Role of serotonin in the lack of sensitization caused by prolonged food deprivation in Aplysia.

Food deprivation may cause neurological dysfunctions including memory impairment. The mollusk Aplysia is a suitable animal model to study prolonged food deprivation-induced memory deficits because it can sustain up to 14 days of food deprivation (14DFD). Sensitization of defensive withdrawal reflexes has been used to illustrate the detrimental effects of 14DFD on memory formation. Under normal feeding conditions (i.e., two days food deprivation, 2DFD), aversive stimuli lead to serotonin (5-HT) release into the hemolymph and neuropil, which mediates sensitization and its cellular correlates including increased excitability of tail sensory neurons (TSNs). Recent studies found that 14DFD prevents both short-term and long-term sensitization, as well as short-term increased excitability of TSNs induced by in vitro aversive training. This study investigated the role of 5-HT in the absence of sensitization and TSN increased excitability under 14DFD. Because 5-HT is synthesized from tryptophan obtained through diet, and its exogeneous application alone induces sensitization and increases TSN excitability, we hypothesized that 1) 5-HT level may be reduced by 14DFD and 2) 5-HT may still induce sensitization and TSN increased excitability in 14DFD animals. Results revealed that 14DFD significantly decreased hemolymph 5-HT level, which may contribute to the lack of sensitization and its cellular correlates, while ganglia 5-HT level was not changed. 5-HT exogenous application induced sensitization in 14DFD Aplysia, albeit smaller than that in 2DFD animals, suggesting that this treatment can only induce partial sensitization in food deprived animals. Under 14DFD, 5-HT increased TSN excitability indistinguishable from that observed under 2DFD. Taken together, these findings characterize 5-HT metabolic deficiency under 14DFD, which may be compensated, at least in part, by 5-HT exogenous application.

Design and methods of a translational, community-based, lifestyle weight management pilot intervention trial in breast cancer survivors with overweight or obesity.

Background: Breast cancer survivors (BCS) with overweight or obesity are at heightened risk of cancer recurrence, cardiometabolic disease, and compromised quality of life. Given the prevalence of significant weight gain during and following breast cancer treatment, there is growing recognition of the need to develop efficacious, widely-accessible, weight management programs for BCS. Unfortunately, access to evidence-based weight management resources for BCS remains limited and little is known of the optimal theoretical basis, program components, and mode of delivery for community-based interventions. The primary aim of the Healthy New Albany Breast Cancer (HNABC) pilot trial was to determine the safety, feasibility, and preliminary efficacy of delivering a translational, evidence-based, and theory-driven lifestyle weight management intervention to BCS with overweight or obesity in the community setting. Methods: HNABC was a single-arm, pilot trial evaluating a 24-week, multi-component intervention leveraging exercise, dietary modification, and group-mediated cognitive behavioral (GMCB) counseling components designed to facilitate lifestyle behavior change and promote sustained independent adherence. Assessments of various objectively-determined and patient-reported outcomes and theory-derived determinants of behavioral adoption and maintenance were obtained at baseline, 3- and 6-month follow-up. Measures of trial feasibility were calculated prospectively throughout the study. Conclusion: Findings from the HNABC pilot trial will provide evidence demonstrating the feasibility and preliminary efficacy of a multi-component, community-based, GMCB lifestyle weight management intervention for BCS. Results will inform the design of a future, large-scale, randomized controlled efficacy trial. If successful, this approach could offer a widely accessible, community-based intervention model for weight management programs in BCS.

Psychosocial Needs of Gynecological Cancer Survivors: Mixed Methods Study.

BACKGROUND: Internet and social media platforms offer insights into the lived experiences of survivors of cancer and their caregivers; however, the volume of narrative data available is often cumbersome for thorough analysis. Survivors of gynecological cancer have unique needs, such as those related to a genetic predisposition to future cancers, impact of cancer on sexual health, the advanced stage at which many are diagnosed, and the influx of new therapeutic approaches. OBJECTIVE: This study aimed to present a unique methodology to leverage large amounts of data from internet-based platforms for mixed methods analysis. We analyzed discussion board posts made by survivors of gynecological cancer on the American Cancer Society website with a particular interest in evaluating the psychosocial aspects of survivorship. METHODS: All posts from the ovarian, uterine, and gynecological cancers (other than ovarian and uterine) discussion boards on the American Cancer Society Cancer Survivors Network were included. Posts were web scraped using Python and organized by psychosocial themes described in the Quality of Cancer Survivorship Care Framework. Keywords related to each theme were generated and verified. Keywords identified posts related to the predetermined psychosocial themes. Quantitative analysis was completed using Python and R Foundation for Statistical Computing packages. Qualitative analysis was completed on a subset of posts as a proof of concept. Themes discovered through latent Dirichlet allocation (LDA), an unsupervised topic modeling technique, were assessed and compared with the predetermined themes of interest. RESULTS: A total of 125,498 posts made by 6436 survivors of gynecological cancer and caregivers between July 2000 and February 2020 were evaluated. Of the 125,489 posts, 23,458 (18.69%) were related to the psychosocial experience of cancer and were included in the mixed methods psychosocial analysis. Quantitative analysis (23,458 posts) revealed that survivors across all gynecological cancer discussion boards most frequently discussed the role of friends and family in care, as well as fatigue, the effect of cancer on interpersonal relationships, and health insurance status. Words related to psychosocial aspects of survivorship most often used in posts included "family," "hope," and "help." Qualitative analysis (20 of the 23,458 posts) similarly demonstrated that survivors frequently discussed coping strategies, distress and worry, the role of family and caregivers in their cancer care, and the toll of managing financial and insurance concerns. Using LDA, we discovered 8 themes, none of which were directly related to psychosocial aspects of survivorship. Of the 56 keywords identified by LDA, 2 (4%), "sleep" and "work," were included in the keyword list that we independently devised. CONCLUSIONS: Web-based discussion platforms offer a great opportunity to learn about patient experiences of survivorship. Our novel methodology expedites the quantitative and qualitative analyses of such robust data, which may be used for additional patient populations.

Type I Interferon signaling controls the accumulation and transcriptomes of monocytes in the aged lung.

Aging is paradoxically associated with a deteriorated immune defense (immunosenescence) and increased basal levels of tissue inflammation (inflammaging). The lung is particularly sensitive to the effects of aging. The immune cell mechanisms underlying physiological lung aging remain poorly understood. Here we reveal that aging leads to increased interferon signaling and elevated concentrations of chemokines in the lung, which is associated with infiltration of monocytes into the lung parenchyma. scRNA-seq identified a novel Type-1 interferon signaling dependent monocyte subset (MO-ifn) that upregulated IFNAR1 expression and exhibited greater transcriptomal changes with aging than the other monocytes. Blockade of type-1 interferon signaling by treatment with anti-IFNAR1 neutralizing antibodies rapidly ablated MO-ifn cells. Treatment with anti-IFNAR1 antibodies also reduced airway chemokine concentrations and repressed the accumulation of the overall monocyte population in the parenchyma of the aged lung. Together, our work suggests that physiological aging is associated with increased basal level of airway monocyte infiltration and inflammation in part due to elevated type-1 interferon signaling.

Group 2 innate lymphoid cells are numerically and functionally deficient in the triple transgenic mouse model of Alzheimer's disease.

BACKGROUND: The immune pathways in Alzheimer's disease (AD) remain incompletely understood. Our recent study indicates that tissue-resident group 2 innate lymphoid cells (ILC2) accumulate in the brain barriers of aged mice and that their activation alleviates aging-associated cognitive decline. The regulation and function of ILC2 in AD, however, remain unknown. METHODS: In this study, we examined the numbers and functional capability of ILC2 from the triple transgenic AD mice (3xTg-AD) and control wild-type mice. We investigated the effects of treatment with IL-5, a cytokine produced by ILC2, on the cognitive function of 3xTg-AD mice. RESULTS: We demonstrate that brain-associated ILC2 are numerically and functionally defective in the triple transgenic AD mouse model (3xTg-AD). The numbers of brain-associated ILC2 were greatly reduced in 7-month-old 3xTg-AD mice of both sexes, compared to those in age- and sex-matched control wild-type mice. The remaining ILC2 in 3xTg-AD mice failed to efficiently produce the type 2 cytokine IL-5 but gained the capability to express a number of proinflammatory genes. Administration of IL-5, a cytokine produced by ILC2, transiently improved spatial recognition and learning in 3xTg-AD mice. CONCLUSION: Our results collectively indicate that numerical and functional deficiency of ILC2 might contribute to the cognitive impairment of 3xTg-AD mice.

Screening and Preventative Strategies for Patients at High Risk for Breast Cancer.

PURPOSE: Current US guidelines recommend more intensive breast cancer screening and preventive strategies for patients at more than 20% lifetime risk for breast and ovarian cancer (high risk for breast and ovarian cancer [HRBOC]). Guidelines recommend that yearly mammograms alternating with magnetic resonance imaging (MRI) screening should be considered as early as 30 years old. Furthermore, BRCA mutation carriers should consider bilateral mastectomy and bilateral oophorectomy after age 35. It was unclear what the uptake of screening and risk-reducing strategies were for patients who were cancer-free and cancer survivors seen by Kaiser Permanente Mid-Atlantic States (KPMAS) Genetics. METHODS: We retrospectively studied female patients (members of KPMAS between 2005 and 2016) diagnosed as HRBOC and/or tested for breast cancer-related mutations by KPMAS Genetics during 2013-2016. We identified cancer diagnoses, mammogram and breast MRI screening, mastectomies, and oophorectomies that occurred before and after the Genetics visit during the study period. RESULTS: Our cohort included 813 women with a HRBOC diagnosis, with a median 51 years of age at diagnosis, 45% White, 38% Black, and 15% other ethnicity. Most cancers occurred prior to the Genetics visit: 513/527 breast cancer diagnoses and 55/57 ovarian cancer diagnoses. Fewer than five prophylactic mastectomies and 89 prophylactic oophorectomies were identified. Among 228 patients who were 30-75 years old, breast cancer-free at the time of HRBOC diagnosis, and members for over 6 months, 190 (83%) had at least one screening test (mammogram or MRI) after the consultation with Genetic, but 79% never had an MRI before or after the consultation. CONCLUSION: Our findings suggest that earlier detection of patients with HRBOC and closer monitoring is needed.

Molecular Characterization of Increased Amplicon Lengths in SARS-CoV-2 Reverse Transcription Loop-Mediated Isothermal Amplification Assays.

Loop-mediated isothermal amplification (LAMP) is a power tool for the amplification of specific RNA and DNA targets. Much like PCR, LAMP requires primers that surround a target amplification region and generates exponential product through a unique highly specific daisy-chain single-temperature amplification reaction. However, until recently, attempts to amplify targets of greater than 200 base pairs (bp) have been mostly unsuccessful and limited to short amplicon targets of less than 150 bp. Although short amplicons have the benefit of a rapid detection (<40 min), they do not allow for the prediction of RNA integrity based on RNA length and possible intactness. In this study, 8 primer sets were developed using 2 LAMP primer-specific software packages against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid gene with insert lengths ranging from 262 to 945 bp in order to amplify and infer the integrity of viral RNA. Because these amplification lengths are greater than the current methods that use an insert length of 130 or less, they require a longer incubation, modified primer and temperature strategies, and the addition of specific adjuncts to prevent nonspecific amplification. This proof of concept study resulted in successful reverse transcription LAMP reactions for amplicon targets of 262, 687, 693, and 945 bp using a clinical nasopharyngeal NP sample, purified SARS-CoV-2 RNA, and crude lysate containing inactivated virus.

All-Cause and Cardiovascular Disease Mortality Among Breast Cancer Survivors in CLUE II, a Long-Standing Community-Based Cohort.

BACKGROUND: There is growing evidence that breast cancer survivors have higher cardiovascular disease (CVD) mortality relative to the general population. Information on temporal patterns for all-cause and CVD mortality among breast cancer survivors relative to cancer-free women is limited. METHODS: All-cause and CVD-related mortality were compared in 628 women with breast cancer and 3140 age-matched cancer-free women within CLUE II, a prospective cohort. We calculated adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) using Cox proportional hazards regression for all-cause mortality, and Fine and Gray models for CVD-related mortality to account for competing risks. RESULTS: Over 25 years of follow-up, 916 deaths occurred (249 CVD related). Breast cancer survivors had an overall higher risk of dying compared with cancer-free women (HR = 1.79, 95% CI = 1.53 to 2.09) irrespective of time since diagnosis, tumor stage, estrogen receptor status, and older age at diagnosis (≥70 years). Risk of death was greatest among older survivors at more than 15 years after diagnosis (HR = 2.69, 95% CI = 1.59 to 4.55). CVD (69.1% ischemic heart disease) was the leading cause of death among cancer-free women and the second among survivors. Survivors had an increase in CVD-related deaths compared with cancer-free women beginning at 8 years after diagnosis (HR = 1.65, 95% CI = 1.00 to 2.73), with the highest risk among older survivors (HR = 2.24, 95% CI = 1.29 to 3.88) and after estrogen receptor-positive disease (HR = 1.85, 95% CI = 1.06 to 3.20). CONCLUSIONS: Breast cancer survivors continue to have an elevated mortality compared with the general population for many years after diagnosis. Preventing cardiac deaths, particularly among older breast cancer patients, could lead to reductions in mortality.

Depletion of NK Cells Improves Cognitive Function in the Alzheimer Disease Mouse Model.

Despite mounting evidence suggesting the involvement of the immune system in regulating brain function, the specific role of immune and inflammatory cells in neurodegenerative diseases remain poorly understood. In this study, we report that depletion of NK cells, a type of innate lymphocytes, alleviates neuroinflammation, stimulates neurogenesis, and improves cognitive function in a triple-transgenic Alzheimer disease (AD) mouse model. NK cells in the brains of triple-transgenic AD mouse model (3xTg-AD) mice exhibited an enhanced proinflammatory profile. Depletion of NK cells by anti-NK1.1 Abs drastically improved cognitive function of 3xTg-AD mice. NK cell depletion did not affect amyloid ß concentrations but enhanced neurogenesis and reduced neuroinflammation. Notably, in 3xTg-AD mice depleted of NK cells, microglia demonstrated a homeostatic-like morphology, decreased proliferative response and reduced expression of neurodestructive proinflammatory cytokines. Together, our results suggest a proinflammatory role for NK cells in 3xTg-AD mice and indicate that targeting NK cells might unlock novel strategies to combat AD.

Hyperchloremia, not Concomitant Hypernatremia, Independently Predicts Early Mortality in Critically Ill Moderate-Severe Traumatic Brain Injury Patients.

BACKGROUND: Hypernatremia has been associated with mortality in neurocritically ill patients, with and without traumatic brain injury (TBI). These studies, however, lack concomitant adjustment for hyperchloremia as a physiologically co-occurring finding despite the associations with hyperchloremia and worse outcomes after trauma, sepsis, and intracerebral hemorrhage. The objective of our study was to examine the association of concomitant hypernatremia and hyperchloremia with in-hospital mortality in moderate-severe TBI (msTBI) patients. METHODS: We retrospectively analyzed prospectively collected data from the OPTIMISM-study and included all msTBI patients consecutively enrolled between 11/2009 and 1/2017. Time-weighted average (TWA) sodium and chloride values were calculated for all patients to examine the unadjusted mortality rates associated with the burden of hypernatremia and hyperchloremia over the entire duration of the intensive care unit stay. Multivariable logistic regression modeling predicting in-hospital mortality adjusted for validated confounders of msTBI mortality was applied to evaluate the concomitant effects of hypernatremia and hyperchloremia. Internal bootstrap validation was performed. RESULTS: Of the 458 patients included for analysis, 202 (44%) died during the index hospitalization. Fifty-five patients (12%) were excluded due to missing data. Unadjusted mortality rates were nearly linearly increasing for both TWA sodium and TWA chloride, and were highest for patients with a TWA sodium > 160 mmol/L (100% mortality) and TWA chloride > 125 mmol/L (94% mortality). When evaluated separately in the multivariable analysis, TWA sodium (per 10 mmol/L change: adjusted OR 4.0 [95% CI 2.1-7.5]) and TWA chloride (per 10 mmol/L change: adjusted OR 3.9 [95% CI 2.2-7.1]) independently predicted in-hospital mortality. When evaluated in combination, TWA chloride remained independently associated with in-hospital mortality (per 10 mmol/L change: adjusted OR 2.9 [95% CI 1.1-7.8]), while this association was no longer observed with TWA sodium values (per 10 mmol/L change: adjusted OR 1.5 [95% CI 0.51-4.4]). CONCLUSIONS: When concomitantly adjusting for the burden of hyperchloremia and hypernatremia, only hyperchloremia was independently associated with in-hospital mortality in our msTBI cohort. Pending validation, our findings may provide the rationale for future studies with targeted interventions to reduce hyperchloremia and improve outcomes in msTBI patients.

Activation of group 2 innate lymphoid cells alleviates aging-associated cognitive decline.

Increasing evidence has challenged the traditional view about the immune privilege of the brain, but the precise roles of immune cells in regulating brain physiology and function remain poorly understood. Here, we report that tissue-resident group 2 innate lymphoid cells (ILC2) accumulate in the choroid plexus of aged brains. ILC2 in the aged brain are long-lived, are relatively resistant to cellular senescence and exhaustion, and are capable of switching between cell cycle dormancy and proliferation. They are functionally quiescent at homeostasis but can be activated by IL-33 to produce large amounts of type 2 cytokines and other effector molecules in vitro and in vivo. Intracerebroventricular transfer of activated ILC2 revitalized the aged brain and enhanced the cognitive function of aged mice. Administration of IL-5, a major ILC2 product, was sufficient to repress aging-associated neuroinflammation and alleviate aging-associated cognitive decline. Targeting ILC2 in the aged brain may provide new avenues to combat aging-associated neurodegenerative disorders.

Critical role of protein kinase G in the long-term balance between defensive and appetitive behaviors induced by aversive stimuli in Aplysia.

This study investigated the signaling cascades involved in the long-term storage of the balance between defensive and appetitive behaviors observed when the mollusk Aplysia is exposed to aversive experience. In Aplysia, repeated trials of aversive stimuli induce concurrent sensitization of defensive withdrawal reflexes and suppression of feeding for at least 24 h. This long-term storage of the balance between withdrawal reflexes and feeding is sustained, at least in part, by increased excitability of the tail sensory neurons (SNs) controlling the withdrawal reflexes, and by decreased excitability of feeding decision-making neuron B51. Nitric oxide (NO) is required for the induction of both long-term sensitization and feeding suppression. At the cellular level, NO is also required for long-term decreased B51 excitability but not for long-term increased SN excitability. Here, we characterized the signaling cascade downstream of NO contributing to the long-term storage of the balance between withdrawal reflexes and feeding. We found protein kinase G (PKG) necessary for both long-term sensitization and feeding suppression, indicating that a NO-PKG cascade governs the long-term storage of the balance between defensive and appetitive responses in Aplysia. The role of PKG on feeding suppression was paralleled at the cellular level where a cGMP-PKG pathway was required for long-term decreased B51 excitability. In the defensive circuit, the cGMP-PKG pathway was not necessary for long-term increased SN excitability, suggesting that other cellular correlates of long-term sensitization might depend on the GMP-PKG cascade to sustain the behavioral change.

Role of nitric oxide in the induction of the behavioral and cellular changes produced by a common aversive stimulus in Aplysia.

Although it is well documented that exposure to aversive stimuli induces modulation of neural circuits and subsequent behavioral changes, the means by which an aversive stimulus concomitantly alters behaviors of different natures (e.g., defensive and appetitive) remains unclear. Here, we addressed this issue by using the learning-induced concurrent modulation of defensive and appetitive behaviors that occurs when the mollusk Aplysia is exposed to aversive stimuli. In Aplysia, aversive stimuli concomitantly enhance withdrawal reflexes (i.e., sensitization) and suppress feeding. Sensitization and feeding suppression, which are expressed in the short term and long term, depending on the training protocol, are accompanied by increased excitability of the tail sensory neurons (TSNs) controlling the withdrawal reflexes, and by decreased excitability of feeding decision-making neuron B51, respectively. Serotonin (5-HT) has been shown to mediate sensitization, but not feeding suppression. In this study, we examined which other neurotransmitter might be responsible for feeding suppression and its underlying cellular changes. Our results indicate that nitric oxide (NO) contributes to both short-term and long-term feeding suppression, as well as to the underlying decreased B51 excitability. NO was also necessary for the induction of long-term sensitization and for the expression of short-term increased TSN excitability in vitro, revealing a previously undocumented interaction between 5-HT and NO signaling cascades in sensitization. Overall, these results revealed a scenario in which multiple modulators contribute to the widespread changes induced by sensitizing stimuli in Aplysia.

cGMP mediates short- and long-term modulation of excitability in a decision-making neuron in Aplysia.

In elementary neural circuits, changes in excitability can have a strong impact in the expression of a given behavior. One example is provided by B51, a neuron with decision-making properties in the feeding neural circuit of the mollusk Aplysia. The excitability of B51 is bidirectionally modulated by external and internal stimuli in a manner that is consistent with the corresponding induced changes in feeding behavior. For example, in operant reward learning, which up-regulates feeding, B51 excitability is increased via a cAMP-dependent mechanism. Conversely, following training protocols with aversive stimuli, which down-regulate feeding, B51 excitability is decreased. In this study, we tested the hypothesis that B51 decreased excitability may be mediated by another cyclic nucleotide, cGMP. Our results revealed that iontophoretic injection of cGMP was capable of inducing both short-term (45 min) and long-term (24 h) reduction of B51 excitability. We next investigated which biochemical trigger could increase cGMP cytosolic levels. The neurotransmitter nitric oxide was found to decrease B51 excitability through the activation of the soluble guanylyl cyclase. These findings indicate that a cGMP-dependent pathway modulates B51 excitability in a manner opposite of cAMP, indicating that distinct cyclic-nucleotide pathways bidirectionally regulate the excitability of a decision-making neuron.

Effects of internal and external factors on the budgeting between defensive and non-defensive responses in Aplysia.

Following exposure to aversive stimuli, organisms budget their behaviors by augmenting defensive responses and reducing/suppressing non-defensive behaviors. This budgeting process must be flexible to accommodate modifications in the animal's internal and/or external state that require the normal balance between defensive and non-defensive behaviors to be adjusted. When exposed to aversive stimuli, the mollusk Aplysia budgets its behaviors by concurrently enhancing defensive withdrawal reflexes (an elementary form of learning known as sensitization) and suppressing feeding. Sensitization and feeding suppression are consistently co-expressed following different training protocols and share common temporal domains, suggesting that they are interlocked. In this study, we attempted to uncouple the co-expression of sensitization and feeding suppression using: 1) manipulation of the animal's motivational state through prolonged food deprivation and 2) extended training with aversive stimuli that induces sensitization lasting for weeks. Both manipulations uncoupled the co-expression of the above behavioral changes. Prolonged food deprivation prevented the expression of sensitization, but not of feeding suppression. Following the extended training, sensitization and feeding suppression were co-expressed only for a limited time (i.e., 24 h), after which feeding returned to baseline levels as sensitization persisted for up to seven days. These findings indicate that sensitization and feeding suppression are not interlocked and that their co-expression can be uncoupled by internal (prolonged food deprivation) and external (extended aversive training) factors. The different strategies, by which the co-expression of sensitization and feeding suppression was altered, provide an example of how budgeting strategies triggered by an identical aversive experience can vary depending on the state of the organism.

A novel in vitro analog expressing learning-induced cellular correlates in distinct neural circuits.

When presented with noxious stimuli, Aplysia exhibits concurrent sensitization of defensive responses, such as the tail-induced siphon withdrawal reflex (TSWR) and suppression of feeding. At the cellular level, sensitization of the TSWR is accompanied by an increase in the excitability of the tail sensory neurons (TSNs) that elicit the reflex, whereas feeding suppression is accompanied by decreased excitability of B51, a decision-making neuron in the feeding neural circuit. The goal of this study was to develop an in vitro analog coexpressing the above cellular correlates. We used a reduced preparation consisting of buccal, cerebral, and pleural-pedal ganglia, which contain the neural circuits controlling feeding and the TSWR, respectively. Sensitizing stimuli were delivered in vitro by electrical stimulation of afferent nerves. When trained with sensitizing stimuli, the in vitro analog expressed concomitant increased excitability in TSNs and decreased excitability in B51, which are consistent with the occurrence of sensitization and feeding suppression induced by in vivo training. This in vitro analog expressed both short-term (15 min) and long-term (24 h) excitability changes in TSNs and B51, depending on the amount of training administered. Finally, in vitro application of serotonin increased TSN excitability without altering B51 excitability, mirroring the in vivo application of the monoamine that induces sensitization, but not feeding suppression.

Differential abundance of CK1α provides selectivity for pharmacological CK1α activators to target WNT-dependent tumors.

Constitutive WNT activity drives the growth of various human tumors, including nearly all colorectal cancers (CRCs). Despite this prominence in cancer, no WNT inhibitor is currently approved for use in the clinic largely due to the small number of druggable signaling components in the WNT pathway and the substantial toxicity to normal gastrointestinal tissue. We have shown that pyrvinium, which activates casein kinase 1α (CK1α), is a potent inhibitor of WNT signaling. However, its poor bioavailability limited the ability to test this first-in-class WNT inhibitor in vivo. We characterized a novel small-molecule CK1α activator called SSTC3, which has better pharmacokinetic properties than pyrvinium, and found that it inhibited the growth of CRC xenografts in mice. SSTC3 also attenuated the growth of a patient-derived metastatic CRC xenograft, for which few therapies exist. SSTC3 exhibited minimal gastrointestinal toxicity compared to other classes of WNT inhibitors. Consistent with this observation, we showed that the abundance of the SSTC3 target, CK1α, was decreased in WNT-driven tumors relative to normal gastrointestinal tissue, and knocking down CK1α increased cellular sensitivity to SSTC3. Thus, we propose that distinct CK1α abundance provides an enhanced therapeutic index for pharmacological CK1α activators to target WNT-driven tumors.

Long-term sensitization training in Aplysia decreases the excitability of a decision-making neuron through a sodium-dependent mechanism.

In Aplysia, long-term sensitization (LTS) occurs concurrently with a suppression of feeding. At the cellular level, the suppression of feeding is accompanied by decreased excitability of decision-making neuron B51. We examined the contribution of voltage-gated Na+ and K+ channels to B51 decreased excitability. In a pharmacologically isolated Na+ channels environment, LTS training significantly increased B51 firing threshold, compared with untrained controls. Conversely, in a pharmacologically isolated K+ channels environment, no differences were observed between trained and untrained animals in either amplitude or area of B51 K+-dependent depolarizations. These findings suggest that Na+ channels contribute to the decrease in B51 excitability induced by LTS training.

Reducing indoor air pollutants with air filtration units in wood stove homes.

BACKGROUND: Biomass burning has been shown to be a major source of poor indoor air quality (IAQ) in developing and higher income countries across the world. Specifically, wood burning for cooking and heating contributes to high indoor concentrations of fine (particles with aerodynamic diameters<2.5µm; PM2.5) and coarse (particles with aerodynamic diameters <10µm and >2.5µm; PMc) particulate matter. Endotoxin, predominantly found within the coarse fraction of airborne particulate matter, is associated with proinflammatory effects and adverse outcomes among susceptible populations. The aim of this study was to assess the efficacy of air filter interventions in reducing indoor PM2.5, PMc, and PMc-associated endotoxin concentrations in homes using a wood stove for primary heating. RESULTS: Homes (n=48) were randomized to receive in-room air filtration units with either a high efficiency filter (i.e. active) or a lower efficiency fiberglass filter (i.e., placebo). The active filter intervention showed a 66% reduction in indoor PM2.5 concentrations (95% CI: 42.2% to 79.7% reduction) relative to the placebo intervention. Both the active and the placebo filters were effective in substantially reducing indoor concentrations of PMc (63.3% and 40.6% average reduction for active and placebo filters, respectively) and PMc-associated endotoxin concentrations (91.8% and 80.4% average reductions, respectively). CONCLUSIONS: These findings support the use of high efficiency air filtration units for reducing indoor PM2.5 in homes using a wood stove for primary heating. We also discovered that using lower efficiency, lower cost filter alternatives can be effective for reducing PMc and airborne endotoxin in homes burning biomass fuel.

Sucralose activates an ERK1/2-ribosomal protein S6 signaling axis.

The sweetener sucralose can signal through its GPCR receptor to induce insulin secretion from pancreatic ß cells, but the downstream signaling pathways involved are not well-understood. Here we measure responses to sucralose, glucagon-like peptide 1, and amino acids in MIN6 ß cells. Our data suggest a signaling axis, whereby sucralose induces calcium and cAMP, activation of ERK1/2, and site-specific phosphorylation of ribosomal protein S6. Interestingly, sucralose acted independently of mTORC1 or ribosomal S6 kinase (RSK). These results suggest that sweeteners like sucralose can influence ß-cell responses to secretagogues like glucose through metabolic as well as GPCR-mediated pathways. Future investigation of novel sweet taste receptor signaling pathways in ß cells will have implications for diabetes and other emergent fields involving these receptors.