Youth Handles Stress Better

Chronic unpredictable stress (CUS) apparently can affect us – or at least female mice – differently based on age.  Thus the paper states: "We found that in young-adult female mice, CUS resulted in decreased anxiety-like behavior and enhanced cognitive performance, whereas in old female mice it led to weight loss, dysregulated locomotion and memory impairment."  It’s a young mouse’s world; the same likely applies to humans, also likely both sexes, but we need to study this.  Abstract:

Stress-related psychopathology is highly prevalent among elderly individuals and is associated with detrimental effects on mood, appetite and cognition. Conversely, under certain circumstances repeated mild-to-moderate stressors have been shown to enhance cognitive performance in rodents and exert stress-inoculating effects in humans. As most stress-related favorable outcomes have been reported in adolescence and young-adulthood, this apparent disparity could result from fundamental differences in how aging organisms respond to stress. Furthermore, given prominent age-related alterations in sex hormones, the effect of chronic stress in aging females remains a highly relevant yet little studied issue. In the present study, female C57BL/6 mice aged 3 (young-adult) and 20-23 (old) months were subjected to 8 weeks of chronic unpredictable stress (CUS). Behavioral outcomes were measured during the last 3 weeks of the CUS protocol, followed by brain dissection for histological and molecular end points. We found that in young-adult female mice, CUS resulted in decreased anxiety-like behavior and enhanced cognitive performance, whereas in old female mice it led to weight loss, dysregulated locomotion and memory impairment. These phenotypes were paralleled by differential changes in the expression of hypothalamic insulin and melanocortin-4 receptors and were consistent with an age-dependent reduction in the dynamic range of stress-related changes in the hippocampal transcriptome. Supported by an integrated microRNA (miRNA)-mRNA expression analysis, the present study proposes that, when confronted with ongoing stress, neuroprotective mechanisms involving the upregulation of neurogenesis, Wnt signaling and miR-375 can be harnessed more effectively during young-adulthood. Conversely, we suggest that aging alters the pattern of immune activation elicited by stress. Ultimately, interventions that modulate these processes could reduce the burden of stress-related psychopathology in late life. Molecular Psychiatry advance online publication, 19 December 2017; doi:10.1038/mp.2017.237.

Discovering New Microbiota

Here is an interesting article about the discovery process of discovering “causal microbes” – microbiota, including new strains, which affect human health positively or negatively.  Some strains have been found that protect mice against colitis, as well as those that produce an antimicrobial peptide in the intestine.  Abstract:

Microbiome-wide association studies have established that numerous diseases are associated with changes in the microbiota. These studies typically generate a long list of commensals implicated as biomarkers of disease, with no clear relevance to disease pathogenesis. If the field is to move beyond correlations and begin to address causation, an effective system is needed for refining this catalogue of differentially abundant microbes and to allow subsequent mechanistic studies. Here we demonstrate that triangulation of microbe-phenotype relationships is an effective method for reducing the noise inherent in microbiota studies and enabling identification of causal microbes. We found that gnotobiotic mice harbouring different microbial communities exhibited differential survival in a colitis model. Co-housing of these mice generated animals that had hybrid microbiotas and displayed intermediate susceptibility to colitis. Mapping of microbe-phenotype relationships in parental mouse strains and in mice with hybrid microbiotas identified the bacterial family Lachnospiraceae as a correlate for protection from disease. Using directed microbial culture techniques, we discovered Clostridium immunis, a previously unknown bacterial species from this family, that-when administered to colitis-prone mice-protected them against colitis-associated death. To demonstrate the generalizability of our approach, we used it to identify several commensal organisms that induce intestinal expression of an antimicrobial peptide. Thus, we have used microbe-phenotype triangulation to move beyond the standard correlative microbiome study and identify causal microbes for two completely distinct phenotypes. Identification of disease-modulating commensals by microbe-phenotype triangulation may be more broadly applicable to human microbiome studies.

What's In The Wine?

Resveratrol, which is found in wine as well as in other foodstuffs, has been thought to have a number of positive health benefits.  Here is a study that shows some activity against bone cancer cells.  Certain signaling pathways are involved, including suppression of Wnt signaling. Abstract:

Osteosarcoma is a high-grade bone sarcoma with strong invasive ability. However, treatment with traditional chemotherapeutic drugs is limited by low tolerability and side effects. Resveratrol has been reported previously to have selective antitumor effect on various tumor cells while little is known about its effects and underlying mechanism in osteosarcoma biology. In this study, we found that resveratrol inhibits proliferation and glycolysis, induces apoptosis and reduces the invasiveness of U2-OS cells in vitro. After treatment with resveratrol, the expression of related Wnt/β-catenin signaling pathway target genes, such as β-catenin, c-myc, cyclin D1, MMP-2 and MMP-9, was downregulated and an increased E-cadherin level was observed as well. Additionally, the dual luciferase assay results also indicated that resveratrol suppressed the activity of Wnt/β-catenin signaling pathway. Interestingly, we noticed that the expression of connexin 43 (Cx43) increased with the prolongation of resveratrol treatment time. To further investigate the relationship between Cx43 and the Wnt/β-catenin signaling pathway in osteosarcoma, we used lentiviral-mediated shRNA to knockdown the expression of Cx43. Knockdown of Cx43 activated the Wnt/β-catenin signaling pathway, promoted proliferation and invasion, and inhibited apoptosis of U2-OS cells. Taken together, our results demonstrate that the antitumor activity of resveratrol against U2-OS cells in vitro occurs through up-regulating Cx43 and E-cadherin, and suppressing the Wnt/β-catenin signaling pathway. Moreover, Cx43 expression is negatively related to the activity of the Wnt/β-catenin pathway in U2-OS cells.

APOE4 And Late-onset Alzheimer Disease

This link is to another paper showing an association between APOE4 and late-onset Alzheimer disease.  Understanding how the APOE4 gene variant enhances risk for this disease can help in the discover of novel therapeutic approaches.  Abstract:

APOE4 is the strongest genetic risk factor for late-onset Alzheimer disease. ApoE4 increases brain amyloid-β pathology relative to other ApoE isoforms. However, whether APOE independently influences tau pathology, the other major proteinopathy of Alzheimer disease and other tauopathies, or tau-mediated neurodegeneration, is not clear. By generating P301S tau transgenic mice on either a human ApoE knock-in (KI) or ApoE knockout (KO) background, here we show that P301S/E4 mice have significantly higher tau levels in the brain and a greater extent of somatodendritic tau redistribution by three months of age compared with P301S/E2, P301S/E3, and P301S/EKO mice. By nine months of age, P301S mice with different ApoE genotypes display distinct phosphorylated tau protein (p-tau) staining patterns. P301S/E4 mice develop markedly more brain atrophy and neuroinflammation than P301S/E2 and P301S/E3 mice, whereas P301S/EKO mice are largely protected from these changes. In vitro, E4-expressing microglia exhibit higher innate immune reactivity after lipopolysaccharide treatment. Co-culturing P301S tau-expressing neurons with E4-expressing mixed glia results in a significantly higher level of tumour-necrosis factor-α (TNF-α) secretion and markedly reduced neuronal viability compared with neuron/E2 and neuron/E3 co-cultures. Neurons co-cultured with EKO glia showed the greatest viability with the lowest level of secreted TNF-α. Treatment of P301S neurons with recombinant ApoE (E2, E3, E4) also leads to some neuronal damage and death compared with the absence of ApoE, with ApoE4 exacerbating the effect. In individuals with a sporadic primary tauopathy, the presence of an ε4 allele is associated with more severe regional neurodegeneration. In individuals who are positive for amyloid-β pathology with symptomatic Alzheimer disease who usually have tau pathology, ε4-carriers demonstrate greater rates of disease progression. Our results demonstrate that ApoE affects tau pathogenesis, neuroinflammation, and tau-mediated neurodegeneration independently of amyloid-β pathology. ApoE4 exerts a 'toxic' gain of function whereas the absence of ApoE is protective.

Essential Genes And Cancer Immunotherapy

Here is a paper looking at what genes may be essential for successful cancer immunotherapy. Abstract:

Somatic gene mutations can alter the vulnerability of cancer cells to T-cell-based immunotherapies. Here we perturbed genes in human melanoma cells to mimic loss-of-function mutations involved in resistance to these therapies, by using a genome-scale CRISPR-Cas9 library that consisted of around 123,000 single-guide RNAs, and profiled genes whose loss in tumour cells impaired the effector function of CD8+ T cells. The genes that were most enriched in the screen have key roles in antigen presentation and interferon-γ signalling, and correlate with cytolytic activity in patient tumours from The Cancer Genome Atlas. Among the genes validated using different cancer cell lines and antigens, we identified multiple loss-of-function mutations in APLNR, encoding the apelin receptor, in patient tumours that were refractory to immunotherapy. We show that APLNR interacts with JAK1, modulating interferon-γ responses in tumours, and that its functional loss reduces the efficacy of adoptive cell transfer and checkpoint blockade immunotherapies in mouse models. Our results link the loss of essential genes for the effector function of CD8+ T cells with the resistance or non-responsiveness of cancer to immunotherapies.

Restoring loss of function (gene therapy) may allow for successful cancer immunotherapy in those patients resistant to that therapeutic approach.  This study is the first necessary step in that direction and is therefore highly encouraging.

Party fair

Hello, everyone! 

It is cold, dark and unforgiving out, so it is time to experiment inside. Today, I decided to celebrate my day off with a "party" lunch. I toasted thinly sliced French bread, and prepared a few new recipes for appetizers. The first appetizer was easy deviled eggs, and the second - a chickpea-avocado spread. 

I happened to have all the ingredients in my refrigerator or the pantry. The toast was delicious with the avocado spread and a piece of roasted red pepper on top (I had a few peppers frozen from a jar). The eggs were spicy and a bit salty (due to the feta cheese). It was great to be inside on a frozen January day and enjoy a slow lunch.

Here are the two recipes:

Easy deviled eggs
Ingredients:
hard boiled eggs
crumbled feta cheese
chicken wing sauce (mine was from the dollar store)

Directions:
Peel the eggs; slice into two halves each egg. Carefully take out the yolks and mix with crumbled feta cheese and the spicy chicken wing sauce. Use any proportions that please you. Place the yolk mixture back into the egg whites, enjoy!

Garbanzo-avocado spread
Ingredients:
one can of garbanzo beans (15 oz)
two ripe avocados
the juice from 1/2 lemon
olive oil
salt
crushed garlic

Directions:
Mash the avocado and the garbanzo beans with a fork, add the salt, garlic, lemon juice and oil to taste. Mix and enjoy!

Mikelifesteer Homemade Uncrustables

Take two pieces of 100% whole wheat bread – I like to use double fiber bread, if available, to enhance the fiber intake. Remove the crust from the bread. Make the filling.  Two fillings that I have tried are:

Peanut butter, reduced fat cream cheese, low-sugar strawberry jam 

Peanut butter, reduced fat cream cheese, Musselman’s apple butter, cinnamon, raisins

In a ratio of approximately two heaping teaspoons of peanut butter to an equivalent amount of the other ingredients combined

You can of course try other components of the filling: prune butter, almond butter, various dried fruit and/or nuts, unsweetened apple sauce, chocolate, honey, wheat germ, etc.

Mix the filling and put in between the bread, and then seal the bread along the edges by pinching together.  Wrap in aluminum foil and bake for 30 minutes at 400 degrees F.  After cooling you can eat or freeze (it freezes very well).  I usually cut in half, so each one made is two servings for me.

As with all the baked materials I make, the homemade version is not going to be as sweet as the store-bought, but it will be healthier – and you’ll know exactly what’s in it, how it was made, etc.  In addition, when you eat healthier, your tastes change, so that you don’t always like very sweet things.

In fact, as a fan of apple pie and various baked goods based on apples – including those I make myself – I find one of the major flaws in store-bought apple pies and other such baked goods is that they are too sweet.  Rather than let the natural sweetness and tartness of the apples come through, they bury it under excessive sugar.  That’s coupled with – at least for the cheaper versions – using mushy apple filling that is barely recognizable as apples; in addition, the crust they have is too thin and too flaky.  I like thicker crust, less sweetness, fresher apples, just the right amount of seasoning – let the apples and apple based products (apple butter or apple sauce) themselves provide most of the flavor.  The same principle applies to these homemade uncrustables – no extra sugar is added; whatever sweetness and sugar is already present in the filling is what provides the flavor.

Myc Oncogene And Immune Detection Of Cancer

Activation of the Myc oncogene in cancer helps produce immune-suppressed conditions that aids in the evasion of tumor immune surveillance.

…we find that co-activation of Myc drives the immediate transition to highly proliferative and invasive adenocarcinomas marked by highly inflammatory, angiogenic, and immune-suppressed stroma. 

It therefore stands to reason that suppression if the Myc signaling can help restore anti-tumor immune function and that is what has been shown to occur, using agents that modify epigenetic changes in genes – changes that involve how the chromatin is modified (methylation, acetylation) instead of DNA sequence changes, with consequent alteration of gene expression. This is hopeful in the quest to improve anti-cancer immunotherapy.  Abstract:

Combining DNA-demethylating agents (DNA methyltransferase inhibitors [DNMTis]) with histone deacetylase inhibitors (HDACis) holds promise for enhancing cancer immune therapy. Herein, pharmacologic and isoform specificity of HDACis are investigated to guide their addition to a DNMTi, thus devising a new, low-dose, sequential regimen that imparts a robust anti-tumor effect for non-small-cell lung cancer (NSCLC). Using in-vitro-treated NSCLC cell lines, we elucidate an interferon α/β-based transcriptional program with accompanying upregulation of antigen presentation machinery, mediated in part through double-stranded RNA (dsRNA) induction. This is accompanied by suppression of MYC signaling and an increase in the T cell chemoattractant CCL5. Use of this combination treatment schema in mouse models of NSCLC reverses tumor immune evasion and modulates T cell exhaustion state towards memory and effector T cell phenotypes. Key correlative science metrics emerge for an upcoming clinical trial, testing enhancement of immune checkpoint therapy for NSCLC.

BMI, Metabolic Syndrome, And Pancreatic Cancer

Here is study linking higher BMI, and higher fasting insulin levels (metabolic syndrome, insulin resistance), with an increased risk for pancreatic cancer.  The burden of morbidity and mortality caused by overweight/obesity is staggering, something to keep in mind when reading all the popular stories on the Internet that attempt to normalize obesity and rant about “fat shaming” and “body shaming.”  Being overweight is literally killing people, why normalize it?  Abstract:

BACKGROUND:

Risk factors for pancreatic cancer include a cluster of metabolic conditions such as obesity, hypertension, dyslipidemia, insulin resistance, and type 2 diabetes. Given that these risk factors are correlated, separating out causal from confounded effects is challenging. Mendelian randomization (MR), or the use of genetic instrumental variables, may facilitate the identification of the metabolic drivers of pancreatic cancer.

METHODS:

We identified genetic instruments for obesity, body shape, dyslipidemia, insulin resistance, and type 2 diabetes in order to evaluate their causal role in pancreatic cancer etiology. These instruments were analyzed in relation to risk using a likelihood-based MR approach within a series of 7110 pancreatic cancer patients and 7264 control subjects using genome-wide data from the Pancreatic Cancer Cohort Consortium (PanScan) and the Pancreatic Cancer Case-Control Consortium (PanC4). Potential unknown pleiotropic effects were assessed using a weighted median approach and MR-Egger sensitivity analyses.

RESULTS:

Results indicated a robust causal association of increasing body mass index (BMI) with pancreatic cancer risk (odds ratio [OR] = 1.34, 95% confidence interval [CI] = 1.09 to 1.65, for each standard deviation increase in BMI [4.6 kg/m2]). There was also evidence that genetically increased fasting insulin levels were causally associated with an increased risk of pancreatic cancer (OR = 1.66, 95% CI = 1.05 to 2.63, per SD [44.4 pmol/L]). Notably, no evidence of a causal relationship was observed for type 2 diabetes, nor for dyslipidemia. Sensitivity analyses did not indicate that pleiotropy was an important source of bias.

CONCLUSIONS:

Our results suggest a causal role of BMI and fasting insulin in pancreatic cancer etiology.

Of Worms And Men

Aging and the decline in function as a result of aging differs between individuals, in part through genetic variation that exists between the individuals.  A study in worms demonstrates one mechanisms whereby genetic differenced can manifest as differences in age-related functioning: through the nervous system.  This may have relevance to humans, as many pathways are similar between C. elegans and H. sapiens.

The rate of behavioural decline in the ageing population is remarkably variable among individuals. Despite the considerable interest in studying natural variation in ageing rate to identify factors that control healthy ageing, no such factor has yet been found. Here we report a genetic basis for variation in ageing rates in Caenorhabditis elegans. We find that C. elegans isolates show diverse lifespan and age-related declines in virility, pharyngeal pumping, and locomotion. DNA polymorphisms in a novel peptide-coding gene, named regulatory-gene-for-behavioural-ageing-1 (rgba-1), and the neuropeptide receptor gene npr-28 influence the rate of age-related decline of worm mating behaviour; these two genes might have been subjected to recent selective sweeps. Glia-derived RGBA-1 activates NPR-28 signalling, which acts in serotonergic and dopaminergic neurons to accelerate behavioural deterioration. This signalling involves the SIR-2.1-dependent activation of the mitochondrial unfolded protein response, a pathway that modulates ageing. Thus, natural variation in neuropeptide-mediated glia-neuron signalling modulates the rate of ageing in C. elegans.