities downwind of these sites, we find that peak vapor concentrations are less than 50 ng/m3 with exposure times of less than an hour, as approximately 99.4% of the vapors are advected out and 99.5% of the particles deposit within the domain. Results of this study indicate pesticide spray drift from a sample of application sites and representative days in Fall may have a limited impact on neighboring communities. However, we strongly suggest that field measurements should be collected for model validation and more rigorous investigation of the actual scale of these impacts when the bulk of pesticide applications across the county, variation in active pesticide ingredients, and potential resuspension of deposited particles are considered.

Manipulation of osteogenic and adipogenic differentiation of human degenerative disc and ligamentum flavum derived progenitor cells using IL-1β, IL-19, and IL-20

PURPOSE

To elucidate whether pro-inflammatory cytokines might influence the commitment of intervertebral disc (IVD)- and ligamentum flavum (LF)-derived progenitor cells toward either osteogenesis or adipogenesis, specifically Interleukin-1β (IL-1β), IL-19, and IL-20.

METHODS

Sixty patients with degenerative spondylolisthesis and lumbar or lumbosacral spinal stenosis were included in the study. Injuries to the spine, infections, and benign or malignant tumors were excluded. From nine patient samples, IVD- and LF-derived cells were isolated after primary culture, and two clinical samples were excluded due to mycoplasma infection. The effects of IL-1β, IL-19, as well as IL-20 in regulating osteogenic and adipogenic differentiation in vitro were investigated.

RESULTS

Primary IVD- and LF-derived cells were found to have a similar cell morphology and profile of surface markers (CD44, CD90, and CD105) as placenta-derived mesenchymal stem cells (MSCs). Primary IVD/LF cells have a high capacity to differentiate into osteocytes and adipocytes. IL-19 had a tendency to promote adipogenesis. IL-20 inhibited osteogenesis and promoted adipogenesis; IL-1β promoted osteogenesis but inhibited adipogenesis.

CONCLUSION

IL-1β, IL-19, and IL-20 impact the adipogenic and osteogenic differentiation of IVD-derived and LF-derived cells. Modulating the expression of IL-1β, IL-19, and IL-20 provides a potential avenue for controlling cell differentiation of IVD- and LF-derived cells, which might have beneficial effect for degenerative spondylolisthesis and spinal stenosis.

Gray Matter Reserve Determines Glymphatic System Function in Young-Onset Alzheimer's Disease: Evidenced by DTI-ALPS and Compared with Age-matched Controls

BACKGROUND

The diffusion tensor imaging analysis along the perivascular space (ALPS)-index can be used to model the glymphatic system in vivo.

AIM

This study explores putative mechanisms between prediction of ALPS-index and cognitive outcomes in young-onset Alzheimer's disease (YOAD) and age-matched controls (CTLs) and analyze whether the link was mediated by the integrity of ALPS-index-anchored cerebral gray matter (GM).

METHODS

We enrolled 130 patients with YOAD and 137 CTLs. All participants underwent three-dimensional T1-weighted MRI, diffusion tensor imaging and cognitive tests. We constructed GM regions correlated with the ALPS-index in the YOAD and CTL groups. For the GM regions significantly correlated with the ALPS-index and cognitive measures, we extracted a 4-mm radius sphere. In the YOAD and CTL groups, we used mediator analysis to explore the ALPS-index as predictor, GM partitions as mediators, and significant cognitive test scores as outcomes.

RESULTS

Patient group had significant lower ALPS-index. The ALPS-index was associated with GM volume in the cerebellar gray, dorsolateral prefrontal, thalamus, superior frontal, amygdala and hippocampus, and these coherent regions coincided with those showing GM atrophy in the YOAD group. Mediation analysis of the YOAD group suggested that the relationships between the ALPS-index and cognitive performance were fully mediated by the integrity of ALPS-index coherent GM areas.

DISCUSSION

Reserved GM mediates the link between the glymphatic system and cognition. Our findings suggest that GM integrity rather than the glymphatic system could serve as a direct cognitive test scores predictor in patients with YOAD. This article is protected by copyright. All rights reserved.

Clinical significance of fractional anisotropy in cerebral white matter regional vulnerability caused by carbon monoxide poisoning: A systematic review and meta-analysis

Carbon monoxide poisoning (COP) can lead to various cerebral white matter (WM) lesions across different disease phases and clinical manifestations, and fractional anisotropy (FA) of diffusion tensor imaging has been widely applied to investigate WM injury in these patients. Here we conduct a systematic review and meta-analysis to investigate the utility of FA in evaluating the regional vulnerability of WM injury caused by COP and explore differences between different disease phases and patient subtypes. We systematically searched PubMed, Medline, Scopus and reference lists of appropriate publications to identify relevant studies. Eight studies with 217 COP patients and 207 healthy controls (HCs) were included. Eight regions of interest were available to investigate regional vulnerability. The results showed the most significant decrease in FA in orbitofrontal subcortical regions. Comparisons of different disease phases revealed lower FA in the centrum semiovale and corpus callosum in the acute phase, while in the chronic phase, only FA in the centrum semiovale remained significantly decreased. Analysis of different patient subtypes showed that the FA values in the splenium of the corpus callosum were significantly decreased in the patients with delayed neurologic sequelae (DNS) but not in the mixed population (with and without DNS). In conclusion, this meta-analysis highlights the frontal-subcortical regional vulnerability in COP. FA changes in the corpus callosum across different disease phases reflect alterations in underlying microstructures. Extended corpus callosum injury involving the splenium could be an imaging biomarker of the occurrence of DNS.

Association of cognition and brain reserve in aging and glymphatic function using diffusion tensor image-along the perivascular space (DTI-ALPS)

The glymphatic system is a fluid-clearance pathway that clears cerebral waste products, and its dysfunction has been associated with protein aggregation diseases such as Alzheimer's disease. To understand how the glymphatic system changes with aging, we enrolled 433 cognitive unimpaired participants (236 women and 197 men, 13 to 88 years) and evaluated the glymphatic function by calculating diffusion tensor imaging analysis along the perivascular space (ALPS) index and explored how the ALPS index is associated with cortical atrophy and cognitive decline in older people. We found a significant inverse correlation between ALPS index and age (ρ=-0.45, p<0.001), with a peak value in people in their thirties. A higher ALPS index indicated a better cortical reserve in regions coincided with the default mode network. Declines in mental manipulation and short-term memory performance in the older participants were associated with a lower ALPS index and cortical atrophy in the amygdala, anterior and posterior cingulate, thalamus and middle frontal regions. Our findings highlight that the ALPS index could be used to evaluate brain reserve and cognitive reserve in older people.

Engineered Nano-carrier Systems for the oral targeted delivery of Follicle Stimulating Hormone: Development, characterization, and, assessment of in vitro and in vivo performance and targetability

Follicle stimulating hormone (FSH) is widely used for the treatment of female infertility, where the level of FSH is suboptimal due to which arrest in follicular development and anovulation takes place. Currently, only parenteral formulations are available for FSH in the market. Due to the drawbacks of parenteral administration and the high market shares of FSH, there is a need for easily accessible oral formulation. Therefore, enteric coated capsules filled with FSH loaded nanostructured lipid carriers (NLCs) or liposomes were prepared. Preliminary studies such as circular dichroism, SDS-PAGE, FTIR and ELISA were conducted to analyze FSH. Prepared formulations were optimized with respect to the size, polydispersity index, zeta potential, and entrapment efficiency using the design of experiments. Optimized formulations were subjected to particle counts and distribution analysis, TEM analysis, in vitro drug release, dissolution of enteric coated capsules, cell line studies, everted sac rat's intestinal uptake study, pharmacokinetics, pharmacodynamics, and stability studies. In the case of liposomes, RGD conjugation was done by carbodiimide chemistry and conjugation was confirmed by FTIR, ¹HNMR and Raman spectroscopy. The prepared formulations were discrete and spherical. The release of FSH from enteric coated capsules was slow and sustained. The increased permeability of nano-formulations was observed in Caco-2 monoculture as well as in Caco-2 and Raji-B co-culture models. NLCs and liposomes showed an improvement in oral bioavailability and efficacy of FSH in rats. This may be due to mainly chylomicron-assisted lymphatic uptake of NLCs; whereas, in the case of liposomes, RGD-based targeting of β1 integrins of M cells on Peyer's patches may be the main reason for the better effect by FSH. FSH was found to be stable chemically and conformationally. Overall, the study reveals the successful development and evaluation of FSH loaded NLCs and liposomes.

Neuropsychiatric Symptoms and Caregiver Stress in Parkinson's Disease with Cognitive Impairment, Alzheimer's Disease, and Frontotemporal Dementia

BACKGROUND

A better understanding of factors associated with caregiver burden might facilitate the construction of coping strategies to improve their clinical outcomes and the comprehensive care model for dementia.

OBJECTIVE

To investigate the cognitive and neuropsychiatric domains that contribute to caregiver burden in three types of neurodegenerative disorders: Parkinson's disease (PD), Alzheimer's disease (AD), and frontotemporal disease (FTD).

METHODS

Eight hundred and fourteen patients and their caregivers were invited to participate; among them, 235 had PD with cognitive impairment; 429 had AD, and 150 had FTD. The evaluation protocol included the Neuropsychiatric Inventory (NPI), the Mini-Mental State Examination, the Chinese Version Verbal Learning Test, the modified Trail Making Test B, semantic fluency, and a geriatric depression score. Statistical comparisons of the cognitive tests, NPI total scores, and caregiver burden among the three diagnosed types of dementia, matched for a Clinical Dementia Rating (CDR) of 0.5 or 1, were performed, and multivariate linear regression models were used to evaluate the parameter significance.

RESULTS

Caregivers for patients with PD and FTD showed significant burden increments when the CDR scores changes from 0.5 to 1. For CDR = 0.5, the PD group had significantly lower caregiver burdens than the AD group, but the NPI total scores were significantly higher. Factors related to caregiver burden were the presence of delusion among all diagnosis groups, while the impact of NPI total scores related to caregiver burden was the highest in FTD, followed by AD and PD.

CONCLUSIONS

At the mild to moderate stages, our results suggested different degrees of significance in terms of the cognitive test scores or NPI subdomains for predicting caregiver stress among the three types of dementia.

Cognitive Decline Related to Diet Pattern and Nutritional Adequacy in Alzheimer's Disease Using Surface-Based Morphometry

Dietary pattern (DP) results in nutrition adequacy and may influence cognitive decline and cortical atrophy in Alzheimer's disease (AD). The study explored DP in 248 patients with AD. Two neurobehavioral assessments (intervals 13.4 months) and two cortical thickness measurements derived from magnetic resonance images (intervals 26.5 months) were collected as outcome measures. Reduced rank regression was used to assess the groups of DPs and a linear mixed-effect model to explore the cortical neurodegenerative patterns. At screening, underweight body mass index (BMI) was related to significant higher lipid profile, impaired cognitive function, smaller cortical thickness, lower protein DP factor loading scores and the non-spouse caregiver status. Higher mini-mental state examination (MMSE) scores were related to the DP of coffee/tea, compared to the lipid/sugar or protein DP group. The underweighted-BMI group had faster cortical thickness atrophy in the pregenual and lateral temporal cortex, while the correlations between cortical thickness degeneration and high HbA1C or low B12 and folate levels were localized in the medial and lateral prefrontal cortex. The predictive model suggested that factors related to MMSE score were related to the caregiver status. In conclusion, normal or overweight BMI, coffee/tea DP group and living with a spouse were considered as protective factors for better cognitive outcomes in patients with AD. The influence of glucose, B12 and folate on the cortical degeneration was spatially distinct from the pattern of AD degeneration.

Impact of Amyloid Pathology in Mild Cognitive Impairment Subjects: The Longitudinal Cognition and Surface Morphometry Data

The amyloid framework forms the central medical theory related to Alzheimer disease (AD), and the in vivo demonstration of amyloid positivity is essential for diagnosing AD. On the basis of a longitudinal cohort design, the study investigated clinical progressive patterns by obtaining cognitive and structural measurements from a group of patients with amnestic mild cognitive impairment (MCI); the measurements were classified by the positivity (Aβ+) or absence (Aβ-) of the amyloid biomarker. We enrolled 185 patients (64 controls, 121 patients with MCI). The patients with MCI were classified into two groups on the basis of their [¹⁸F]flubetaben or [¹⁸F]florbetapir amyloid positron-emission tomography scan (Aβ+ vs. Aβ-, 67 vs. 54 patients) results. Data from annual cognitive measurements and three-dimensional T1 magnetic resonance imaging scans were used for between-group comparisons. To obtain longitudinal cognitive test scores, generalized estimating equations were applied. A linear mixed effects model was used to compare the time effect of cortical thickness degeneration. The cognitive decline trajectory of the Aβ+ group was obvious, whereas the Aβ- and control groups did not exhibit a noticeable decline over time. The group effects of cortical thickness indicated decreased entorhinal cortex in the Aβ+ group and supramarginal gyrus in the Aβ- group. The topology of neurodegeneration in the Aβ- group was emphasized in posterior cortical regions. A comparison of the changes in the Aβ+ and Aβ- groups over time revealed a higher rate of cortical thickness decline in the Aβ+ group than in the Aβ- group in the default mode network. The Aβ+ and Aβ- groups experienced different APOE ε4 effects. For cortical-cognitive correlations, the regions associated with cognitive decline in the Aβ+ group were mainly localized in the perisylvian and anterior cingulate regions. By contrast, the degenerative topography of Aβ- MCI was scattered. The memory learning curves, cognitive decline patterns, and cortical degeneration topographies of the two MCI groups were revealed to be different, suggesting a difference in pathophysiology. Longitudinal analysis may help to differentiate between these two MCI groups if biomarker access is unavailable in clinical settings.

Mechanical Stretch Induced Osteogenesis on Human Annulus Fibrosus Cells through Upregulation of BMP-2/6 Heterodimer and Activation of P38 and SMAD1/5/8 Signaling Pathways

Degenerative disc disease (DDD) is an important cause of low back pain. Repetitive tensile stress from the daily motion of the spine predisposes it to injury of the annulus fibrosus (AF) which causes IVD degeneration. This study aims to determine the causal relationship between mechanical stretch and osteogenesis in the AF cells of IVD as affected by bone morphogenic proteins (BMPs), specifically BMP-2/6 heterodimers. Our results found that 15% tensile stress (high cyclic stretching, HCS) may induce the expression of osteogenesis-related markers (Runx2, osterix) by upregulating BMP-2/6 heterodimeric ligands and their receptors on the human AF cell line. HCS also induced transient phosphorylation of p38 mitogen-activated protein (MAP) kinase and SMAD1/5/8. Neutralizing antibodies to the BMP-2/6 receptor (ALK3) blocked the expression of Runx2 and osterix, as well as the phosphorylation of p38 and SMAD1/5/8. In addition, treatment with a p38 MAPK inhibitor (SB203580) or siRNA to neutralize the effects of SMAD1/5/8 suppressed tensile stress-induced Runx2 and osterix expression. Mechanical stretching induces activation of p38 MAP kinase and SMAD1/5/8 signaling pathways, followed by the upregulation of BMP-2/6 heterodimer expression, thereby stimulating osteogenic Runx2 and osterix expression on AF cells. HCS may accelerate the progression of IVD degeneration by promoting an osteogenic response.

Mechanical Stretch-Induced NLRP3 Inflammasome Expression on Human Annulus Fibrosus Cells Modulated by Endoplasmic Reticulum Stress

Excessive mechanical loading is a major cause of spinal degeneration, typically originating from a tear in the annulus fibrosus (AF). Endoplasmic reticulum (ER) stress and NLRP3 (NOD-, LRR- and pyrin domain-containing protein 3) inflammasome have been implicated in the pathogenesis of intervertebral disc (IVD) degeneration. However, the causal relationship between the mechanical stretching of AF cells and the NLRP3 inflammasome response associated with ER stress remains scarce. To elucidate the pathogenesis and regulatory mechanisms of mechanical stretch-induced IVD degeneration, human AF cell lines were subjected to different degrees of cyclic stretching to simulate daily spinal movements. Our results indicated that 15% high cyclic stretch (HCS) induced the expression of NLRP3 and interleukin-1 beta (IL-1β) and was also responsible for the increased expression of NADPH (nicotinamide adenine dinucleotide phosphate) oxidase 2 (NOX2) and reactive oxygen species (ROS) in human AF cells. In addition, HCS increased the expression of glucose-regulated protein 78 (GRP78), an ER stress chaperone, which was neutralized with tauroursodeoxycholic acid (TUDCA), an ER stress inhibitor. In addition, HCS was found to induce thioredoxin-interacting protein (TXNIP) expression and NLRP3 inflammasome activation, which can be suppressed by si-NOX2 or the NOX2 inhibitor GSK2795039. Consequently, HCS upregulated ER stress and ROS production, leading to increased NLRP3 and IL-1β expression in human AF cells, and may further accelerate IVD degeneration.

Structural Covariance Network as an Endophenotype in Alzheimer's Disease-Susceptible Single-Nucleotide Polymorphisms and the Correlations With Cognitive Outcomes

The cognitive manifestations of Alzheimer’s disease (AD) are related to brain network degeneration, and genetic differences may mediate network degeneration. Several AD-susceptible loci have been reported to involve amyloid or tau cascades; however, their relationships with gray matter (GM) volume and cognitive outcomes have yet to be established. We hypothesized that single-nucleotide polymorphism genotype groups may interact with apolipoprotein E4 (ApoE4) status or independently exert an effect on cognitive outcomes. We also hypothesized that GM structural covariance networks (SCNs) may serve as an endophenotype of the genetic effect, which, in turn, may be related to neurobehavior test scores. Gray matter SCNs were constructed in 324 patients with AD using T1 magnetic resonance imaging with independent component analysis (ICA). We assessed the effects of 15 genetic loci (rs9349407, rs3865444, rs670139, rs744373, rs3851179, rs11136000, rs3764650, rs610932, rs6887649, rs7849530, rs4866650, rs3765728, rs34011, rs6656401, and rs597668) using additive, recessive, and dominant models on cognitive outcomes. Statistical analysis was performed to explore the independent role of each locus, interactions with ApoE4 status, and relationships to GM ICA network intensity score. For outcome measures, we used the Mini-Mental State Examination (MMSE), Cognitive Abilities Screening Instrument (CASI) total score, and short-term memory (STM) subscores, adjusted for the covariates of education, disease duration, and age. Clinically, the CD2AP G allele showed a protective role in MMSE, CASI total, and CASI-STM scores independently or via interactions with non-ApoE4 status, while the CR1 A genotype group was associated with lower STM subscores independent of ApoE4 status. Three loci showed synergic interactions with ApoE4: BIN 1, MS4A6A, and FTMT. Of the 15 meaningful ICA components, 5 SCNs (anterior and posterior hippocampus, right temporal, left thalamus, default mode network) showed relationships with general cognitive performance, in which only the ApoE4 and MS4A6A genotype groups were independently related to the hippocampus network. The genetic loci MS4A6A, BIN1, CLU, CR1, BIN1, PICALM, and FGF1 influenced the networks independently or in synergy. This study suggests that AD-susceptible loci may each exert clinical significance independently through interactions with ApoE4 status or through SCNs as an endophenotype and that this effect is associated with the cognitive outcomes.

Functional MRI and ApoE4 genotype for predicting cognitive decline in amyloid-positive individuals

Background:

In light of advancements in machine learning techniques, many studies have implemented machine learning approaches combined with data measures to predict and classify Alzheimer’s disease. Studies that predicted cognitive status with longitudinal follow-up of amyloid-positive individuals remain scarce, however.

Objective:

We developed models based on voxel-wise functional connectivity (FC) density mapping and the presence of the ApoE4 genotype to predict whether amyloid-positive individuals would experience cognitive decline after 1 year.

Methods:

We divided 122 participants into cognitive decline and stable cognition groups based on the participants’ change rates in Mini-Mental State Examination scores. In addition, we included 68 participants from Alzheimer’s Disease Neuroimaging Initiative (ADNI) database as an external validation data set. Subsequently, we developed two classification models: the first model included 99 voxels, and the second model included 99 voxels and the ApoE4 genotype as features to train the models by Wide Neural Network algorithm with fivefold cross-validation and to predict the classes in the hold-out test and ADNI data sets.

Results:

The results revealed that both models demonstrated high accuracy in classifying the two groups in the hold-out test data set. The model for FC demonstrated good performance, with a mean F1-score of 0.86. The model for FC combined with the ApoE4 genotype achieved superior performance, with a mean F1-score of 0.90. In the ADNI data set, the two models demonstrated stable performances, with mean F1-scores of 0.77 in the first and second models.

Conclusion:

Our findings suggest that the proposed models exhibited promising accuracy for predicting cognitive status after 1 year in amyloid-positive individuals. Notably, the combination of FC and the ApoE4 genotype increased prediction accuracy. These findings can assist clinicians in predicting changes in cognitive status in individuals with a high risk of Alzheimer’s disease and can assist future studies in developing precise treatment and prevention strategies.

Exploration of several plants from Baung Forest on bone formation cell models

OBJECTIVES

Osteoporosis is an ailment described by a skeletal degradation of bone skeletal dominating to increases the chance of fracture. In order to find out the bone formation agents from Baung Forest plants, this research analyzed the effects of 96% ethanol extract of several plants from Baung Forest on antioxidant activity and the effect of osteoblast differentiation-related to the bone formation on the most potent extract.

METHODS

The antioxidant effect and osteoblast differentiation of 96% ethanol extracts were evaluated by measuring DPPH scavenging and alkaline phosphatase in p-nitrophenyl phosphate effects by the enzyme-linked immunosorbent assay (ELISA) reader method, respectively.

RESULTS

The 96% ethanol extract of Elaeocarpus serratus L. from Baung Forest had the strongest DPPH radical scavenging as anti oxidant (82.17%) and stimulated osteoblast differentiation (116%). Then, this extract had been fractionated based on polarity to become hexane, ethyl acetate, butanol, and aqueous fractions. All the fractions stimulated their alkaline phosphatase (ALP) activity to 138.11 ± 9.72%, 108 ± 5.05%, 148.56 ± 8.47, and 144.58 ± 1.04, respectively.

CONCLUSIONS

The extract and fractions of E. serratus L. can successfully inhibit DPPH radical scavenging value and increase ALP activities as markers of osteoblast functions.

The effect of deer antler from East Kalimantan to increase trabecular bone density and calcium levels in serum on osteoporotic mice

OBJECTIVES

Glucocorticoid-induced osteoporosis (dexamethasone) is a primary cause of secondary osteoporosis by the decreasing formation and increasing resorption activities. Previously, the in vitro study showed that 70% ethanol and aqueous extract of deer antler have increased alkaline phosphatase in osteoblast cell that known as marker of bone formation. The mind of this study is to analyze the effect of deer antlers in increasing the bone trabecular density of osteoporosis-induced male mice.

METHODS

This study used a post-test control group design. A total of 54 healthy male mice were randomly divided to nine groups, i.e., healthy control, osteoporotic, positive control, 70% ethanol (4, 8, and 12 mg/kg BW), and aqueous extracts (4, 8, and 12 mg/kg BW) of deer antler groups. All of the interventions were given 1 mL of test sample for 4 weeks orally. The bone densities were determined using histomorphometry by Image J and Adobe Photoshop. The statistical data were performed using SPSS 23 and statistical significance was set at p<0.05.

RESULTS

The results showed that alendronate group, 70% ethanol, and aqueous extract groups increased bone density and calcium levels in serum (p<0.05) compared to osteoporotic group in dose dependent manner. It indicated that 70% ethanol and aqueous extract of deer antler stimulating bone turnover and aqueous extract showed the highest.

CONCLUSIONS

Dexamethasone induction for 4 weeks caused osteoporotic mice and the administration of 70% ethanol and aqueous extracts of deer antler from East Kalimantan increased trabecular bone density and calcium levels in dose dependent manner.

The Effect of Rusa unicolor Antler Deer Extracts from East Kalimantan in Bone Turnover Cell Models

Objectives

Osteoporosis is a condition characterized by skeletal degradation of osseous tissue resulting in an escalated chance of broken bones. Traditionally, Rusa unicolor horn from East Kalimantan is used to treat many diseases, including conditions associated with bone turnover. The aim of the present research was to analyze the effects of 70% ethanol and aqueous extracts of R. unicolor antler's horn from East Kalimantan on nitric oxide inhibition, osteoblast differentiation, and mineralization related to bone turnover.

Materials and Methods

Nitric oxide inhibition of the extracts in lipopolysaccharide-stimulated RAW 264.7 macrophages was evaluated by Griess reagent, while the effects of extracts on osteoblast differentiations were measured by alkaline phosphatase in p-nitrophenyl phosphate. Their effects on mineralization was determined using alizarin red staining.

Results

The 70% ethanol and aqueous extracts inhibited cell inflammation (40% and 80%, respectively) and stimulated osteoblast differentiation (65% and 52%, respectively). In the mineralization test, the aqueous extract showed an effect two times higher than that of 70% ethanol extract.

Conclusion

The extracts can effectively degrade inflammatory marker expression and preserve osteoblast functions.

N-acetylgalactosamine-6-sulfatase (GALNS), Similar to Glycodelin, Is a Potential General Biomarker for Multiple Malignancies

BACKGROUND/AIM

The aim of this study was to evaluate N-acetylgalactosamine-6-sulfatase (GALNS) as a new biomarker candidate for detecting lung cancer. Glycodelin or PAEP, the serum levels of which are known to be elevated in lung and other cancers, served as a benchmark for comparison.

PATIENTS AND METHODS

A total of 170 serum samples from healthy controls and patients with pneumonia, lung cancer, breast cancer, colon cancer, liver cancer, and head and neck cancer were analyzed for the levels of GALNS and PAEP by ELISA.

RESULTS

The median serum levels of GALNS and PAEP in all cancer types as well as pneumonia patients were significantly higher than those of the healthy controls.

CONCLUSION

In addition to previously known cancers, the median serum levels of PAEP were also found to be higher in liver and head and neck cancer patients. GALNS and PAEP are promising general biomarkers for multiple cancers and deserve further evaluation.

A gelatin/collagen/polycaprolactone scaffold for skin regeneration

Background

A tissue-engineered skin substitute, based on gelatin (“G”), collagen (“C”), and poly(ε-caprolactone) (PCL; “P”), was developed.

Method

G/C/P biocomposites were fabricated by impregnation of lyophilized gelatin/collagen (GC) mats with PCL solutions, followed by solvent evaporation. Two different GC:PCL ratios (1:8 and 1:20) were used.

Results

Differential scanning calorimetry revealed that all G/C/P biocomposites had characteristic melting point of PCL at around 60 °C. Scanning electron microscopy showed that all biocomposites had similar fibrous structures. Good cytocompatibility was present in all G/C/P biocomposites when incubated with primary human epidermal keratinocytes (PHEK), human dermal fibroblasts (PHDF) and human adipose-derived stem cells (ASCs) in vitro. All G/C/P biocomposites exhibited similar cell growth and mechanical characteristics in comparison with C/P biocomposites. G/C/P biocomposites with a lower collagen content showed better cell proliferation than those with a higher collagen content in vitro. Due to reasonable mechanical strength and biocompatibility in vitro, G/C/P with a lower content of collagen and a higher content of PCL (GC_LP_H) was selected for animal wound healing studies. According to our data, a significant promotion in wound healing and skin regeneration could be observed in GC_LP_H seeded with adipose-derived stem cells by Gomori’s trichrome staining.

Conclusion

This study may provide an effective and low-cost wound dressings to assist skin regeneration for clinical use.

MAOA-VNTR Genotype Effects on Ventral Striatum-Hippocampus Network in Alzheimer's Disease: Analysis Using Structural Covariance Network and Correlation with Neurobehavior Performance

Functional polymorphisms in the promoter region of the monoamine oxidase A (MAOA) gene are associated with brain MAOA activity and transcriptional efficiency in patients with Alzheimer's disease (AD). This study investigated structural covariance networks mediated by MAOA-variable number tandem repeat (VNTR) genotypes in patients with AD, and assessed whether this effect was associated with sex. A total of 193 patients with AD were classified into four genotype groups based on MAOA transcriptional efficiency (female low [L], low-high + high activity groups [LH + H]; male L, male H groups). Structural covariance networks were constructed focusing on triple-network and striatal networks. Covariance strength was analyzed in the four groups, and the genotype and sex main effects and their interactions were analyzed. Significant peak cluster volumes were correlated with neurobehavioral scores to establish the clinical significance. MAOA genotypes mediated the structural covariance strength on the dorsolateral prefrontal cortex (dLPFC)-caudate axis in both sexes, but a higher covariance strength was shown in the female L group and male H group. The independent effect of male sex was related to higher covariance strength in the frontal medial superior region in the dLPFC, dorsal caudate (DC), and ventral superior striatum (VSs) seeds. In contrast, female sex had higher covariance strength in the frontal opercular areas anchored by the dLPFC, DC, and VSs seeds. Topographies showing higher covariance strength with sex interactions were found in the male H group and female L group in the dLPFC supplementary motor axis, DC-SMA, and DC-precentral axis. In our patients with AD, MAOA-VNTR polymorphisms and sex had independent and interactive effects on structural covariance networks, of which the dLPFC-, VSs-, and DC-anchored networks represented major endophenotypes that determined cognitive outcomes. The sex-genotype interaction model suggested that male high activity and female low activity may modulate brain morphometric connectivity and determine cognitive scores.

Adequacy of nutrition and body weight in patients with early stage dementia: The cognition and aging study

BACKGROUND & AIMS

Recent evidence highlights the effects of obesity, diabetes and hypertension in the development of Alzheimer's disease. Involuntary body weight changes in patients with different stages of dementia can be related to clinical factors of the patient per se or support from their caregivers. Understanding the interactions among factors is important to establish a monitoring paradigm to guide treatment strategies.

METHODS

A total of 345 patients with very mild (n = 224) and mild stage (n = 121) dementia were enrolled from a multi-disciplinary dementia clinic. Clinical data (comorbidities, Mini-Mental State Examination [MMSE] scores, neuropsychiatric inventory [NPI] scores, eating behavior questionnaire), nutritional state (Mini-Nutritional Assessment [MNA] or MNA short form [MNA-SF]) and body mass index (BMI) were recorded. Nutritional state and BMI served as the two major outcome measures, and factors for analysis included diagnosis, dementia severity and clinical data.

RESULTS

There was a significant correlation between MNA-SF and MNA (r = .898, p < 0.01), but a 24% mismatch in case dislocation was found using the at-risk or malnutrition criteria. Factors related to obesity included male sex, higher MNA-SF and MNA scores, diabetes mellitus and hypertension, while acceptable discrimination for obesity (BMI≧23 kg/m²) was obtained with a MNA-SF score of 12/13 or MNA score of 21/22. NPI was the only independent factor related to both MNA-SF (β = -.06, P < 0.001) and MNA (β = -.1, P < 0.001). A BMI of 22-23 kg/m² was adequate in this group of patients with early stage dementia from nutritional and comorbidity perspectives. After controlling for BMI, the patients with advanced dementia had higher swallowing problem and appetite change scores.

CONCLUSIONS

In these patients with early stage dementia, a higher BMI indicated adequate nutritional status and higher MMSE, but also higher rates of comorbidities, diabetes mellitus and hypertension.

Development of a Novel Pre-Vascularized Three-Dimensional Skin Substitute Using Blood Plasma Gel

Skin substitutes with existing vascularization are in great demand for the repair of full-thickness skin defects. In the present study, we hypothesized that a pre-vascularized skin substitute can potentially promote wound healing. Novel three-dimensional (3D) skin substitutes were prepared by seeding a mixture of human endothelial progenitor cells (EPCs) and fibroblasts into a human plasma/calcium chloride formed gel scaffold, and seeding keratinocytes onto the surface of the plasma gel. The capacity of the EPCs to differentiate into a vascular-like tubular structure was evaluated using immunohistochemistry analysis and WST-8 assay. Experimental studies in mouse full-thickness skin wound models showed that the pre-vascularized gel scaffold significantly accelerated wound healing 7 days after surgery, and resembled normal skin structures after 14 days post-surgery. Histological analysis revealed that pre-vascularized gel scaffolds were well integrated in the host skin, resulting in the vascularization of both the epidermis and dermis in the wound area. Moreover, mechanical strength analysis demonstrated that the healed wound following the implantation of the pre-vascularized gel scaffolds exhibited good tensile strength. Taken together, this novel pre-vascularized human plasma gel scaffold has great potential in skin tissue engineering.

2 dyn/cm2 shear force upregulates kruppel-like factor 4 expression in human chondrocytes to inhibit the interleukin-1β-activated nuclear factor-κB

The shear force effect on human chondrocytes is time and magnitude dependent. Recently, kruppel-like factor (KLF) 4 has been identified as a pleiotropic protein and its activity in cells is dependent on different stimuli and/or cell types. The role of KLF4 in chondrocytes is still unclear and there has been no report determining whether shear force regulates KLF4 levels in chondrocytes. Hence, this study was carried out to investigate the role of KLF4 in human chondrocytes under shear force stimulation and the underlying mechanism. Human primary and SW1353 chondrocytes were used in this study. The shear forces at 2, 5, or 15 dyn/cm² intensity were applied to both types of human chondrocytes. The specific small interfering RNAs, activators, and inhibitors were used to study the detailed mechanism of shear force. The presented results showed that 2, but not 5 and 15, dyn/cm² shear force increases KLF4 expression in human primary and SW1353 chondrocytes. Extracellular signal-regulated kinase 5 induced peroxisome proliferator-activated receptor γ transcription activity to increase KLF4 transcription. Moreover, the KLF4 induction in human chondrocytes in response to 2 dyn/cm² shear force could attenuate interleukin (IL)-1β-stimulated nuclear factor-κB activation. These results elucidate the role of KLF4 in antagonizing the effect of IL-1β in human chondrocytes under 2 dyn/cm² shear force stimulation and provide a possible mechanism to demonstrate the protection of moderate forces or exercises in cartilage.

Metformin increases the cytotoxicity of oxaliplatin in human DLD-1 colorectal cancer cells through down-regulating HMGB1 expression

Colorectal cancer (CRC) is the fourth most common cause of cancer death worldwide. Chemotherapy has been the major strategy for treating patients with advanced CRC. Oxaliplatin (OXA) is used as both an adjuvant and neoadjuvant anticancer agent available to treat advanced CRC. High-mobility group box 1 protein (HMGB1) is a critical regulator of cell death and survival. HMGB1 overexpression has been shown to be resistant to cytotoxic agents. In addition, Metformin, a widely used drug for diabetes, has emerged as a potential anticancer agent. In this study, we examined whether HMGB1 plays a role in the OXA- and/or metformin-induced cytotoxic effect on CRC cells. The results showed that treatment with OXA increased HMGB1 expression in the ERK1/2- and Akt-dependent manners in DLD-1 cells. HMGB1 gene knockdown enhanced the cytotoxicity and cell growth inhibition of OXA. Moreover, OXA-increased HMGB1 expression was by inducing NF-κB-DNA-binding activity to in DLD-1 cells. Compared to a single agent, OXA combined with metformin administration resulted in cytotoxicity and cell growth inhibition synergistically, accompanied with reduced HMGB1 level. These findings may have implications for the rational design of future drug regimens incorporating OXA and metformin for the treatment of CRC.

Combined effect of acid-sensing ion channel 3 and transient receptor potential vanilloid 1 gene polymorphisms on blood pressure variations in Taiwanese

Objectives:

Both acid-sensing ion channel acid-sensing ion channel 3 (ASIC3) and transient receptor potential vanilloid 1 (TRPV1) have been proposed to be involved in the pathophysiology of hypertension. Common colocalization of ASIC3 and TRPV1 channels in the same sensory neuron has been reported. We aimed to study the combined ASIC3 and TRPV1 gene polymorphisms in the risk of hypertension.

Materials and Methods:

To test the statistical association between genetic polymorphisms of the ASIC3 and TRPV1 genes and blood pressure (BP) variations in Taiwanese, 551 unrelated individuals (286 men and 265 women) having routine health examinations were recruited. The participants had no history of cardiovascular disease or use of medication for hypertension.

Results:

Six ASIC3 and four TRPV1 gene polymorphisms were genotyped, and only the ASIC3 rs2288646 polymorphism was associated with variations in BP in the participants. In subgroup analysis, we found participants carrying the combined ASIC3 rs2288646 AA or AG and TRPV1 rs8065080 CC genotypes (combined genotypes) had significantly higher systolic, mean and diastolic BP compared with the other subgroups (P = 0.009, 0.003, and 0.006, respectively, after Bonferroni correction). Interaction analysis also revealed significant gene-gene interaction in the systolic, mean, and diastolic BP in the ASIC3 and TRPV1 genotypes (interaction P = 0.006, 0.002, and 0.002, respectively). A trend of increasing frequencies of the combined genotype was observed in normotensive, prehypertensive, and hypertensive subgroups (P for trend = 0.001), as well as in those with higher systolic and diastolic BPs (P for trend = 9.13 × 10⁻⁴ and P for trend = 5.5 × 10⁻⁵, respectively).

Conclusion:

Our data show a combined effect of ASIC3 and TRPV1 gene polymorphisms in BP variations in Taiwanese. These results suggest that the interaction between ASIC3 and TRPV1 is involved in BP regulation.

Liposome-Encapsulated Baicalein Suppressed Lipogenesis and Extracellular Matrix Formation in Hs68 Human Dermal Fibroblasts

The dermis of human skin contains large numbers of fibroblasts that are responsible for the production of the extracellular matrix (ECM) that supporting skin integrity, elasticity and wound healing. Previously, an in vivo study demonstrated that dermal fibroblasts siting in the lower dermis are capable to convert into skin adipose layer and hence fibroblast lipogenesis may vary the structure and elasticity of dermis. In the present study, Hs68 human dermal fibroblasts were utilized as an in vitro model to study the lipogenesis via using adipogenic differentiation medium (ADM). Baicalein, isolated from Scutellaria baicalensis, is one of the flavonoids to inhibit adipocyte differentiation due to high antioxidant activity in vitro. In order to develop a suitable formulation for baicalein (a poorly water-soluble drug), soybean phosphatidylcholine (SPC) was used to prepare baicalein-loaded liposomes to enhance drug bioavailability. Our results demonstrated that liposome-encapsulated baicalein protected cell viability and increased cellular uptake efficiency of Hs68 fibroblasts. Lipid accumulation, triglyceride synthesis and gene expressions of lipogenesis enzymes (FABP4 and LPL) were significantly increased in ADM-stimulated Hs68 fibroblasts but subsequently suppressed by liposome-encapsulated baicalein. In addition, ADM-induced TNF-α expression and related inflammatory factors was down-regulated by liposome-encapsulated baicalein. Through ADM-induced lipogenesis, the protein expression of elastin, type I and type III collagens increased remarkably, whereas liposome-encapsulated baicalein can down-regulate ADM-induced ECM protein synthesis. Taken together, we found that liposome-encapsulated baicalein can inhibit ADM-induced lipid accumulation and ECM formation in Hs68 fibroblasts through the suppression of lipogenesis enzymes and inflammatory responses. Liposome-encapsulated baicalein may have the potential to improve wound healing and restore skin structure after skin injury.

Leptin induces MMP1/13 and ADAMTS 4 expressions through bone morphogenetic protein-2 autocrine effect in human chondrocytes

The induction of bone morphogenetic protein (BMP)2 in injured and arthritis articular cartilage has been proposed, but the precise mechanism has not been clearly clarified. Our previous study has found that leptin could stimulate the BMP2 autocrine effect to increase the anabolic collagen II expression when it initiates the catabolic response in human chondrocytes. It has been suggested that this BMP2 autocrine effect contributes to a reparative role in leptin-stimulated human chondrocytes. In this study, we further determined whether this BMP2 autocrine effect also affect the expressions of catabolic matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinase with thrombospondin motif (ADAMTS). Human primary and SW1353 chondrocytes were used in this study. It was shown that leptin could induce the expressions of MMP1, 3, and 13 and ADAMTS4 and 5 in both human primary and SW1353 chondrocytes. Leptin-increased MMP1/13 (not MMP3) and ADAMTS4 (not ADAMTS5) expressions were affected by the leptin-upregulated BMP2 and its specific downstream Smad1/5 signaling. Moreover, both HDAC3 and 4 are involved in regulating leptin-induced BMP2 upregulation and then affect MMP1 and 13 and ADAMTS4 expression. Both HDAC3 and 4 also affect leptin-increased MMP3 mRNA expression but not through BMP2 autocrine effect of leptin induction. Our results further elucidated the role of BMP2 autocrine effect in matrix-degrading enzymes expressions under leptin stimulation. The findings in this study provide new insights into the possible mechanism of BMP2 induction in leptin-stimulated chondrocytes and in leptin-induced OA development.

The Impact of Lipid Types and Liposomal Formulations on Osteoblast Adiposity and Mineralization

Recent studies have demonstrated that fat accumulation in bone cells is detrimental to bone mass. Both adipocytes and osteoblasts are derived from common multipotent mesenchymal stem cells (MSCs) and hence the presence of fat may increase adipocyte proliferation, differentiation and fat accumulation while inhibiting osteoblast differentiation and bone formation. Lipids are common constituents in supramolecular vesicles (e.g., micelles or liposomes) that serve as drug delivery systems. Liposomal formulations such as Meriva^® were proven to decrease joint pain and improve joint function in osteoarthritis (OA) patients. In this study, we evaluated how lipid types and liposomal formulations affect osteoblast behavior including cell viability, differentiation, mineralization and inflammation. Various liposomal formulations were prepared using different types of lipids, including phosphatidylcholine (PC), 1,2-dioleoyl-sn-glycero-3-phospho-ethanolamine (DOPE), cholesterol (Chol), 3β-[N-(N′,N′-dimethylaminoethane)-carbamoyl] cholesterol hydrochloride (DC-cholesterol HCl), and 1,2-dioleoyl-3-trimethylammonium-propane chloride salt (DOTAP) to investigate the impact on osteoblast differentiation and inflammation. The results indicated that cationic lipids, DC-cholesterol and DOTAP, presented higher dose-dependent cytotoxicity and caused high level of inflammatory responses. Due to the natural properties of lipids, all the lipids can induce lipid droplet formation in osteoblasts but the level of lipid droplet accumulation was different. In comparison with cationic lipids, neutral lipids induced less adiposity, and maintained high osteoblast mineralization. Similar to previous researches, we also confirmed an inverse relationship between lipid droplet formation and osteoblast mineralization in 7F2 mouse osteoblasts. Importantly, PC containing liposomes (PC only and PC/DOTAP) suppressed IL-1β-induced gene expression of COX-2 and MMP-3 but not Chol/DOTAP liposomes or DC-Chol/DOPE liposomes. Taken together, we suggested that PC contained liposomes could provide the best liposomal formulation for the treatment of bone diseases.

Restoration of skin pigmentation after deep partial or full-thickness burn injury

Significant skin pigmentation changes occur when patients suffer deep burn injuries. These pigmentation disorders may cause not only cosmetic and psychological issues, but more importantly it increases the risk of skin cancer or photoaging. Severe burns significantly effect on the process of repigmentation as the pigmentation is tightly regulated by cell proliferation and differentiation of melanocytes and melanocyte stem cells which are housing in the epidermis and hair follicles of the skin. In the present review, we discuss the possible mechanisms to replenish the melanocytes from the healthy epidermis and hair follicles surrounding burn wounds. The molecular mechanisms of skin repigmentation following healing of burn injuries includes the differentiation of melanoblasts into melanocytes, the distribution and responses of melanocytes and melanocyte stem cells after burn injury, and the regulation of melanin production. We also reviewed advanced therapeutic strategies to treat pigmentation disorders, such as convectional surgery, laser, UV treatment and emerging concepts in skin tissue-engineering.

Evaluation of the protective effects of curcuminoid (curcumin and bisdemethoxycurcumin)-loaded liposomes against bone turnover in a cell-based model of osteoarthritis

Curcumin (Cur) and bisdemethoxycurcumin (BDMC), extracted from Curcuma longa, are poorly water-soluble polyphenol compounds that have shown anti-inflammatory potential for the treatment of osteoarthritis. To increase cellular uptake of Cur and BDMC in bone tissue, soybean phosphatidylcholines were used for liposome formulation. In this study, curcuminoid (Cur and BDMC)-loaded liposomes were characterized in terms of particle size, encapsulation efficiency, liposome stability, and cellular uptake. The results show that there is about 70% entrapment efficiency of Cur and BDMC in liposomes and that particle sizes are stable after liposome formation. Both types of liposome can inhibit macrophage inflammation and osteoclast differential activities. In comparison with free drugs (Cur and BDMC), curcuminoid-loaded liposomes were less cytotoxic and expressed high cellular uptake of the drugs. Of note is that Cur-loaded liposomes can prevent liposome-dependent inhibition of osteoblast differentiation and mineralization, but BDMC-loaded liposomes could not. With interleukin (IL)-1β stimulation, curcuminoid-loaded liposomes can successfully downregulate the expression of inflammatory markers on osteoblasts, and show a high osteoprotegerin (OPG)/receptor activator of nuclear factor κB ligand (RANKL) ratio to prevent osteoclastogenesis. In the present study, we demonstrated that Cur and BDMC can be successfully encapsulated in liposomes and can reduce osteoclast activity and maintain osteoblast functions. Therefore, curcuminoid-loaded liposomes may slow osteoarthritis progression.

Shear stress modulates macrophage-induced urokinase plasminogen activator expression in human chondrocytes

Introduction

Synovial macrophages, which can release proinflammatory factors, are responsible for the upregulation of cartilage-breakdown proteases and play critical roles in cartilage degradation during the progression of osteoarthritis (OA). In addition, shear stress exerts multifunctional effects on chondrocytes by inducing the synthesis of catabolic or anabolic genes. However, the interplay of macrophages, chondrocytes, and shear stress during the regulation of cartilage function remains poorly understood. We investigated the mechanisms underlying the modulation of human chondrocyte urokinase plasminogen activator (uPA) expression by macrophages and shear stress.

Methods

Human chondrocytes were stimulated by peripheral blood-macrophage- conditioned medium (PB-MCM), or exposure of chondrocytes cultured in PB-MCM to different levels of shear stress (2 to 20 dyn/cm²). Real-time polymerase chain reaction was used to analyze uPA gene expression. Inhibitors and small interfering RNA were used to investigate the mechanism for the effects of PB-MCM and shear stress in chondrocytes.

Results

Stimulation of human chondrocytes with PB-MCM was found to induce uPA expression. We demonstrated that activation of the JNK and Akt pathways and NF-κB are critical for PB-MCM-induced uPA expression. Blocking assays by using IL-1ra further demonstrated that IL-1β in PB-MCM is the major mediator of uPA expression in chondrocytes. PB-MCM-treated chondrocytes subjected to a lower level of shear stress showed inhibition of MCM-induced JNK and Akt phosphorylation, NF-κB activation, and uPA expression. The PB-MCM-induced uPA expression was suppressed by AMP-activated protein kinase (AMPK) agonist. The inhibitor or siRNA for AMPK abolished the shear-mediated inhibition of uPA expression.

Conclusions

These data support the hypothesis that uPA upregulation stimulated by macrophages may play an active role in the onset of OA and in the shear-stress protection against this induction.

Clinical development of liposome-based drugs: formulation, characterization, and therapeutic efficacy

Research on liposome formulations has progressed from that on conventional vesicles to new generation liposomes, such as cationic liposomes, temperature sensitive liposomes, and virosomes, by modulating the formulation techniques and lipid composition. Many research papers focus on the correlation of blood circulation time and drug accumulation in target tissues with physicochemical properties of liposomal formulations, including particle size, membrane lamellarity, surface charge, permeability, encapsulation volume, shelf time, and release rate. This review is mainly to compare the therapeutic effect of current clinically approved liposome-based drugs with free drugs, and to also determine the clinical effect via liposomal variations in lipid composition. Furthermore, the major preclinical and clinical data related to the principal liposomal formulations are also summarized.

The Effect of Polymer Molecular Weight and UV Radiation on Physical Properties and Bioactivities of PCL Films

Biodegradable polymers, such as polycaprolactone (PCL), have been well studied in the application of tissue engineering and drug delivery systems due to their favourable biocompatibility profiles. However, little research has discussed the influence of the molecular weight of these polymers on cell behaviours. Here, PCL films were synthesized using polymers with various molecular weight and the physical characteristics of these films and their effect on cell growth were evaluated. Results showed that the tensile strength and elongation rate of PCL films increased from 1.82 MPa and 95.3% to 2.01 MPa and 741.6% when the molecular weight (Mn) of polymers increased from 40,000 to 80,000. A significant difference in polymer crystallinity was also observed between these formulations. Moreover, we found that prolonged exposure to UV radiation of these films could lead to the breakdown of polymer chains and consequently increased the crystallinity of PCL films with a corresponding reduction in the tensile strength. Using Hs68 human foreskin fibroblasts, PCL films prepared using high molecular weight polymers (CAPA 6800) displayed a higher cell proliferation rate compared to ones prepared using low molecular weight polymers (CAPA 6400 and 6500). In contrast, a higher cell proliferation rate was observed for PCL films made of low molecular weight polymers, especially CAPA 6500, when H9c2 rat heart myoblasts were used. In conclusion, polymer molecular weight can alter the

Vaginal delivery of siRNA using a novel PEGylated lipoplex-entrapped alginate scaffold system

Sustained vaginal delivery of siRNA has been precluded by the mucosal barrier lining the vaginal tract. In contrast to prior reports, we showed that conventional lipoplexes administered intravaginally are unable to reach the vaginal epithelium under normal physiological conditions. Here we have developed a novel alginate scaffold system containing muco-inert PEGylated lipoplexes to provide a sustained vaginal presence of lipoplexes in vivo and to facilitate the delivery of siRNA/oligonucleotides into the vaginal epithelium. These PEGylated lipoplex-entrapped alginate scaffolds (PLAS) were fabricated using a freeze-drying method and the entrapment efficiency, release rate, and efficacy were characterized. We demonstrated that the PLAS system had an entrapment efficiency of ~50%, which released PEGylated lipoplexes gradually both in vitro and in vivo. While the presence of alginate diminished the cell uptake efficiency of PEGylated lipoplexes in vitro, as expected, we showed a six-fold increase their uptake into the vaginal epithelium compared to existing transfection systems following intravaginal administration in mice. A significant knockdown of Lamin A/C level was also observed in vaginal tissues using siLamin A/C-containing PLAS system in vivo. Overall, our results indicated the potential of the biodegradable PLAS system for the sustained delivery of siRNA/oligonucleotides to vaginal epithelium.

The proliferation and differentiation of placental-derived multipotent cells into smooth muscle cells on fibrillar collagen

Type I collagen constitutes a major portion of the extracellular matrix (ECM) in arterial wall and it is the major substrate for cell growth and differentiation. The goal of this study was to evaluate the differentiation and proliferation of placenta-derived multipotent cells (PDMCs) on polymerized type I collagen fibrils and monomer collagen. PDMCs grown on both polymerized collagen and monomer collagen with transforming growth factor (TGF)-beta treatment increases the expression of smooth muscle cell (SMC)-specific markers, including calponin, alpha-smooth muscle actin (alpha-SMA) and smooth muscle-myosin heavy chain (SM-MHC). Polymerized collagen increased the expressions of p21(CIP1) and p27(KIP1); decreased cyclin A, cyclin D1, cyclin-dependent protein kinase 2 (Cdk2); and led to G(0)/G(1) arrest in PDMCs. Furthermore, PDMC-differentiated SMCs exhibited significant collagen contractility in the presence or absence of endothelin-1 (ET-1) stimulation. By using specific inhibitors and small interfering RNA (siRNA), we demonstrated that p38 MAPK pathway and serum response factor (SRF)-DNA binding activity is critical for the polymerized collagen-induced PDMC differentiation into SMCs. Thus, polymerized collagen exhibits the great potential in inducing PDMCs differentiation into SMCs, and exerts anti-proliferative effect on PDMC-differentiated SMCs.

Targeting of ICAM-1-directed immunoliposomes specifically to activated endothelial cells with low cellular uptake: use of an optimized procedure for the coupling of low concentrations of antibody to liposomes

Targeted delivery of therapeutics to the endothelium is an important goal in the treatment of inflammatory diseases. The aim of this work was to exploit the overexpression of intercellular adhesion molecule-1 (ICAM-1) on activated endothelial cells for the targeting of anti-ICAM-1-coupled immunoliposomes with the intent for further use as drug carriers. Immunoliposomes were prepared from using an optimized method for the coupling of low concentrations of antibody to liposomes, thereby preventing the loss of antibody through the derivatization, extraction, and activation process. This is especially suitable for limiting ligand conjugates that are isolated or synthesized in small quantities, such as monoclonal antibodies (mAbs). To investigate the functionality of the resulting immunoliposomes, the specificity of binding and cellular internalization studies of liposomes, either nonconjugated or conjugated with mAbs to ICAM-1 or to irrelevant IgG to high endothelial venule (HEV) cells, were analyzed by fluorescence microplate spectroscopy at 4 and 37°C. Immunoliposomes specifically directed against ICAM-1 were shown to bind selectively and specifically to tumor necrosis factor alpha-activated endothelial cells in vitro, with minimal cellular internalization. This study provides a novel delivery system that has the potential for targeting therapeutics to inflammatory tissue.

Regulation of plasminogen activator inhibitor 1 expression in human osteoarthritic chondrocytes by fluid shear stress: role of protein kinase Calpha

OBJECTIVE

To test a fluid flow system for the investigation of the influence of shear stress on expression of plasminogen activator inhibitor 1 (PAI-1) in human osteoarthritic (OA) articular chondrocytes (from lesional and nonlesional sites) and human SW-1353 chondrocytes.

METHODS

Human SW-1353 chondrocytes and OA and normal human articular chondrocytes were cultured on type II collagen-coated glass plates under static conditions or placed in a flow chamber to form a closed fluid-circulation system for exposure to different levels of shear stress (2-20 dyn/cm2). Real-time polymerase chain reaction was used to analyze PAI-1 gene expression, and protein kinase C (PKC) inhibitors and small interfering RNA were used to investigate the mechanism of shear stress-induced signal transduction in SW-1353 and OA (lesional and nonlesional) articular chondrocytes.

RESULTS

There was a significant reduction in PAI-1 expression in OA chondrocytes obtained from lesional sites compared with those obtained from nonlesional sites. In SW-1353 chondrocytes subjected to 2 hours of shear flow, moderate shear stresses (5 and 10 dyn/cm2) generated significant PAI-1 expression, which was regulated through PKCalpha phosphorylation and Sp-1 activation. These levels of shear stress also increased PAI-1 expression in articular chondrocytes from nonlesional sites and from normal healthy cartilage through the activation of PKCalpha and Sp-1 signal transduction, but no effect of these levels of fluid shear stress was observed on OA chondrocytes from lesional sites.

CONCLUSION

OA chondrocytes from lesional sites and those from nonlesional sites of human cartilage have differential responses to shear stress with regard to PAI-1 gene expression, and therefore diverse functional consequences can be observed.

Shear stress inhibits homocysteine-induced stromal cell-derived factor-1 expression in endothelial cells

RATIONALE

Hyperhomocysteinemia contributes to vascular dysfunction and risks of cardiovascular diseases. Stromal cell-derived factor (SDF)-1, a chemokine expressed by endothelial cells (ECs), is highly expressed in advanced atherosclerotic lesions. The interplays among homocysteine, chemokines, and shear stress in regulating vascular endothelial function are not clearly understood.

OBJECTIVE

To investigate the mechanisms for modulations of EC SDF-1 expression by homocysteine and shear stress.

METHODS AND RESULTS

Homocysteine stimulation induced dose- and time-dependent SDF-1 expression and phosphorylation of mitogen-activated protein kinases extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38. By using specific inhibitors, small interfering (si)RNA, and dominant negative mutants, we demonstrated that activation of JNK pathway is critical for the homocysteine-induced SDF-1 expression. Transcription factor ELISA and chromatin immunoprecipitation assays showed that homocysteine increased Sp1- and AP-1-DNA binding activities in ECs. Inhibition of Sp1 and AP-1 activations by specific siRNA blocked the homocysteine-induced SDF-1 promoter activity and expression. Preshearing of ECs for 1 to 4 hours at 20 dyn/cm2 inhibited the homocysteine-induced JNK phosphorylation, Sp1 and AP-1 activation, and SDF-1 expression. The homocysteine-induced SDF-1 expression was suppressed by NO donor. Inhibitor or siRNA for endothelial NO synthase abolished the shear inhibition of SDF-1 expression.

CONCLUSIONS

Our findings serve to elucidate the molecular mechanisms underlying the homocysteine induction of SDF-1 expression in ECs and the shear stress protection against this induction.

Development of a novel method for formulating stable siRNA-loaded lipid particles for in vivo use

PURPOSE

A simple yet novel method was developed to prepare stable PEGylated siRNA-loaded lipid particles which are suitable for in vivo use.

METHODS

PEGylated siRNA-loaded lipid particles were formulated by hydration of a freeze-dried matrix. The effect of various formulation parameters on the size and homogeneity of resulting particles was studied. Particles prepared using this method were compared to those prepared using an established post-insertion procedure for the entrapment efficiency, stability, in vitro biological activity as well as in vivo biodistribution.

RESULTS

Using this hydration method, a particle size of less than 200 nm can be obtained with high siRNA entrapment efficiency (>90%) and high gene-silencing efficiency. Following intravenous administration into mice, these particles achieved a similar degree of accumulation in subcutaneous tumours but displayed less liver uptake compared to the post-insertion formulations. Importantly, in contrast to post-insertion preparations, particles made by hydration method retained 100% of their gene-silencing efficiency after storage at room temperature for 1 month.

CONCLUSIONS

This paper describes a simple method of formulating PEGylated siRNA-loaded lipid particles. Given the ease of preparation, long term stability and favourable characteristics for in vivo delivery, our work represents an advance in lipid formulation of siRNA for in vivo use.

Characterisation of the macroporosity of polycaprolactone-based biocomposites and release kinetics for drug delivery

Microporous, biocomposite matrices comprising a continuous phase of poly(epsilon-caprolactone) (PCL) and a dispersed phase of lactose or gelatin particles with defined size range (45-90, 90-125 and 125-250 microm) were produced by precipitation casting from solutions of PCL in acetone. Scanning electron microscopy (SEM) analysis revealed a characteristic surface morphology of particulates interspersed amongst crystalline lamellae of the polymer phase. Rapid release of around 80% of the lactose content occurred in PBS at 37 degrees C in 3 days, whereas biocomposites containing gelatin particles of size range 90-125 and 125-250 microm, respectively, displayed gradual and highly efficient release of around 90% of the protein phase over 21 days. A highly porous structure was obtained on extraction of the water-soluble phase. Micro-computed tomography (Micro-CT) and image analysis enabled 3-D visualisation and quantification of the internal pore size distribution. A maximum fractional pore area of 10.5% was estimated for gelatin-loaded matrices. Micro-CT analysis confirmed the presence of an extensive system of macropores, sufficiently connected to permit protein diffusion, but an absence of high volume, inter-pore channels. Thus tissue integration would be confined to the matrix surface initially if the designs investigated were used as tissue-engineering scaffolds, with the core potentially providing a depot system for controlled delivery of growth factors.

Production of mycelia and exo-biopolymer from molasses by Cordyceps sinensis 16 in submerged culture

The molecular weight of exo-biopolymer obtained from a submerged culture of Cordyceps sinensis 16 consisted of a main unit and a subunit of 126 and 68 kDa, respectively. The optimal medium for the production of mycelia and exo-biopolymer was determined to be molasses containing 2% sucrose, 0.9% yeast extract, 0.3% K2HPO4, and 0.4% CaCl2. Using optimized medium, maximum productions of mycelia and exo-biopolymer in shake-flask culture were 54.0 g/L and 28.4 g/L, respectively. This study suggests that large-scale production of mycelia and exo-biopolymer by C. sinensis 16 is possible in submerged culture.