Obesity and cancer

An update on the secretory functions of brown, white, and beige adipose tissue: Towards therapeutic applications

Adipose tissue, including white adipose tissue (WAT), brown adipose tissue (BAT), and beige adipose tissue, is vital in modulating whole-body energy metabolism. While WAT primarily stores energy, BAT dissipates energy as heat for thermoregulation. Beige adipose tissue is a hybrid form of adipose tissue that shares characteristics with WAT and BAT. Dysregulation of adipose tissue metabolism is linked to various disorders, including obesity, type 2 diabetes, cardiovascular diseases, cancer, and infertility. Both brown and beige adipocytes secrete multiple molecules, such as batokines, packaged in extracellular vesicles or as soluble signaling molecules that play autocrine, paracrine, and endocrine roles. A greater understanding of the adipocyte secretome is essential for identifying novel molecular targets in treating metabolic disorders. Additionally, microRNAs show crucial roles in regulating adipose tissue differentiation and function, highlighting their potential as biomarkers for metabolic disorders. The browning of WAT has emerged as a promising therapeutic approach in treating obesity and associated metabolic disorders. Many browning agents have been identified, and nanotechnology-based drug delivery systems have been developed to enhance their efficacy. This review scrutinizes the characteristics of and differences between white, brown, and beige adipose tissues, the molecular mechanisms involved in the development of the adipocytes, the significant roles of batokines, and regulatory microRNAs active in different adipose tissues. Finally, the potential of WAT browning in treating obesity and atherosclerosis, the relationship of BAT with cancer and fertility disorders, and the crosstalk between adipose tissue with circadian system and circadian disorders are also investigated.

Metabolic Biomarkers Assessed with PET/CT Predict Sex-Specific Longitudinal Outcomes in Patients with Diffuse Large B-Cell Lymphoma

In many cancers, including lymphoma, males have higher incidence and mortality than females. Emerging evidence demonstrates that one mechanism underlying this phenomenon is sex differences in metabolism, both with respect to tumor nutrient consumption and systemic alterations in metabolism, i.e., obesity. We wanted to determine if visceral fat and tumor glucose uptake with fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) could predict sex-dependent outcomes in patients with diffuse large B-cell lymphoma (DLBCL). We conducted a retrospective analysis of 160 patients (84 males; 76 females) with DLBCL who had imaging at initial staging and after completion of therapy. CT-based relative visceral fat area (rVFA), PET-based SUVmax normalized to lean body mass (SULmax), and end-of-treatment FDG-PET 5PS score were calculated. Increased rVFA at initial staging was an independent predictor of poor OS only in females. At the end of therapy, increase in visceral fat was a significant predictor of poor survival only in females. Combining the change in rVFA and 5PS scores identified a subgroup of females with visceral fat gain and high 5PS with exceptionally poor outcomes. These data suggest that visceral fat and tumor FDG uptake can predict outcomes in DLBCL patients in a sex-specific fashion.

Impact of obesity on outcome of severe bacterial infections

Introduction

Obesity is a rapidly growing global health concern with considerable negative impact on life-time expectancy. It has yet not been clarified if and how obesity impacts outcomes of severe bacterial infections. The aim of this study was to determine how body mass index impacts outcome of severe bacterial infections in a well-defined population-based cohort.

Methods

This study is based on a cohort of 2196 patients included in a Swedish prospective, population-based, consecutive observational study of the incidence of community-onset severe sepsis and septic shock in adults. All patients with weight and height documented in the medical records on admission were included.

Results

The case fatality rate (CFR) was negatively correlating with increasing BMI. Outcomes included 28-day CFR (p-value = 0.002), hospital CFR (p-value = 0.039) and 1-year CFR (p-value<0.001). When BMI was applied as continuous variable in a multiple logistic regression together with other possible covariates, we still could discern that BMI was associated with decreasing 28-day CFR (OR = 0.93, 95% CI 0.88–0.98, p-value = 0.009) and 1-year CFR (OR = 0.94, 95% CI 0.91–0.97, p-value<0.001).

Conclusion

The hypothesis and paradox of obesity being associated with higher survival rates in severe bacterial infections was confirmed in this prospective, population-based observational study.

Gut Microbiota and Gynecological Cancers: A Summary of Pathogenetic Mechanisms and Future Directions

Over the past 20 years, important relationships between the microbiota and human health have emerged. A link between alterations of microbiota composition (dysbiosis) and cancer development has been recently demonstrated. In particular, the composition and the oncogenic role of intestinal bacterial flora has been extensively investigated in preclinical and clinical studies focusing on gastrointestinal tumors. Overall, the development of gastrointestinal tumors is favored by dysbiosis as it leads to depletion of antitumor substances (e.g., short-chain fatty acids) produced by healthy microbiota. Moreover, dysbiosis leads to alterations of the gut barrier, promotes a chronic inflammatory status through activation of toll-like receptors, and causes metabolic and hormonal dysregulations. However, the effects of these imbalances are not limited to the gastrointestinal tract and they can influence gynecological tumor carcinogenesis as well. The purpose of this Review is to provide a synthetic update about the mechanisms of interaction between gut microbiota and the female reproductive tract favoring the development of neoplasms. Furthermore, novel therapeutic approaches based on the modulation of microbiota and their role in gynecological oncology are discussed.

Transcriptome Analysis of Subcutaneous Adipose Tissue from Severely Obese Patients Highlights Deregulation Profiles in Coding and Non-Coding Oncogenes

Obesity is a major risk factor for a large number of secondary diseases, including cancer. Specific insights into the role of gender differences and secondary comorbidities, such as type 2 diabetes (T2D) and cancer risk, are yet to be fully identified. The aim of this study is thus to find a correlation between the transcriptional deregulation present in the subcutaneous adipose tissue of obese patients and the oncogenic signature present in multiple cancers, in the presence of T2D, and considering gender differences. The subcutaneous adipose tissue (SAT) of five healthy, normal-weight women, five obese women, five obese women with T2D and five obese men were subjected to RNA-sequencing, leading to the identification of deregulated coding and non-coding RNAs, classified for their oncogenic score. A panel of DE RNAs was validated via Real-Time PCR and oncogene expression levels correlated the oncogenes with anthropometrical parameters, highlighting significant trends. For each analyzed condition, we identified the deregulated pathways associated with cancer, the prediction of possible prognosis for different cancer types and the lncRNAs involved in oncogenic networks and tissues. Our results provided a comprehensive characterization of oncogenesis correlation in SAT, providing specific insights into the possible molecular targets implicated in this process. Indeed, the identification of deregulated oncogenes also in SAT highlights hypothetical targets implicated in the increased oncogenic risk in highly obese subjects. These results could shed light on new molecular targets to be specifically modulated in obesity and highlight which cancers should receive the most attention in terms of better prevention in obesity-affected patients.

Angiogenesis in Adipose Tissue: The Interplay Between Adipose and Endothelial Cells

Obesity is a worldwide health problem, and as its prevalence increases, so does the burden of obesity-associated co-morbidities like type 2 diabetes or cardiovascular diseases (CVDs). Adipose tissue (AT) is an endocrine organ embedded in a dense vascular network. AT regulates the production of hormones, angiogenic factors, and cytokines. During the development of obesity, AT expands through the increase in fat cell size (hypertrophy) and/or fat cell number (hyperplasia). The plasticity and expansion of AT is related to its angiogenic capacities. Angiogenesis is a tightly orchestrated process, which involves endothelial cell (EC) proliferation, migration, invasion, and new tube formation. The expansion of AT is accelerated by hypoxia, inflammation, and structural remodeling of blood vessels. The paracrine signaling regulates the functional link between ECs and adipocytes. Adipocytes can secrete both pro-angiogenic molecules, e.g., tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), or vascular endothelial growth factor (VEGF), and anti-angiogenic factors, e.g., serpins. If the pro-angiogenic molecules dominate, the angiogenesis is dysregulated and the endothelium becomes dysfunctional. However, if anti-angiogenic molecules are overexpressed relative to the angiogenic regulators, the angiogenesis is repressed, and AT becomes hypoxic. Furthermore, in the presence of chronic nutritional excess, endothelium loses its primary function and contributes to the inflammation and fibrosis of AT, which increases the risk for CVDs. This review discusses the current understanding of ECs function in AT, the cross-talk between adipose and ECs, and how obesity can lead to its dysfunction. Understanding the interplay of angiogenesis with AT can be an approach to therapy obesity and obesity-related diseases such as CVDs.

High levels of leptin and non-high molecular weight-adiponectin in patients with colorectal cancer: Association with chemotherapy and common genetic polymorphisms

Colorectal cancer (CRC) is the third most frequently diagnosed cancer worldwide. Leptin and adiponectin are hormones produced by adipose tissues, which exhibit opposing effects on tumor growth. Leptin promotes tumor development and metastasis, whereas adiponectin attenuates this. The aim of the present study was to assess the possible association between leptin and adiponectin [both high molecular weight (HMW) and non-HMW factions] levels with CRC, CRC response to chemotherapy, and to study the relationship between LEPR (rs6588147), ADIPO (rs266729), LEP (rs2167270), and ADIPO (rs822369) polymorphisms and CRC. A total of 32 blood samples collected from CRC patients were analyzed to identify the serum levels of leptin and adiponectin, and the presence of CRC related polymorphisms. A total of 25 healthy subjects were recruited in the control group. Serum levels of leptin and adiponectin were detected using ELISA whereas DNA from patients and controls was amplified and analyzed using PCR-restriction fragment length polymorphism assay. The results showed that the levels of leptin and non-HMW adiponectin were significantly higher in CRC patients compared with the controls (P<0.05). In addition, HMW adiponectin was significantly higher in patients receiving chemotherapy. The association between LEPR (rs6588147), ADIPO (rs266729), LEP (rs2167270) and ADIPO (rs822369) polymorphisms and CRC was not significant (P>0.05). In conclusion, higher leptin and non-HMW adiponectin levels may be associated with increased CRC. Chemotherapy may positively influence the levels of HMW adiponectin. No association between LEPR (rs6588147), ADIPO (rs266729), LEP (rs2167270) and ADIPO (rs822369) polymorphisms with CRC was found.

Obesity attenuates the effect of sleep apnea on active TGF-ß1 levels and tumor aggressiveness in patients with melanoma

Active transforming growth factor-β1 (TGF-β1), a cytokine partially regulated by hypoxia and obesity, has been related with poor prognosis in several tumors. We determine whether obstructive sleep apnea (OSA) increases serum levels of active TGF-β1 in patients with cutaneous melanoma (CM), assess their relationship with melanoma aggressiveness and analyze the factors related to TGF-β1 levels in obese and non-obese OSA patients. In a multicenter observational study, 290 patients with CM were underwent sleep studies. TGF-β1 was increased in moderate-severe OSA patients vs. non-OSA or mild OSA patients with CM. In OSA patients, TGF-β1 levels correlated with mitotic index, Breslow index and melanoma growth rate, and were increased in presence of ulceration or higher Clark levels. In CM patients, OSA was associated with higher TGF-β1 levels and greater melanoma aggressiveness only in non-obese subjects. An in vitro model showed that IH-induced increases of TGF-β1 expression in melanoma cells is attenuated in the presence of high leptin levels. In conclusion, TGF-β1 levels are associated with melanoma aggressiveness in CM patients and increased in moderate-severe OSA. Moreover, in non-obese patients with OSA, TGF-β1 levels correlate with OSA severity and leptin levels, whereas only associate with leptin levels in obese OSA patients.

The Identification of Characteristic Macro- and Micronutrients and the Bioactive Components of Indonesian Local Brown Rice as a Functional Feed in Obesity Nutrition Therapy

Background:

Public interest and awareness of the use of functional food as an obesity nutrition therapy are increasing.

Objective:

This study aims to analyze the content of energy, macronutrients, minerals (magnesium, manganese, and potassium), and bioactive components (fiber, β-glucan) in Indonesian varieties of brown rice compared to white rice, to provide precise information on the nutritional content of brown rice as a functional food in obesity nutrition therapy.

Methods:

This research took the form of a laboratory analysis to identify the content of energy, macronutrients, fiber, β-glucan, magnesium, manganese, and potassium in brown rice varieties Sinta Nur. The energy content of rice was analyzed using bomb calorimetry; macronutrients were analyzed by spectrophotometry, gravimetric extraction, and acid-base titration; dietary fiber, and β-glucan were analyzed by enzymatic methods; and mineral contents were analyzed by spectrophotometry and atomic absorption spectrophotometry.

Results:

The results demonstrated that the energy and macronutrient content of brown rice are higher than white rice. However, brown rice also has dietary fiber and β-glucan contents that are 5 times higher than white rice. For the macronutrient, in brief, magnesium content was 7.7 times higher, potassium was 5.7 times higher, and manganese was 1.59 times higher within the brown rice. Cooked rice is known for lower nutritional value, but the nutritional value of Indonesian brown rice is still higher than white rice.

Conclusion:

The results of this study indicate that brown rice has nutrient content and bioactive components that allegedly contribute to higher obesity intervention than white rice.

The Early Results of the Laparoscopic Mini-Gastric Bypass/One Anastomosis Gastric Bypass on Patients with Different Body Mass Index

Introduction. Obesity is among the newest health matters that human beings are struggling with. Length of bypassed intestine is important in achievement of most weight loss and least nutritional and absorptive disorders. This study has aimed to assess short-term metabolic and nutritional effects of laparoscopic mini-gastric bypass/one anastomosis gastric bypass (MGB/OAGB) with a loop bypass length of 180 centimeters (cm) and compare these factors among patients with a body mass index (BMI) of 40-45 and 45-50 kilograms per square meter (kg/m²).

METHODS

25 patients were put in group 1 (BMI = 40-45 kg/m²) and 25 patients in group 2 (BMI = 45-50 kg/m²). Patients' BMI, postoperative weight, excess weight loss, and laboratory tests including fasting blood sugar (FBS), lipid profile, serum iron (Fe), ferritin, total iron-binding capacity (TIBC), 25-OH vitamin D, vitamin B12, liver function tests, and albumin were recorded preoperatively and within 3- and 6-month follow-up.

RESULTS

Weight loss and BMI reduction was significantly more in patients with higher BMI level (P=0.007), and excess weight loss was higher in patients with lower preoperative BMI level (P=0.007), and excess weight loss was higher in patients with lower preoperative BMI level (P=0.007), and excess weight loss was higher in patients with lower preoperative BMI level (.

CONCLUSION

Based on this study, 180-cm intestinal bypassed length works for patients with a BMI level of 40-45 and 45-50 kg/m², according to their significant decrease in weight, BMI, and improving glycolipid profile.

Inflammation related miRNAs as an important player between obesity and cancers

The growing trend in addition to their burden, prevalence, and death has made obesity and cancer two of the most concerning diseases worldwide. Obesity is an important risk factor for common types of cancers where the risk of some cancers is directly related to the obesity. Various inflammatory mechanisms and increased level of pro-inflammatory cytokines have been investigated in many previous studies, which play key roles in the pathophysiology and development of both of these conditions. On the other hand, in the recent years, many studies have individually focused on the biomarker's role and therapeutic targeting of microRNAs (miRNAs) in different types of cancers and obesity including newly discovered small noncoding RNAs (sncRNAs) which regulate gene expression and RNA silencing. This study is a comprehensive review of the main inflammation related miRNAs in obesity/obesity related traits. For the first time, the main roles of miRNAs in obesity related cancers have been discussed in response to the question raised in the following hypothesis; do the main inflammatory miRNAs link obesity with obesity-related cancers regarding their role as biomarkers? Graphical abstractConceptual design of inflammatory miRNAs which provide link between obesity and cancers.

Does Bariatric Surgery Affect the Incidence of Endometrial Cancer Development? A Systematic Review

Obesity has been linked to an increased prevalence in multiple cancers. Studies have suggested a reduction in the overall risk of cancer after bariatric surgery. We reviewed the evidence for bariatric surgery reducing the risk of endometrial cancer. Data was extracted from PubMed, EMBASE, and Medline to perform a systematic review. Thirty-one full text articles were identified from 265 abstracts. Nine observational studies were relevant to endometrial cancer. In the five controlled studies, 462 of 113,032 (0.4%) patients receiving bariatric surgery versus 11,997 of 848,864 (1.4%) controls developed endometrial cancer, odds ratio of 0.317 (95% CI 0.161 to 0.627) using random effects model (P < 0.001). Bariatric surgery seems to reduce the risk of endometrial cancer; however, more research is required.

Comparison of Life-Time Death Probability due to Malignant Tumors in Different Regions of China Based on Chinese Surveillance Sites

Objective: To estimate and comparably analyze the life-time death probability (LDP) caused by malignant tumors in different regions in 2004 and 2014. Methods: LDP was calculated by a probability additive formula and based on an abridged life table. Data on age-specific mortality was obtained from the National Cause-of- Death Surveillance Dataset in 2014 using surveillance sites in China and data on age-specific mortality was collected from the third retrospective investigation of death cause in China in 2004. Results: LDP caused by malignant tumors, lung cancer, gastric cancer, liver cancer, esophageal cancer, colorectal, and anal cancer were 19.2%, 5.6%, 2.8%, 2.8%, 1.7%, 1.3%, respectively. In addition, we calculated LDP caused by malignant tumors in three different regions of China. LDP caused by malignant tumors were 21.2%, 6.1%, 3.1%, 2.8%, 2.0%, and 1.5% in the eastern region, were 18.3%, 5.5%, 2.7%, 3.0%, 1.5%, and 1.1% in the central region, and were 16.7%, 4.6%, 2.3%, 2.8%, 1.6%, and 1.2% in the western region, respectively. Additionally, LDP caused by malignant tumors in 2004 and 2015 were compared. We found that LDPs caused by malignant tumors, lung cancer, and colorectal cancer have increased in the past decade, while LDPs caused by gastric cancer, liver cancer, and esophageal cancer have experienced a decreasing trend. Conclusions: Malignant tumors were still the main cause of death in one’s life time, giving rise to LDP. LDP caused by malignant tumours has two divisions. First, traditional upper digestive system cancers related to long-term chronic infection, such as esophageal cancer, gastric cancer, and liver cancer, which has shown a significant downward trend. Second, lung and colorectal cancers related to the environmental factors and lifestyle, which are on the rise.

Does Bariatric Surgery Affect the Incidence of Breast Cancer Development? A Systematic Review

We reviewed the evidence for bariatric surgery reducing the risk of breast cancer. Data was extracted from multiple libraries, including PubMed, EMBASE, and Medline, to perform a systematic review. Abstracts were reviewed by two independent reviewers. Thirty-eight full-text articles were identified from 1171 abstracts. Four studies were included for meta-analysis; 114 of 10,533 (1.1%) patients receiving bariatric surgery versus 516 of 20,130 (2.6%) controls developed breast cancer, odds ratio 0.564 (95% CI 0.453 to 0.702) using a fixed effects model (P < 0.001) and odds ratio 0.585 (95% CI 0.247 to 1.386) using a random effects model (P 0.223). Bariatric surgery may reduce the risk of breast cancer. More research is required due to heterogeneity of studies, difficulty in identifying accurate controls, and limited follow-up.

Young Adult Risk Factors for Cancer: Obesity, Inflammation, and Sociobehavioral Mechanisms

INTRODUCTION

The paper assesses social disparities in the burdens of metabolic and inflammatory risks for cancer in the U.S. young adult population and examines psychosocial and behavioral mechanisms in such disparities.

METHODS

Using data of 7,889 individuals aged 12-32 years from the National Longitudinal Study of Adolescent to Adult Health from 1994 to 2009, generalized linear models were used to assess the sex, race/ethnicity, and SES differences in the risks of obesity and inflammation, measured by C-reactive protein. Further tests examined the extent to which social isolation, smoking, physical inactivity, alcohol abuse, and illicit drug use explain social differentials in each biomarker outcome.

RESULTS

Women, blacks, Hispanics, and socioeconomically disadvantaged groups had higher risks of obesity and elevated C-reactive protein, with the SES gradients being more pronounced in female participants. Health-related behaviors showed large variation across sex, race, and SES strata. After adjusting for these behavioral variables, sex, and race disparities in obesity and excess inflammation in blacks diminished, whereas the adolescent SES disparity in obesity remained. The associations of adolescent and young adult SES disadvantage and inflammation were also explained by behavioral mechanisms. Behavioral factors associated with higher risks of obesity and inflammation differed, with the exception of fast food consumption, a risk factor for both.

CONCLUSIONS

This study provides new knowledge of social distribution of early life exposures to physiologic precedents to cancer development later in life with implications for prevention and early intervention of modifiable risky behaviors in adolescents and young adults.

Adipocyte-derived exosomes promote lung cancer metastasis by increasing MMP9 activity via transferring MMP3 to lung cancer cells

Obesity is involved in tumor progression. However, the corresponding mechanisms remain largely unknown. Here, we report that adipocytes increase the invasive ability of tumor cells by producing exosomes with a high level of MMP3. Compared with 3T3-L1 cells, 3T3-L1 adipocytes are enriched in MMP3 protein and can transfer MMP3 to 3LL lung cancer cells. Then, MMP3 activates MMP9 activity in 3LL cells and promotes invasion in vitro and in vivo via MMP9. Furthermore, MMP3 protein levels in lung tumor tissues from obese patients are increased compared with those of non-obese patients. In addition, MMP3 protein levels are positively correlated with MMP9 activity in tumor tissues. Therefore, our results reveal a novel mechanism in the adipocyte-derived exosome-mediated promotion of lung tumor metastasis, which extends our knowledge regarding obesity and tumor progression.

Obesity and cancer: the role of adipose tissue and adipo-cytokines-induced chronic inflammation

Adipose tissue in addition to its ability to keep lipids is now recognized as a real organ with both metabolic and endocrine functions. Recent studies demonstrated that in obese animals is established a status of adipocyte hypoxia and in this hypoxic state interaction between adipocytes and stromal vascular cells contribute to tumor development and progression. In several tumors such as breast, colon, liver and prostate, obesity represents a poor predictor of clinical outcomes. Dysfunctional adipose tissue in obesity releases a disturbed profile of adipokines with elevated levels of pro-inflammatory factors and a consequent alteration of key signaling mediators which may be an active local player in establishing the peritumoral environment promoting tumor growth and progression. Therefore, adipose tissue hypoxia might contribute to cancer risk in the obese population. To date the precise mechanisms behind this obesity-cancer link is not yet fully understood. In the light of information provided in this review that aims to identify the key mechanisms underlying the link between obesity and cancer we support that inflammatory state specific of obesity may be important in obesity-cancer link.

Clinical Scenario of the Metabolic Syndrome

The term metabolic syndrome (MeS) refers to a cluster of associated symptoms composed of impaired fasting glucose, abdominal obesity, hypertension, and dyslipidemia. MeS is associated with an increased risk of cardiovascular and diabetes-associated morbidity and mortality. The increased amount of visceral fat together with a chronic inflammatory state predisposes to the development of arteriosclerosis. Furthermore, insulin resistance (IR) and dyslipidemia are associated with fatty liver disease. In addition, MeS is linked to non-cardiovascular diseases such as cancer as well as psychiatric or endocrine disorders. Here, we discuss the clinical impact of MeS in cardiovascular and non-cardiovascular diseases to highlight the importance of prevention, early diagnosis, and multifactorial treatment of high-risk individuals.

The Relationship between Obesity, Prostate Tumor Infiltrating Lymphocytes and Macrophages, and Biochemical Failure

BACKGROUND

Obesity reflects a chronic inflammatory environment that may contribute to prostate cancer progression and poor treatment outcomes. However, it is not clear which mechanisms drive this association within the tumor microenvironment. The aim of this pilot study was to examine prostatic inflammation via tumor infiltrating lymphocytes and macrophages characterized by obesity and cancer severity.

METHODS

We studied paraffin-embedded prostatectomy tissue from 99 participants (63 non-obese and 36 obese) from the Study of Clinical Outcomes, Risk and Ethnicity (University of Pennsylvania). Pathologists analyzed the tissue for type and count of lymphocytes and macrophages, including CD3, CD8, FOXP3, and CD68. Pathology data were linked to clinical and demographic variables. Statistical analyses included frequency tables, Kruskal-Wallis tests, Spearman correlations, and multivariable models.

RESULTS

We observed positive univariate associations between the number of CD68 cells and tumor grade (p = 0.019). In multivariable analysis, CD8 counts were associated with time to biochemical failure (HR = 1.09, 95% CI = 1.004-1.192, p-value = 0.041.) There were no differences in lymphocytes or macrophages by obesity status or BMI.

CONCLUSIONS

The number of lymphocytes and macrophages in the tumor microenvironment did not differ by obesity status. However, these inflammation markers were associated with poor prostate cancer outcomes. Further examination of underlying mechanisms that influence obesity-related effects on prostate cancer outcomes is warranted. Such research will guide immunotherapy protocols and weight management as they apply to diverse patient populations and phenotypes.

Role of MCP-1 on inflammatory processes and metabolic dysfunction following high-fat feedings in the FVB/N strain

Background

MCP-1 is known to be an important chemokine for macrophage recruitment. Thus, targeting MCP-1 may prevent the perturbations associated with macrophage-induced inflammation in adipose tissue. However, inconsistencies in the available animal literature have questioned the role of this chemokine in this process. The purpose of this study was to examine the role of MCP-1 on obesity-related pathologies.

Methods

Wild-type (WT) and MCP-1 deficient mice on an FVB/N background were assigned to either low-fat-diet (LFD) or high-fat-diet (HFD) treatment for a period of 16 weeks. Body weight and body composition were measured weekly and monthly, respectively. Fasting blood glucose and insulin, and glucose tolerance were measured at 16 weeks. Macrophages, T cell markers, inflammatory mediators, and markers of fibrosis were examined in the adipose tissue at sacrifice.

Results

As expected, HFD increased adiposity (body weight, fat mass, fat percent, and adipocyte size), metabolic dysfunction (impaired glucose metabolism and insulin resistance) macrophage number (CD11b⁺F480⁺ cells, and gene expression of EMR1 and CD11c), T cell markers (gene expression of CD4 and CD8), inflammatory mediators (pNFκB and pJNK, and mRNA expression of MCP-1, CCL5, CXCL14, TNF-α, and IL-6), and fibrosis (expression of IL-10, IL-13, TGF-β, and MMP2) (P<0.05). However, contrary to our hypothesis, MCP-1 deficiency exacerbated many of these responses resulting in a further increase in adiposity (body weight, fat mass, fat percent and adipocyte size), metabolic dysregulation, macrophage markers (EMR1), inflammatory cell infiltration, and fibrosis (formation of type I and III collagens, mRNA expression of IL-10 and MMP2) (P<0.05).

Conclusions

These data suggest that MCP-1 may be a necessary component of the inflammatory response required for adipose tissue protection, remodeling, and healthy expansion in the FVB/N strain in response to HFD feedings.