Lcn2 mediates adipocyte-muscle-tumor communication and hypothermia in pancreatic cancer cachexia

Integrative metabolic profiling of hypothalamus and skeletal muscle in a mouse model of cancer cachexia

Cancer cachexia is a multifactorial metabolic syndrome characterized by progressive weight loss, muscle wasting, and systemic inflammation. Despite its clinical significance, the underlying mechanisms linking central and peripheral metabolic changes remain incompletely understood. In this study, we employed a murine model of cancer cachexia induced by intraperitoneal injection of Lewis lung carcinoma (LLC1) cells to investigate tissue-specific metabolic adaptations. Cachectic mice exhibited reduced food intake, body weight loss, impaired thermoregulation, and decreased energy expenditure. Metabolomic profiling of serum, skeletal muscle, and hypothalamus revealed distinct metabolic shifts, with increased fatty acid and ketone body utilization and altered amino acid metabolism. Notably, hypothalamic metabolite changes diverged from peripheral tissues, showing decreased neurotransmitter-related metabolites and enhanced lipid-based energy signatures. Gene expression analysis further confirmed upregulation of glycolysis- and lipid oxidation-related genes in both hypothalamus and muscle. These findings highlight coordinated yet compartmentalized metabolic remodeling in cancer cachexia and suggest that hypothalamic adaptations may play a central role in the systemic energy imbalance associated with cachexia progression.

The mechanisms and effects of lactylation modification in different kinds of cancers

Lactylation, a recently identified post-translational modification, has garnered significant attention for its associations with various diseases, particularly its critical role in tumor progression and treatment. It is emerging as a potential clinical target. The elevated metabolic activity of cancer cells often leads to excessive lactate accumulation, a phenomenon termed the "Warburg effect", which is a hallmark of the tumor microenvironment. Recent research reveals that lactate is not merely a metabolic byproduct but also serves as a substrate for protein lactylation, influencing tumor development by regulating cellular signaling, gene expression, and immune responses. This dual role has become a focal point for scientists and clinicians seeking novel therapeutic strategies targeting lactate-related pathways. Despite growing interest, the detailed mechanisms and therapeutic applications of lactylation across different cancer types remain inadequately explored. This review synthesizes current findings on lactylation mechanisms in various tumors, highlights potential therapeutic targets, and offers new perspectives to advance cancer treatment.

Lipocalin-2 promotes NSCLC progression by activating the JAK2/STAT3 signaling pathway

BACKGROUND

Non-small cell lung cancer (NSCLC) remains a leading cause of cancer-related mortality worldwide. Lipocalin-2 (LCN2), a pleiotropic protein implicated in tumorigenesis and cancer progression, has been associated with multiple malignancies. However, its precise role in NSCLC and the underlying molecular mechanisms remain incompletely understood. This study aimed to elucidate the function of LCN2 in NSCLC, with a particular focus on its involvement in the Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signaling pathway.

METHODS

LCN2 expression in NSCLC tissues was comprehensively analyzed using bioinformatics tools, including the Universal Analysis of Cancer (UALCAN), The Cancer Genome Atlas (TCGA), UCSC-XENA, and Gene Expression Omnibus (GEO) databases. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting were employed to assess LCN2 expression levels in NSCLC cell lines. The functional impact of LCN2 on NSCLC cells, including proliferation, apoptosis, and metastasis, were assessed through a series of in vitro assays, such as Cell Counting Kit-8 (CCK-8), EdU, wound healing, and transwell migration and invasion assays. An in vivo xenograft model was established to investigate the effects of LCN2 on tumor growth and metastasis. Additionally, the involvement of the JAK2/STAT3 signaling pathway was examined using western blotting and pharmacological inhibition with AG490.

RESULTS

LCN2 was significantly upregulated in NSCLC tissues and cell lines, and its elevated expression correlated with poor prognosis. Functional analyses demonstrated that LCN2 knockdown suppressed NSCLC cell proliferation, migration, and invasion while promoting apoptosis. Mechanistically, LCN2 was found to activate the JAK2/STAT3 pathway by interacting with SOCS3, and pharmacological blockade of this pathway effectively abrogated the oncogenic effects of LCN2 overexpression.

CONCLUSIONS

This study identifies LCN2 as a potential oncogene in NSCLC, driving tumor progression through activation of the JAK2/STAT3 signaling pathway. These findings suggest that targeting LCN2 or its downstream signaling components may represent a promising therapeutic strategy for NSCLC.

Ancestral bisphenol A exposure led to non-alcoholic fatty liver disease and sex-specific alterations in proline and bile metabolism pathways in the liver

Endocrine-disrupting chemicals can induce metabolic alterations, resulting in diseases such as obesity, diabetes, and fatty liver disease, which can be inherited by offspring inhabiting uncontaminated environments. Bisphenol A (BPA), a well-known endocrine disruptor, can induce endocrine disruption, leading to metabolic disorders in subsequent generations without further exposure to BPA via nongenetic transgenerational inheritance. Using medaka as an animal model, we reported that ancestral BPA exposure leads to transgenerational nonalcoholic fatty liver disease (NAFLD) in grandchildren four generations after the initial exposure. It is unclear if transgenerational NAFLD developed because ancestral BPA exposure differs from that developed due to direct and continuous BPA exposure because the transgenerational disease develops in the absence of the stressor. We induced transgenerational NAFLD in medaka with ancestral BPA exposure (10 µg/L) at the F0 generation and examined transcriptional and metabolomic alterations in the liver of the F4 generation fish that continued to develop NAFLD. To understand the etiology of NAFLD in unexposed generations, we performed nontargeted liquid chromatography-mass spectrometry-based metabolomic analysis in combination with bulk RNA sequencing and determined biomarkers, co-expressed gene networks, and sex-specific pathways triggered in the liver. An integrated analysis of metabolomic and transcriptional alterations revealed a positive association with the severity of the NAFLD disease phenotype. Females showed increased NAFLD severity and had metabolic disruption involving proline metabolism, tryptophan metabolism, and bile metabolism pathways. The present results provide the transcriptional and metabolomic underpinning of metabolic disruption caused by ancestral BPA exposure, providing avenues for further research to understand the development and progression of transgenerational NAFLD caused by ancestral bisphenol A exposure.

From fat storage to immune hubs: the emerging role of adipocytes in coordinating the immune response to infection

Adipose tissue is a rich source of diverse cell populations, including immune cells, adipocytes and stromal cells. Interactions between these different cell types are now appreciated to be critical for maintaining tissue structure and function, by governing processes such as adipogenesis, lipolysis and differentiation of white to beige adipocytes. Interactions between these cells also drive inflammation in obesity, leading to an expansion of adipose tissue immune cells, and the secretion of proinflammatory cytokines from immune cells and from adipocytes themselves. However, in evolutionary terms, obesity is a recent phenomenon, raising the question of why adipocytes evolved to express factors that influence the immune response. Studies of various pathogens indicate that adipocytes are highly responsive to infection, altering their metabolic profiles in a way that can be used to release nutrients and fuel the immune response. In the case of infection with the extracellular parasite Trypanosoma brucei, attenuating the ability of adipocytes to sense the cytokine IL-17 results in a loss of control of the local immune response and an increased pathogen load. Intriguingly, comparisons of the adipocyte response to infection suggest that the immune responses of these cells occur in a pathogen-dependent manner, further confirming their complexity. Here, with a focus on murine adipose tissue, we discuss the emerging concept that, in addition to their canonical function, adipocytes are immune signalling hubs that integrate and disseminate signals from the immune system to generate a local environment conducive to pathogen clearance.

The lipocalin saga: Insights into its role in cancer-associated cachexia

Cancer-associated cachexia (CAC) is a debilitating condition, observed in patients with advanced stages of cancer. It is marked by ongoing weight loss, weakness, and nutritional impairment. Lower tolerance of chemotherapeutic agents and radiation therapy makes it difficult to treat CAC. Anorexia is a significant contributor to worsening CAC. Anorexia can be found in the early or advanced stages of cancer. Anorexia in cancer patients arises from a confluence of factors. Tumor-related inflammatory cytokines can directly impact the gastrointestinal tract, leading to dysphagia and compromised gut function. Additionally, increased serotonin and hormonal disruptions lead to early satiety, suppressing appetite. Due to the complexities in the pathogenesis of the disease, identifying druggable targets is a challenge. Research is ongoing to identify novel targets for the treatment of this condition. Recent research suggests a potential link between elevated levels of Lipocalin 2 (LCN2) and cachexia in cancer patients. LCN2, a glycoprotein primarily released by neutrophils, is implicated in numerous illnesses, including skin disorders, cancer, atherosclerosis, and type 2 diabetes. LCN2 suppresses hunger by binding to the melanocortin-4 receptors. Several in vitro, in vivo, and clinical studies indicate the association between LCN2 levels and appetite suppression. Further research should be explored emphasizing the significance of well-crafted clinical trials to confirm LCN2's usefulness as a therapeutic target and its ability to help cancer patients who are suffering from the fatal hallmark of cachexia. This review explores LCN2's function in the multifaceted dynamics of CAC and anorexia.

Stable Transmission of DNA Methylation Epimutations from Germlines to the Liver and Their Association with Fatty Liver Disease in Medaka

Background

Environmental stressors can induce heritable traits in organisms across phyla, with distinct epigenetic alterations in gametes and phenotypic outcomes across several generations. However, the mechanisms underlying such intergenerational inheritance, mainly from the germline to the germline and from the germline to the soma, are enigmatic, given that postfertilization embryos and germline cells reprogram the epigenome in each generation to gain their cellular identity. Here, we report stable germline transmission of differential DNA methylation alterations (epimutations) and their associations with nonalcoholic fatty liver disease (NAFLD) in medaka exposed to a model estrogenic chemical but a ubiquitous environmental contaminant, bisphenol A (BPA).

Results

Ancestral BPA exposure in the F0 generation led to advanced NAFLD in the unexposed grandchildren generation (F2) of medaka. The F2 liver transcriptome and histopathology revealed a severe NAFLD phenotype in females. Whole-genome bisulfite sequencing of the sperm and liver revealed a gradual shift in promoter methylation from F0 sperm (hypomethylated) to F1 sperm (mix of hypo- and hypermethylated) and F2 liver (predominantly hypermethylated). Many differentially methylated promoters (DMPs) overlapped in F0 sperm, F1 sperm, and F2 liver, regardless of sex. In females, stable transmission of 1511 DMPs was found across three generations, which are associated with protein-coding genes, miRNAs, and others and linked to NAFLD and nonalcoholic steatohepatitis (NASH). Among them, 27 canonical genes maintained consistently hypermethylated promoters across three generations, with significant downregulation of their expression and enrichment in NAFLD-related pathways, mainly fat digestion, glycerolipid metabolism, and steroid biosynthesis.

Conclusions

The present results demonstrate stable inter- and transgenerational germline-to-germline and germline-to-soma transmission of environmentally induced DNA epimutations with F0 and F1 gametic epimutations, predicting the F2 liver phenotype-a clear transgenerational passage of the disease phenotype in medaka.

Deciphering molecular crosstalk mechanisms between skeletal muscle atrophy and KRAS-mutant pancreatic cancer: a literature review

Background and Objective

Cachexia-induced skeletal muscle atrophy is a critical manifestation in Kirsten rat sarcoma viral oncogene homologue (KRAS)-mutant pancreatic cancer (PC) patients, predominantly characterized by a shift in metabolic equilibrium towards catabolism that accelerates protein degradation in myofibers and leads to muscle atrophy. This metabolic reprogramming not only supports tumor growth but also precipitates energy depletion in skeletal muscle tissues. Exploring these mechanisms reveals potential therapeutic targets in the metabolic and proteolytic pathways associated with KRAS-mutant PC.

Methods

A comprehensive search for literature was conducted in PubMed, Web of Science, Google Scholar and other search engines up to May 21st, 2024. Studies on PC models and patients were included.

Key Content and Findings

The crosstalk between KRAS-mutant PC and skeletal muscle atrophy can be categorized into four principal domains: (I) KRAS-driven metabolic reprogramming in cancer cells leads to the depletion of muscle energy reserves, thereby influencing the reallocation of myofiber energy towards fueling cancer cell; (II) KRAS-mutant cancer cells rely on nutrient-scavenging pathways, resulting in altered cytokine profiles, increased ubiquitin mRNA expression and autophagy-lysosome pathway, which facilitate myotube degradation and inhibit muscle regeneration, thereby disrupting muscular homeostasis and causing a one-way nutrient flux; (III) tumor-induced oxidative stress inflicts damage on myotubes, highlighting the detrimental effects of reactive oxygen species on muscle structure; (IV) KRAS-mutant cancer cells remodulate immune cell dynamics within the tumor environment, thereby reshaping host immunity. Together, these findings illuminate the intricate interplay between KRAS-mutant PC and skeletal muscle atrophy, mapping the pathophysiological framework that is crucial for understanding sarcopenia and related disorders.

Conclusions

This comprehensive analysis advances our understanding of the complex etiology of cancer cachexia and stimulates the development of targeted therapeutic strategies.

Identification of neutrophil extracellular traps (NETs)-related molecular clusters in prostate cancer: Implications for predicting biochemical recurrence

OBJECTIVE

To identify neutrophil extracellular traps (NETs)-related molecular clusters and establish a novel gene signature for predicting biochemical recurrence in prostate cancer (PCa).

METHODS

The transcriptome and clinicaldata of PCa sampleswere obtained from The TCGA and GEO databases. To identify NET-related molecular clusters, consensus clustering analyses were performed. Using univariate Cox and Lasso regression analysis, a novel NETs-related prognostic model was formulated. To evaluate the validity of the model, both internal and external validations were carried out. At last, preliminary experimental validations were performed to verify the biological functions of ANXA3 in PCa cells.

RESULTS

After screening 75 NETs-related prognostic genes, two NET-related clusters with significantly different clinical features, immune cell infiltration, and biochemical recurrence were established. Next, a new NET-related model was constructed. In training, test, whole TCGA, and GEO cohorts, the biochemical recurrences free survival of the patients with high-risk scores was considerably lower. The AUCs for the four cohorts were 0.827, 0.696, 0.757, and 0.715, respectively. Subgroup analysis suggested that the novel NETs-related prognostic model has a strong clinical value in the identification of high-risk patients. Finally, we confirmed that chemotherapy might be more beneficial for patients at low risk. In preliminary experiments, the inhibition of ANXA3 could reduce the invasion, migration, and proliferation of PCa cells.

CONCLUSIONS

We have identified novel NETs-related clusters and developed a NETs-related model for PCa that has excellent predictive performance for predicting biochemical recurrences as well as chemotherapy efficacy.

Crosstalk between pancreatic cancer and adipose tissue: Molecular mechanisms and therapeutic implications

The incidence rate of pancreatic cancer, a fatal illness with a meager 5-year survival rate, has been on the rise in recent times. When individuals accumulate excessive amounts of adipose tissue, the adipose organ becomes dysfunctional due to alterations in the adipose tissue microenvironment associated with inflammation and metabolism. This phenomenon may potentially contribute to the aberrant accumulation of fat that initiates pancreatic carcinogenesis, thereby influencing the disease's progression, resistance to treatment, and metastasis. This review presents a summary of the impact of pancreatic steatosis, visceral fat, cancer-associated adipocytes and lipid diets on the advancement of pancreatic cancer, as well as the reciprocal effects of pancreatic cancer on adipose tissue. Understanding the molecular mechanisms underlying the relationship between dysfunctional adipose tissue and pancreatic cancer better may lead to the discovery of new therapeutic targets for the disease's prevention and individualized treatment. This is especially important given the rising global incidence of obesity, which will improve the pancreatic cancer treatment options that are currently insufficient.

Transcriptional analysis of cancer cachexia: conserved and unique features across preclinical models and biological sex

Studies suggest heterogeneity in cancer cachexia (CC) among models and biological sexes, yet examinations comparing models and sexes are scarce. We compared the transcriptional landscape of skeletal muscle across murine CC models and biological sexes during early and late CC. Global gene expression analyses were performed on gastrocnemius [Lewis lung carcinoma (LLC)], quadriceps (KPC-pancreatic), and tibialis anterior [Colon-26 (C26)-colorectal and ApcMin/+] muscles across biological sexes. Differentially expressed genes (DEGs) were identified using an adj-P value of <0.05, followed by pathway and computational cistrome analyses. Integrating all controls, early and late stages of all models and sexes revealed up to 68% of DEGs and pathways were enriched at early and late CC, indicating a conserved transcriptional profile during CC development. Comparing DEGs and pathways within sexes and across models, in early CC, the transcriptional response was highly heterogeneous. At late stage, 11.5% of upregulated and 10% of downregulated genes were shared between models in males, whereas 18.9% of upregulated and 7% of downregulated DEGs were shared in females. Shared DEGs were enriched in proteasome and mitophagy/autophagy pathways (upregulated), and downregulation of energy metabolism pathways in males only. Between sexes, though the proportion of shared DEGs was low (<16%), similar pathway enrichment was observed, including proteasome and mitophagy at late-stage CC. In early CC, oncostatin M receptor (Osmr) upregulation was the only commonality across all models and sexes, whereas CLOCK and ARNTL/BMAL1 were predicted transcriptional factors associated with dysregulations in all three male models. This study highlights sex and model differences in CC progression and suggests conserved transcriptional changes as potential therapeutic targets.NEW & NOTEWORTHY This study is among the first to integrate and compare the skeletal muscle transcriptional landscape across multiple preclinical models and biological sexes. We highlight that 1) early CC transcriptional changes are two-thirds conserved at late stages, 2) DEGs are largely model and sex specific, and 3) transcriptional factors including CLOCK and ARNTL/BMAL1, which influence early CC gene expression, might represent a global therapeutic target with a chance of efficacy across various cancer types.

A comprehensive review of animal models for cancer cachexia: Implications for translational research

Cancer cachexia is a multifactorial syndrome characterized by progressive weight loss and a disease process that nutritional support cannot reverse. Although progress has been made in preclinical research, there is still a long way to go in translating research findings into clinical practice. One of the main reasons for this is that existing preclinical models do not fully replicate the conditions seen in clinical patients. Therefore, it is important to understand the characteristics of existing preclinical models of cancer cachexia and pay close attention to the latest developments in preclinical models. The main models of cancer cachexia used in current research are allogeneic and xenograft models, genetically engineered mouse models, chemotherapy drug-induced models, Chinese medicine spleen deficiency models, zebrafish and Drosophila models, and cellular models. This review aims to revisit and summarize the commonly used animal models of cancer cachexia by evaluating existing preclinical models, to provide tools and support for translational medicine research.

Exploring heterogeneity: a dive into preclinical models of cancer cachexia

Cancer cachexia (CC) is a multifactorial and complex syndrome experienced by up to 80% of patients with cancer and implicated in ∼40% of cancer-related deaths. Given its significant impact on patients' quality of life and prognosis, there has been a growing emphasis on elucidating the underlying mechanisms of CC using preclinical models. However, the mechanisms of cachexia appear to differ across several variables including tumor type and model and biologic variables such as sex. These differences may be exacerbated by variance in experimental approaches and data reporting. This review examines literature spanning from 2011 to March 2024, focusing on common preclinical models of CC, including Lewis Lung Carcinoma, pancreatic KPC, and colorectal colon-26 and Apcmin/+ models. Our analysis reveals considerable heterogeneity in phenotypic outcomes, and investigated mechanisms within each model, with particular attention to sex differences that may be exacerbated through methodological differences. Although searching for unified mechanisms is critical, we posit that effective treatment approaches are likely to leverage the heterogeneity presented by the tumor and pertinent biological variables to direct specific interventions. In exploring this heterogeneity, it becomes critical to consider methodological and data reporting approaches to best inform further research.

Medaka liver developed Human NAFLD-NASH transcriptional signatures in response to ancestral bisphenol A exposure

The progression of fatty liver disease to non-alcoholic steatohepatitis (NASH) is a leading cause of death in humans. Lifestyles and environmental chemical exposures can increase the susceptibility of humans to NASH. In humans, the presence of bisphenol A (BPA) in urine is associated with fatty liver disease, but whether ancestral BPA exposure leads to the activation of human NAFLD-NASH-associated genes in the unexposed descendants is unclear. In this study, using medaka fish as an animal model for human NAFLD, we investigated the transcriptional signatures of human NAFLD-NASH and their associated roles in the pathogenesis of the liver of fish that were not directly exposed, but their ancestors were exposed to BPA during embryonic and perinatal development three generations prior. Comparison of bulk RNA-Seq data of the liver in BPA lineage male and female medaka with publicly available human NAFLD-NASH patient data revealed transgenerational alterations in the transcriptional signature of human NAFLD-NASH in medaka liver. Twenty percent of differentially expressed genes (DEGs) were upregulated in both human NAFLD patients and medaka. Specifically in females, among the total shared DEGs in the liver of BPA lineage fish and NAFLD patient groups, 27.69% were downregulated, and 20% were upregulated. Of all DEGs, 52.31% of DEGs were found in ancestral BPA-lineage females, suggesting that NAFLD in females shared the majority of human NAFLD gene networks. Pathway analysis revealed beta-oxidation, lipoprotein metabolism, and HDL/LDL-mediated transport processes linked to downregulated DEGs in BPA lineage males and females. In contrast, the expression of genes encoding lipogenesis-related proteins was significantly elevated in the liver of BPA lineage females only. BPA lineage females exhibiting activation of myc, atf4, xbp1, stat4, and cancerous pathways, as well as inactivation of igf1, suggest their possible association with an advanced NAFLD phenotype. The present results suggest that gene networks involved in the progression of human NAFLD and the transgenerational NAFLD in medaka are conserved and that medaka can be an excellent animal model to understand the development and progression of liver disease and environmental influences in the liver.

Sex-specific expression of the human NAFLD-NASH transcriptional signatures in the liver of medaka with a history of ancestral bisphenol A exposure

The progression of fatty liver disease to non-alcoholic steatohepatitis (NASH) is a leading cause of death in humans. Lifestyles and environmental chemical exposures can increase the susceptibility of humans to NASH. In humans, the presence of bisphenol A (BPA) in urine is associated with fatty liver disease, but whether ancestral BPA exposure leads to the activation of human NAFLD-NASH-associated genes in the unexposed descendants is unclear. In this study, using medaka fish as an animal model for human NAFLD, we investigated the transcriptional signatures of human NAFLD-NASH and their associated roles in the pathogenesis of the liver of fish who were not directly exposed but their ancestors were exposed to BPA during embryonic and perinatal development three generations prior. Comparison of bulk RNA-Seq data of the liver in BPA lineage male and female medaka with publicly available human NAFLD-NASH patient data revealed transgenerational alterations in the transcriptional signature of human NAFLD-NASH in medaka liver. Twenty percent of differentially expressed genes (DEGs) were upregulated in both human NAFLD patients and medaka. Specifically in females, among the total shared DEGs in the liver of BPA lineage fish and NAFLD patient groups, 27.69% DEGs were downregulated and 20% DEGs were upregulated. Off all DEGs, 52.31% DEGs were found in ancestral BPA-lineage females, suggesting that NAFLD in females shared majority of human NAFLD gene networks. Pathway analysis revealed beta-oxidation, lipoprotein metabolism, and HDL/LDL-mediated transport processes linked to downregulated DEGs in BPA lineage males and females. In contrast, the expression of genes encoding lipogenesis-related proteins was significantly elevated in the liver of BPA lineage females only. BPA lineage females exhibiting activation of myc, atf4, xbp1, stat4, and cancerous pathways, as well as inactivation of igf1, suggest their possible association with an advanced NAFLD phenotype. The present results suggest that gene networks involved in the progression of human NAFLD and the transgenerational NAFLD in medaka are conserved and that medaka can be an excellent animal model to understand the development and progression of liver disease and environmental influences in the liver.

Adipose tissue rearrangement in cancer cachexia: The involvement of β3-adrenergic receptor associated pathways

Cancer-associated cachexia (CAC) is a complex multiple organ syndrome that significantly contributes to reduced quality of life and increased mortality among many cancer patients. Its multifactorial nature makes its early diagnosis and effective therapeutic interventions challenging. Adipose tissue is particularly impacted by cachexia, typically through increased lipolysis, browning and thermogenesis, mainly at the onset of the disease. These processes lead to depletion of fat mass and contribute to the dysfunction of other organs. The β-adrenergic signalling pathways are classical players in the regulation of adipose tissue metabolism. They are activated upon sympathetic stimulation inducing lipolysis, browning and thermogenesis, therefore contributing to energy expenditure. Despite accumulating evidence suggesting that β3-adrenergic receptor stimulation may be crucial to the adipose tissue remodelling during cachexia, the literature remains controversial. Moreover, there is limited knowledge regarding sexual dimorphism of adipose tissue in the context of cachexia. This review paper aims to present the current knowledge regarding adipose tissue wasting during CAC, with a specific focus on the role of the β3-adrenergic receptor, placing it as a potential therapeutic target against cachexia.

Lipocalin 2-A bone-derived anorexigenic and β-cell promoting signal: From mice to humans

The skeleton is traditionally known for its structural support, organ protection, movement, and maintenance of mineral homeostasis. Over the last 10 years, bone has emerged as an endocrine organ with diverse physiological functions. The two key molecules in this context are fibroblast growth factor 23 (FGF23), secreted by osteocytes, and osteocalcin, a hormone produced by osteoblasts. FGF23 affects mineral homeostasis through its actions on the kidneys, and osteocalcin has beneficial effects in improving glucose homeostasis, muscle function, brain development, cognition, and male fertility. In addition, another osteoblast-derived hormone, lipocalin 2 (LCN2) has emerged into the researchers' field of vision. In this review, we mainly focus on LCN2's role in appetite regulation and glucose metabolism and also briefly introduce its effects in other pathophysiological conditions, such as nonalcoholic fatty liver disease, sarcopenic obesity, and cancer-induced cachexia.

Carnosol analogue WK-63 alleviated cancer cachexia by inhibiting NF-κB and activating AKT pathways in muscle while inhibiting NF-κB and AMPK pathways in adipocyte

Cancer cachexia is a systemic metabolic disorder syndrome characterized by severe wasting of muscle and adipose tissues while is lack of effective therapeutic approaches. Carnosol (CS) was found in our previous study to exhibit ameliorating effects on cancer cachexia. In the present study, we designed and synthesized 49 CS analogues by structural modification of CS. Results of activity screening revealed that, among the analogues, WK-63 exhibited better effects than CS in ameliorating atrophy of C2C12 myotubes induced by conditioned medium of C26 tumor cells. WK-63 could also dose-dependently alleviate adipocyte lipolysis of mature 3 T3-L1 cells induced by C26 tumor cell conditioned medium. WK-63 alleviated myotube atrophy by inhibiting Nuclear Factor kappa-B (NF-κB) and activating the Protein Kinase B (AKT) signaling pathway, and also alleviated fat loss by inhibiting NF-κB and Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) signaling pathways. Results of pharmacokinetic (PK) assay showed that, compared with other analogues, WK-63 exhibited longer half-life (T1/2) and mean residence time (MRTs), as well as a larger concentration curve area (AUC0-t). These findings suggested that WK-63 might exert optimal effects in vivo. In the C26 tumor-bearing mice model, administration of WK-63 ameliorated the body weight loss and also improved the weight loss of epididymal adipose tissue. WK-63 is expected to be a novel therapeutic option for the treatment of cancer cachexia.

Lipocalin-2 promotes adipose-macrophage interactions to shape peripheral and central inflammatory responses in experimental autoimmune encephalomyelitis

OBJECTIVE

Accumulating evidence suggests that dysfunctional adipose tissue (AT) plays a major role in the risk of developing multiple sclerosis (MS), the most common immune-mediated and demyelinating disease of the central nervous system. However, the contribution of adipose tissue to the etiology and progression of MS is still obscure. This study aimed at deciphering the responses of AT in experimental autoimmune encephalomyelitis (EAE), the best characterized animal model of MS.

RESULTS AND METHODS

We observed a significant AT loss in EAE mice at the onset of disease, with a significant infiltration of M1-like macrophages and fibrosis in the AT, resembling a cachectic phenotype. Through an integrative and multilayered approach, we identified lipocalin2 (LCN2) as the key molecule released by dysfunctional adipocytes through redox-dependent mechanism. Adipose-derived LCN2 shapes the pro-inflammatory macrophage phenotype, and the genetic deficiency of LCN2 specifically in AT reduced weight loss as well as inflammatory macrophage infiltration in spinal cord in EAE mice. Mature adipocytes downregulating LCN2 reduced lipolytic response to inflammatory stimuli (e.g. TNFα) through an ATGL-mediated mechanism.

CONCLUSIONS

Overall data highlighted a role LCN2 in exacerbating inflammatory phenotype in EAE model, suggesting a pathogenic role of dysfunctional AT in MS.

The PCOS-NAFLD Multidisease Phenotype Occurred in Medaka Fish Four Generations after the Removal of Bisphenol A Exposure

As a heterogeneous reproductive disorder, polycystic ovary syndrome (PCOS) can be caused by genetic, diet, and environmental factors. Bisphenol A (BPA) can induce PCOS and nonalcoholic fatty liver disease (NAFLD) due to direct exposure; however, whether these phenotypes persist in future unexposed generations is not currently understood. In a previous study, we observed that transgenerational NAFLD persisted in female medaka for five generations (F4) after exposure to an environmentally relevant concentration (10 μg/L) of BPA. Here, we demonstrate PCOS in the same F4 generation female medaka that developed NAFLD. The ovaries contained immature follicles, restricted follicular progression, and degenerated follicles, which are characteristics of PCOS. Untargeted metabolomic analysis revealed 17 biomarkers in the ovary of BPA lineage fish, whereas transcriptomic analysis revealed 292 genes abnormally expressed, which were similar to human patients with PCOS. Metabolomic-transcriptomic joint pathway analysis revealed activation of the cancerous pathway, arginine-proline metabolism, insulin signaling, AMPK, and HOTAIR regulatory pathways, as well as upstream regulators esr1 and tgf signaling in the ovary. The present results suggest that ancestral BPA exposure can lead to PCOS phenotypes in the subsequent unexposed generations and warrant further investigations into potential health risks in future generations caused by initial exposure to EDCs.

New insights into the role of adipocytes in pancreatic cancer progression: paving the way towards novel therapeutic targets

Pancreatic cancer (PC) remains one of the most lethal malignancies across the world, which is due to delayed diagnosis and resistance to current therapies. The interactions between pancreatic tumor cells and their tumor microenvironment (TME) allow cancer cells to escape from anti-cancer therapies, leading to difficulties in treating PC. With endocrine function and lipid storage capacity, adipose tissue can maintain energy homeostasis. Direct or indirect interaction between adipocytes and PC cells leads to adipocyte dysfunction characterized by morphological change, fat loss, abnormal adipokine secretion, and fibroblast-like transformation. Various adipokines released from dysfunctional adipocytes have been reported to promote proliferation, invasion, metastasis, stemness, and chemoresistance of PC cells via different mechanisms. Additional lipid outflow from adipocytes can be taken into the TME and thus alter the metabolism in PC cells and surrounding stromal cells. Besides, the trans-differentiation potential enables adipocytes to turn into various cell types, which may give rise to an inflammatory response as well as extracellular matrix reorganization to modulate tumor burden. Understanding the molecular basis behind the protumor functions of adipocytes in PC may offer new therapeutic targets.

Cancer cachexia as a blueprint for treating obesity

Effective pharmacological treatments to achieve significant and sustained weight loss in obese individuals remain limited. Here, we apply a 'reverse engineering' approach to cancer cachexia, an extreme form of dysregulated energy balance resulting in net catabolism. We discuss three phenotypic features of the disease, summarize the underlying molecular checkpoints, and explore their translation to obesity research. We then provide examples for established pharmaceuticals, which follow a reverse engineering logic, and propose additional targets that may be of relevance for future studies. Finally, we argue that approaching diseases from this perspective may prove useful as a generic strategy to fuel the development of innovative therapies.

Metabolic and histomorphological changes of adipose tissue in cachexia

PURPOSE OF REVIEW

To describe the role of the main changes occurring in adipose tissue during cachexia and how these affects patient's outcomes, with a specific focus on cancer.

RECENT FINDINGS

In cachexia, the changes within the adipose tissue have been recently described as the presence of inflammatory infiltration (T-lymphocytes and macrophages), enhanced fibrosis, and the occurrence of beige adipocytes (i.e., browning). The latter one is a process driving cachexia enhancing thermogenesis, primarily via modulation of uncoupling protein 1. Also, increased lipolysis of white adipose tissue, especially in cancer, via higher expression of hormone sensible and adipose tissue triglyceride lipases, was detected in experimental models and in human adipose tissue. Other systemic metabolic alterations occur in association with changes in adiposity, including insulin resistance and increased inflammation, all conditions associated with a worse outcome. Moreover, these profound metabolic alterations were shown to be implicated in several consequences, including extreme and progressive unvoluntary body weight loss.

SUMMARY

Alterations in adiposity occur early during cachexia. Adipose tissue atrophy, as well as metabolic changes of white adipose tissues were observed to be pivotal in cachexia, and to be implicated in several clinical complications and poor prognosis.Further research is necessary to clarify the mechanisms underlying the loss of adiposity and therefore to identify novel therapeutic options to counteract this phenomenon in cachexia.