Panaxynol improves crypt and mucosal architecture, suppresses colitis-enriched microbes, and alters the immune response to mitigate colitis.

Ulcerative colitis (UC) is an idiopathic inflammatory disease of the large intestine, which impacts millions worldwide. Current interventions aimed at treating UC symptoms can have off-target effects, invoking the need for alternatives that may provide similar benefits with less unintended consequences. This study builds on our initial data, which showed that panaxynol-a novel, potent, bioavailable compound found in American ginseng-can suppress disease severity in murine colitis. Here we explore the underlying mechanisms by which panaxynol improves both chronic and acute murine colitis. Fourteen-week-old C57BL/6 female mice were either given three rounds of dextran sulfate sodium (DSS) in drinking water to induce chronic colitis or one round to induce acute colitis. Vehicle or panaxynol (2.5 mg/kg) was administered via oral gavage three times per week for the study duration. Consistent with our previous findings, panaxynol significantly (P < 0.05) improved the disease activity index and endoscopic scores in both models. Using the acute model to examine potential mechanisms, we show that panaxynol significantly (P < 0.05) reduced DSS-induced crypt distortion, goblet cell loss, and mucus loss in the colon. 16S Sequencing revealed panaxynol altered microbial composition to suppress colitis-enriched genera (i.e., Enterococcus, Eubacterium, and Ruminococcus). In addition, panaxynol significantly (P < 0.05) suppressed macrophages and induced regulatory T-cells in the colonic lamina propria. The beneficial effects of panaxynol on mucosal and crypt architecture, combined with its microbial and immune-mediated effects, provide insight into the mechanisms by which panaxynol suppresses murine colitis. Overall, this data is promising for the use of panaxynol to improve colitis in the clinic.NEW & NOTEWORTHY In the current study, we report that panaxynol ameliorates chemically induced murine colitis by improving colonic crypt and mucosal architecture, suppressing colitis-enriched microbes, reducing macrophages, and promoting the differentiation of regulatory T-cells in the colonic lamina propria. This study suggests that this novel natural compound may serve as a safe and effective treatment option for colitis patients.

Potential of Plant-Derived Compounds in Preventing and Reversing Organ Fibrosis and the Underlying Mechanisms.

Increased production of extracellular matrix is a necessary response to tissue damage and stress. In a normal healing process, the increase in extracellular matrix is transient. In some instances; however, the increase in extracellular matrix can persist as fibrosis, leading to deleterious alterations in organ structure, biomechanical properties, and function. Indeed, fibrosis is now appreciated to be an important cause of mortality and morbidity. Extensive research has illustrated that fibrosis can be slowed, arrested or even reversed; however, few drugs have been approved specifically for anti-fibrotic treatment. This is in part due to the complex pathways responsible for fibrogenesis and the undesirable side effects of drugs targeting these pathways. Natural products have been utilized for thousands of years as a major component of traditional medicine and currently account for almost one-third of drugs used clinically worldwide. A variety of plant-derived compounds have been demonstrated to have preventative or even reversal effects on fibrosis. This review will discuss the effects and the underlying mechanisms of some of the major plant-derived compounds that have been identified to impact fibrosis.

The complex heterogeneity of immune cell signatures across wasting tissues with C26 and 5-fluorouracil-induced cachexia.

Immune cell-driven pathways are linked to cancer cachexia. Tumor presence is associated with immune cell infiltration whereas cytotoxic chemotherapies reduce immune cell counts. Despite these paradoxical effects, both cancer and chemotherapy can cause cachexia; however, our understanding of immune responses in the cachexia condition with cancer and chemotherapy is largely unknown. We sought to advance our understanding of the immunology underlying cancer and cancer with chemotherapy-induced cachexia. CD2F1 mice were given 106 C26 cells, followed by five doses of 5-fluorouracil (5FU; 30 mg/kg LM, ip) or PBS. Indices of cachexia and tumor (TUM), skeletal muscle (SKM), and adipose tissue (AT) immune cell populations were examined using high-parameter flow cytometry. Although 5FU was able to stunt tumor growth, % body weight loss and muscle mass were not different between C26 and C26 + 5FU. C26 increased CD11b+Ly6g+ and CD11b+Ly6cInt inflammatory myeloid cells in SKM and AT; however, both populations were reduced with C26 + 5FU. tSNE analysis revealed 24 SKM macrophage subsets wherein 8 were changed with C26 or C26 + 5FU. C26 + 5FU increased SKM CD11b-CD11c+ dendritic cells, CD11b-NK1.1+ NK-cells, and CD11b-B220+ B-cells, and reduced Ly6cHiCX3CR1+CD206+CD163IntCD11c-MHCII- infiltrated macrophages and other CD11b+Ly6cHi myeloid cells compared with C26. Both C26 and C26 + 5FU had elevated CD11b+F480+CD206+MHCII- or more specifically Ly6cLoCX3CR1+CD206+CD163IntCD11c-MHCII- profibrotic macrophages. 5FU suppressed tumor growth and decreased SKM and AT inflammatory immune cells without protecting against cachexia suggesting that these cells are not required for wasting. However, profibrotic cells and muscle inflammatory/atrophic signaling appear consistent with cancer- and cancer with chemotherapy-induced wasting and remain potential therapeutic targets.NEW & NOTEWORTHY Despite being an immune-driven condition, our understanding of skeletal muscle and adipose tissue immune cells with cachexia is limited. Here, we identified immune cell populations in tumors, skeletal muscle, and adipose tissue in C26 tumor-bearing mice with/without 5-fluorouracil (5FU). C26 and C26 + 5FU had increased skeletal muscle profibrotic macrophages, but 5FU reduced inflammatory myeloid cells without sparing mass. Tumor presence and chemotherapy have contrasting effects on certain immune cells, which appeared not necessary for wasting.

Obesity worsens mitochondrial quality control and does not protect against skeletal muscle wasting in murine cancer cachexia.

BACKGROUND: More than 650 million people are obese (BMI > 30) worldwide, which increases their risk for several metabolic diseases and cancer. While cachexia and obesity are at opposite ends of the weight spectrum, leading many to suggest a protective effect of obesity against cachexia, mechanistic support for obesity's benefit is lacking. Given that obesity and cachexia are both accompanied by metabolic dysregulation, we sought to investigate the impact of obesity on skeletal muscle mass loss and mitochondrial dysfunction in murine cancer cachexia. METHODS: Male C57BL/6 mice were given a purified high fat or standard diet for 16 weeks before being implanted with 106 Lewis lung carcinoma (LLC) cells. Mice were monitored for 25 days, and hindlimb muscles were collected for cachexia indices and mitochondrial assessment via western blotting, high-resolution respirometry and transmission electron microscopy (TEM). RESULTS: Obese LLC mice experienced significant tumour-free body weight loss similar to lean (-12.8% vs. -11.8%, P = 0.0001) but had reduced survival (33.3% vs. 6.67%, χ2  = 10.04, P = 0.0182). Obese LLC mice had reduced muscle weights (-24%, P < 0.0354) and mCSA (-16%, P = 0.0004) with similar activation of muscle p65 (P = 0.0337), and p38 (P = 0.0008). ADP-dependent coupled respiration was reduced in both Obese and Obese LLC muscle (-30%, P = 0.0072) consistent with reductions in volitional cage activity (-39%, P < 0.0001) and grip strength (-41%, P < 0.0001). TEM revealed stepwise reductions in intermyofibrillar and subsarcolemmal mitochondrial size with Obese (IMF: -37%, P = 0.0009; SS: -21%, P = 0.0101) and LLC (IMF: -40%, P = 0.0019; SS: -27%, P = 0.0383) mice. Obese LLC mice had increased pAMPK (T172; P = 0.0103) and reduced FIS1 (P = 0.0029) and DRP1 (P < 0.0001) mitochondrial fission proteins, which were each unchanged in Lean LLC. Further, mitochondrial TEM analysis revealed that Obese LLC mice had an accumulation of damaged and dysfunctional mitochondria (IMF: 357%, P = 0.0395; SS: 138%, P = 0.0174) in concert with an accumulation of p62 (P = 0.0328) suggesting impaired autophagy and clearance of damaged mitochondria. Moreover, we observed increases in electron lucent vacuoles only in Obese LLC muscle (IMF: 421%, P = 0.0260; SS: 392%, P = 0.0192), further supporting an accumulation of damaged materials that cannot be properly cleared in the obese cachectic muscle. CONCLUSIONS: Taken together, these results demonstrate that obesity is not protective against cachexia and suggest exacerbated impairments to mitochondrial function and quality control with a particular disruption in the removal of damaged mitochondria. Our findings highlight the need for consideration of the severity of obesity and pre-existing metabolic conditions when determining the impact of weight status on cancer-induced cachexia and functional mitochondrial deficits.

Emodin reduces surgical wounding-accelerated tumor growth and metastasis via macrophage suppression in a murine triple-negative breast cancer model.

It has been suspected that tumor resection surgery itself may accelerate breast cancer (BC) lung metastasis in some patients. Emodin, a natural anthraquinone found in the roots and rhizomes of various plants, exhibits anticancer activity. We examined the perioperative use of emodin in our established surgery wounding murine BC model. Emodin reduced primary BC tumor growth and metastasis in the lungs in both sham and surgical wounded mice, consistent with a reduction in proliferation and enhanced apoptosis (primary tumor and lungs). Further, emodin reduced systemic inflammation, most notably the number of monocytes in the peripheral blood and reduced pro-tumoral M2 macrophages in the primary tumor and the lungs. Consistently, we show that emodin reduces gene expression of select macrophage markers and associated cytokines in the primary tumor and lungs of wounded mice. Overall, we demonstrate that emodin is beneficial in mitigating surgical wounding accelerated lung metastasis in a model of triple-negative BC, which appears to be mediated, at least in part, by its actions on macrophages. These data support the development of emodin as a safe, low-cost, and effective agent to be used perioperatively to alleviate the surgery triggered inflammatory response and consequential metastasis of BC to the lungs.

Platelet status in cancer cachexia progression in ApcMin/+ mice.

Cachexia, a complex wasting syndrome, significantly affects the quality of life and treatment options for cancer patients. Studies have reported a strong correlation between high platelet count and decreased survival in cachectic individuals. Therefore, this study aimed to investigate the immunopathogenesis of cancer cachexia using the ApcMin/+ mouse model of spontaneous colorectal cancer. The research focused on identifying cellular elements in the blood at different stages of cancer cachexia, assessing inflammatory markers and fibrogenic factors in the skeletal muscle, and studying the behavioral and metabolic phenotype of ApcMin/+ mice at the pre-cachectic and severely cachectic stages. Platelet measurements were also obtained from other animal models of cancer cachexia - Lewis Lung Carcinoma and Colon 26 adenocarcinoma. Our study revealed that platelet number is elevated prior to cachexia development in ApcMin/+ mice and can become activated during its progression. We also observed increased expression of TGFß2, TGFß3, and SMAD3 in the skeletal muscle of pre-cachectic ApcMin/+ mice. In severely cachectic mice, we observed an increase in Ly6g, CD206, and IL-10 mRNA. Meanwhile, IL-1ß gene expression was elevated in the pre-cachectic stage. Our behavioral and metabolic phenotyping results indicate that pre-cachectic ApcMin/+ mice exhibit decreased physical activity. Additionally, we found an increase in anemia at pre-cachectic and severely cachectic stages. These findings highlight the altered platelet status during early and late stages of cachexia and provide a basis for further investigation of platelets in the field of cancer cachexia.

The synthetic food dye, Red 40, causes DNA damage, causes colonic inflammation, and impacts the microbiome in mice.

The incidence of colorectal cancer (CRC) among young people has been on the rise for the past four decades and its underlying causes are only just starting to be uncovered. Recent studies suggest that consuming ultra-processed foods and pro-inflammatory diets may be contributing factors. The increase in the use of synthetic food colors in such foods over the past 40 years, including the common synthetic food dye Allura Red AC (Red 40), coincides with the rise of early-onset colorectal cancer (EOCRC). As these ultra-processed foods are particularly appealing to children, there is a growing concern about the impact of synthetic food dyes on the development of CRC. Our study aimed to investigate the effects of Red 40 on DNA damage, the microbiome, and colonic inflammation. Despite a lack of prior research, high levels of human exposure to pro-inflammatory foods containing Red 40 highlight the urgency of exploring this issue. Our results show that Red 40 damages DNA both in vitro and in vivo and that consumption of Red 40 in the presence of a high-fat diet for 10 months leads to dysbiosis and low-grade colonic inflammation in mice. This evidence supports the hypothesis that Red 40 is a dangerous compound that dysregulates key players involved in the development of EOCRC.

Panaxynol alleviates colorectal cancer in a murine model via suppressing macrophages and inflammation.

Currently available colorectal cancer (CRC) therapies have limited efficacy and severe adverse effects that may be overcome with the alternative use of natural compounds. We previously reported that panaxynol (PA), a bioactive component in American ginseng, possesses anticancer properties in vitro and suppresses murine colitis through its proapoptotic and anti-inflammatory properties. Because colitis is a predisposing factor of CRC and inflammation is a major driver of CRC, we sought to evaluate the therapeutic potential of PA in CRC. Azoxymethane-dextran sodium sulfate (AOM/DSS) mice (C57BL/6) were administered 2.5 mg/kg PA or vehicle 3 times/wk via oral gavage over 12 wk. PA improved clinical symptoms (P ≤ 0.05) and reduced tumorigenesis (P ≤ 0.05). This improvement may be reflective of PA's restorative effect on intestinal barrier function; PA upregulated the expression of essential tight junction and mucin genes (P ≤ 0.05) and increased the abundance of mucin-producing goblet cells (P ≤ 0.05). Given that macrophages play a substantial role in the pathogenesis of CRC and that we previously demonstrated that PA targets macrophages in colitis, we next assessed macrophages. We show that PA reduces the relative abundance of colonic macrophages within the lamina propria (P ≤ 0.05), and this was consistent with a reduction in the expression of important markers of macrophages and inflammation (P ≤ 0.05). We further confirmed PA's inhibitory effects on macrophages in vitro under CRC conditions (P ≤ 0.05). These results suggest that PA is a promising therapeutic compound to treat CRC and improve clinical symptoms given its ability to inhibit macrophages and modulate the inflammatory environment in the colon.NEW & NOTEWORTHY We report that panaxynol (PA) reduces colorectal cancer (CRC) by improving the colonic and tumor environment. Specifically, we demonstrate that PA improves crypt morphology, upregulates crucial tight junction and mucin genes, and promotes the abundance of mucin-producing goblet cells. Furthermore, PA reduces macrophages and associated inflammation, important drivers of CRC, in the colonic environment. This present study provides novel insights into the potential of PA as a therapeutic agent to ameliorate CRC tumorigenesis.

Prevalence of health behaviors among cancer survivors in the United States.

PURPOSE: We determined the proportion of cancer survivors who met each of five health behavior guidelines recommended by the American Cancer Society (ACS), including consuming fruits and vegetables at least five times/day, maintaining a body mass index (BMI) < 30 kg/m2, engaging in 150 min or more of physical activity weekly, not currently smoking, and not excessively drinking alcohol. METHODS: Using data from the 2019 Behavioral Risk Factor Surveillance System (BRFSS), 42,727 survey respondents who reported a previous diagnosis of cancer (excluding skin cancer) were included. Weighted percentages with 95% confidence intervals (95% CI) were estimated for the five health behaviors accounting for BRFSS' complex survey design. RESULTS: The weighted percentage of cancer survivors who met ACS guidelines was 15.1% (95%CI: 14.3%, 15.9%) for fruit and vegetable intake; 66.8% (95%CI: 65.9%, 67.7%) for BMI < 30 kg/m2; 51.1% (95%CI: 50.1%, 52.1%) for physical activity; 84.9% (95%CI: 84.1%, 85.7%) for not currently smoking; and 89.5% (95%CI: 88.8%, 90.3%) for not drinking excessive alcohol. Adherence to ACS guidelines among cancer survivors generally increased with increasing age, income, and education. CONCLUSIONS: While the majority of cancer survivors met the guidelines for not smoking and limiting alcohol drinking, one-third had elevated BMI, almost half did not meet recommended physical activity levels, and the majority had inadequate fruit and vegetable intake. IMPLICATIONS FOR CANCER SURVIVORS: Adherence to guidelines was lowest among younger cancer survivors and those with lower income and education, suggesting these may be populations where resources could be targeted to have the greatest impact.

Effect of a Plant-Based vs Omnivorous Soul Food Diet on Weight and Lipid Levels Among African American Adults: A Randomized Clinical Trial.

Importance: More African American individuals die from cardiovascular disease (CVD) than any other chronic disease condition. Despite this disparity, African American individuals are underrepresented in nutrition and CVD interventions. Objective: To compare the effects of an entirely plant-based (vegan) or low-fat omnivorous (omni) diet on change in body weight and lipids during a 2-year intervention. Design, Setting, and Participants: The Nutritious Eating With Soul (NEW Soul) study was a 2-year, randomized clinical trial conducted in 2 cohorts (2018-2020 and 2019-2021) that took place in a university teaching kitchen in Columbia, South Carolina (before March 2020), and via online videoconference sessions (after March 2020). Participants included African American adults aged 18 to 65 years with overweight or obesity (body mass index of 25.0-49.9) and without type 2 diabetes, uncontrolled thyroid disease, recent weight loss, or pregnancy. Data assessors and statisticians were blinded to study condition. Data analysis was performed from March to June 2022. Interventions: The intervention included weekly nutrition classes for 6 months biweekly classes for 6 months, and monthly classes for 12 months. Dietary interventions either emphasized no animal product intake (vegan) or a low-fat omnivorous diet (omni). Both dietary patterns emphasized soul food cuisine (traditional African American southern foodways). Main Outcomes and Measures: Primary outcomes included change in body weight and lipid measures at 12 months. Results: There were 568 participants who completed an online screening questionnaire; 409 were excluded and 159 were randomized (77 to the vegan group and 82 to the omni group). Of the 159 participants (mean [SD] age, 48.4 [10.6] years; 126 female [79%]) who began the study, the main outcome of body weight was obtained for 121 participants (76%) at 12 months. There were no differences in outcomes between groups, including 12-month changes in weight (mean, -2.39 kg [95% CI, -3.48 to -1.30 kg] for the vegan group vs -2.03 kg [95% CI, -3.07 to -1.00 kg] for the omni group; P = .64), total cholesterol (-1.05 mg/dL [95% CI, -9.60 to 7.50 mg/dL] for the vegan group vs 1.66 mg/dL [95% CI, -7.20 to 10.50 mg/dL] for the omni group; P = .67), or low-density lipoprotein cholesterol (mean, -2.56 mg/dL [95% CI, -9.52 to 4.40 mg/dL] for the vegan group vs -0.79 mg/dL [95% CI, -7.98 to 6.40 mg/dL] for the omni group; P = .73). Weight loss at 12 months among cohort 1, whose weight was assessed in 2019 before the COVID-19 pandemic, was significantly greater than that for cohort 2, whose weight was assessed summer 2020 during COVID-19 (-3.45 kg [95% CI, -4.67 to -2.22 kg] vs -1.24 kg [95% CI, -2.24 to -0.25 kg]; P = .01). Conclusions and Relevance: In this randomized clinical trial examining weight loss and CVD risk factor reduction among African American adults, there were no differences between the groups, and the magnitude of changes overall was small. Trial Registration: ClinicalTrials.gov Identifier: NCT03354377.

Surgical wounding enhances pro-tumor macrophage responses and accelerates tumor growth and lung metastasis in a triple negative breast cancer mouse model.

Approximately one-third of all breast cancer mortality results from metastatic recurrence after initial success of surgery and/or therapy. Although primary tumor removal is widely accepted as beneficial, it has long been suspected that surgery itself contributes to accelerated metastatic recurrence. We investigated surgical wounding's impact on tumor progression and lung metastasis in a murine model of triple negative breast cancer (TNBC). Ten-week-old female mice were inoculated with 4 T1 cells (week 0) and were either subjected to a 2 cm long cutaneous contralateral incision (wounded) or control (non-wounded) on week 2 and monitored for 3 weeks (week 5). Mice with surgical wounding displayed significantly accelerated tumor growth observable as early as 1-week post wounding. This was confirmed by increased tumor volume and tumor weight, post-mortem. Further, surgical wounding increased metastasis to the lungs, as detected by IVIS imaging, in vivo and ex vivo (week 5). As expected then, wounded mice displayed decreased apoptosis and increased proliferation in both the primary tumor and in the lungs. Flow cytometry revealed that primary tumors from wounded mice exhibited increased tumor associated macrophages and specifically M2-like macrophages, which are important in promoting tumor development, maintenance, and metastasis. Immunofluorescence staining and gene expression data further confirms an increase in macrophages in both the primary tumor and the lungs of wounded mice. Our data suggests that surgical wounding accelerates tumor progression and lung metastasis in a mouse model of TNBC, which is likely mediated, at least in part by an increase in macrophages.

Congenital adiponectin deficiency mitigates high-fat-diet-induced obesity in gonadally intact male and female, but not in ovariectomized mice.

Epidemiological literature indicates that women are less susceptible to type II diabetes (T2D) than males. The general consensus is that estrogen is protective, whereas its deficiency in post-menopause is associated with adiposity and impaired insulin sensitivity. However, epidemiological data suggests that males are more prone to developing T2D, and at a lower BMI, compared to females during post-menopausal years; suggesting that another factor, other than estrogen, protects females. We proposed to determine if adiponectin (APN) serves as this protective factor. An initial experiment was performed in which gonadally intact male and female mice were fed either a purified low-fat diet (LFD) or high-fat diet (HFD) (40% kcals from fat) for 16 weeks. An additional group of HFD ovariectomy (OVX) mice were included to assess estrogen deficiency's impact on obesity. Body composition, adipose tissue inflammation, ectopic lipid accumulation as well as glucose metabolism and insulin resistance were assessed. In corroboration with previous data, estrogen deficiency (OVX) exacerbated HFD-induced obesity in female mice. However, despite a higher body fat percentage and a similar degree of hepatic and skeletal muscle lipid accumulation, female OVX HFD-fed mice exhibited enhanced insulin sensitivity relative to HFD-fed males. Therefore, a subsequent HFD experiment was performed utilizing male and female (both gonadally intact and OVX) APN deficient mice (APN-/-) and wildtype littermates to determine if APN is the factor which protects OVX females from the similar degree of metabolic dysfunction as males in the setting of obesity. Indirect calorimetry was used to determine observed phenotype differences. APN deficiency limited adiposity and mitigated HFD-induced insulin resistance and adipose tissue inflammation in gonadally intact male and female, but not in OVX mice. Using indirect calorimetry, we uncovered that slight, but non-statistically significant differences in food intake and energy expenditure leading to a net difference in energy balance likely explain the reduced body weight exhibited by male APN-deficient mice. In conclusion, congenital APN deficiency is protective against obesity development in gonadally intact mice, however, in the setting of estrogen deficiency (OVX) this is not true. These findings suggest that gonadal status dictates the protective effects of congenital APN deficiency in the setting of HFD-induced obesity.

Sub-chronic oral toxicity screening of quercetin in mice.

BACKGROUND: Quercetin is an organic flavonoid present in several fruits and vegetables. The anti-inflammatory, antiviral, antioxidant, cardio-protective, anti-carcinogenic and neuroprotective properties demonstrated by this dietary supplement endorses it as a possible treatment for inflammatory diseases and cancer. Unfortunately, conflicting research has cast uncertainties on the toxicity of quercetin. The main purpose of this study was to determine if quercetin has any toxic properties in mice at doses that have shown efficacy in pre-clinical studies regarding cancer, cancer therapy, and their off-target effects. METHODS: A sub-chronic toxicity study of quercetin was examined in male and female CD2F1 mice. Three different doses of quercetin (62, 125, and 250 mg/kg of diet) were infused into the AIN-76A purified diet and administered to mice ad libitum for 98 days. Body weight (BW), food consumption, water intake, body composition, blood count, behavior, and metabolic phenotype were assessed at various timepoints during the course of the experiment. Tissue and organs were evaluated for gross pathological changes and plasma was used to measure alkaline phosphatase (AP), aspartate transaminase (AST), and alanine transaminase (ALT). RESULTS: We found that low (62 mg/kg of diet), medium (125 mg/kg of diet), and high (250 mg/kg of diet) quercetin feeding had no discernible effect on body composition, organ function, behavior or metabolism. CONCLUSIONS: In summary, our study establishes that quercetin is safe for use in both female and male CD2F1 mice when given at ~ 12.5, 25, or 50 mg/kg of BW daily doses for 14 weeks (i.e. 98 days). Further studies will need to be conducted to determine any potential toxicity of quercetin following chronic ingestion.

Cross talk between the gut microbiome and host immune response in ulcerative colitis: nonpharmacological strategies to improve homeostasis.

Ulcerative colitis (UC) is a chronic disease that is characterized by diffuse inflammation of the colonic and rectal mucosa. The burden of UC is rising globally with significant disparities in levels and trends of disease in different countries. The pathogenesis of UC involves the presence of pathogenic factors including genetic, environmental, autoimmune, and immune-mediated components. Evidence suggests that disturbed interactions between the host immune system and gut microbiome contribute to the origin and development of UC. Current medications for UC include antibiotics, corticosteroids, and biological drugs, which can have deleterious off-target effects on the gut microbiome, contributing to increased susceptibility to severe infections and chronic immunosuppression. Alternative, nonpharmacological, and behavioral interventions have been proposed as safe and effective treatments to alleviate UC, while also holding the potential to improve overall life quality. This mini-review will discuss the interactions between the immune system and the gut microbiome in the case of UC. In addition, we suggest nonpharmacological and behavioral strategies aimed at restoring a proper microbial-immune relationship.

miR155 deficiency reduces breast tumor burden in the MMTV-PyMT mouse model.

miRNA155 (miR155) has emerged as an important regulator of breast cancer (BrCa) development. Studies have consistently noted an increase in miR155 levels in serum and/or tissues in patients with BrCa. However, what is less clear is whether this increase in miR155 is a reflection of oncogenic or tumor suppressive properties. To study the effects of miR155 in a transgenic model of BrCA, we developed an MMTV-PyMT mouse deficient in miR155 (miR155-/- PyMT). miR155-/- mice (n = 11) exhibited reduced tumor number and volume palpations at ∼14-18 wk of age compared with miR155 sufficient littermates (n = 12). At 19 wk, mammary glands were excised from tumors for RT-PCR, and tumors were counted, measured, and weighed. miR155-/- PyMT mice exhibited reduced tumor volume, number, and weight, which was confirmed by histopathological analysis. There was an increase in apoptosis with miR155 deficiency and a decrease in proliferation. As expected, miR155 deficiency resulted in upregulated gene expression of suppressor of cytokine signaling 1 (Socs1)-its direct target. There was a reduction in gene expression of macrophage markers (CD68, Adgre1, Itgax, Mrc1) with miR-155-/- and this was confirmed with immunofluorescence staining for F4/80. miR155-/- increased expression of M1 macrophage marker Nos2 and reduced expression of M2 macrophage markers IL-10, IL-4, Arg1, and MMP9. Overall, miR155 deficiency reduced BrCA and improved the tumor microenvironment through the reduction of genes associated with protumorigenic processes. However, given the inconsistencies in the literature, additional studies are needed before any attempts are made to harness miR155 as a potential oncogenic or tumor suppressive miRNA.NEW & NOTEWORTHY To examine the effects of miR155 in a transgenic model of breast cancer, we developed an MMTV-PyMT mouse-deficient in miR155. We demonstrate that global loss of miR155 resulted in blunted tumor growth through modulating the tumor microenvironment. Specifically, miR155-deficient mice had smaller and less invasive tumors, an increase in apoptosis and a decrease in proliferation, a reduction in tumor-associated macrophages, and the expression of genes associated with protumoral processes.

Breast cancer cell-derived microRNA-155 suppresses tumor progression via enhancing immune cell recruitment and antitumor function.

Evidence suggests that increased microRNA-155 (miR-155) expression in immune cells enhances antitumor immune responses. However, given the reported association of miR-155 with tumorigenesis in various cancers, a debate is provoked on whether miR-155 is oncogenic or tumor suppressive. We aimed to interrogate the impact of tumor miR-155 expression, particularly that of cancer cell-derived miR-155, on antitumor immunity in breast cancer. We performed bioinformatic analysis of human breast cancer databases, murine experiments, and human specimen examination. We revealed that higher tumor miR-155 levels correlate with a favorable antitumor immune profile and better patient outcomes. Murine experiments demonstrated that miR-155 overexpression in breast cancer cells enhanced T cell influx, delayed tumor growth, and sensitized the tumors to immune checkpoint blockade (ICB) therapy. Mechanistically, miR-155 overexpression in breast cancer cells upregulated their CXCL9/10/11 production, which was mediated by SOCS1 inhibition and increased phosphorylated STAT1 (p-STAT1)/p-STAT3 ratios. We further found that serum miR-155 levels in breast cancer patients correlated with tumor miR-155 levels and tumor immune status. Our findings suggest that high serum and tumor miR-155 levels may be a favorable prognostic marker for breast cancer patients and that therapeutic elevation of miR-155 in breast tumors may improve the efficacy of ICB therapy via remodeling the antitumor immune landscape.

5-Fluorouracil disrupts skeletal muscle immune cells and impairs skeletal muscle repair and remodeling.

5-Fluorouracil (5FU) remains a first-line chemotherapeutic for several cancers despite its established adverse side effects. Reduced blood counts with cytotoxic chemotherapies not only expose patients to infection and fatigue, but can disrupt tissue repair and remodeling, leading to lasting functional deficits. We sought to characterize the impact of 5FU-induced leukopenia on skeletal muscle in the context of remodeling. First, C57BL/6 mice were subjected to multiple dosing cycles of 5FU and skeletal muscle immune cells were assessed. Second, mice given 1 cycle of 5FU were subjected to 1.2% BaCl2 intramuscularly to induce muscle damage. One cycle of 5FU induced significant body weight loss, but only three dosing cycles of 5FU induced skeletal muscle mass loss. One cycle of 5FU reduced skeletal muscle CD45+ immune cells with a particular loss of infiltrating CD11b+Ly6cHi monocytes. Although CD45+ cells returned following three cycles, CD11b+CD68+ macrophages were reduced with three cycles and remained suppressed at 1 mo following 5FU administration. One cycle of 5FU blocked the increase in CD45+ immune cells 4 days following BaCl2; however, there was a dramatic increase in CD11b+Ly6g+ neutrophils and a loss of CD11b+Ly6cHi monocytes in damaged muscle with 5FU compared with PBS. These perturbations resulted in increased collagen production 14 and 28 days following BaCl2 and a reduction in centralized nuclei and myofibrillar cross-sectional area compared with PBS. Together, these results demonstrate that cytotoxic 5FU impairs muscle damage repair and remodeling concomitant with a loss of immune cells that persists beyond the cessation of treatment.NEW & NOTEWORTHY We examined the common chemotherapeutic 5-fluorouracil's (5FU) impact on skeletal muscle immune cells and skeletal muscle repair. 5FU monotherapy decreased body weight and muscle mass, and perturbed skeletal muscle immune cells. In addition, 5FU decreased skeletal muscle immune cells and impaired infiltration following damage contributing to disrupted muscle repair. Our results demonstrate 5FU's impact on skeletal muscle and provide a potential explanation for why some patients may be unable to properly repair damaged tissue.

Obesity reduced survival with 5-fluorouracil and did not protect against chemotherapy-induced cachexia or immune cell cytotoxicity in mice.

Fluorouracil/5-flourouracil (5FU) is a first-line chemotherapy drug for many cancer types; however, its associated toxicities contribute to poor quality of life and reduced dose intensities negatively impacting patient prognosis. While obesity remains a critical risk factor for most cancers, our understanding regarding how obesity may impact chemotherapy's toxicities is extremely limited. C56BL/6 mice were given high fat (Obese) or standard diets (Lean) for 4 months and then subjected to three cycles of 5FU (5d-40 mg/kg Lean Mass, 9d rest) or PBS vehicle control. Shockingly, only 60% of Obese survived 3 cycles compared to 100% of Lean, and Obese lost significantly more body weight. Dihydropyrimidine dehydrogenase (DPD), the enzyme responsible for 5FU catabolism, was reduced in obese livers. Total white blood cells, neutrophils, and lymphocytes were reduced in Obese 5FU compared to Lean 5FU and PBS controls. While adipocyte size was not affected by 5FU in Obese, skeletal muscle mass and myofibrillar cross section area were decreased following 5FU in Lean and Obese. Although adipose tissue inflammatory gene expression was not impacted by 5FU, distinct perturbations to skeletal muscle inflammatory gene expression and immune cell populations (CD45+ Immune cells, CD45+CD11b+CD68+ macrophages and CD45+CD11b+Ly6clo/int macrophage/monocytes) were observed in Obese only. Our evidence suggests that obesity induced liver pathologies and reduced DPD exacerbated 5FU toxicities. While obesity has been suggested to protect against cancer/chemotherapy-induced cachexia and other toxicities, our results demonstrate that obese mice are not protected, but rather show evidence of increased susceptibility to 5FU-induced cytotoxicity even when dosed for relative lean mass.

Nonpharmacological approaches for improving gut resilience to chemotherapy.

PURPOSE OF REVIEW: Mucositis of the gastrointestinal tract is a debilitating side effect of chemotherapy that negatively influences treatment tolerance and patient life quality. This review will evaluate the recent literature on nonpharmacological strategies that have the potential to improve chemotherapy-induced mucositis (CIM). RECENT FINDINGS: Alternatives to pharmacological approaches have shown great promise in preventing CIM. Natural products, including curcumin, ginseng, quercetin, and patchouli all show potential in mitigating CIM. In addition, dietary patterns, such as the elemental diet, high fiber diet, and diets high in amino acids have documented benefits in preventing CIM. Perhaps the greatest advancement coming to this arena in recent years is in the field of probiotics. Indeed, research on single species as well as probiotic mixtures show potential in reducing CIM insofar as probiotics are now being suggested for treatment of CIM by governing bodies. Although behavioral interventions including psychological interventions and exercise interventions have shown promise in reducing cancer therapy-related side effects, more work in this domain is warranted and particularly in the context of CIM. SUMMARY: Alternatives to pharmacological approaches show great potential for use in prevention and treatment of CIM and should be further developed for use in the clinic.

Emodin reduces tumor burden by diminishing M2-like macrophages in colorectal cancer.

Emodin, a natural anthraquinone, has been shown to have antitumorigenic properties and may be an effective therapy for colorectal cancer (CRC). However, its clinical development has been hampered by a poor understanding of its mechanism of action. The purpose of this study was to 1) evaluate the efficacy of emodin in mouse models of intestinal/colorectal cancer and 2) to examine the impact of emodin on macrophage behavior in the context of CRC. We used a genetic model of intestinal cancer (ApcMin/+) and a chemically induced model of CRC [azoxymethane/dextran sodium sulfate (AOM/DSS)]. Emodin was administered orally (40 or 80 mg/kg in AOM/DSS and 80 mg/kg in ApcMin/+) three times a week to observe its preventative effects. Emodin reduced polyp count and size in both rodent models (P < 0.05). We further analyzed the colon microenvironment of AOM/DSS mice and found that mice treated with emodin exhibited lower protumorigenic M2-like macrophages and a reduced ratio of M2/M1 macrophages within the colon (P < 0.05). Despite this, we did not detect any significant changes in M2-associated cytokines (IL10, IL4, and Tgfb1) nor M1-associated cytokines (IL6, TNFα, IL1ß, and IFNγ) within excised polyps. However, there was a significant increase in NOS2 expression (M1 marker) in mice treated with 80 mg/kg emodin (P < 0.05). To confirm emodin's effects on macrophages, we exposed bone marrow-derived macrophages (BMDMs) to C26 colon cancer cell conditioned media. Supporting our in vivo data, emodin reduced M2-like macrophages. Overall, these data support the development of emodin as a natural compound for prevention of CRC given its ability to target protumor macrophages.NEW & NOTEWORTHY Our study confirms that emodin is an effective primary therapy against the onset of genetic and chemically induced sporadic colorectal cancer. We established that emodin reduces the M2-like protumorigenic macrophages in the tumor microenvironment. Furthermore, we provide evidence that emodin may be acting to antagonize the P2X7 receptor within the bone tissue and consequently decrease the activation of proinflammatory cells, which may have implications for recruitment of cells to the tumor microenvironment.