Immune Defect As A Cause Of Alzheimer's Disease

An interesting hypothesis, abstract:

Inflammation is an immune activity designed to protect the host from pathogens and noxious agents. In its low-intensity form, presence of an inflammatory process must be inferred from appropriate biomarkers. Occult neuroinflammation is not just secondary to Alzheimer's disease (AD) but may contribute to its pathogenesis and promote its progression. A leaky blood-brain barrier (BBB) has been observed in early AD and may play a role in its initiation and development. Studies of the temporal evolution of AD's biomarkers have shown that, in AD, the brain's amyloid burden correlates poorly with cognitive decline. In contrast, cognitive deficits in AD correlate well with synapse loss. Oligomeric forms of amyloid-beta (oAβs) can be synaptotoxic and evidence of their deposition inside synaptic terminals of cognition-associated neurons explains early memory loss in AD better than formation of extracellular Aβ plaques. Among innate immune cells that reside in the brain, microglia sense danger signals represented by proteins like oAβ and become activated by neuronal damage such as that caused by bacterial endotoxins. The resulting reactive microgliosis has been implicated in generating the chronic form of microglial activation believed to promote AD's development. Genome-wide association studies (GWASs) have yielded data from patients with sporadic AD indicating that its causes include genetic variation in the innate immune system. Recent preclinical studies have reported that β-hydroxybutyrate (βOHB) may protect the brain from the adverse effects of both the nucleotide-binding oligomerization domain (NOD)-like receptor protein 3 (NLRP3) inflammasome and the deacetylation of histone. Consequently, there is an urgent need for clinical investigations designed to test whether an orally administered βOHB preparation, such as a ketone ester, can have a similar beneficial effect in human subjects.

Immune problems and inflammation may be at the heart of many chronic disorders.  Hopefully, β-hydroxybutyrate  will be helpful.  Doing everything possible to improve immune function and reduce (unnecessary) inflammation may be helpful as well.

Potential Parkinson’s Therapeutic Agent

See this.  Abstract:

Activation of microglia by classical inflammatory mediators can convert astrocytes into a neurotoxic A1 phenotype in a variety of neurological diseases1,2. Development of agents that could inhibit the formation of A1 reactive astrocytes could be used to treat these diseases for which there are no disease-modifying therapies. Glucagon-like peptide-1 receptor (GLP1R) agonists have been indicated as potential neuroprotective agents for neurologic disorders such as Alzheimer's disease and Parkinson's disease3-13. The mechanisms by which GLP1R agonists are neuroprotective are not known. Here we show that a potent, brain-penetrant long-acting GLP1R agonist, NLY01, protects against the loss of dopaminergic neurons and behavioral deficits in the α-synuclein preformed fibril (α-syn PFF) mouse model of sporadic Parkinson's disease14,15. NLY01 also prolongs the life and reduces the behavioral deficits and neuropathological abnormalities in the human A53T α-synuclein (hA53T) transgenic mouse model of α-synucleinopathy-induced neurodegeneration 16 . We found that NLY01 is a potent GLP1R agonist with favorable properties that is neuroprotective through the direct prevention of microglial-mediated conversion of astrocytes to an A1 neurotoxic phenotype. In light of its favorable properties, NLY01 should be evaluated in the treatment of Parkinson's disease and related neurologic disorders characterized by microglial activation.

Preventing Neuronal Disease Through The Microbiota

Once again, modifying the microbiota through diet can prevent neuroimmune and neuroinflammatory disease.

The gut-brain-axis refers to the bidirectional communication between the enteric nervous system and the central nervous system. Mounting evidence supports the premise that the intestinal microbiota plays a pivotal role in its function and has led to the more common and perhaps more accurate term gut-microbiota-brain axis. Numerous studies have identified associations between an altered microbiome and neuroimmune and neuroinflammatory diseases. In most cases, it is unknown if these associations are cause or effect; notwithstanding, maintaining or restoring homeostasis of the microbiota may represent future opportunities when treating or preventing these diseases. In recent years, several studies have identified the diet as a primary contributing factor in shaping the composition of the gut microbiota, and in turn, the mucosal and systemic immune systems. In this review, we will discuss the potential opportunities and challenges with respect to modifying and shaping the microbiota through diet and nutrition in order to treat or prevent neuroimmune and neuroinflammatory disease.

The Appendix and IBD

Take home points: The appendix most likely is not just a “vestigial remnant” but may play a role as a “microbiota reservoir.”  Also, the appendix may play a role in inflammatory bowel disease, particularly ulcerative colitis, and for some of these patients, an appendectomy may be helpful.  Abstract:

The human appendix has long been considered as a vestigial organ, an organ that has lost its function during evolution. In recent years, however, reports have emerged that link the appendix to numerous immunological functions in humans. Evidence has been presented for an important role of the appendix in maintaining intestinal health. This theory suggests that the appendix may be a reservoir or 'safe house' from which the commensal gut flora can rapidly be reestablished if it is eradicated from the colon. However, the appendix may also have a role in the development of inflammatory bowel disease (IBD). Several large epidemiological cohort studies have demonstrated the preventive effect of appendectomy on the development of ulcerative colitis, a finding that has been confirmed in murine colitis models. In addition, current studies are examining the possible therapeutic effect of an appendectomy to modulate disease course in patients with ulcerative colitis. This literature review assesses the current knowledge about the clinical and immunological aspects of the vermiform appendix in IBD and suggests that the idea of the appendix as a vestigial remnant should be discarded.

Against Colitis And Cancer

Chronic inflammation of the colon can increase risk for cancer; an antibody to a pro-inflammatory mediator can reduce inflammation in a mouse model, reducing cancer risk through the modulation of important cancer- related signaling pathways that can be affected by inflammation.  This is a promising therapeutic approach.  Abstract:

The association between chronic inflammation and cancer has long been recognized. The inflammatory bowel disease ulcerative colitis frequently progresses to colon cancer; however, the underlying mechanism is still unclear. S100a9 has been emerged as an important pro-inflammatory mediator in acute and chronic inflammation, and the aberrant expression of S100a9 also contributes to tumorigenic processes such as cell proliferation, angiogenesis, metastasis, and immune evasion. We previously revealed that S100a8 and S100a9 are highly activated and play an important role in the process of colitis-associated carcinogenesis, which suggests an attractive therapeutic target for ulcerative colitis and related colon cancer. Here, we report that administration of a neutralizing anti-S100a9 antibody significantly ameliorated dextran sulfate sodium (DSS)-induced colitis and accompanied by diminished cellular infiltrate of innate immunity cells (macrophages, neutrophils, and dendritic cells) and production of pro-inflammatory cytokines (Tnfα, Il1β, Ifnγ, Il6, Il17a, Il23a, Il4, and Il12a). The protective effect of anti-S100a9 antibody treatment was also observed in azoxymethane (AOM)/DSS-induced colitis-associated cancer (CAC) mouse model. The inflammatory response, tumor cell proliferation, and immune cells infiltration in the colon tissues were suppressed by anti-S100a9 antibody. Gene expression profiling showed that key pathways known to be involved in CAC development, such as Wnt signaling pathway, PI3K-Akt signaling pathway, cytokine-cytokine receptor interaction, and ECM-receptor interaction pathway, were suppressed after treatment with anti-S100a9 antibody in CAC mice. In view of the protective effect of neutralizing anti-S100a9 antibody against DSS-induced colitis and AOM/DSS-induced CAC in mouse model, this study suggests that anti-S100a9 antibody may provide a novel therapeutic approach to treat ulcerative colitis and may decrease the risk for developing CAC.

Lost In Inflammation

An interesting article about the immune system in Hepatitis A infection is here.

Western Diet And Inflammation

A Western diet can not only promote cancer in mice, it also causes inflammation, and even after the mice are switched back to their normal diet, myeloid cells show enhanced immune response.  This change seems dependent on the product of the NLRP3 gene.  Thus, the high fat, calorie-dense Western diet can contribute to long-term, pro-inflammatory, negative alterations in the immune system and this likely is relevant for humans as well as mice.

Long-term epigenetic reprogramming of innate immune cells in response to microbes, also termed "trained immunity," causes prolonged altered cellular functionality to protect from secondary infections. Here, we investigated whether sterile triggers of inflammation induce trained immunity and thereby influence innate immune responses. Western diet (WD) feeding of Ldlr-/- mice induced systemic inflammation, which was undetectable in serum soon after mice were shifted back to a chow diet (CD). In contrast, myeloid cell responses toward innate stimuli remained broadly augmented. WD-induced transcriptomic and epigenomic reprogramming of myeloid progenitor cells led to increased proliferation and enhanced innate immune responses. Quantitative trait locus (QTL) analysis in human monocytes trained with oxidized low-density lipoprotein (oxLDL) and stimulated with lipopolysaccharide (LPS) suggested inflammasome-mediated trained immunity. Consistently, Nlrp3-/-/Ldlr-/- mice lacked WD-induced systemic inflammation, myeloid progenitor proliferation, and reprogramming. Hence, NLRP3 mediates trained immunity following WD and could thereby mediate the potentially deleterious effects of trained immunity in inflammatory diseases.

Eating more fruits and vegetables may indeed be a good idea.

Inflammation, Immune Cells, And Liver Cancer

Chronic inflammation due to non-alcoholic fatty liver disease alters immune cells, resulting in more cells that produce factors that suppress anti-cancer immunity, therefore increasing the risk for liver cancer.  Note that non-alcoholic fatty liver disease is associated with metabolic syndrome, which is itself associated with being overweight/obese.  An association between poor weight control and liver cancer>  You do the math. Abstract:

The role of adaptive immunity in early cancer development is controversial. Here we show that chronic inflammation and fibrosis in humans and mice with non-alcoholic fatty liver disease is accompanied by accumulation of liver-resident immunoglobulin-A-producing (IgA+) cells. These cells also express programmed death ligand 1 (PD-L1) and interleukin-10, and directly suppress liver cytotoxic CD8+ T lymphocytes, which prevent emergence of hepatocellular carcinoma and express a limited repertoire of T-cell receptors against tumour-associated antigens. Whereas CD8+ T-cell ablation accelerates hepatocellular carcinoma, genetic or pharmacological interference with IgA+ cell generation attenuates liver carcinogenesis and induces cytotoxic T-lymphocyte-mediated regression of established hepatocellular carcinoma. These findings establish the importance of inflammation-induced suppression of cytotoxic CD8+ T-lymphocyte activation as a tumour-promoting mechanism.

Inflammation Memory

By The original uploader was Samir at English Wikipedia - Transferred from en.wikipedia to Commons., CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=2107303

Here is an interesting study that suggests a form of “inflammation memory” exists.  Therefore, in epithelial stem cells that have already been exposed to acute inflammation there is a molecular “memory” of the event, which enables a more rapid response for subsequent inflammatory exposures.   While this has some benefits in dealing with the immediate need for a response to certain stimuli, this increased sensitivity may contribute to autoimmune diseases and cancer.  From the preventive and therapeutic angle, it is therefore important to study.  Abstract:

The skin barrier is the body's first line of defence against environmental assaults, and is maintained by epithelial stem cells (EpSCs). Despite the vulnerability of EpSCs to inflammatory pressures, neither the primary response to inflammation nor its enduring consequences are well understood. Here we report a prolonged memory to acute inflammation that enables mouse EpSCs to hasten barrier restoration after subsequent tissue damage. This functional adaptation does not require skin-resident macrophages or T cells. Instead, EpSCs maintain chromosomal accessibility at key stress response genes that are activated by the primary stimulus. Upon a secondary challenge, genes governed by these domains are transcribed rapidly. Fuelling this memory is Aim2, which encodes an activator of the inflammasome. The absence of AIM2 or its downstream effectors, caspase-1 and interleukin-1β, erases the ability of EpSCs to recollect inflammation. Although EpSCs benefit from inflammatory tuning by heightening their responsiveness to subsequent stressors, this enhanced sensitivity probably increases their susceptibility to autoimmune and hyperproliferative disorders, including cancer.

Does Maternal Gut Microbiota Affect Autism Risk?

This paper linked here shows that certain gut microbiota can trigger inflammatory responses in female mice that increases the chances of offspring with abnormalities associated with maternal immune activation; in humans, such abnormalities include autism.  Thus, if these findings also apply to humans, a possible link between the gut microbiota of the mother and risk of autism in the child.  Abstract:

Maternal immune activation (MIA) contributes to behavioural abnormalities associated with neurodevelopmental disorders in both primate and rodent offspring. In humans, epidemiological studies suggest that exposure of fetuses to maternal inflammation increases the likelihood of developing autism spectrum disorder. In pregnant mice, interleukin-17a (IL-17a) produced by T helper 17 (TH17) cells (CD4+ T helper effector cells involved in multiple inflammatory conditions) induces behavioural and cortical abnormalities in the offspring exposed to MIA. However, it is unclear whether other maternal factors are required to promote MIA-associated phenotypes. Moreover, the underlying mechanisms by which MIA leads to T cell activation with increased IL-17a in the maternal circulation are not well understood. Here we show that MIA phenotypes in offspring require maternal intestinal bacteria that promote TH17 cell differentiation. Pregnant mice that had been colonized with mouse commensal segmented filamentous bacteria or human commensal bacteria that induce intestinal TH17 cells were more likely to produce offspring with MIA-associated abnormalities. We also show that small intestine dendritic cells from pregnant, but not from non-pregnant, females secrete IL-1β, IL-23 and IL-6 and stimulate T cells to produce IL-17a upon exposure to MIA. Overall, our data suggest that defined gut commensal bacteria with a propensity to induce TH17 cells may increase the risk of neurodevelopmental disorders in the offspring of pregnant mothers undergoing immune system activation owing to infections or autoinflammatory syndromes.

Reducing Inflammation To Combat Cardiovascular Disease

By Transferred from en.wikipedia to Commons., CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=2816579

Typically, cardiovascular disease is approached by reducing lipid levels (doctors usually prescribe medication, although dietary changes, and exercise, in our opinion should be focused more on). However, reducing inflammation can reduce the risk of cardiovascular disease independent of lowering lipid levels.  This is an important approach that expands the therapeutic toolkit against cardiovascular disease and underscores the importance of inflammation for cardiovascular problems (and many other diseases as well). The full paper is here; read the abstract below:

Background Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. Results At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P=0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P=0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P=0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P=0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P=0.31). Conclusions Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846 .).

Obesity, Cell Signaling, And Cancer

Let's take a look at the abstract from this paper:

Epidemiological studies have convincingly suggested that obesity is an important risk factor for postmenopausal breast cancer, but the mechanisms responsible for this relationship are still not fully understood. We hypothesize that obesity creates a low-grade inflammatory microenvironment, which stimulates Wnt-signaling and thereby promotes the development of breast cancer. To test this hypothesis, we evaluated the correlations between expression of multiple inflammatory cytokines and Wnt pathway downstream genes in mammary tissues from women (age ≥ 50) undergoing reduction mammoplasty. Moreover, we specifically examined the role of tumor necrosis factor-α (TNF-α), an important proinflammatory cytokine associated with obesity and a possible modulator of the Wnt pathway. The regulatory effects of TNF-α on Wnt pathway targets were measured in an ex vivo culture of breast tissue treated with anti-TNF-α antibody or TNF-α recombinant protein. We found that BMI was positively associated with the secretion of inflammatory cytokines IL-1β, IL-6 and TNF-α, all of which were negatively correlated with the expression of SFRP1. The transcriptional expression of Wnt-signaling targets, AXIN2 and CYCLIN D1, were higher in mammary tissue from women with BMI ≥ 30 compared to those with BMI < 30. Our ex vivo work confirmed that TNF-α is causally linked to the up-regulation of active β-CATENIN, a key component in the Wnt pathway, and several Wnt-signaling target genes (i.e. CYCLIN D1, AXIN2, P53 and COX-2). Collectively, these findings indicate that obesity-driven inflammation elevates Wnt-signaling in mammary tissue and thereby creates a microenvironment conducive to the development of breast cancer.

So, in summary, inflammation that can result from obesity may induce cell signaling, creating a favorable environment for the development of breast cancer.  I believe this would more generally apply to most other forms of cancer as well. Yet another reason to prevent/reverse excessive weight gain.

Crystal Deodorant

This is a product I personally use.

The typical deodorants one finds in stores irritate my skin, causing intense itching, redness, inflammation, pain, and skin darkening. I tried some so-called "natural deodorants" but the same thing happened after a while. However, the crystal deodorants do not cause any skin problems. I was initially skeptical that the product would actually work as a deodorant, but it does, apparently by inhibiting the growth of odor-causing bacteria.

MLL1, Aging, Cancer, And Inflammation

Here are the key points concerning an enzyme linking aging, inflammation, and cancer, with possible therapeutic implications:
 

Aged and damaged cells frequently undergo a form of proliferation arrest called cellular senescence. These fading cells increase in human tissues with aging and are thought to contribute to age-related increases in both cancer and inflammation. The secretion of such inflammatory compounds as cytokines, growth factors, and proteases is called the senescence-associated secretory phenotype, or SASP.

"Since tumor-promoting inflammation is one of the hallmarks of cancer, these findings suggest that MLL1 inhibitors may be highly potent anti-cancer drugs through both direct epigenetic effects on proliferation-promoting genes, as well as through the inhibition of inflammation in the tumor microenvironment," says first author Brian Capell, MD, PhD, a medical fellow in the lab of Shelley Berger, PhD, the Daniel S. Och University Professor in the Departments of Cell & Developmental Biology, Genetics , and Biology.

Knowing that MLL1 has been implicated in cell-cycle regulation, when the researchers inhibited MLL1, proliferation-promoting genes were shut down and the DNA damage response and resulting inflammation was suppressed. Indeed, in the case of applying this result to fighting cancer, this is a desired effect, since an increase in inflammation can promote both the development and progression of cancer.

"In cancer, this could be a potent one-two punch, by blocking both proliferation-promoting genes as well as the cancerous inflammation," Capell explained. "One could imagine taking an MLL1 inhibitor as a primary treatment, but also as an adjuvant therapy to tamp down the rampant inflammation caused by drugs like chemotherapies. More speculatively, given that the SASP has been implicated in numerous other age-related disorders, it will be worth testing the effects of MLL1 inhibition in other aging and inflammatory disease models."

More on intermittent fasting and reduced calorie intake

In October 2015, I posted on the ability of intermittent fasting (i.e., the regimen in which food intake is limited within six to eight hours for each 24 hours) to counteract cancer progression. The likely mechanism is the depletion of glucose, which is a primary source of energy for some (but not all) cancer cells. 

Intermittent fasting, however, has more benefits. Here is what I have found so far: 

• Intermittent fasting allows for a renewal of our immune system. It has been established that fasting promotes the regeneration of hematopoietic stem cells, which are responsible for the production of our immune cells. 

•  Reduced calorie intake decreases metabolism and attenuates telomere erosion; both effects may protect cells from DNA damage and therefore, from aging and cancer. I have previously written on the connection between telomere length and cancer risk. It remains to be seen, however, whether intermittent fasting without calorie restriction has the same benefits.

• Fasting counteracts inflammation, because it contributes to the generation of metabolites such as hydroxybutyrate (a ketone body) and lactic acid. It has been documented that these molecules bind receptors on macrophages, and suppress inflammation.

• Intermittent fasting can reduce acne by suppressing inflammation-associated signaling pathways (some of which are induced by our diet).

The bottom line is that the same way lean spending is good for your net worth, being lean on calorie intake boosts your health.