Monitoring Pathogen-Induced Sickness in Mice and Rats

Dietary Flaxseed and Flaxseed Oil Differentially Modulate Aspects of the Microbiota Gut-Brain Axis Following an Acute Lipopolysaccharide Challenge in Male C57Bl/6 Mice

The microbiota gut-brain axis (mGBA) is an important contributor to mental health and neurological and mood disorders. Lipopolysaccharides (LPS) are endotoxins that are components of Gram-negative bacteria cell walls and have been widely shown to induce both systemic and neuro-inflammation. Flaxseed (Linum usitatissimum) is an oilseed rich in fibre, n3-poly-unsaturated fatty acid (alpha-linolenic acid (ALA)), and lignan, secoisolariciresinol diglucoside, which all can induce beneficial effects across varying aspects of the mGBA. The objective of this study was to determine the potential for dietary supplementation with flaxseed or flaxseed oil to attenuate LPS-induced inflammation through modulation of the mGBA. In this study, 72 5-week-old male C57Bl/6 mice were fed one of three isocaloric diets for 3 weeks: (1) AIN-93G basal diet (BD), (2) BD + 10% flaxseed (FS), or (3) BD + 4% FS oil (FO). Mice were then injected with LPS (1 mg/kg i.p) or saline (n = 12/group) and samples were collected 24 h post-injection. Dietary supplementation with FS, but not FO, partially attenuated LPS-induced systemic (serum TNF-α and IL-10) and neuro-inflammation (hippocampal and/or medial prefrontal cortex IL-10, TNF-α, IL-1β mRNA expression), but had no effect on sickness and nest-building behaviours. FS-fed mice had enhanced fecal microbial diversity with increased relative abundance of beneficial microbial groups (i.e., Lachnospiraceae, Bifidobacterium, Coriobacteriaceae), reduced Akkermansia muciniphila, and increased production of short-chain fatty acids (SCFAs), which may play a role in its anti-inflammatory response. Overall, this study highlights the potential for flaxseed to attenuate LPS-induced inflammation, in part through modulation of the intestinal microbiota, an effect which may not be solely driven by its ALA-rich oil component.

Environmental enrichment alters LPS-induced changes in BDNF and PSD-95 expressions during puberty

Puberty is a critical period of cortical reorganization and increased synaptogenesis. Healthy cortical reorganization and synaptic growth require sufficient environmental stimuli and minimalized stress exposure during pubertal development. Exposure to impoverished environments or immune challenges impact cortical reorganization and reduce the expression of proteins associated with neuronal plasticity (BDNF) and synaptogenesis (PSD-95). Environmentally enriched (EE) housing includes improved social-, physical-, and cognitive stimulation. We hypothesized that enriched housing environment would mitigate pubertal stress-induced decreases in BDNF and PSD-95 expressions. Three-week-old male and female CD-1 mice (n = 10 per group) were housed for three weeks in either EE, social or deprived housing conditions. At 6 weeks of age, mice were treated with either lipopolysaccharide (LPS) or saline eight hours prior to tissue collection. Male and female EE mice displayed greater BDNF and PSD-95 expressions in the medial prefrontal cortex and hippocampus compared to socially housed and deprived housed mice. LPS treatment decreased BDNF expression in all the brain regions examined in EE mice, except for the CA3 region of the hippocampus, where EE housing successfully mitigated the pubertal LPS-induced decrease in BDNF expression. Interestingly, LPS-treated mice housed in deprived conditions displayed unexpected increases in BDNF and PSD-95 expressions throughout the medial prefrontal cortex and hippocampus. Both enriched and deprived housing conditions moderate how an immune challenge influences BDNF and PSD-95 expressions in a region-specific manner. These findings also emphasize the vulnerability of brain plasticity during puberty to various environmental factors.

Pubertal consumption of R. badensis subspecies acadiensis modulates LPS-induced immune responses and gut microbiome dysbiosis in a sex-specific manner

Puberty is a critical period of development characterized by significant brain remodeling and increased vulnerability to immune challenges. Exposure to an immune challenge such as LPS during puberty can result in inflammation and gut dysbiosis which may lead to altered brain functioning and psychiatric illnesses later in life. However, treatment with probiotics during puberty has been found to mitigate LPS-induced peripheral and central inflammation, prevent LPS-induced changes to the gut microbiota and protect against enduring behavioural disorders in a sex-specific manner. Recent findings from our laboratory revealed that pubertal R. badensis subspecies acadiensis (R. badensis subsp. acadiensis) treatment prevents LPS-induced depression-like behavior and alterations in 5HT1A receptor expression in a sex-specific manner. However, the underlying mechanism remains unclear. Thus, the aim of this study was to gain mechanistic insights and to investigate the ability of R. badensis subsp. acadiensis consumption during puberty to mitigate the effects of LPS treatment on the immune system and the gut microbiome. Our results revealed that pubertal treatment with R. badensis subsp. acadiensis reduced sickness behaviors in females more than males in a time-specific manner. It also mitigated LPS-induced increases in pro-inflammatory cytokines in the blood and in TNFα mRNA expression in the prefrontal cortex and the hippocampus of female mice. There were sex-dependent differences in microbiome composition that persisted after LPS injection or R. badensis subsp. acadiensis consumption. R. badensis subsp. acadiensis had greater impact on the microbiota of male mice but female microbiota's were more responsive to LPS treatment. This suggested that female mice microbiota's may be more prone to modulation by this probiotic. These findings emphasize the sex-specific effects of probiotic use during puberty on the structure of the gut microbiome and the immune system and highlight the critical role of gut colonization with probiotics during adolescence on immunomodulation and prevention of the enduring effects of infections.

Sources and Translational Relevance of Heterogeneity in Maternal Immune Activation Models

The epidemiological literature reporting increased risk for neurodevelopmental and psychiatric disorders after prenatal exposure to maternal immune activation (MIA) is still evolving, and so are the attempts to model this association in animals. Epidemiological studies of MIA offer the advantage of directly evaluating human populations but are often limited in their ability to uncover pathogenic mechanisms. Animal models, on the other hand, are limited in their generalizability to psychiatric disorders but have made significant strides toward discovering causal relationships and biological pathways between MIA and neurobiological phenotypes. Like in any other model system, both planned and unplanned sources of variability exist in animal models of MIA. Therefore, the design, implementation, and interpretation of MIA models warrant a careful consideration of these sources, so that appropriate strategies can be developed to handle them satisfactorily. While every research group may have its own strategy to this aim, it is essential to report the methodological details of the chosen MIA model in order to enhance the transparency and comparability of models across research laboratories. Even though it poses a challenge for attempts to compare experimental findings across laboratories, variability does not undermine the utility of MIA models for translational research. In fact, variability and heterogenous outcomes in MIA models offer unique opportunities for new discoveries and developments in this field, including the identification of disease pathways and molecular mechanisms determining susceptibility and resilience to MIA. This review summarizes the most important sources of variability in animal models of MIA and discusses how model variability can be used to investigate neurobiological and immunological factors causing phenotypic heterogeneity in offspring exposed to MIA.

The acute effects of antimicrobials and lipopolysaccharide on the cellular mechanisms associated with neurodegeneration in pubertal male and female CD1 mice

Exposure to stressors during puberty can cause enduring effects on brain functioning and behaviours related to neurodegeneration. However, the mechanisms underlying these effects remain unclear. The gut microbiome is a complex and dynamic system that could serve as a possible mechanism through which early life stress may increase the predisposition to neurodegeneration. Therefore, the current study was designed to examine the acute effects of pubertal antimicrobial and lipopolysaccharide (LPS) treatments on the cellular mechanisms associated with neurodegenerative disorders in male and female mice. At five weeks of age, male and female CD-1 mice received 200 μL of broad-spectrum antimicrobials or water, through oral gavage, twice daily for seven days. Mice received an intraperitoneal (i.p.) injection of either saline or LPS at 6 weeks of age (i.e., pubertal period). Sickness behaviours were recorded and mice were euthanized 8 h post-injection. Following euthanasia, brains and blood samples were collected. The results indicated that puberal antimicrobial and LPS treatment induced sex-dependent changes in biomarkers related to sickness behaviour, peripheral inflammation, intestinal permeability, and neurodegeneration. The findings suggest that pubertal LPS and antimicrobial treatment may increase susceptibility to neurodegenerative diseases later in life, particularly in males.

•

Pubertal antimicrobial and LPS treatment increase cytokine concentrations.

•

Antimicrobial and LPS treatment have sex-specific effects on intestinal permeability.

•

They also induce sex-specific changes in neurodegenerative markers.

•

Antimicrobial treatment did not potentiate LPS-induced sickness behaviours.

Sex-specific responses of the pubertal neuroimmune axis in CD-1 mice

The mechanistic relationship between the sexually dimorphic neuroimmune system and the sex-specific outcomes of a pubertal immune challenge is unclear. Therefore, we examined sex differences in the progression of cytotoxic microglial responses and blood-brain barrier (BBB) disruption to a peripubertal lipopolysaccharide (LPS) treatment in brain regions relevant to stress responses and cognitive function. Six-week-old (i.e., stress-sensitive pubertal period) male and female CD-1 mice were treated with LPS (1.5 ​mg/kg body weight, ip) or 0.9% saline (LPS-matched volume, ip). Sex and treatment differences in microglial (Iba1⁺) and apoptotic neuronal (caspase-3⁺/NeuN⁺) and non-neuronal (caspase-3⁺/NeuN⁻) expression were examined in the hippocampus, medial prefrontal cortex (mPFC), and paraventricular nucleus 24 ​h (sickness), one week (symptomatic recovery) and four weeks (early adulthood) post-treatment (n ​= ​8/group). Microglial morphology was quantified with fractal analyses. Group differences in BBB permeability to ¹⁴C-sucrose were examined 24 ​h (whole-brain, hippocampus, prefrontal cortex, hypothalamus, and cerebellum) and one week (whole-brain) post-treatment. The acute effects of pubertal LPS were specific to females (i.e., global BBB disruption, altered microglial expression and morphology in the mPFC and hippocampus, increased hippocampal apoptosis). The residual effects of pubertal LPS-induced sickness observed in microglia persisted into adulthood in a sex- and region-specific manner. In addition to highlighting these sex-specific responses of the pubertal neuroimmune system, we report baseline region-specific sex differences in microglia spanning puberty through adulthood. We propose that these sex differences in neuroimmune-neurovascular interactions during the stress-sensitive pubertal period create sex biases in stress-related disorders of brain and behaviour.

•

Pubertal LPS alters baseline sex differences in microglial numbers and morphology.

•

Pubertal CD-1 mice mount sexually dimorphic neuroimmune responses to systemic LPS.

•

Treatment effects on microglial expression and morphology differ by sex and region.

•

The acute LPS-induced effects were specific to females.

Adolescent use of potential novel probiotic Rouxiella badensis subsp. acadiensis (Canan SV-53) mitigates pubertal LPS-Induced behavioral changes in adulthood in a sex-specific manner by modulating 5HT1A receptors expression in specific brain areas

Adolescence is a critical period of development during which the brain undergoes significant remodeling that impacts behavior later in life. Exposure to stress, and especially immune challenge, during this period triggers changes in brain function resulting in the development of mental disorders in adulthood, such as depression and anxiety. Previous studies from our laboratory have shown that a single exposure to LPS (lipopolysaccharide) during puberty causes enduring depression-like behaviour in females and anxiety-like behaviours in males. However, administration of probiotics during puberty blocked the enduring effects of LPS on depression-like and anxiety-like behaviors in female and male mice, respectively. These results suggest that the gut microbiome is a mediator of the effects of stress on mental health. The objective of the current study is to examine the effectiveness of a novel probiotic Rouxiella badensis subsp. acadiensis (Canan SV-53) in blocking LPS-induced anxiety-like and depression-like behaviors in adult male and female mice. Our results showed that Rouxiella badensis subsp. acadiensis (Canan SV-53) blocked LPS-induced depression-like behavior in female mice. We also found that pubertal treatment with Rouxiella badensis subsp. acadiensis (Canan SV-53) mitigated the LPS-induced decrease in 5HT1A expression in CA1 as well as the LPS-induced increase in 5HT1A expression in the raphe-nuclei in female mice. Contrary to our predictions, pubertal LPS treatment at 6 weeks of age did not induce enduring anxiety-like behavior in males. There was also no difference in anxiety-like behavior between the LPS-sucrose and LPS-probiotic male groups. However, pubertal LPS treatment increased the expression of 5HT1A receptors in the DRN in males, while probiotic exposure mitigated this increase. Our study highlights the consequences of stress exposure (immune challenge) on mental health in adulthood taking into consideration 5HT1A receptors expression at different regions of the brain. It also emphasizes on the importance of considering adolescence as window of opportunities during which probiotic use can alleviate the long-term neural and behavioral alterations induced by stress.

•

Pubertal LPS treatment causes enduring depression-like behaviour in females not males.

•

Pubertal LPS treatment increases 5HT1A expression in the raphe nucleus.

•

LPS treatment decreases 5HT1A expression in the hippocampus in a sex-specific manner.

•

Treatment with a novel probiotic blocks LPS-induced depression-like behavior in females.

•

Pubertal probiotic treatment blocks LPS-induced changes in 5HT1A receptor expression in the brain.

Pubertal LPS treatment selectively alters PSD-95 expression in male CD-1 mice

Puberty includes a highly stress-sensitive period with significant sex differences in the neurophysiological and behavioural outcomes of a peripheral immune challenge. Sex differences in the pubertal neuroimmune network's responses to systemic LPS may explain some of these enduring sex-specific outcomes of a pubertal immune challenge. However, the functional implications of these sex-specific neuroimmune responses on the local microenvironment are unclear. Western blots were used to examine treatment- and sex-related changes in expression of regulatory proteins in inflammation (NFκB), cell death (AIF), oxidative stress (SOD-1), and synaptic plasticity (PSD-95) following symptomatic recovery (i.e., one week post-treatment) from pubertal immune challenge. Across the four examined brain regions (i.e., hippocampus, PFC, hypothalamus, and cerebellum), only PSD-95 levels were altered one week post-treatment by the pubertal LPS treatment. Unlike their female counterparts, seven-week-old males showed increased PSD-95 expression in the hippocampus (p < .05). AIF, SOD-1, and NFκB levels in both sexes were unaffected by treatment (all p > .05), which suggests appropriate resolution of NFκB-mediated immune responses to pubertal LPS without stimulating AIF-mediated apoptosis and oxidative stress. We also report a significant male-biased sex difference in PSD-95 levels in the PFC and in cerebellar expression of SOD-1 during puberty (all p < .05). These findings highlight the sex-specific vulnerability of the pubertal hippocampus to systemic LPS and suggest that a pubertal immune challenge may expedite neurodevelopment in the hippocampus in a sex-specific manner.

Body language signals for rodent social communication

Integration of social cues to initiate adaptive emotional and behavioral responses is a fundamental aspect of animal and human behavior. In humans, social communication includes prominent nonverbal components, such as social touch, gestures and facial expressions. Comparative studies investigating the neural basis of social communication in rodents has historically been centered on olfactory signals and vocalizations, with relatively less focus on non-verbal social cues. Here, we outline two exciting research directions: First, we will review recent observations pointing to a role of social facial expressions in rodents. Second, we will review observations that point to a role of 'non-canonical' rodent body language: body posture signals beyond stereotyped displays in aggressive and sexual behavior. In both sections, we will outline how social neuroscience can build on recent advances in machine learning, robotics and micro-engineering to push these research directions forward towards a holistic systems neurobiology of rodent body language.

Adolescent social instability stress leads to immediate and lasting sex-specific changes in the neuroendocrine-immune-gut axis in rats

Social instability stress (SS; daily 1 h isolation and change of cage partner from postnatal day (P) 30-45) in adolescence produces elevations in corticosterone during the procedure in male and female rats, but no lasting changes in hypothalamic-pituitary-adrenal (HPA) responses to psychological stressors, although deficits in social and cognitive function are evident in adulthood. Here we investigated the effects of SS in corticosterone response to an immune challenge (lipopolysaccharide, LPS, 0.1 mg/kg), on gene expression in the hippocampus, and on gut microbiota, when tested soon- (P46) or long- (P70) after SS. The temporal pattern of corticosterone release after LPS differed between SS and control rats irrespective of the time since SS exposure in females, whereas in males, SS did not alter corticosterone release after LPS. Expression of genes in the hippocampus relevant to immune and HPA function differed between saline-treated SS and control rats depending on sex and time tested, but with lasting consequences of SS in both sexes. LPS-treatment altered hippocampal gene expression, with bigger effects of LPS evident in control than in SS female rats, and the opposite in male rats. Further, effects sometimes depended on the age at time of LPS treatment. SS and control rats differed in both fecal and colon microbiome composition in all but P46 males, and stress history, sex, and age influenced the effects of an immune challenge on the gut microbiome. In sum, adolescent stress history has consequences for immune function into adulthood that may involve effects on the gut microbiome.

Hydroxysteroid (17β) dehydrogenase 12 is essential for metabolic homeostasis in adult mice

Hydroxysteroid 17β dehydrogenase 12 (HSD17B12) is suggested to be involved in the elongation of very long chain fatty acids. Previously, we have shown a pivotal role for the enzyme during mouse development. In the present study we generated a conditional Hsd17b12 knockout (HSD17B12cKO) mouse model by breeding mice homozygous for a floxed Hsd17b12 allele with mice expressing the tamoxifen-inducible Cre recombinase at the ROSA26 locus. Gene inactivation was induced by administering tamoxifen to adult mice. The gene inactivation led to a 20% loss of body weight within 6 days, associated with drastic reduction in both white (83% males, 75% females) and brown (65% males, 60% females) fat, likely due to markedly reduced food and water intake. Furthermore, the knockout mice showed sickness behavior and signs of liver toxicity, specifically microvesicular hepatic steatosis and increased serum alanine aminotransferase (4.6-fold in males, 7.7-fold in females). The hepatic changes were more pronounced in females than males. Proinflammatory cytokines, such as interleukin-6 (IL-6), IL-17, and granulocyte colony-stimulating factor, were increased in the HSD17B12cKO mice indicating an inflammatory response. Serum lipidomics study showed an increase in the amount of dihydroceramides, despite the dramatic overall loss of lipids. In line with the proposed role for HSD17B12 in fatty acid elongation, we observed accumulation of ceramides, dihydroceramides, hexosylceramides, and lactosylceramides with shorter than 18-carbon fatty acid side chains in the serum. The results indicate that HSD17B12 is essential for proper lipid homeostasis and HSD17B12 deficiency rapidly results in fatal systemic inflammation and lipolysis in adult mice.

CXCL5-mediated recruitment of neutrophils into the peritoneal cavity of Gdf15-deficient mice protects against abdominal sepsis

Sepsis is a life-threatening organ dysfunction condition caused by a dysregulated host response to an infection. Here we report that the circulating levels of growth and differentiation factor-15 (GDF15) are strongly increased in septic shock patients and correlate with mortality. In mice, we find that peptidoglycan is a potent ligand that signals through the TLR2-Myd88 axis for the secretion of GDF15, and that Gdf15-deficient mice are protected against abdominal sepsis due to increased chemokine CXC ligand 5 (CXCL5)-mediated recruitment of neutrophils into the peritoneum, leading to better local bacterial control. Our results identify GDF15 as a potential target to improve sepsis treatment. Its inhibition should increase neutrophil recruitment to the site of infection and consequently lead to better pathogen control and clearance.

Sickness Behavior Score Is Associated with Neuroinflammation and Late Behavioral Changes in Polymicrobial Sepsis Animal Model

The use of reliable scores is a constant development in critical illness. According to Sepsis-3 consensus, the use of Sequential Organ Failure Assessment (SOFA) score of 2 or more is associated with a higher mortality of sepsis patients. In experimental research, due murine animal model limitations, the use of a score systems can be an alternative to assess sepsis severity. In this work, we suggest a sickness behavior score (SBS) that uses physiological variables to assess sepsis severity and mortality. Animals were evaluated daily by the presence of six indicators of sickness behavior: temperature alteration, preference of water/sucrose, liquid intake, food intake, body weight, and movimentation. Male adult Wistar rats were evaluated daily after sepsis induction by cecal ligation and puncture (CLP) or laparotomy only (sham) for determination of SBS. Oxidative stress, IL-6, and HPA axis markers (corticosterone and adrenal gland weight) were evaluated 24 h after CLP to determine the correlation with the acute SBS and neuroinflammation. Also, BDNF and four cognitive behavioral tests were correlated with the chronic SBS, i.e., sum of 8 days after surgery. In result, septic rats presented higher SBS than sham animals. Sepsis severity markers were associated with acute and chronic SBS. Also, SBS was negative correlated with the cognitive tests. In conclusion, SBS shows to be reliable score to predict sepsis severity and mortality. The use of score system provides the analysis of global sickness behavior, beyond evaluation of each parameter individually.

Pubertal immune stress transiently alters spatial memory processes in adulthood

Pubertal immune challenge can permanently alter hippocampus-dependent memory processes in a sex-specific manner. Although gonadal hormones can influence various cognitive processes, their role in regulating the cognitive sequelae to pubertal immune challenge has not been thoroughly assessed. We examined whether a pubertal immune challenge could affect hippocampus-dependent memory functions in adulthood and whether these effects are regulated by gonadal steroid hormones. We hypothesized that exposure to an immune challenge during puberty would induce sex-specific deficits in the behavioral and cellular correlates of hippocampus-dependent memory during adulthood. At six weeks of age, during the stress-vulnerable pubertal period, male and female CD-1 mice were injected with either saline or the bacterial endotoxin lipopolysaccharide (LPS). Three weeks later, mice underwent either gonadectomy or sham-surgery. At ten weeks of age (i.e., in adulthood), mice began behavioral testing in an open field, Barnes maze, and Morris water maze. Brain tissue was collected at 17 weeks of age and stained for doublecortin and Ki67 to examine migrating neuronal progenitor cells and cellular proliferation in the neurogenic subgranular zone (SGZ) and the cornus ammonis (CA)1 and CA3 regions of the hippocampus. Pubertal LPS treatment impaired learning during adulthood in both sexes and increased cellular proliferation in the CA1 region in castrated males only. Although adult sex hormones did not reliably modulate these changes, gonadectomy impaired learning during the Morris water maze in both sexes. Learning deficits were more prominent during the Barnes maze, which suggests a stress-dependent expression of LPS-induced cognitive deficits. Neurogenesis in the SGZ and cellular proliferation in the CA3 were not affected by pubertal LPS treatment or gonadectomy. These novel findings emphasize the sensitivity of developing cognitive processes during puberty to immune challenges and suggest a possible mechanism for learning-based difficulties in adulthood.

The adaptive immune and stress responses of adult female CD1 mice following exposure to a viral mimetic

Exposure to a bacterial endotoxin during puberty induces long-term changes to reproductive and non-reproductive behaviours. While the underlying mechanisms remain unknown, we have recently shown that there are age and sex differences in acute immune and stress responses following immune challenge. Given that it is unclear whether viral infections result in similar age and sex differences, the objective of this study was to examine the acute immune and stress responses following exposure to polyinosinic:polycytidylic acid (poly(I:C)), a viral mimetic, in CD1 mice and to investigate the role of gonadal hormones in these responses. CD1 male and female mice underwent sham-surgery or gonadectomy at 5 or 9 weeks of age. Following one week of recovery, at 6 (pubertal group) or 10 (adult group) weeks of age, mice were treated with either saline or poly(I:C). Poly(I:C) treatment induced greater sickness behaviour in males compared to females and increased peripheral corticosterone in adult mice relative to their pubertal counterparts. Changes in body temperature and central c-Fos expression were more prominent in adult females. Gonadectomy worsened poly(I:C)-induced sickness behaviour and altered body temperature in both sexes. The results demonstrate that adult females display the most pronounced acute changes in body temperature, corticosterone release, and c-Fos expression but show the fastest recovery in sickness behavior, indicating that, compared to males, females display an adaptive physiological response following immune stress due to higher circulating estradiol and progesterone.

Maternal immune activation: reporting guidelines to improve the rigor, reproducibility, and transparency of the model

The 2017 American College of Neuropychopharmacology (ACNP) conference hosted a Study Group on 4 December 2017, Establishing best practice guidelines to improve the rigor, reproducibility, and transparency of the maternal immune activation (MIA) animal model of neurodevelopmental abnormalities. The goals of this session were to (a) evaluate the current literature and establish a consensus on best practices to be implemented in MIA studies, (b) identify remaining research gaps warranting additional data collection and lend to the development of evidence-based best practice design, and (c) inform the MIA research community of these findings. During this session, there was a detailed discussion on the importance of validating immunogen doses and standardizing the general design (e.g., species, immunogenic compound used, housing) of our MIA models both within and across laboratories. The consensus of the study group was that data does not currently exist to support specific evidence-based model selection or methodological recommendations due to lack of consistency in reporting, and that this issue extends to other inflammatory models of neurodevelopmental abnormalities. This launched a call to establish a reporting checklist focusing on validation, implementation, and transparency modeled on the ARRIVE Guidelines and CONSORT (scientific reporting guidelines for animal and clinical research, respectively). Here we provide a summary of the discussions in addition to a suggested checklist of reporting guidelines needed to improve the rigor and reproducibility of this valuable translational model, which can be adapted and applied to other animal models as well.