The Placebo Response in Double-Blind Randomised Trials Evaluating Regenerative Therapies for Parkinson’s Disease: A Systematic Review and Meta-Analysis

In the field of stem cell technologies, exciting advances are taking place leading to translational research to develop cell-based therapies which may replace dopamine releasing neurons lost in patients with Parkinson’s disease (PD). A major influence on trial design has been the assumption that the use of sham operated comparator groups is required in the implementation of randomised double-blind trials to evaluate the placebo response and effects associated with the surgical implantation of cells. The aim of the present review is to identify the improvements in motor functioning and striatal dopamine release in patients with PD who have undergone sham surgery. Of the nine published trials, there was at the designated endpoints, a pooled average improvement of 4.3 units, with 95% confidence interval of 3.1 to 5.6 on the motor subscale of the Unified Parkinson’s Disease Scale in the ‘OFF’ state. This effect size indicates a moderate degree of improvement in the motor functioning of the patients in the sham surgical arms of the trials. Four of the nine trials reported the results of 18 F-fluorodopa PET scans, indicating no improvements of dopaminergic nigrostriatal neurones following sham surgery. Therefore, while the initial randomised trials relying on the use of sham operated controls were justified on methodological grounds, we suggest that the analysis of the evidence generated by the completed and published trials indicates that placebo controlled trials are not necessary to advance and evaluate the safety and efficacy of emerging regenerative therapies for PD.

Hippocampal Expression of Cytochrome P450 1B1 in Penetrating Traumatic Brain Injury

Hippocampal dysfunction contributes to multiple traumatic brain injury sequala. Female rodents’ outcome is superior to male which has been ascribed the neuroprotective sex hormones 17β-estradiol and progesterone. Cytochrome P450 1B1 (CYP1B1) is an oxidative enzyme influencing the neuroinflammatory response by creating inflammatory mediators and metabolizing neuroprotective 17β-estradiol and progesterone. In this study, we aimed to describe hippocampal CYP1B1 mRNA expression, protein presence of CYP1B1 and its key redox partner Cytochrome P450 reductase (CPR) in both sexes, as well as the effect of penetrating traumatic brain injury (pTBI). A total 64 adult Sprague Dawley rats divided by sex received pTBI or sham-surgery and were assigned survival times of 1-, 3-, 5- or 7 days. CYP1B1 mRNA was quantified using in-situ hybridization and immunohistochemistry performed to verify protein colocalization. CYP1B1 mRNA expression was present in all subregions but greatest in CA2 irrespective of sex, survival time or intervention. At 3-, 5- and 7 days post-injury, expression in CA2 was reduced in male rats subjected to pTBI compared to sham-surgery. Females subjected to pTBI instead exhibited increased expression in all CA subregions 3 days post-injury, the only time point expression in CA2 was greater in females than in males. Immunohistochemical analysis confirmed neuronal CYP1B1 protein in all hippocampal subregions, while CPR was limited to CA1 and CA2. CYP1B1 mRNA is constitutively expressed in both sexes. In response to pTBI, females displayed a more urgent but brief regulatory response than males. This indicates there may be sex-dependent differences in CYP1B1 activity, possibly influencing inflammation and neuroprotection in pTBI.

Differential Effects of Lateral and Medial Entorhinal Cortex Lesions on Trace, Delay and Contextual Fear Memories

The entorhinal cortex (EC), with connections to the hippocampus, amygdala, and neocortex, is a critical, yet still underexplored, contributor to fear memory. Previous research suggests possible heterogeneity of function among its lateral (LEC) and medial (MEC) subregions. However, it is not well established what unique roles these subregions serve as the literature has shown mixed results depending on target of manipulation and type of conditioning used. Few studies have manipulated both the LEC and MEC within the same experiment. The present experiment systematically manipulated LEC and MEC function to examine their potential roles in fear memory expression. Long-Evans rats were trained using either trace or delay fear conditioning. The following day, rats received an N-methyl-D-aspartate (NMDA)-induced lesion to the LEC or MEC or received a sham surgery. Following recovery, rats were given an 8-min context test in the original context. The next day, rats were tested for tone freezing in a novel context with three discrete tone presentations. Further, rats were tested for hyperactivity in an open field under both dark and bright light gradient conditions. Results: Following either LEC or MEC lesion, freezing to context was significantly reduced in both trace and delay conditioned rats. LEC-lesioned rats consistently showed significantly less freezing following tone-offset (trace interval, or equivalent, and intertrial interval) in both trace and delay fear conditioned rats. Conclusions: These data suggest that the LEC may play a role in the expression of a conjunctive representation between the tone and context that mediates the maintenance of post-tone freezing.

Metabolomics Coupled with Pathway Analysis Provides Insights into Sarco-Osteoporosis Metabolic Alterations and Estrogen Therapeutic Effects in Mice

Postmenopausal osteoporosis (PMOP) and sarcopenia are common diseases that predominantly affect postmenopausal women. In the occurrence and development of these two diseases, they are potentially pathologically connected with each other at various molecular levels. However, the application of metabolomics in sarco-osteoporosis and the metabolic rewiring happening throughout the estrogen loss-replenish process have not been reported. To investigate the metabolic alteration of sarco-osteoporosis and the possible therapeutical effects of estradiol, 24 mice were randomly divided into sham surgery, ovariectomy (OVX), and estradiol-treated groups. Three-dimensional reconstructions and histopathology examination showed significant bone loss after ovariectomy. Estrogen can well protect against OVX-induced bone loss deterioration. UHPLC-Q-TOF/MS was preformed to profile semi- polar metabolites of skeletal muscle samples from all groups. Metabolomics analysis revealed metabolic rewiring occurred in OVX group, most of which can be reversed by estrogen supplementation. In total, 65 differential metabolites were identified, and pathway analysis revealed that sarco-osteoporosis was related to the alterations in purine metabolism, glycerophospholipid metabolism, arginine biosynthesis, tryptophan metabolism, histidine metabolism, oxidative phosphorylation, and thermogenesis, which provided possible explanations for the metabolic mechanism of sarco-osteoporosis. This study indicates that an UHPLC-Q-TOF/MS-based metabolomics approach can elucidate the metabolic reprogramming mechanisms of sarco-osteoporosis and provide biological evidence of the therapeutical effects of estrogen on sarco-osteoporosis.

Adaptive and pathological connectivity responses in Parkinson’s disease brain networks

Functional imaging has been used extensively to identify and validate disease-specific networks as biomarkers in neurodegenerative disorders. It is not known, however, if connectivity patterns in these networks differ with disease progression compared to the beneficial adaptations that may also occur over time. To distinguish the two responses, we focused on assortativity, the tendency for network connections to link nodes with similar properties. High assortativity is associated with unstable, inefficient flow through the network. Low assortativity, by contrast, involves more diverse connections that are also more robust and efficient. We found that in Parkinson’s disease (PD), network assortativity increased with over time. Assoratitivty was high in clinically aggressive genetic variants, but low for genes associated with slow progression. Dopaminergic treatment increased assortativity despite improving motor symptoms, but subthalamic gene therapy, which remodels PD networks, reduced this measure compared to sham surgery. Assortativity may therefore be useful in evaluating disease-modifying therapies.

Protective Effect of Catechin Hydrate on Spinal Cord Ischemia-reperfusion Injury in Rats

Background: Aortic artery stenosis leads to Ischemia-Reperfusion (I-R) injury, which can cause certain clinical expressions, such as paraplegia. Objectives: To appraise the effect of Catechin Hydrate (CH) against spinal cord I-R injury. Materials & Methods: A total of 35 male rats (250-300 g) were divided randomly into five groups: intact, sham surgery, dimethyl sulfoxide (I-R+DMSO), low-dose CH (I-R+10 mg/kg CH), and high-dose CH (I-R+20 mg/kg CH). Abdominal aorta clamping was done for 60 min. Seventy-two hours after I-R, animals were evaluated for neurologic function, biochemical analysis, and histology. The data analysis was conducted by SPSS v. 16 using ANOVA and Kruskal-Wallis and Mann-Whitney U tests. Results: The mean Motor Deficit Index (MDI) score and white matter damage in the CH (20 mg/kg) group were lower than in the DMSO group (P=0.032). The mean plasma levels of malondialdehyde (MDA) and superoxide dismutase (SOD) in the CH groups were lower than that of the DMSO group (P<0.05). The plasma level of Total Antioxidant Capacity (TAC) in the CH (20 mg/kg) group was higher than in the DMSO group (P=0.032). In addition, the plasma level of catalase in the CH (20 mg/kg) group was higher than in the DMSO and CH (10 mg/kg) groups (P<0.001). The average number of normal motor neurons in the experimental groups was lower than in the sham surgery group (P<0.001).

Attenuation of Trauma-induced Osteoarthritis by Repetitive Intra-articular Administration of Peripheral Blood Derived Mesenchymal Stem Cells

Background: Osteoarthritis (OA) is a chronic joint disease, characterized by articular cartilage degradation, subchondral bone hardening, and inflammation of the whole synovial joint. There is no pharmacological treatment in slowing down OA progression, leading to costly surgical interventions eventually. Cell therapy using chondrocytes or progenitor cells from different sources has been reported in clinical trials for OA management with some success, but outcomes are varied. Peripheral blood derived mesenchymal stem cells (PB-MSCs) are promising cells owing to their easy collection, superior migration, and differentiation potentials. In the current study, we evaluated the effect of intra-articular administration of PB-MSCs on the progression of OA in mice.Methods: C57BL/6J mice (8-10 weeks old male) were subjected to destabilization of the medial meniscus surgeries (DMM) on their right joints following protocols as previously reported. The mice after DMM were randomly treated with saline (vehicle control), PB-MSCs, or adipose tissue derived MSCs (AD-MSCs) (n = 7 per group). The mice treated with sham surgery were regarded as sham controls (n = 7). PB-MSCs and AD-MSCs were harvested and cultured according to previous published protocols, and pre-labeled with BrdU for 48 h before use. PB-MSCs or AD-MSCs (5 × 105 cells/mouse; passage 3~5) were injected into the right knee joints thrice post-surgery (except sham surgery group). The mice were euthanized at 8 weeks post-surgery and knee joint samples were collected for micro-CT and histological examinations.Results: PB-MSCs administration significantly reduced hardening of subchondral bone comparing to vehicle controls. Safranin O staining showed that PB-MSCs treatment ameliorated degeneration of articular cartilage, which is comparable to AD-MSCs treatment. The expression of catabolic marker MMP13 was significantly reduced in articular cartilage of PB-MSCs-treated groups comparing to vehicle controls. Co-expression of BrdU and Sox9 were detected, indicating injected PB-MSCs differentiated towards chondrocytes in situ. Reduced level of IL-6 in the peripheral sera of PB-MSCs- and AD-MSCs-treated mice was also determined. Conclusions: Repetitive administration of PB-MSCs or AD-MSCs halted OA progression through inhibiting cartilage degradation and inflammation. PB-MSCs may become a promising cell source for cartilage tissue repair and alleviation of OA progression.

Circulating Metabolomic Analysis following Cecal Ligation and Puncture in Young and Aged Mice Reveals Age-Associated Temporal Shifts in Nicotinamide and Histidine/Histamine Metabolic Pathways

Introduction. Aged individuals are at higher risk for morbidity and mortality following acute stressors than similarly stressed young people. Evaluation of age-associated metabolic changes could lead to the identification of specific therapeutic targets to improve outcomes from acute stressors, such as infections, in the elderly. We thus compared the plasma metabolomes of both young and old mice following cecal ligation and puncture (CLP), an accepted model of acute infection and stress. Methods. Young (9-17 wks) and aged (78-96 wks) male C57bl/6 mice were subjected to a retro-orbital bleed and two-week recovery prior to sham surgery (laparotomy alone) or CLP. Animals were sacrificed at 4 h, 8 h, or 12 h following intervention, and plasma was isolated from blood for subsequent analysis. Metabolomic analysis of samples were performed (Metabolon; Durham, NC). Results. Aged animals demonstrated greater intraprocedural mortality than young (30.2% vs. 17.4%, χ 2 p = 0.0004 ), confirming enhanced frailty. Principal component analysis and partial-least squares discriminant analysis of 566 metabolites demonstrated distinct metabolomic shifts following sham surgery or CLP in both young and aged animals. Identification of metabolites of interest using a consensus statistical approach revealed that both the histidine/histamine pathway and the nicotinamide pathway have significant age-associated alterations following CLP. Conclusions. The application of untargeted plasma metabolomics identified key pathways underpinning metabolomic responses to CLP in both young and aged animals. Ultimately, these data provide a robust foundation for future mechanistic studies that may assist in improving outcomes in frail patients in response to acute stressors such as infection, trauma, or surgery.

Expression and related mechanisms of miR-330-3p and S100B in an animal model of cartilage injury

Objective To investigate the roles of and relationship between microRNA (miR)-330-3p and S100 calcium-binding protein B (S100B) in an animal model of cartilage injury. Methods This study included 30 New Zealand male rabbits randomly divided into three groups: an intervention group, a model group and a sham surgery control group. Modelling was performed in the intervention and model groups, but in the sham surgery group, only the skin was cut. After modelling, the intervention and model groups were injected with the miR-330-3p overexpression vector GV268-miR-330-3p or the control GV268-N-ODN vector, respectively, twice a week for 7 weeks. Results Levels of interleukin-1β and tumour necrosis factor-α in the synovial fluid were significantly higher in the model group than in the intervention and control groups. The level of miR-330-3p in the cartilage tissue was significantly higher in the control group than in the model group but it was significantly lower compared with the intervention group. Levels of S100B, fibroblast growth factor receptor 1 and fibroblast growth factor-2 in the cartilage tissue of rabbits in the model group were significantly higher compared with the control and intervention groups. Conclusion These findings demonstrate that the upregulation of miR-330-3p can inhibit the expression of S100B.

Sevoflurane and Desflurane Exposures Following Aneurysmal Subarachnoid Hemorrhage Confer Multifaceted Protection against Delayed Cerebral Ischemia

Numerous studies have demonstrated the ability of isoflurane conditioning to provide multifaceted protection against aneurysmal subarachnoid hemorrhage (SAH)-associated delayed cerebral ischemia (DCI); however, preclinical studies have not yet examined whether other commonly used inhalational anesthetics in neurological patients such as sevoflurane or desflurane are also protective against SAH-induced neurovascular deficits. We therefore sought to identify the potential for sevoflurane and desflurane conditioning to protect against DCI in an endovascular perforation mouse model of SAH. Neurological function was assessed daily via neuroscore. Large artery vasospasm and microvessel thrombosis were assessed three days after SAH or sham surgery. Four groups were examined: Sham, SAH + room air, SAH + 2% Sevoflurane, and SAH + 6% Desflurane. For the SAH groups, one hour after surgery, mice received 2% sevoflurane, 6% desflurane, or room air for one hour. We found that conditioning with sevoflurane or desflurane attenuated large artery vasospasm, reduced microvessel thrombosis, and improved neurologic function. Given their frequent clinical use and strong safety profile in patients (including those with SAH), these data strongly support further studies to validate these findings in preclinical and clinical studies and to elucidate the mechanisms by which these agents might be acting.