Progesterone with vitamin D affords better neuroprotection against excitotoxicity in cultured cortical neurons than progesterone alone

An updated systematic review of neuroprotective agents in the treatment of spinal cord injury

This systematic review aims to summarize the findings from all clinical randomized trials assessing the efficacy of potential neuroprotective agents in influencing the outcomes of acute spinal cord injuries (SCI). Following the PRISMA guidelines, we conducted comprehensive searches in four electronic databases (PubMed, Scopus, Cochrane Library, and Web of Science) up to September 5th, 2023. Our analysis included a total of 30 studies. We examined the effects of 15 substances/drugs: methylprednisolone, tirilazad mesylate, erythropoietin, nimodipine, naloxone, Sygen, Rho protein antagonist, granulocyte colony-stimulating factor, autologous macrophages, autologous bone marrow cells, vitamin D, progesterone, riluzole, minocycline, and blood alcohol concentration. Notable improvements in neurological outcomes were observed with progesterone plus vitamin D and granulocyte colony-stimulating factor. In contrast, results for methylprednisolone, erythropoietin, Sygen, Rho Protein, and Riluzole were inconclusive, primarily due to insufficient sample size or outdated evidence. No significant differences were found in the remaining evaluated drugs. Progesterone plus vitamin D, granulocyte colony-stimulating factor, methylprednisolone, Sygen, Rho Protein, and Riluzole may enhance neurological outcomes in acute SCI cases. It is worth noting that different endpoints or additional subgroup analyses may potentially alter the conclusions of individual trials. Therefore, certain SCI grades may benefit more from these treatments than others, while the overall results may remain inconclusive.

A Novel In Vitro Platform Development in the Lab for Modeling Blast Injury to Microglia

Traumatic brain injury (TBI), which is mainly caused by impact, often results in chronic neurological abnormalities. Since the pathological changes in vivo during primary biomechanical injury are quite complicated, the in-depth understanding of the pathophysiology and mechanism of TBI depends on the establishment of an effective experimental in vitro model. Usually, a bomb explosive blast was employed to establish the in vitro model, while the process is complex and unsuitable in the lab. Based on water-hammer, we have developed a device system to provide a single dynamic compression stress on living cells. A series of amplitude (∼5.3, ∼9.8, ∼13.5 MPa) were generated to explore the effects of dynamic compression loading on primary microglia within 48 h. Apoptosis experiments indicated that primary microglia had strong tolerance to blast waves. In addition, the generation of intercellular reactive oxygen species and secretory nitric oxide was getting strongly enhanced and recovered within 48 h. In addition, there is a notable release of pro-inflammatory cytokine by microglia. Our work provides a reproducible and peaceable method of loading single dynamic compression forces to cells in vitro. Microglia showed an acute inflammatory response to dynamic loadings, while no significant cell death was observed. This insight delivers a new technological approach that could open new areas to a better understanding of the mechanism of cell blast injuries.

Paraventricular Vitamin D Receptors Are Required for Glucose Tolerance in Males but Not Females

When delivered directly into the brain, vitamin D, can improve glucose levels in male mice. Additionally, the loss of the vitamin D receptor (VDR) in male mice's paraventricular hypothalamus (PVH) results in impaired glucose tolerance. Data in humans shows that low vitamin D levels are detrimental to glucose homeostasis, an effect that may be more prominent in men. However, it is unknown if vitamin D action in the brain is required for normal glucose regulation in female mice. This study shows that in both viral and genetic models, male mice with obesity and PVH VDR loss have impaired glucose tolerance while female mice are unaffected. Weights were unaltered in both sexes by PVH VDR loss. Additionally, PVH VDR loss did not cause any glucose abnormalities in either sex when the mice were on a chow diet. Utilizing electrophysiology studies, we show PVH VDR loss resulted in decreased baseline firing frequency and resting membrane potential in males, but not females. Additionally, male mice with PVH VDR loss had impaired miniature excitatory postsynaptic currents (mEPSC), while females were unaffected. Interestingly, the PVH neurons of both sexes were activated by exogenous vitamin D (1,25-dihydroxyvitamin D3), an effect dependent upon the VDR. Thus, there is sexual dimorphism, for the actions of the PVH VDR on glucose regulation. PVH VDRs are necessary for normal glucose homeostasis in males but not females and this may be secondary to actions of the VDR on neuronal activity.

Stroke-Induced Peripheral Immune Dysfunction in Vitamin D-Deficient Conditions: Modulation by Progesterone and Vitamin D

Vitamin D deficiency (Ddef) alters morphology and outcomes after a stroke. We investigated the interaction of Ddef following post-stroke systemic inflammation and evaluated whether administration of progesterone (P) or vitamin D (D) will improve outcomes. Ddef rats underwent stroke with lipopolysaccharide (LPS)-induced systemic inflammation. Rats were randomly divided into 9 groups and treated with P, D, or vehicle for 4 days. At day 4, rats were tested on different behavioral parameters. Markers of neuronal inflammation, endoplasmic reticulum stress, oxidative stress, white matter integrity, and apoptosis were measured along with immune cell populations from the spleen, thymus, and blood. Severely altered outcomes were observed in the Ddef group compared to the D-sufficient (Dsuf) group. Stroke caused peripheral immune dysfunction in the Dsuf group which was worse in the Ddef group. Systemic inflammation exacerbated injury outcomes in the Dsuf group and these were worse in the Ddef group. Monotherapy with P/D showed beneficial functional effects but the combined treatment showed better outcomes than either alone. Ddef as a comorbid condition with stroke worsens stroke outcomes and can delay functional recovery. Combination treatment with P and D might be promising for future stroke therapeutics in Ddef.

Preoperative Serum Level of Vitamin D is a Possible Protective Factor for Peritumoral Brain Edema of Meningioma: A Cross Sectional Study

Meningioma is associated with the development of vasogenic edema defined as disrupted blood brain barrier. Vitamin D3 through its own nuclear receptor can regulate the expression of many effective agents on the integrity of the blood brain barrier. This study aimed to investigate the association between preoperative serum levels of 25(OH)D and peritumoral brain edema in patients with meningioma. One hundred and twelve patients with meningioma completed the study. Serum 25(OH)D levels assessment and magnetic resonance imaging (MRI) were done for all patients at the beginning of the study. The percentage of edema index (EI) was used to estimate the extent of peritumoral brain edema through preoperative MRI. The median serum level of 25(OH)D in the patients with the percentage of EI < 100% was significantly higher than those with > 100% (65.58 vs. 37.33, P < 0.001). The median percentage of EI was 24.9. Preoperative serum levels of 25(OH)D had an inverse and significant correlation with the percentage of EI as by increasing each 1 ng/mL of serum 25(OH)D, EI was decreased approximately 4% (95% CI; -5.984 to -1.952, P < 0.001). Vitamin D may be a protective factor for peritumoral brain edema of meningioma.

Neuroprotective Agents as an Adjuvant Treatment in Patients With Acute Spinal Cord Injuries: A Qualitative Systematic Review of Randomized Trials

STUDY DESIGN

This was a systematic literature review.

OBJECTIVE

The objective of this study was to evaluate randomized clinical trials that address potential neuroprotective agents used to improve neurological outcome in patients with spinal cord injury (SCI).

SUMMARY OF BACKGROUND DATA

Clinical treatment of acute SCI has evolved significantly, but neurological recovery of severely injured patients remains modest. Neuroprotective agents may act to limit secondary damage in the sequence of pathophysiologic insults that occur after primary SCI.

METHODS

We performed a systematic review in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines of all clinical randomized trials that evaluated potential neuroprotective agents (drugs, stem cells, and any type of medicative interventions) in neurological outcome of acute SCI. All the studies were graded according to their level of evidence in accordance with the Oxford Level of Evidence-based Medicine.

RESULTS

A total of 16 randomized clinical trials were included and fully analyzed in our review. The following 12 substances/drugs were analyzed: methylprednisolone (MP), naloxone, tirilizad, nimodipine, Sygen, autologous incubated macrophages, autologous bone marrow cells, minocycline, erythropoietin, ganglioside, vitamin D, and progesterone. Modest benefits were attributed to minocycline and Sygen (without statistical significance), and some benefits were obtained with erythropoietin and progesterone plus vitamin D in neurological outcome. For MP, the benefits are also controversial and may be attributed to statistical artifacts and with a high risk of adverse effects. The other substances did not change the final outcome. All studies were considered as grade B of recommendation (100%) and levels of evidences as B2 (81.25%) and B3 (18.75%).

CONCLUSIONS

Our review reported some potential substances that may improve neurological outcome in acute SCI: MP, vitamin D associated with progesterone, and erythropoietin. Their potential benefits were modest in the evaluated studies, requiring further randomized clinical trials with large samples of patients, without statistical artifacts, for routine clinical use. Furthermore, potential adverse effects must be considered with the use of neuroprotective agents in SCI. Until then, the use of these substances may be experimental or restricted to specific clinical situations.

Vitamin D supplementation has no effects on progression of motor dysfunction in amyotrophic lateral sclerosis (ALS)

OBJECTIVES

To investigate the effects of cholecalciferol supplementation on the progression of motor disability in a cohort of amyotrophic lateral sclerosis (ALS) patients with low blood 25-hydroxyvitamin D3 [25(OH)D] levels, on the basis of the hypothesis of potential neuroprotective effects of vitamin D supplementation.

METHODS

Forty-eight ALS patients, 34 with deficient (<20 ng/mL) and 14 with insufficient (20-29 ng/mL) serum levels of 25(OH)D, were randomized and treated by 3 different doses of cholecalciferol [50.000, 75.000 and 100.000 international units (IU) /month] and evaluated after 6-months. Assessment of motor dysfunction at baseline and after 6 months included ALS Functional Rating Scale-Revised (ALFRS-R) and upper motor neuron (UMN) scores and blood samples for 25(OH)D levels.

RESULTS

Clinical data of 33 patients were available after 6 months. Analysis of Covariance (ANCOVA), with pre-treatment measurements included as covariate, did not show statistically significant differences in the ALSFRS-R (p > 0.05) and UMN (p > 0.05) among the patient groups who underwent 3 different doses of cholecalciferol. Conversely, the treatment with 75.000 IU/month or 100.000 IU/month induced a significant increase in serum levels of 25(OH)D in comparison with the supplementation with 50.000 IU/month; no significant differences were found between 75.000 IU/month and 100.000 IU/month.

CONCLUSIONS

Our findings highlighted that 6-month supplementation of vitamin D in ALS patients had no significant effects on motor dysfunction. However, it is recommended to prevent medical complications of vitamin D deficiency in ALS patients as well as in other populations of neurodegenerative patients, characterized by low mobility and decreased sun exposure.

Focus on 1,25-Dihydroxyvitamin D3 in the Peripheral Nervous System

In this review, we draw attention to the roles of calcitriol (1,25-dihydroxyvitamin D3) in the trophicity of the peripheral nervous system. Calcitriol has long been known to be crucial in phosphocalcium homeostasis. However, recent discoveries concerning its involvement in the immune system, anti-cancer defenses, and central nervous system development suggest a more pleiotropic role than previously thought. Several studies have highlighted the impact of calcitriol deficiency as a promoting factor of various central neurological diseases, such as multiple sclerosis, amyotrophic lateral sclerosis, Parkinson's disease, and Alzheimer's disease. Based on these findings and recent publications, a greater role for calcitriol may be envisioned in the peripheral nervous system. Indeed, calcitriol is involved in myelination, axonal homogeneity of peripheral nerves, and neuronal-cell differentiation. This may have useful clinical consequences, as calcitriol supplementation may be a simple means to avoid the onset and/or development of peripheral nervous-system disorders.

Repurposing and repositioning neurosteroids in the treatment of traumatic brain injury: A report from the trenches

The field of neuroprotection after brain injuries has been littered with failed clinical trials. Finding a safe and effective treatment for acute traumatic brain injury remains a serious unmet medical need. Repurposing drugs that have been in use for other disorders is receiving increasing attention as a strategy to move candidate drugs more quickly to trial while reducing the very high cost of new drug development. This paper describes our own serendipitous discovery of progesterone's neuroprotective potential, and the strategies we are using in repurposing and developing this hormone for use in brain injuries-applications very different from its classical uses in treating disorders of the reproductive system. We have been screening and testing a novel analog that maintains progesterone's therapeutic properties while overcoming its physiochemical challenges, and testing progesterone in combination treatment with another pleiotropic hormone, vitamin D. Finally, our paper, in the context of the problems and pitfalls we have encountered, surveys some of the factors we found to be critical in the clinical translation of repurposed drugs. This article is part of the Special Issue entitled 'Drug Repurposing: old molecules, new ways to fast track drug discovery and development for CNS disorders'.

Progesterone improves neurocognitive outcomes following therapeutic cranial irradiation in mice

Despite improved therapeutic methods, CNS toxicity resulting from cancer treatment remains a major cause of post-treatment morbidity. More than half of adult patients with cranial irradiation for brain cancer develop neurobehavioral/cognitive deficits that severely impact quality of life. We examined the neuroprotective effects of the neurosteroid progesterone (PROG) against ionizing radiation (IR)-induced neurobehavioral/cognitive deficits in mice. Male C57/BL mice were exposed to one of two fractionated dose regimens of IR (3Gy×3 or 3Gy×5). PROG (16mg/kg; 0.16mg/g) was given as a pre-, concurrent or post-IR treatment for 14days. Mice were tested for short- and long-term effects of IR and PROG on neurobehavioral/cognitive function on days 10 and 30 after IR treatment. We evaluated both hippocampus-dependent and -independent memory functions. Locomotor activity, elevated plus maze, novel object recognition and Morris water maze tests revealed behavioral deficits following IR. PROG treatment produced improvement in behavioral performance at both time points in the mice given IR. Western blot analysis of hippocampal and cortical tissue showed that IR at both doses induced astrocytic activation (glial fibrillary acidic protein), reactive macrophages/microglia (CD68) and apoptosis (cleaved caspase-3) and PROG treatment inhibited these markers of brain injury. There was no significant difference in the degree of deficit in any test between the two dose regimens of IR at either time point. These findings could be important in the context of patients with brain tumors who may undergo radiotherapy and eventually develop cognitive deficits.

Progesterone-mediated angiogenic activity of endothelial progenitor cell and angiogenesis in traumatic brain injury rats were antagonized by progesterone receptor antagonist

OBJECTIVES

Progesterone (P4) has the potential therapeutic effects for traumatic brain injury (TBI) whose recovery depended on the enhanced angiogenesis. Endothelial progenitor cell (EPC) plays an essential role in vascular biology. We previously demonstrated that P4 administration improved circulating EPC level and neurological recovery of rat with TBI. Here, we hypothesized that P4 augmented angiogenic potential of EPC and the angiogenesis-related neurorestoration after TBI through classical progesterone receptor (PR).

MATERIALS AND METHODS

EPC derived from rats were stimulated with graded concentrations (0, 10^-10 , 10^-9 , 5 × 10^-9 , 10^-8 , 10^-7  mol/L) of P4 or 10^-6  mol/L ulipristal acetate (UPA, a PR antagonist). Male rats were subjected to cortical impact injury and treated with (i) DMSO (dimethyl sulfoxide), (ii) P4 and (iii) P4 and UPA.

RESULTS

It showed that P4 improved the angiogenic potential of EPC, including tube formation, adhesion, migration and vascular endothelial growth factor secretion, in a dose-dependent fashion with the maximal effect achieved at 10^-9  mol/L P4. High concentration (10^-7  mol/L) of P4 impaired the angiogenic potential of EPC. Notably, 10^-6  mol/L UPA antagonized the stimulatory effects of 10^-9  mol/L P4. After administrating P4, a significant improvement of neurological function and the restoration of the leaked blood-brain barrier were observed as well as a reduction of the brain water content. Both vessel density and expression of occludin of vessels were increased. When UPA was administered with P4, the neural restoration and angiogenesis were all reversed. Western blot showed that 10^-9  mol/L P4 increased the content of PRA and PRB of EPC, while 10^-7  mol/L P4 reduced the content of both PR isoforms, but there was no change found in the TBI rats.

CONCLUSIONS

It may suggest that P4-mediated angiogenic activity of EPC and angiogenesis in TBI rats were antagonized by PR antagonist.

The role of hormesis in the functional performance and protection of neural systems

This paper addresses how hormesis, a biphasic dose response, can protect and affect performance of neural systems. Particular attention is directed to the potential role of hormesis in mitigating age-related neurodegenerative diseases, genetically based neurological diseases, as well as stroke, traumatic brain injury, seizure, and stress-related conditions. The hormetic dose response is of particular significance since it mediates the magnitude and range of neuroprotective processes. Consideration of hormetic dose-response concepts can also enhance the quality of study designs, including sample size/statistical power strategies, selection of treatment groups, dose spacing, and temporal/repeat measures’ features.

Effects of progesterone and vitamin D on outcome of patients with acute traumatic spinal cord injury; a randomized, double-blind, placebo controlled study

BACKGROUND

Steroid hormones offer promising therapeutic perspectives during the acute phase of spinal cord injury (SCI) while the role of progesterone and vitamin D remain controversial. The aim of the current study was to investigate the effects of progesterone and vitamin D on functional outcome of patients with acute traumatic SCI.

METHODS

This was a randomized clinical trial including 64 adult patients with acute traumatic SCI admitted within 8 hours of injury. All the patients received methylprednisolone on admission according to standard protocol (30 mg/kg as bolus dose and 15 mg/kg each 3 hours up to 24 hours). Patients were randomly assigned to receive intramuscular injection of 0.5 mg/kg progesterone twice daily and 5µg/kg oral vitamin D3 twice daily up to 5 days (n = 32) or placebo (n = 32). Patients were visited 6 days, 3 and 6 months after injury and motor and sensory function was assessed according to American Spinal Injury Association (ASIA) score.

RESULTS

There was no significant difference between two study groups regarding age (P = 0.341), sex (P = 0.802) and therapy lag (P = 0.609). The motor powers and sensory function increased significantly after 6 months in both study groups. Those who received progesterone and vitamin D had significantly higher motor powers and sensory function after 6 months of therapy. Those who received the therapy within 4 hours of injury, had significantly higher motor powers and sensory function 6 months after treatment in progesterone and vitamin D group. Therapy lag was negatively associated with 6-month motor powers and sensory function in progesterone and vitamin D group.

CONCLUSIONS

Administration of progesterone and vitamin D in acute phase of traumatic SCI is associated with better functional recovery and outcome.

Vitamin D in clinically isolated syndrome: evidence for possible neuroprotection

BACKGROUND AND PURPOSE

Vitamin D status has been associated with inflammatory activity in multiple sclerosis (MS), but it is not known if it is associated with gray matter volume, the loss of which predicts long-term disability in MS. The association of vitamin D levels with brain volume measures and inflammatory activity in patients with clinically isolated syndrome (CIS) was investigated.

METHODS

In the phase 2 CIS trial of atorvastatin, 25-hydroxyvitamin D levels were evaluated for their age-adjusted associations with normalized gray matter and brain parenchymal volumes on brain magnetic resonance imaging (MRI). The relationships between 25-hydroxyvitamin D levels and clinical and MRI measures of inflammatory activity were also assessed.

RESULTS

In 65 patients in this substudy, each 25 nmol/l higher 25-hydroxyvitamin D level was associated with 7.8 ml higher gray matter volume (95% confidence interval 1.0, 14.6, P = 0.025). There was a tendency for an inverse association of average 25-hydroxyvitamin D levels and the composite end-point of ≥3 new brain T2 lesions or ≥1 relapse within a year (odds ratio per 25 nmol/l higher 25-hydroxyvitamin D level 0.66, 95% confidence interval 0.41, 1.08, P = 0.096).

CONCLUSIONS

Vitamin D status may impact neurodegeneration after CIS, although these results should be replicated in a second study. If confirmed in clinical trials, vitamin D supplementation may reduce long-term disability.

Embracing failure: What the Phase III progesterone studies can teach about TBI clinical trials

Background: Despite positive preclinical studies and two positive Phase II clinical trials, two large Phase III clinical trials of progesterone treatment of acute traumatic brain injury (TBI) recently ended with negative results, so a 100% failure rate continues to plague the field of TBI trials.

Methods: This paper reviews and analyses the trial structures and outcomes and discusses the implications of these failures for future drug and clinical trial development. Persistently negative trial outcomes have led to disinvestment in new drug research by companies and policy-makers and disappointment for patients and their families, failures which represent a major public health concern. The problem is not limited to TBI. Failure rates are high for trials in stroke, sepsis, cardiology, cancer and orthopaedics, among others.

Results: This paper discusses some of the reasons why the Phase III trials have failed. These reasons may include faulty extrapolation from pre-clinical data in designing clinical trials and the use of subjective outcome measures that accurately reflect neither the nature of the deficits nor long-term quantitative recovery.

Conclusions: Better definitions of injury and healing and better outcome measures are essential to change the embrace of failure that has dominated the field for over 30 years. This review offers suggestions to improve the situation.

1,25-Dihydroxyvitamin D3 attenuates endotoxin-induced production of inflammatory mediators by inhibiting MAPK activation in primary cortical neuron-glia cultures

BACKGROUND

Neuroinflammation occurs in insulted regions of the brain and may be due to reactive oxygen species (ROS), nitric oxide (NO), cytokines, and chemokines produced by activated glia. Excessive production of neurotoxic molecules causes further neuronal damage. Low levels of vitamin D3 are a risk factor for various brain diseases.

METHODS

Using the bacterial endotoxin, lipopolysaccharide (LPS), to induce neuroinflammation in primary cortical neuron-glia cultures, we investigated how 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) affected neuroinflammation.

RESULTS

LPS (100 ng/ml) induced the accumulation of nitrite and the production of ROS, interleukin (IL)-6, and macrophage inflammatory protein (MIP)-2 in time-dependent manners. Inhibition of p38 and extracellular signal-regulated kinase (ERK) but not c-Jun N-terminal kinase (JNK) mitogen-activated protein kinase (MAPK) by 20 μM of SB203580, PD98059, and SP600125, significantly reduced LPS-induced ROS production, NO accumulation, and inducible NO synthase (iNOS) expression, respectively. LPS-induced IL-6 and MIP-2 were significantly attenuated by inhibition of p38, ERK, and JNK MAPK. Cotreatment with 1,25(OH)2D3 attenuated LPS-induced ROS production, NO accumulation, and iNOS expression in concentration-dependent manners. 1,25(OH)2D3 also reduced LPS-induced production of IL-6 and MIP-2. Similarly, iNOS, IL-6, and MIP-2 mRNA expression in cells treated with LPS significantly increased, whereas this effect was attenuated by 1,25(OH)2D3. Moreover, LPS-induced phosphorylation of p38, ERK, and JNK MAPK was significantly inhibited by 1,25(OH)2D3.

CONCLUSIONS

Our findings indicate that 1,25(OH)2D3 reduced the LPS-stimulated production of inflammatory molecules in neuron-glia cultures by inhibiting MAPK pathways and the production of downstream inflammatory molecules. We suggest that 1,25(OH)2D3 can be used to alleviate neuroinflammation in various brain injuries.

Combination Therapies for Traumatic Brain Injury: Retrospective Considerations

Patients enrolled in clinical trials for traumatic brain injury (TBI) may present with heterogeneous features over a range of injury severity, such as diffuse axonal injury, ischemia, edema, hemorrhage, oxidative damage, mitochondrial and metabolic dysfunction, excitotoxicity, inflammation, and other pathophysiological processes. To determine whether combination therapies might be more effective than monotherapy at attenuating moderate TBI or promoting recovery, the National Institutes of Health funded six preclinical studies in adult and immature male rats to evaluate promising acute treatments alone and in combination. Each of the studies had a solid rationale for its approach based on previous research, but only one reported significant improvements in long-term outcomes across a battery of behavioral tests. Four studies had equivocal results because of a lack of sensitivity of the outcome assessments. One study demonstrated worse results with the combination in comparison with monotherapies. While specific research findings are reported elsewhere, this article provides an overview of the study designs, insights, and recommendations for future research aimed at therapy development for TBI.

The Synergistic Effect of Combination Progesterone and Temozolomide on Human Glioblastoma Cells

Glioblastoma multiforme (GBM) is the most common and most aggressive malignant brain tumor. Despite optimal treatment and evolving standard of care, the median survival of patients diagnosed with GBM is only 12–15 months. In this study, we combined progesterone (PROG) and temozolomide (TMZ), a standard chemotherapeutic agent for human GBM, to test whether PROG enhances the antitumor effects of TMZ and reduces its side effects. Two WHO grade IV human GBM cells lines (U87MG and U118MG) and primary human dermal fibroblasts (HDFs) were repeatedly exposed to PROG and TMZ either alone or in combination for 3 and 6 days. Cell death was measured by MTT reduction assay. PROG and TMZ individually induced tumor cell death in a dose-dependent manner. PROG at high doses produced more cell death than TMZ alone. When combined, PROG enhanced the cell death-inducing effect of TMZ. In HDFs, PROG did not reduce viability even at the same high cytotoxic doses, but TMZ did so in a dose-dependent manner. In combination, PROG reduced TMZ toxicity in HDFs. PROG alone and in combination with TMZ suppressed the EGFR/PI3K/Akt/mTOR signaling pathway and MGMT expression in U87MG cells, thus suppressing cell proliferation. PROG and TMZ individually reduced cell migration in U87MG cells but did so more effectively in combination. PROG enhances the cytotoxic effects of TMZ in GBM cells and reduces its toxic side effects in healthy primary cells.

A functional relay from progesterone to vitamin D in the immune system

Progesterone is a steroid hormone that promotes and maintains pregnancy. Vitamin D (vit. D), another steroid hormone, regulates calcium levels and bone health among many of its functions. The two hormones play important roles also in regulating the immune system. Recently, we discovered that the vitamin D receptor (VDR) is induced in T cells by progesterone. This finding connects the function of progesterone to that of vit. D and suggests that the two steroid hormones cooperate with each other for sequential and effective regulation of the immune system. Potential implications of the regulation in health and disease are discussed.

A Combination Therapy of Nicotinamide and Progesterone Improves Functional Recovery following Traumatic Brain Injury

Neuroprotection, recovery of function, and gene expression were evaluated in an animal model of traumatic brain injury (TBI) after a combination treatment of nicotinamide (NAM) and progesterone (Prog). Animals received a cortical contusion injury over the sensorimotor cortex, and were treated with either Vehicle, NAM, Prog, or a NAM/Prog combination for 72 h and compared with a craniotomy only (Sham) group. Animals were assessed in a battery of behavioral, sensory, and both fine and gross motor tasks, and given histological assessments at 24 h post-injury to determine lesion cavity size, degenerating neurons, and reactive astrocytes. Microarray-based transcriptional profiling was used to determine treatment-specific changes on gene expression. Our results confirm the beneficial effects of treatment with either NAM or Prog, demonstrating significant improvements in recovery of function and a reduction in lesion cavitation, degenerating neurons, and reactive astrocytes 24 h post-injury. The combination treatment of NAM and Prog led to a significant improvement in both neuroprotection at 24 h post-injury and recovery of function in sensorimotor related tasks when compared with individual treatments. The NAM/Prog-treated group was the only treatment group to show a significant reduction of cortical loss 24 h post-injury. The combination appears to affect inflammatory and immune processes, reducing expression of a significant number of genes in both pathways. Further preclinical trials using NAM and Prog as a combination treatment should be conducted to identify the window of opportunity, determine the optimal duration of treatment, and evaluate the combination in other pre-clinical models of TBI.

Progesterone attenuates aquaporin-4 expression in an astrocyte model of ischemia/reperfusion

Previous studies have suggested that progesterone may be involved in neuroprotection by preventing brain edema. In this study, we assessed the effects of progesterone on aquaporin-4 (AQP4) expression in an ischemia/reperfusion model of cultured rat astrocytes, and further explored the possible role of the protein kinase C (PKC) pathway in this course. We evaluate primary culture astrocytes exposed to 4 h oxygen-glucose deprivation (OGD) followed by 24 h reperfusion (OGD4h/R24h) as a means of simulating cortex ischemia and reperfusion, and test the effect of progesterone on AQP4 expression in response to OGD4h/R24h. Besides, the cell viability was assessed by MTT reduction and lactate dehydrogenase release assay, accompanied by cell morphology survey. At a concentration of 1 and 2 μM, progesterone significantly attenuated AQP4 at the level of both protein and mRNA and ameliorated the cell viability of astrocytes from OGD/reperfusion injury. Moreover, this effect was blocked by the PKC inhibitor Ro31-8220, which was employed before the OGD. These results indicate that progesterone exerts the protective effects and attenuates AQP4 expression in an astrocyte model of ischemia/reperfusion depending on the PKC signal pathway.

Diminished brain resilience syndrome: A modern day neurological pathology of increased susceptibility to mild brain trauma, concussion, and downstream neurodegeneration

The number of sports-related concussions has been steadily rising in recent years. Diminished brain resilience syndrome is a term coined by the lead author to describe a particular physiological state of nutrient functional deficiency and disrupted homeostatic mechanisms leading to increased susceptibility to previously considered innocuous concussion. We discuss how modern day environmental toxicant exposure, along with major changes in our food supply and lifestyle practices, profoundly reduce the bioavailability of neuro-critical nutrients such that the normal processes of homeostatic balance and resilience are no longer functional. Their diminished capacity triggers physiological and biochemical 'work around' processes that result in undesirable downstream consequences. Exposure to certain environmental chemicals, particularly glyphosate, the active ingredient in the herbicide, Roundup(®), may disrupt the body's innate switching mechanism, which normally turns off the immune response to brain injury once danger has been removed. Deficiencies in serotonin, due to disruption of the shikimate pathway, may lead to impaired melatonin supply, which reduces the resiliency of the brain through reduced antioxidant capacity and alterations in the cerebrospinal fluid, reducing critical protective buffering mechanisms in impact trauma. Depletion of certain rare minerals, overuse of sunscreen and/or overprotection from sun exposure, as well as overindulgence in heavily processed, nutrient deficient foods, further compromise the brain's resilience. Modifications to lifestyle practices, if widely implemented, could significantly reduce this trend of neurological damage.

Comparison of the effect of minocycline and simvastatin on functional recovery and gene expression in a rat traumatic brain injury model

The goal of this study was to compare the effects of minocycline and simvastatin on functional recovery and brain gene expression after a cortical contusion impact (CCI) injury. Dosage regimens were designed to provide serum concentrations in a rat model in the range obtained with clinically approved doses; minocycline 60 mg/kg q12h and simvastatin 10 mg/kg q12h for 72 h. Functional recovery was assessed using motor and spatial learning tasks and neuropathological measurements. Microarray-based transcriptional profiling was used to determine the effect on gene expression at 24 h, 72 h, and 7 days post-CCI. Gene Ontology analysis (GOA) was used to evaluate the effect on relevant biological pathways. Both minocycline and simvastatin improved fine motor function, but not gross motor or cognitive function. Minocycline modestly decreased lesion size with no effect of simvastatin. At 24 h post-CCI, GOA identified a significant effect of minocycline on chemotaxis, blood circulation, immune response, and cell to cell signaling pathways. Inflammatory pathways were affected by minocycline only at the 72 h time point. There was a minimal effect of simvastatin on gene expression 24 h after injury, with increasing effects at 72 h and 7 days. GOA identified a significant effect of simvastatin on inflammatory response at 72 h and 7 days. In conclusion, treatment with minocycline and simvastatin resulted in significant effects on gene expression in the brain reflecting adequate brain penetration without producing significant neurorestorative effects.

Maternal vitamin D levels and the autism phenotype among offspring

We tested whether maternal vitamin D insufficiency during pregnancy is related to the autism phenotype. Serum 25(OH)-vitamin D concentrations of 929 women were measured at 18 weeks' pregnancy. The mothers of the three children with a clinical diagnosis of autism spectrum disorder had 25(OH)-vitamin D concentrations above the population mean. The offspring of 406 women completed the Autism-Spectrum Quotient in early adulthood. Maternal 25(OH)-vitamin D concentrations were unrelated to offspring scores on the majority of scales. However, offspring of mothers with low 25(OH)-vitamin D concentrations (<49 nmol/L) were at increased risk for 'high' scores (≥2SD above mean) on the Attention Switching subscale (odds ratio: 5.46, 95% confidence interval: 1.29, 23.05). The involvement of maternal vitamin D during pregnancy in autism requires continued investigation.

Progesterone and vitamin D: Improvement after traumatic brain injury in middle-aged rats

Progesterone (PROG) and vitamin D hormone (VDH) have both shown promise in treating traumatic brain injury (TBI). Both modulate apoptosis, inflammation, oxidative stress, and excitotoxicity. We investigated whether 21 days of VDH deficiency would alter cognitive behavior after TBI and whether combined PROG and VDH would improve behavioral and morphological outcomes more than either hormone alone in VDH-deficient middle-aged rats given bilateral contusions of the medial frontal cortex. PROG (16 mg/kg) and VDH (5 μg/kg) were injected intraperitoneally 1 h post-injury. Eight additional doses of PROG were injected subcutaneously over 7 days post-injury. VDH deficiency itself did not significantly reduce baseline behavioral functions or aggravate impaired cognitive outcomes. Combination therapy showed moderate improvement in preserving spatial and reference memory but was not significantly better than PROG monotherapy. However, combination therapy significantly reduced neuronal loss and the proliferation of reactive astrocytes, and showed better efficacy compared to VDH or PROG alone in preventing MAP-2 degradation. VDH+PROG combination therapy may attenuate some of the potential long-term, subtle, pathophysiological consequences of brain injury in older subjects.

Vitamin D: Update 2013: From rickets prophylaxis to general preventive healthcare

Vitamin D has received a lot of attention recently as a result of a meteoric rise in the number of publications showing that vitamin D plays a crucial role in a plethora of physiological functions and associating vitamin D deficiency with many acute and chronic illnesses including disorders of calcium metabolism, autoimmune diseases, some cancers, type 2 diabetes mellitus, infectious diseases and cardiovascular disease. The recent data on vitamin D from experimental, ecological, case-control, retrospective and prospective observational studies, as well as smaller intervention studies, are significant and confirm the sunshine vitamin's essential role in a variety of physiological and preventative functions. The results of these studies justify the recommendation to improve the general vitamin D status in children and adults by means of a healthy approach to sunlight exposure, consumption of foods containing vitamin D and supplementation with vitamin D preparations. In general, closer attention should therefore be paid to vitamin D deficiency in medical and pharmaceutical practice than has been the case hitherto.

Roles of vitamin D in amyotrophic lateral sclerosis: possible genetic and cellular signaling mechanisms

Evidence suggests that there are aberrations in the vitamin D-endocrine system in subjects with amyotrophic lateral sclerosis (ALS). Here, we review the relationship between vitamin D and ALS. Vitamin D deficiency was reported in patients with ALS. Dietary vitamin D₃ supplementation improves functional capacity in the G93A transgenic mouse model of ALS. Genetic studies have provided an opportunity to identify the proteins that link vitamin D to ALS pathology, including major histocompatibility complex (MHC) class II molecules, toll-like receptors, poly(ADP-ribose) polymerase-1, heme oxygenase-1, and calcium-binding proteins, as well as the reduced form of nicotinamide adenine dinucleotide phosphate. Vitamin D also exerts its effect on ALS through cell-signaling mechanisms, including glutamate, matrix metalloproteinases, mitogen-activated protein kinase pathways, the Wnt/β-catenin signaling pathway, prostaglandins, reactive oxygen species, and nitric oxide synthase.

In conclusion, vitamin D may have a role in ALS. Further investigation of vitamin D in ALS patients is needed.

A clinical/translational perspective: can a developmental hormone play a role in the treatment of traumatic brain injury?

Despite decades of laboratory research and clinical trials, a safe and effective treatment for traumatic brain injury (TBI) has yet to be put into successful clinical use. I suggest that much of the problem can be attributed to a reductionist perspective and attendant research strategy directed to finding or designing drugs that target a single receptor mechanism, gene, or brain locus. This approach fails to address the complexity of TBI, which leads to a cascade of systemic toxic events in the brain and throughout the body that may persist over long periods of time. Attention is now turning to pleiotropic drugs: drugs that act on multiple genomic, proteomic and metabolic pathways to enhance morphological and functional outcomes after brain injury. Of the various agents now in clinical trials, the neurosteroid progesterone (PROG) is gaining attention despite the widespread assumption that it is "just a female hormone" with limited, if any, neuroprotective properties. This perspective should change. PROG is also a powerful developmental hormone that plays a critical role in protecting the fetus during gestation. I argue here that development, neuroprotection and cellular repair have a number of properties in common. I discuss evidence that PROG is pleiotropically neuroprotective and may be a useful therapeutic and neuroprotective agent for central nervous system injury and some neurodegenerative diseases.

Combination treatment with progesterone and vitamin D hormone is more effective than monotherapy in ischemic stroke: the role of BDNF/TrkB/Erk1/2 signaling in neuroprotection

We investigated whether combinatorial post-injury treatment with progesterone (P4) and vitamin D hormone (VDH) would reduce ischemic injury more effectively than P4 alone in an oxygen glucose deprivation (OGD) model in primary cortical neurons and in a transient middle cerebral artery occlusion (tMCAO) model in rats. In the OGD model, P4 and VDH each showed neuroprotection individually, but combination of the "best" doses did not show substantial efficacy; instead, the lower dose of VDH in combination with P4 was the most effective. In the tMCAO model, P4 and VDH were given alone or in combination at different times post-occlusion for 7 days. In vivo data confirmed the in vitro findings and showed better infarct reduction at day 7 and functional outcomes (at 3, 5 and 7 days post-occlusion) after combinatorial treatment than when either agent was given alone. VDH, but not P4, upregulated heme oxygenase-1, suggesting a pathway for the neuroprotective effects of VDH differing from that of P4. The combination of P4 and VDH activated brain-derived neurotrophic factor and its specific receptor, tyrosine kinase receptor-B. Under specific conditions VDH potentiates P4's neuroprotective efficacy and should be considered as a potential partner of P4 in a low-cost, safe and effective combinatorial treatment for stroke.

Postconcussion syndrome: a review of pathophysiology and potential nonpharmacological approaches to treatment

The incidence of all-cause concussions in the United States is estimated to range from 1.6 to 3.8 million annually, with the reported number of sport- or recreation-related concussions increasing dramatically, especially in youth sports.(1,2) Additionally, the use of roadside bombs in Iraq and Afghanistan has propelled the incidence of concussion and other traumatic brain injuries to the highest levels ever encountered by the US military. As a result, there has also been a marked increase in postconcussion syndrome (PCS) and the associated cognitive, emotional, and memory disabilities associated with the condition. Unfortunately, however, there have been no significant advancements in the understanding or treatment of PCS for decades. The current management of PCS mainly consists of rest, reduction of sensory inputs, and treating symptoms as needed. Recently, researchers investigating the underlying mechanisms of PCS have proposed that activation of the immune inflammatory response may be an underlying pathophysiology that occurs in those who experience prolonged symptoms after a concussion. This article reviews the literature and summarizes the immune inflammatory response known as immunoexcitotoxicity. This article also discusses the use of nonpharmacological agents for the management of PCS that directly address this underlying mechanism.

Comparison of the administration of progesterone versus progesterone and vitamin D in improvement of outcomes in patients with traumatic brain injury: A randomized clinical trial with placebo group

Background:

Due to the heterogeneity of traumatic brain injury (TBI), many of single treatments have not been successful in prevention and cure of these kinds of injuries. The neuroprotective effect of progesterone drug on severe brain injuries has been identified, and recently, the neuroprotective effect of vitamin D has also been studied as the combination of these two drugs has shown better effects on animal samples in some studies. This study was conducted to examine the effect of vitamin D and progesterone on brain injury treatment after brain trauma.

Materials and Methods:

This study was performed on patients with severe brain trauma (Glasgow Coma Scale (GCS) ≤ 8) from April to September, 2011. The patients were divided to 3 groups (placebo, progesterone, progesterone-vitamin D), each with 20 people. Upon the patients’ admission, their GCS and demographic information were recorded. After 3 months, they were reassessed, and their GCS and GOS (Glasgow outcome scale) were recorded. The collected data were analyzed using SPSS 18 software (SPSS Inc., Chicago IL, USA).

Results:

Before intervention, GCS mean of the placebo, progesterone, and progesterone-vitamin D groups were 6.3 ± 0.88, 6.31 ± 0.87, and 6 ± 0.88, respectively. They increased to 9.16 ± 1.11, 10.25 ± 1.34, and 11.27 ± 2.27, respectively 3 months after intervention. There was a significant difference among GCS means of the 3 groups (P-value = 0.001). GOS was classified to 2 main categories of favorable and unfavorable recovery, of which, favorable recovery in placebo, progesterone, and progesterone-vitamin D was 25%, 45%, and 60%, respectively which showed a statistical significant difference among the groups (P-value = 0.03).

Conclusion:

The results showed that recovery rate in patients with severe brain trauma in the group receiving progesterone and vitamin D together was significantly higher than that of progesterone group, which was in turn higher than that of placebo group.

Progesterone inhibition of neuronal calcium signaling underlies aspects of progesterone-mediated neuroprotection

Progesterone is being utilized as a therapeutic means to ameliorate neuron loss and cognitive dysfunction following traumatic brain injury. Although there have been numerous attempts to determine the means by which progesterone exerts neuroprotective effects, studies describing the underlying molecular mechanisms are lacking. What has become clear, however, is the notion that progesterone can thwart several physiological processes that are detrimental to neuron function and survival, including inflammation, edema, demyelination and excitotoxicity. One clue regarding the means by which progesterone has restorative value comes from the notion that these aforementioned biological processes all share the common theme of eliciting pronounced increases in intracellular calcium. Thus, we propose the hypothesis that progesterone regulation of calcium signaling underlies its ability to mitigate these cellular insults, ultimately leading to neuroprotection. Further, we describe recent findings that indicate neuroprotection is achieved via progesterone block of voltage-gated calcium channels, although additional outcomes may arise from blockade of various other ion channels and neurotransmitter receptors. This article is part of a Special Issue entitled 'Neurosteroids'.

A CD11d monoclonal antibody treatment reduces tissue injury and improves neurological outcome after fluid percussion brain injury in rats

Traumatic brain injury (TBI) is an international health concern often resulting in chronic neurological abnormalities, including cognitive deficits, emotional disturbances, and motor impairments. An anti-CD11d monoclonal antibody that blocks the CD11d/CD18 integrin and vascular cell adhesion molecule (VCAM)-1 interaction following experimental spinal cord injury improves functional recovery, while reducing the intraspinal number of neutrophils and macrophages, oxidative activity, and tissue damage. Since the mechanisms of secondary injury in the brain and spinal cord are similar, we designed a study to evaluate fully the effects of anti-CD11d treatment after a moderate lateral fluid percussion TBI in the rat. Rats were treated at 2 h after TBI with either the anti-CD11d antibody or an isotype-matched control antibody 1B7, and both short (24- to 72-h) and long (4-week) recovery periods were examined. The anti-CD11d integrin treatment reduced neutrophil and macrophage levels in the injured brain, with concomitant reductions in lipid peroxidation, astrocyte activation, amyloid precursor protein accumulation, and neuronal loss. The reduced neuroinflammation seen in anti-CD11d-treated rats correlated with improved performance on a number of behavioral tests. At 24 h, the anti-CD11d group performed significantly better than the 1B7 controls on several water maze measures of spatial cognition. At 4 weeks post-injury the anti-CD11d-treated rats had better sensorimotor function as assessed by the beam task, and reduced anxiety-like behaviors, as evidenced by elevated-plus maze testing, compared to 1B7 controls. These findings suggest that neuroinflammation is associated with behavioral deficits after TBI, and that anti-CD11d antibody treatment is a viable strategy to improve neurological outcomes after TBI.

Progesterone and low-dose vitamin D hormone treatment enhances sparing of memory following traumatic brain injury

Progesterone (PROG) has been shown to protect the brain from traumatic injury and is now in Phase III clinical trials. Our work shows that PROG's beneficial effects can be reduced in vitamin D hormone (VDH)-deficient subjects. VDH can modulate neuronal apoptosis, trophic factors, inflammation, oxidative stress, excitotoxicity, and myelin and axon repair. We investigated whether VDH combined with PROG could improve behavioral outcomes more than PROG alone in VDH-sufficient rats given bilateral contusions of the medial frontal cortex. PROG and different doses of VDH (1 μg/kg, VDH1; 2.5 μg/kg, VDH2; 5 μg/kg, VDH3) were injected intraperitoneally 1 h post-injury. Eight additional doses of PROG were given subcutaneously over 8 days with tapering over the last 2 days. Neurobehavioral tests, necrotic cavity, neuronal death and activation of astrocytes were evaluated 21 days post-injury. We found that PROG and PROG + VDH preserve spatial memory processing. VDH1 + PROG improved performance in acquisition more effectively than PROG alone, indicating that the low VDH dose is optimal for combination therapy. There were no significant differences in necrotic cavity size among the groups. The density of positive staining for reactive astrocytes (glial fibrillary acidic protein (GFAP)) increased and the cell bodies and processes of GFAP-positive cells were enlarged in the PROG + VDH1 group. Our data indicate that the combination of PROG and VDH is more effective than PROG alone in preserving spatial and reference memory, and that PROG plus low-dose VDH can activateGFAP reactions up to 21 days after injury. This effect may be one of the mechanisms underlying PROG's neuroprotective effects in combination with VDH.

Maternal serum vitamin D levels during pregnancy and offspring neurocognitive development

OBJECTIVES

To determine the association between maternal serum 25(OH)-vitamin D concentrations during a critical window of fetal neurodevelopment and behavioral, emotional, and language outcomes of offspring.

METHODS

Serum 25(OH)-vitamin D concentrations of 743 Caucasian women in Perth, Western Australia (32°S) were measured at 18 weeks pregnancy and grouped into quartiles. Offspring behavior was measured with the Child Behavior Checklist at 2, 5, 8, 10, 14, and 17 years of age (n range = 412-652). Receptive language was assessed with the Peabody Picture Vocabulary Test-Revised at ages 5 (n = 534) and 10 (n = 474) years. Raw scores were converted to standardized scores, incorporating cutoffs for clinically significant levels of difficulty.

RESULTS

χ(2) analyses revealed no significant associations between maternal 25(OH)-vitamin D serum quartiles and offspring behavioral/emotional problems at any age. In contrast, there were significant linear trends between quartiles of maternal vitamin D levels and language impairment at 5 and 10 years of age. Multivariate regression analyses, incorporating a range of confounding variables, found that the risk of women with vitamin D insufficiency (≤46 nmol/L) during pregnancy having a child with clinically significant language difficulties was increased close to twofold compared with women with vitamin D levels >70 nmol/L.

CONCLUSIONS

Maternal vitamin D insufficiency during pregnancy is significantly associated with offspring language impairment. Maternal vitamin D supplementation during pregnancy may reduce the risk of developmental language difficulties among their children.

Novel actions of progesterone: what we know today and what will be the scenario in the future?

Objectives

This article is aimed to review the novel actions of progesterone, which otherwise is considered as a female reproductive hormone. The article focuses on its important physiological actions in males too and gives an overview of its novel perspectives in disorders of central and peripheral nervous system.

Key findings

Progesterone may have a potential benefit in treatment of traumatic brain injury, various neurological disorders and male related diseases like benign prostatic hypertrophy (BPH), prostate cancer and osteoporosis. Norethisterone (NETA), a progesterone derivative, decreases bone mineral loss in male castrated mice suggesting its role in osteoporosis. In the future, progesterone may find use as a male contraceptive too, but still needs confirmatory trials for safety, tolerability and acceptability. Megestrol acetate, a progesterone derivative is preferred in prostatic cancer. Further, it may find utility in nicotine addiction, traumatic brain injury (recently entered Phase III trial) and Alzheimer's disease, diabetic neuropathy and crush injuries. Studies also suggest role of progesterone in stroke, for which further clinical trials are needed. The non genomic actions of progesterone may be in part responsible for these novel actions.

Summary

Although progesterone has shown promising role in various non-hormonal benefits, further clinical studies are needed to prove its usefulness in conditions like stroke, traumatic brain injury, neuropathy and crush injury. In male related illnesses like BPH and prostatic Ca, it may prove a boon in near future. New era of hormonal male contraception may be initiated by use of progesterone along with testosterone.

Progesterone increases circulating endothelial progenitor cells and induces neural regeneration after traumatic brain injury in aged rats

Vascular remodeling plays a key role in neural regeneration in the injured brain. Circulating endothelial progenitor cells (EPCs) are a mediator of the vascular remodeling process. Previous studies have found that progesterone treatment of traumatic brain injury (TBI) decreases cerebral edema and cellular apoptosis and inhibits inflammation, which in concert promote neuroprotective effects in young adult rats. However, whether progesterone treatment regulates circulating EPC level and fosters vascular remodeling after TBI have not been investigated. In this study, we hypothesize that progesterone treatment following TBI increases circulating EPC levels and promotes vascular remodeling in the injured brain in aged rats. Male Wistar 20-month-old rats were subjected to a moderate unilateral parietal cortical contusion injury and were treated with or without progesterone (n=54/group). Progesterone was administered intraperitoneally at a dose of 16mg/kg at 1 h post-TBI and was subsequently injected subcutaneously daily for 14 days. Neurological functional tests and immnunostaining were performed. Circulating EPCs were measured by flow cytometry. Progesterone treatment significantly improved neurological outcome after TBI measured by the modified neurological severity score, Morris Water Maze and the long term potentiation in the hippocampus as well as increased the circulating EPC levels compared to TBI controls (p<0.05). Progesterone treatment also significantly increased CD34 and CD31 positive cell number and vessel density in the injured brain compared to TBI controls (p<0.05). These data indicate that progesterone treatment of TBI improves multiple neurological functional outcomes, increases the circulating EPC level, and facilitates vascular remodeling in the injured brain after TBI in aged rats.

Vitamin D3 deficiency differentially affects functional and disease outcomes in the G93A mouse model of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a neuromuscular disease characterized by motor neuron death in the central nervous system. Vitamin D supplementation increases antioxidant activity, reduces inflammation and improves motor neuron survival. We have previously demonstrated that vitamin D(3) supplementation at 10× the adequate intake improves functional outcomes in a mouse model of ALS.

OBJECTIVE

To determine whether vitamin D deficiency influences functional and disease outcomes in a mouse model of ALS.

METHODS

At age 25 d, 102 G93A mice (56 M, 46 F) were divided into two vitamin D(3) groups: 1) adequate (AI; 1 IU D(3)/g feed) and 2) deficient (DEF; 0.025 IU D(3)/g feed). At age 113 d, tibialis anterior (TA), quadriceps (quads) and brain were harvested from 42 mice (22 M and 20 F), whereas the remaining 60 mice (34 M and 26 F) were followed to endpoint.

RESULTS

During disease progression, DEF mice had 25% (P=0.022) lower paw grip endurance AUC and 19% (P=0.017) lower motor performance AUC vs. AI mice. Prior to disease onset (CS 2), DEF mice had 36% (P=0.016) lower clinical score (CS) vs. AI mice. DEF mice reached CS 2 six days later vs. AI mice (P=0.004), confirmed by a logrank test which revealed that DEF mice reached CS 2 at a 43% slower rate vs. AI mice (HR= .57; 95% CI: 0.38, 1.74; P=0.002). Body weight-adjusted TA (AI: r=0.662, P=0.001; DEF: r=0.622, P=0.006) and quads (AI: r=0.661, P=0.001; DEF: r=0.768; P<0.001) weights were strongly correlated with age at CS 2.

CONCLUSION

Vitamin D(3) deficiency improves early disease severity and delays disease onset, but reduces performance in functional outcomes following disease onset, in the high-copy G93A mouse.

Progesterone and vitamin d hormone as a biologic treatment of traumatic brain injury in the aged

There is growing recognition that traumatic brain injury is a highly variable and complex systemic disorder that is refractory to therapies that target individual mechanisms. It is even more complex in elderly persons, in whom frailty, previous comorbidities, altered metabolism, and a long history of medication use are likely to complicate the secondary effects of brain trauma. Progesterone, one of the few neuroprotective agents that has shown promise for the treatment of acute brain injury, is now in national and international phase 3 multicenter trials. New findings show that vitamin D hormone (VDH) and VDH deficiency in the aging process (and across the developmental spectrum) may interact with progesterone and treatment for traumatic brain injury. In this article we review the use of progesterone and VDH as biologics-based therapies along with recent studies demonstrating that the combination of progesterone and VDH may promote better functional outcomes than either treatment independently.

Stuck at the bench: Potential natural neuroprotective compounds for concussion

Background:

While numerous laboratory studies have searched for neuroprotective treatment approaches to traumatic brain injury, no therapies have successfully translated from the bench to the bedside. Concussion is a unique form of brain injury, in that the current mainstay of treatment focuses on both physical and cognitive rest. Treatments for concussion are lacking. The concept of neuro-prophylactic compounds or supplements is also an intriguing one, especially as we are learning more about the relationship of numerous sub-concussive blows and/or repetitive concussive impacts and the development of chronic neurodegenerative disease. The use of dietary supplements and herbal remedies has become more common place.

Methods:

A literature search was conducted with the objective of identifying and reviewing the pre-clinical and clinical studies investigating the neuroprotective properties of a few of the more widely known compounds and supplements.

Results:

There are an abundance of pre-clinical studies demonstrating the neuroprotective properties of a variety of these compounds and we review some of those here. While there are an increasing number of well-designed studies investigating the therapeutic potential of these nutraceutical preparations, the clinical evidence is still fairly thin.

Conclusion:

There are encouraging results from laboratory studies demonstrating the multi-mechanistic neuroprotective properties of many naturally occurring compounds. Similarly, there are some intriguing clinical observational studies that potentially suggest both acute and chronic neuroprotective effects. Thus, there is a need for future trials exploring the potential therapeutic benefits of these compounds in the treatment of traumatic brain injury, particularly concussion.

Progesterone inhibition of voltage-gated calcium channels is a potential neuroprotective mechanism against excitotoxicity

The therapeutic use of progesterone following traumatic brain injury has recently entered phase III clinical trials as a means of neuroprotection. Although it has been hypothesized that progesterone protects against calcium overload following excitotoxic shock, the exact mechanisms underlying the beneficial effects of progesterone have yet to be determined. We found that therapeutic concentrations of progesterone to be neuroprotective against depolarization-induced excitotoxicity in cultured striatal neurons. Through use of calcium imaging, electrophysiology and the measurement of changes in activity-dependent gene expression, progesterone was found to block calcium entry through voltage-gated calcium channels, leading to alterations in the signaling of the activity-dependent transcription factors NFAT and CREB. The effects of progesterone were highly specific to this steroid hormone, although they did not appear to be receptor mediated. In addition, progesterone did not inhibit AMPA or NMDA receptor signaling. This analysis regarding the effect of progesterone on calcium signaling provides both a putative mechanism by which progesterone acts as a neuroprotectant, as well as affords a greater appreciation for its potential far-reaching effects on cellular function.

Progesterone blocks multiple routes of ion flux

The administration of progesterone as a neuroprotective agent following traumatic brain injury has recently entered phase III clinical trials. Previous work has demonstrated that therapeutic concentrations of progesterone decrease excitotoxicity through direct inhibition of voltage-gated calcium channels, an action independent of the nuclear progesterone receptor. Here we report using cultured rat striatal neurons that these same concentrations of progesterone also block voltage-gated potassium channels, sodium channels and GABA(A) currents. The actions of progesterone act at the surface membrane of neurons in a steroid specific, voltage-independent, concentration-dependent manner. Notably, these broad actions of progesterone on ion channel and neurotransmitter receptor function mirror those of dihydropyridines, and indicate potential shared mechanisms of action, the prospective of additional therapeutic applications, and possibly, untoward effects.

Progesterone inhibits the growth of human neuroblastoma: in vitro and in vivo evidence

We investigated the antitumorogenic effects of progesterone (P4) in a human neuroblastoma (SK-N-AS) cell line in vitro and in a mouse xenograft model of neuroblastoma. The safety of P4 was tested in rat primary cortical neurons and human foreskin fibroblasts (HFF-1). At high doses, P4 significantly (P < 0.05) decreased SK-N-AS cell viability in vitro, and this effect was not blocked either by 5α-reductase inhibitor, finasteride or the P4 receptor antagonist RU486. Even at very high doses, P4 did not induce any cell death in healthy primary cortical neurons or HFF-1. The bioavailability of P4 24 h after the last injection in the serum of treated animals was significantly (P < 0.05) higher (10-33 μg/mL) than in untreated animals. In nude mice, P4 (50 and 100 mg/kg) inhibited neuroblastoma growth by ~50% over 8 d of treatment. No drug toxicity was observed in the mice, as measured by body weight and activity. P4 suppressed the expression of vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMP-9, MMP-2), which are involved in tumor vascular development. High-dose P4 inhibited tumor growth by suppressing cell proliferation and inducing apoptosis, as evidenced by the expression of proliferating cell nuclear antigen and cleaved caspase-3. P4 significantly increased the expression of P4 receptor isoform-A and suppressed phospho-Akt (Ser437) expression. In conclusion, at high doses, P4 effectively inhibits the growth of solid neuroblastoma tumor and has high bioavailability, selective toxicity and a high margin of safety, making it a possible candidate for further study as a potential clinical treatment of neuroblastoma.