Prehabilitation Ameliorates Gut Ischemia Reperfusion Injury in Mice.

INTRODUCTION: We previously demonstrated that prehabilitation by running on a treadmill leads to improved survival after gut ischemia reperfusion (I/R) in mice. The purpose of this research was to examine whether prehabilitation attenuates inflammatory responses after gut I/R in mice. MATERIALS AND METHODS: Male C57BL/6J mice (n = 92) were assigned to the sedentary (n = 46) or the exercise (n = 46) group. The exercise group ran on a treadmill for 4 wk, while the sedentary mice did not exercise. After the 4-week pretreatment, all mice underwent gut I/R and the blood, urine, small intestine, lung, liver, and gastrocnemius were harvested prior to ischemia or at 0, 3, 6, or 24 h after reperfusion. Histologically demonstrated organ damage, cytokine levels in the blood, gut and gastrocnemius, myeloperoxidase activity in the gut, 8-hydroxy-2'-deoxyguanosine levels in urine and the gut, and adenosine triphosphate (ATP) and ATP + ADP + adenosine monophosphate levels in the gut and gastrocnemius were evaluated. RESULTS: The treadmill exercise reduced gut and lung injuries at 3 h and liver injury at 6 h after reperfusion. Running on the treadmill also decreased proinflammatory cytokine levels in the blood at 6 h, gut at 3 h and gastrocnemius at 6 h after reperfusion, myeloperoxidase activity in the gut prior to ischemia, and 6 h after reperfusion and the urinary 8-hydroxy-2'-deoxyguanosine level at 24 h after reperfusion, while ATP levels in exercised mice prior to ischemia and 3 h after reperfusion were increased in the intestine as compared to the levels in sedentary mice. CONCLUSIONS: Prehabilitation with treadmill exercise reduces inflammatory responses after gut I/R and may exert protective actions against gut I/R.

Early biomarkers for kidney injury in heat-related illness patients: a prospective observational study at Japanese Self-Defense Force Fuji Hospital.

BACKGROUND: Since heatstroke-induced acute kidney injury (AKI) can progress to chronic kidney disease, it would be useful to detect heatstroke-induced AKI and severe heat-related illness in the early phase. We studied the epidemiology of heat-related illness among patients in the Japanese Ground Self-Defense Force and evaluated the relationship between heat-related illness severity and early urinary biomarkers for AKI. METHODS: We enrolled patients who were diagnosed with heat-related illness at the Self-Defense Force Fuji Hospital from 1 May to 30 September 2020. We compared the urinary kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), liver fatty acid-binding protein (L-FABP), N-acetyl-ß-D-glucosaminidase (NAG) and ß2-microglobulin levels according to the severity of heat-related illness as defined by positive scores for the Japanese Association of Acute Medicine Heatstroke Working Group (JAAM-HS-WG) criteria (0, mild; 1, moderate; ≥2, severe). RESULTS: Of the 44 patients, kidney injury, defined as serum creatinine (sCr) ≥1.2 mg/dL, was seen in 9 (20.5%) patients. Urinary NAG, NGAL and L-FABP levels were significantly higher in the ≥2 JAAM-HS-WG criteria group than in the 0 group. Furthermore, urinary L-FABP levels were positively correlated with sCr levels. In contrast, the urinary KIM-1 levels showed the best correlation with serum cystatin C (sCysC) among these biomarkers. CONCLUSIONS: We conclude even mild to moderate heatstroke could lead to AKI. Urinary L-FABP is useful for detecting heatstroke-induced AKI and patients with severe heat-related illness requiring immediate treatment. Urinary KIM-1 may detect heatstroke-induced AKI in terms of sCysC, although it was not related to the severity of heat-related illness.

Heat acclimation ameliorated heat stress-induced acute kidney injury and prevented changes in kidney macrophages and fibrosis.

Heatstroke can cause acute kidney injury (AKI), which reportedly progresses to chronic kidney disease. Kidney macrophages may be involved in such injury. Although heat acclimation (HA) provides thermal resilience, its renoprotective effect and mechanism remain unclear. To investigate heat stress-induced kidney injuries in mice and the mitigating effect of HA on them, male C57/BL6J mice were exposed to heat stress (40°C, 1 h) with or without 5-day HA (38°C, 3 h/day) prior to heat stress. Heat stress damaged kidney proximal tubules with an elevation of urinary kidney injury molecule-1. Kidney fibrosis was observed on day 7 and correlated with urinary kidney injury molecule-1 levels on day 3. Kidney resident macrophages decreased on day 1, whereas the number of infiltrating macrophages in the kidney did not change. Both subsets of macrophages polarized to the proinflammatory M1 phenotype on day 1; however, they polarized to the anti-inflammatory M2 phenotype on day 7. HA significantly ameliorated heat stress-induced proximal tubular damage and kidney fibrosis. HA substantially increased heat shock protein 70 expression in the tubules before heat stress and reduced the elevation of cleaved caspase-3 expression after heat stress. HA also induced heat shock protein 70 expression of resident macrophages and prevented heat stress-induced changes in both subsets of kidney macrophages. These results provide pathophysiological data supporting the renoprotective effect of HA. Further studies are needed to confirm that HA can prevent kidney damage due to heat stress in humans.NEW & NOTEWORTHY Heat stress could induce acute kidney injury. Although heat acclimation (HA) reportedly provides thermal tolerance, its effect on heat stress-induced kidney damage remains unclear. This study showed that 5-day HA ameliorates mouse kidney tubular damage and subsequent fibrosis caused by heat stress. It also demonstrated that HA enhances intracellular heat shock protein 70 expression in tubular cells and prevents a decrease in kidney resident macrophages, which explains the renoprotective effect of HA.

Impact of modifiable healthy lifestyle adoption on lifetime gain from middle to older age.

OBJECTIVE: this study explored whether the modification of selected lifestyles is likely to increase life expectancy from middle age onwards, regardless of the presence of major comorbidities. METHODS: we examined a prospective cohort of 20,373 men and 26,247 women aged 40-80 years. Eight modifiable lifestyle factors were assessed: consumption of fruit, fish and milk, walking and/or sports participation, body-mass index, smoking status, alcohol consumption and sleep duration. Modifiable healthy lifestyle factors scored one point each, for a maximum of eight points. The impact of modifiable healthy lifestyle adoption on lifetime gain during the ages of 40-102 years was analysed. FINDINGS: during the median 21 years of follow-up, 8,966 individuals (3,683 men and 5,283 women) died. Life expectancy at 40 years (95% confidence intervals) for 7-8 health lifestyle points was 46.8 (45.6-48.1) and 51.3 (50.0-52.6) years for men and women, respectively. The potential impact of modifiable healthy lifestyle adoption on lifetime gain persisted over the age of 80 years or more, in individuals with ≥5 factors (P < 0.001), particularly older men. The benefits were more pronounced among patients with major comorbidities, such as cardiovascular disease, cancer, hypertension, diabetes, kidney disease and those with multimorbidity throughout all age categories. CONCLUSION: adopting modifiable healthy lifestyles was associated with lifetime gain, even in individuals aged 80 years or more, regardless of the presence of any major comorbidities in each life stage since middle age. The findings imply the importance of improving the one's lifestyle for an increased lifespan, even among older patients and/or those with multimorbidity.

Influence of a Low-Carbohydrate High-Fat Diet on Peritoneal Inflammation, Cancer-Associated Lymphocytes, and Survival in a Murine Carcinomatous Peritonitis Model.

BACKGROUND: Low-carbohydrate high-fat diets (LCHFDs) are thought to be beneficial for metabolic support in patients with advanced cancer. However, whether LCHFDs affect the progression of carcinomatous peritonitis (CP) remains unclear. Our study examined the influence of a lard-based LCHFD on host immunity and survival in a murine CP model. METHODS: Mice were fed either a normal diet (ND) or an LCHFD ad libitum. On day 7, Panc02 cancer cells were inoculated intraperitoneally. Mice were killed on days 7, 21, and 35, and cytokine levels in the peritoneal fluid, as well as the number and phenotypes of peritoneal, splenic, and tumor-infiltrating lymphocytes were measured. Survival studies were performed with both ad libitum and isocaloric feeding in other sets of mice. RESULTS: The levels of all cytokines significantly increased in the LCHFD group compared with those in the ND group on day 21. The tumor necrosis factor α and interleukin-10 levels were higher in the LCHFD group than in the ND group on day 35. In the LCHFD group, the regulatory T-cell (Treg) number was significantly higher in the peritoneal cavity and tumor. The survival times were worse in the LCHFD group than in the ND group. CONCLUSION: The ad libitum, lard-based LCHFD feeding of CP mice increases the peritoneal cytokine levels, which may reduce splenic, anticancer lymphocytes and increase the number of Tregs in the peritoneal cavity and tumor. The detrimental effects of LCHFD are linked to dietary composition rather than overfeeding.

Influences of Short-Term Fasting and Carbohydrate Supplementation on Gut Immunity and Mucosal Morphology in Mice.

BACKGROUND: Preoperative carbohydrate (CHO) supplementation has been recommended in enhanced recovery after surgery protocols. However, the effects of CHO supplementation on gut and systemic immunity are not well understood. METHODS: Mice (n = 60) were randomized to 1 of the following 5 groups: control (ad lib feeding), 12-hour fasting without CHO administration (fasting), and 12 hours of fasting with CHO administration at 2, 4, and 8 hours before sacrifice. Then, lymphocytes were isolated from gut-associated lymphoid tissue, that is, Peyer's patches, the intraepithelial space, and the lamina propria of the small intestine. These lymphocyte numbers and phenotypes were evaluated. IgA levels in respiratory and small-intestinal washings were determined by ELISA. Morphology, proliferation, and apoptosis of the intestinal epithelium were also evaluated histologically. RESULTS: Although there were no significant differences in IgA levels among the 5 groups, fasting decreased intraepithelial and lamina propria, but not Peyer's patches lymphocyte numbers. CHO at 2 hours prevented lymphocyte loss in intraepithelial, whereas CHO at 4 hours reversed lamina propria lymphocytes numbers. Percentages of lymphocyte phenotypes were similar in each site among the 5 groups. Fasting caused villous atrophy; however, CHO at 2 hours restored villous structure along with maintenance of epithelial cell proliferation rate. CONCLUSIONS: Only 12 hours of fasting causes marked gut-associated lymphoid tissue cell loss along with gut atrophy. However, CHO at 2 hours preserves gut immunity and morphology not completely but moderately.

Effects of semielemental diet containing whey peptides on Peyer's patch lymphocyte number, immunoglobulin A levels, and intestinal morphology in mice.

BACKGROUND: Enteral nutrition (EN) is the gold standard of nutritional therapy for critically ill or severely injured patients, because EN promotes gut and hepatic immunity, thereby preventing infectious complications as compared with parenteral nutrition. However, there are many EN formulas with different protein and fat contents. Their effects on gut-associated lymphoid tissue remain unclear. Recently, semielemental diets (SEDs) containing whey peptides as a nitrogen source have been found to be beneficial in patients with malabsorption or pancreatitis. Herein, we examined the influences of various dietary formulations on gut immunity to clarify the advantages of SEDs over elemental diets. METHODS: Forty-four male Institute of Cancer Research mice were randomized to four groups: chow (CH: n = 5), intragastric total parenteral nutrition (IG-TPN: n = 13), elemental diet (ED: n = 13), and SED (n = 13). The CH group received CH diet ad libitum, whereas the IG-TPN, ED (Elental, Ajinomoto, Japan), and SED (Peptino, Terumo, Japan) groups were given their respective diets for 5 day via gastrostomy. After 5 days, the mice were killed to obtain whole small intestines. Peyer's patch (PP) lymphocytes were harvested and counted. Their subpopulations were evaluated by flow cytometry. Immunoglobulin A (IgA) levels in intestinal and respiratory tract washings were measured with enzyme-linked immunosorbent assay. Villous height (VH) and crypt depth in the distal intestine were measured by light microscopy. RESULTS: SED increased the PP cell number and intestinal or respiratory IgA levels to those of CH mice, while ED partially restored these parameters. The IG-TPN group showed the lowest PP cell number and IgA levels among the four groups. VH was significantly greater in the CH than in the other groups. VH in the ED and SED groups also exceeded in the IG-TPN group, while being similar in these two groups. No significant crypt depth differences were observed among the four groups. CONCLUSIONS: SED administration can be recommended for patients unable tolerate complex enteral diets or a normal diet in terms of not only absorption and tolerability but also maintenance of gut immunity.

The influence of dietary restriction on hepatic mononuclear cell numbers and functions in mice.

BACKGROUND: Surgical patients with gastrointestinal malignancies are at increased risk for malnutrition. However, the mechanism by which dietary restriction (DR), one form of malnutrition, impairs hepatic immunity remains to be clarified. The present study was designed to examine the influence of DR on hepatic mononuclear cell (MNC) numbers, subpopulations, and cytokine productions (tumor necrosis factor α [TNF-α], interferon gamma [IFN-γ], and interleukin 10 [IL-10]) in response to lipopolysaccharide (LPS) in mice. Immunoglobulin (Ig) A levels in the gallbladder and histopathologic changes in the liver were also assessed. MATERIAL AND METHODS: Male Institute of Cancer Research mice were randomly assigned to three dietary groups: ad libitum (AD), mild restriction (MR), and severe restriction (SR). The AD, MR, and SR groups received daily mouse chow in amounts of 190, 133, and 76 g/kg, respectively, for 7 d. After the mice had been fed for 7 d, hepatic MNCs were isolated. Total hepatic MNCs were counted and subpopulations were determined by flow cytometry. Cytokine productions (TNF-α, IFN-γ, and IL-10) by hepatic MNCs in response to LPS were measured. Blood samples were analyzed for hepatobiliary biochemical parameters. IgA levels in gallbladder bile were measured with enzyme-linked immunosorbent assay. In addition, liver histologies were examined. RESULTS: Hepatic MNC numbers were significantly lower in the MR and SR groups than in the AD group, with no significant difference between the MR and SR groups. The percentage of B cells was significantly lower in the SR group than in the MR and AD groups, whereas the T-cell percentage was higher in the SR group than in the MR and AD groups. The percentage of Kupffer cells was significantly lower in the SR group than in the AD group, whereas that in the MR group was midway between those in the SR and AD groups. TNF-α and IL-10 levels in hepatic MNC culture supernatants were increased LPS-dose dependently in the AD group. However, the increase was slight in the MR group and absent in the SR group. The IgA levels in gallbladder bile were significantly lower in the SR and MR groups than in the AD group. On the basis of hematoxylin and eosin staining of hepatic sections, livers from the SR group showed atrophic hepatocytes and sinusoidal dilatation, whereas these changes were absent in the AD group. CONCLUSIONS: DR decreases hepatic MNC number with subpopulation changes, reduces IgA levels in gallbladder bile, blunts cytokine production by hepatic MNCs, and induces pathologic damage in the liver, which may be an important mechanism underlying the impaired host defense associated with malnutrition.

An inverse U-shaped association of late and peak insulin levels during an oral glucose load with glucose intolerance in a Japanese population: a cross-sectional study.

The current study investigated the association of post-load insulin levels with glucose tolerance in a Japanese population. A total of 1450 Japanese employees who underwent a 75-g oral glucose tolerance test (OGTT) were included. Glucose tolerance was assessed by 120-min glucose levels during a 75-g OGTT. A penalized cubic regression spline model analysis revealed that the 60- and 120-min insulin levels, but not 0- or 30-min insulin levels, had an inverse U-shaped relationship to the 120-min glucose level. Furthermore, peak insulin level followed an inverse U shape in relation to the 120-min glucose level, whereas the peak of insulin appeared at a later point in time as the 120-min glucose level increased. These associations were similarly observed in both obese and non-obese subgroups, although obesity was associated with higher insulin levels. Peak insulin levels also demonstrated an inverse U shape in association with 0-min glucose levels and indices of ß cell function, assessed by the disposition index and the ß-cell function index. In conclusion, peak insulin levels followed an inverse U shape in relation to glucose intolerance in a Japanese population, whereas the impairment of glucose tolerance was associated with a delay in the time to reach peak insulin levels.

Influence of fish to soybean oil ratio on hepatic mononuclear cell function and survival after intraportal bacterial challenge in parenterally fed mice.

BACKGROUND: Parenteral nutrition (PN) is indispensable for meeting the caloric and substrate needs of patients who cannot receive adequate amounts of enteral nutrition. However, PN decreases hepatic mononuclear cell (MNC) numbers and impairs their functions. We examined the effects of various ratios of ω-3 to ω-6 polyunsaturated fatty acids on hepatic MNC number and function in a murine model. We focused on serum liver enzymes, lipid metabolism, cytokine production, histopathology, and the outcomes of an intraportal bacterial challenge. MATERIAL AND METHODS: In experiment 1, male Institute of Cancer Research mice were randomized to CHOW, 67%, 33%, 16%, 8%, 4%, and 0% fish oil (FO)-PN groups. After receiving their respective diets for 5 days, 1.0 × 10(7) Pseudomonas aeruginosa were delivered by intraportal injection. Survival was observed ≤ 7 days after injection. Liver histologies after intraportal bacterial challenge were examined in the CHOW, 33%, 8%, and 0% FO-PN groups. In experiment 2, the mice were divided into 4 groups: CHOW, 33%, 8%, and 0% FO-PN. After the mice had been fed for 5 days, MNC were isolated. Hepatic MNC were counted and cytokine productions (tumor necrosis factor [TNF]-α and interleukin [IL]-10) by MNC in response to lipopolysaccharide (LPS) were measured. Blood samples were analyzed for lipid metabolism and hepatobiliary biochemical parameters. Liver histologies were also examined. RESULTS: In experiment 1, survival times were significantly shorter in the 4% and 0% FO-PN groups than in the CHOW group. Survival rates at 168 hours were 100%, 64%, 86%, 73%, 67%, 11%, and 13% in the CHOW, 67%, 33%, 16%, 8%, 4%, and 0% FO-PN groups, respectively. At 72 hours after intraportal bacterial challenge, the 0% FO-PN group showed severe tissue damage, whereas such damage was reduced in the 8% and 33% FO-PN groups. In experiment 2, the CHOW, 33%, 8%, and 0% FO-PN groups showed LPS dose-dependent increases in TNF-α levels. IL-10 levels were also LPS dose-dependently increased in the CHOW and 33% FO-PN groups. However, no marked changes were observed in response to LPS stimulation in either the 8% or the 0% FO-PN group. There were no differences in serum levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, or total bilirubin among these 4 groups. In the 0% FO-PN group, serum total cholesterol levels were greater than those in the 8% and 33% FO-PN groups. Without bacterial challenge, livers from the 0% FO-PN group showed steatosis, but these changes were attenuated in the 8% and 33% FO-PN groups. CONCLUSION: The 30-40% ratio of FO to soybean oil with 20% of total calories supplied by lipid seems to be the best PN for preservation of hepatic MNC number and function.

Intravenous administration of high-dose Paclitaxel reduces gut-associated lymphoid tissue cell number and respiratory immunoglobulin A concentrations in mice.

BACKGROUND: Chemotherapy remains a mainstay of treatment for cancer patients. However, anti-cancer drugs frequently cause a wide range of side effects, including leukopenia and gastrointestinal toxicity. These adverse effects can lead to treatment delays or necessitate temporary dose reductions. Although chemotherapy-related changes in gut morphology have been demonstrated, the influences of chemotherapeutic regimens on gut immunity are understood poorly. This study aimed to examine whether the anti-cancer drug paclitaxel (PTX) impairs gut immunity in mice. METHODS: Male ICR mice were randomized into three groups: Control, low-dose PTX (low PTX; 2 mg/kg), or high-dose PTX (high PTX; 4 mg/kg). A single intravenous dose was given. On day seven after the injection, lymphocytes from Peyer patches (PP), intraepithelial (IE) spaces, and the lamina propria (LP) were counted and analyzed by flow cytometry (CD4(+), CD8(+), αßTCR(+), γδTCR(+), B220(+)). Immunoglobulin A (IgA) concentrations were measured in small intestinal and respiratory tract washings. RESULTS: Total, CD4(+) and γδTCR(+) lymphocyte numbers in PPs were significantly lower in the high PTX than in the control group. The CD4(+) lymphocyte numbers in the IE spaces were significantly lower in both PTX groups than in the control group. Respiratory tract IgA concentrations were lower in the high PTX than in the control group. CONCLUSION: The present data suggest high-dose PTX impairs mucosal immunity, possibly rendering patients more vulnerable to infection. Careful dose selection and new therapies may be important for maintaining mucosal immunity during PTX chemotherapy.

Effects of adding butyric acid to PN on gut-associated lymphoid tissue and mucosal immunoglobulin A levels.

BACKGROUND: Parenteral nutrition (PN) causes intestinal mucosal atrophy, gut-associated lymphoid tissue (GALT) atrophy and dysfunction, leading to impaired mucosal immunity and increased susceptibility to infectious complications. Therefore, new PN formulations are needed to maintain mucosal immunity. Short-chain fatty acids have been demonstrated to exert beneficial effects on the intestinal mucosa. We examined the effects of adding butyric acid to PN on GALT lymphocyte numbers, phenotypes, mucosal immunoglobulin A (IgA) levels, and intestinal morphology in mice. METHODS: Male Institute of Cancer Research mice (n = 103) were randomized to receive either standard PN (S-PN), butyric acid-supplemented PN (Bu-PN), or ad libitum chow (control) groups. The mice were fed these respective diets for 5 days. In experiment 1, cells were isolated from Peyer's patches (PPs) to determine lymphocyte numbers and phenotypes (αßTCR(+), γδTCR(+), CD4(+), CD8(+), B220(+) cells). IgA levels in small intestinal washings were also measured. In experiment 2, IgA levels in respiratory tract (bronchoalveolar and nasal) washings were measured. In experiment 3, small intestinal morphology was evaluated. RESULTS: Lymphocyte yields from PPs and small intestinal, bronchoalveolar, and nasal washing IgA levels were all significantly lower in the S-PN group than in the control group. Bu-PN moderately, but significantly, restored PP lymphocyte numbers, as well as intestinal and bronchoalveolar IgA levels, as compared with S-PN. Villous height and crypt depth in the small intestine were significantly decreased in the S-PN group vs the control group, however Bu-PN restored intestinal morphology. CONCLUSIONS: A new PN formula containing butyric acid is feasible and would ameliorate PN-induced impairment of mucosal immunity.

Parenteral nutrition rapidly reduces hepatic mononuclear cell numbers and lipopolysaccharide receptor expression on Kupffer cells in mice.

BACKGROUND: Parenteral nutrition (PN) reduces the number of hepatic mononuclear cell (MNCs) and impairs their function, resulting in poor survival after intraportal bacterial challenge in mice. Our recent animal study demonstrated resumption of enteral nutrition after PN to rapidly restore hepatic MNC numbers (in 12 hours) and lipopolysaccharide (LPS) receptor expression on Kupffer cells (in 48 hours). The present study examined the time courses of hepatic MNC number reductions and LPS receptor expression changes in mice receiving PN. METHODS: Male mice (n = 49) from the Institute of Cancer Research were divided into chow (n = 8), PN0.5 (n = 8), PN1 (n = 8), PN2 (n = 9), PN3 (n = 9), and PN5 (n = 7) groups. The chow group was given chow with an intravenous saline infusion. The PN groups were fed parenterally for 0.5, 1, 2, 3, or 5 days following the chow-feeding courses. After 7 days of nutrition support, hepatic MNCs were isolated and counted. The expression of LPS receptors on Kupffer cells was analyzed by flow cytometry. RESULTS: Hepatic MNC numbers rapidly reached their lowest level in the PN0.5 and PN1 groups but were somewhat restored thereafter and remained stable after the third day, without significant differences between any 2 of the PN groups. CD14 and Toll-like receptor 4/MD-2 expressions both showed significant reductions in the PN1 group compared with the chow group and gradually decreased to their lowest levels in the PN5 group. CONCLUSIONS: PN administration rapidly reduces hepatic MNC numbers and LPS receptor expression on Kupffer cells.