Cordycepin promotes browning of white adipose tissue through an AMP-activated protein kinase (AMPK)-dependent pathway

Cordyceps as potential therapeutic agents for atherosclerosis

Atherosclerosis is a leading cause of mortality and morbidity worldwide. Despite the challenges in managing atherosclerosis, researchers continue to investigate new treatments and complementary therapies. Cordyceps is a traditional Chinese medicine that has recently gained attention as a potential therapeutic agent for atherosclerosis. Numerous studies have demonstrated the effectiveness of cordyceps in treating atherosclerosis through various pharmacological actions, including anti-inflammatory and antioxidant activities, lowering cholesterol, inhibiting platelet aggregation, and modulating apoptosis or autophagy in vascular endothelial cells. Notably, the current misuse of the terms cordyceps and Ophiocordyceps sinensis has caused confusion among researchers, and complicated the current academic research on cordyceps. This review focuses on the chemical composition, pharmacological actions, and underlying mechanisms contributing to the anti-atherosclerotic effects of cordyceps and the mycelium of Ophiocordyceps spp. This review provides a resource for the research on the development of new drugs for atherosclerosis from cordyceps. Please cite this article as: Zhang Y, Liu SJ. Cordyceps as potential therapeutic agents for atherosclerosis. J Integr Med. 2024; 22(2): 102-114.

Natural compounds as obesity pharmacotherapies

Obesity has become a serious global public health problem, affecting over 988 million people worldwide. Nevertheless, current pharmacotherapies have proven inadequate. Natural compounds have garnered significant attention due to their potential antiobesity effects. Over the past three decades, ca. 50 natural compounds have been evaluated for the preventive and/or therapeutic effects on obesity in animals and humans. However, variations in the antiobesity efficacies among these natural compounds have been substantial, owing to differences in experimental designs, including variations in animal models, dosages, treatment durations, and administration methods. The feasibility of employing these natural compounds as pharmacotherapies for obesity remained uncertain. In this review, we systematically summarized the antiobesity efficacy and mechanisms of action of each natural compound in animal models. This comprehensive review furnishes valuable insights for the development of antiobesity medications based on natural compounds.

Dose-dependent action of cordycepin on the microbiome-gut-brain-adipose axis in mice exposed to stress

The high risk for anxiety and depression among individuals with stress has become a growing concern globally. Stress-related mental disorders are often accompanied by symptoms of metabolic dysfunction. Cordycepin is a Chinese herbal medicine commonly used for its metabolism-enhancing effects. We aimed to investigate the dose-dependent effects of cordycepin on psycho-metabolic disorders induced by stress. Our behavioral tests revealed that 12.5 mg/kg cordycepin by oral gavage significantly attenuated the anxiety- and depression-like behaviors induced by stress in mice. At 25 mg/kg, cordycepin restored the reduced weight and cell size of adipose tissues caused by stress. Besides ameliorating the metabolic dysbiosis of gut microbiota due to stress, cordycepin significantly reduced the elevated contents of 5-hydroxyindoleacetic acid in the serum and prefrontal cortex at 12.5 mg/kg and reversed the decrease in adipose induced by stress at 25 mg/kg. Correlation analyses further revealed that 12.5 mg/kg cordycepin reversed stress-induced changes in the intestinal microbiome of NK4A214_group and decreased serum Myristic acid and PC(15:0/18:1(11Z)) and cytokines, such as IFN-γ and IL-1β. 25 mg/kg cordycepin reversed stress-induced changes in the abundances of Prevoteaceae_UCG-001 and Desulfovibrio, increased serum L-alanine level, and decreased serum Inosine-5'-monophosphate level. Cordycepin thereby ameliorated the anxiety- and depression-like behaviors as well as disturbances in the adipose metabolism of mice exposed to stress. Overall, these findings offer evidence indicating that the prominent effects of cordycepin in the brain and adipose tissues are dose dependent, thus highlight the importance of evaluating the precise therapeutic effects of different cordycepin doses on psycho-metabolic diseases.

Ponatinib modulates the metabolic profile of obese mice by inhibiting adipose tissue macrophage inflammation

Obesity-induced metabolic syndrome is a rapidly growing conundrum, reaching epidemic proportions globally. Chronic inflammation in obese adipose tissue plays a key role in metabolic syndrome with a series of local and systemic effects such as inflammatory cell infiltration and inflammatory cytokine secretion. Adipose tissue macrophages (ATM), as one of the main regulators in this process, are particularly crucial for pharmacological studies on obesity-related metabolic syndrome. Ponatinib, a multi-targeted tyrosine kinase inhibitor originally used to treat leukemia, has recently been found to improve dyslipidemia and atherosclerosis, suggesting that it may have profound effect on metabolic syndrome, although the mechanisms underlying have not yet been revealed. Here we discovered that ponatinib significantly improved insulin sensitivity in leptin deficient obese mice. In addition to that, ponatinib treatment remarkably ameliorated high fat diet-induced hyperlipidemia and inhibited ectopic lipid deposition in the liver. Interestingly, although ponatinib did not reduce but increase the weight of white adipose tissue (WAT), it remarkably suppressed the inflammatory response in WAT and preserved its function. Mechanistically, we showed that ponatinib had no direct effect on hepatocyte or adipocyte but attenuated free fatty acid (FFA) induced macrophage transformation from pro-inflammatory to anti-inflammatory phenotype. Moreover, adipocytes co-cultured with FFA-treated macrophages exhibited insulin resistance, while pre-treat these macrophages with ponatinib can ameliorate this process. These results suggested that the beneficial effects of ponatinib on metabolic disorders are achieved by inhibiting the inflammatory phenotypic transformation of ATMs, thereby maintaining the physiological function of adipose tissue under excessive obesity. The data here not only revealed the novel therapeutic function of ponatinib, but also provided a theoretical basis for the application of multi-target tyrosine kinase inhibitors in metabolic diseases.

Turning Hot into Cold: Immune Microenvironment Reshaping for Atherosclerosis Attenuation Based on pH-Responsive shSiglec-1 Delivery System

Current atherosclerosis treatment is based on a combination of cholesterol-lowering medication and low-fat diets; however, the clinical effect is unsatisfactory. It has been shown that the level of immune cell infiltration and pro-inflammatory factors in the atherosclerotic immune microenvironment (AIM) play important roles in the development and progression of atherosclerosis. Therefore, we hypothesized that reshaping "hot AIM" into "cold AIM" could attenuate atherosclerosis. For this purpose, we designed a pH-responsive and charge-reversible nanosystem, referred to as Au-PEI/shSiglec-1/PEI-acetylsalicylic acid (ASPA NPs) to effectively deliver shSiglec-1, which blocked the interactions between macrophages with CD8⁺ T/NKT cells, thus inhibiting immune cell infiltration. Further, we demonstrated that acetylsalicylic acid (ASA), detached from the pH-responsive PEI-ASA polymer, and inhibited lipid accumulation in macrophage, thereby decreasing the lipid antigen presentation. Additionally, reduced macrophage-produced inflammatory factors by ASA and low CD8⁺ T/NKT cell infiltration levels synergistically inhibit Th17 cell differentiation, thus further dramatically attenuating inflammation in AIM by decreasing the IL-17A production. Eventually, ASPA NPs efficiently reshaped AIM by inhibiting immune cell infiltration, lipid antigen presentation, and pro-inflammation, which provided a feasible therapeutic strategy for atherosclerosis immunotherapy.

Dihydromyricetin ameliorates diet-induced obesity and promotes browning of white adipose tissue by upregulating IRF4/PGC-1α

BACKGROUND

Promoting the browning of white adipose tissue (WAT) is a promising approach for the treatment of obesity and related comorbidities because it increases energy expenditure. In this study, we investigated whether Dihydromyricetin (DHM), a flavonoid component, could ameliorate diet-induced obesity through promoting the browning of WAT.

METHODS

Male C57BL/6 J mice were received a high-fat diet (HFD) to induce obesity and subsequently were treated with DHM (100 mg/kg/day) or vehicle for 4 weeks. The effects of DHM on weight reduction and metabolic phenotype improvement were observed in the mice. The expression of genes and protein involved in browning of WAT were assessed in inguinal WAT (iWAT) of the mice. Then, the effect of DHM on the inducing browning program was verified in adipocytes differentiated from stromal vascular fraction (SVF) cells of mouse iWAT. Finally, the mechanism by which DHM improves the browning of WAT was explored using RNA-seq and luciferase reporter assay.

RESULTS

We find that DHM reduces body weight, decreases WAT mass, improves glucose and lipid metabolic disorders, and ameliorates hepatic steatosis in diet-induced obese (DIO) mice. Further studies show that DHM induces WAT browning, which is manifested by increased expression of uncoupling protein 1 (UCP1) and peroxisome proliferator-activated receptor gamma coactivator (PGC)-1α and enhanced mitochondrial activity in iWAT and primary adipocytes. In addition, we also find that DHM enhances interferon regulatory factor 4 (IRF4) expression, which is a key transcriptional regulator of PGC-1α.

CONCLUSION

Our findings identify that DHM prevents obesity by inducing the browning of WAT through the upregulation of IRF4/PGC-1α, which may have potential therapeutic implications for the treatment of obesity.

Equisetin is an anti-obesity candidate through targeting 11β-HSD1

Obesity is increasingly prevalent globally, searching for therapeutic agents acting on adipose tissue is of great importance. Equisetin (EQST), a meroterpenoid isolated from a marine sponge-derived fungus, has been reported to display antibacterial and antiviral activities. Here, we revealed that EQST displayed anti-obesity effects acting on adipose tissue through inhibiting adipogenesis in vitro and attenuating HFD-induced obesity in mice, doing so without affecting food intake, blood pressure or heart rate. We demonstrated that EQST inhibited the enzyme activity of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), a therapeutic target of obesity in adipose tissue. Anti-obesity properties of EQST were all offset by applying excessive 11β-HSD1's substrates and 11β-HSD1 inhibition through knockdown in vitro or 11β-HSD1 knockout in vivo. In the 11β-HSD1 bypass model constructed by adding excess 11β-HSD1 products, EQST's anti-obesity effects disappeared. Furthermore, EQST directly bond to 11β-HSD1 protein and presented remarkable better intensity on 11β-HSD1 inhibition and better efficacy on anti-obesity than known 11β-HSD1 inhibitor. Therefore, EQST can be developed into anti-obesity candidate compound, and this study may provide more clues for developing higher effective 11β-HSD1 inhibitors.

Rutin promotes white adipose tissue "browning" and brown adipose tissue activation partially through the calmodulin-dependent protein kinase kinase β/AMP-activated protein kinase pathway

Promoting white adipose tissue (WAT) "browning" and brown adipose tissue (BAT) activation could contribute to increasing energy expenditure. We explored the mechanisms by which the natural compound rutin induced adipose tissue differentiation and ameliorated obesity in vivo and in vitro. 3T3-L1 preadipocytes were cultured in adipogenic differentiation media with/out rutin. Male C57BL/6 mice (n = 6) were fed a high-fat diet (HFD) for 12 weeks with/out rutin. In HFD-fed mice, rutin treatment significantly inhibited weight gain, improved the metabolic profile of plasma samples, decreased the weights of epididymal WAT (eWAT), inguina WAT (iWAT), and liver, and adipocyte size. Furthermore, rutin also increased the expression of uncoupling protein 1 (Ucp-1) and other thermogenic markers in the WAT and BAT. In 3T3-L1 cells, rutin effectively reduced the formation of lipid droplets, stimulated the expression of thermogenic markers, and reduced the expression of adipogenic genes. Additionally, rutin markedly upregulated the AMP-activated protein kinase (AMPK) pathway, and these effects were diminished by treatment with the AMPK inhibitor compound C (CC). Pretreatment with the calmodulin-dependent protein kinase kinase β (CaMKKβ) inhibitor STO-609 blocked the induction of thermogenic markers in 3T3-L1 cells by rutin. Our results indicated that rutin increased energy consumption, induced WAT "browning" and BAT activation, and thus was a promising target for the development of new therapeutic approaches to improve adipose tissue energy metabolism.

Cordycepin alleviated metabolic inflammation in Western diet-fed mice by targeting intestinal barrier integrity and intestinal flora

Metabolic inflammation is a crucial factor in the pathogenesis of obesity and promotes related complications. Accumulating evidence has indicated that regulating intestinal integrity and the gut microbiota may be new treatment strategies for metabolic inflammation and obesity. Cordycepin has been reported to improve obesity, but the mechanism is not yet clear. Here, we showed that cordycepin considerably alleviated systemic inflammation while reducing body weight gain and metabolic disorders in Western diet (WD)-fed mice. Further investigations showed that cordycepin significantly ameliorated WD-induced damage to the intestinal barrier and decreased the leakage of lipopolysaccharide (LPS) into the blood in mice by suppressing intestinal inflammation, oxidative stress damage, and decreasing intestinal epithelial cell apoptosis and pyroptosis. In addition, by using metagenomic sequencing, we found that cordycepin can also regulate the homeostasis of intestinal flora, including selectively increasing the abundance of Akkermansia muciniphila and reducing the production of fecal LPS. Besides, we demonstrated that the intestinal flora partially mediated the beneficial effects of cordycepin on improving intestinal barrier function, and obesity-related symptoms in WD-fed mice by a fecal microbiota transplantation experiment. Hence, our findings provided new insights into the role of cordycepin in improving metabolic inflammation and obesity from the perspective of regulating the intestinal barrier function and intestinal flora, and further provided data support for the utility of cordycepin in the treatment of obesity and its complications.

MicroRNA-665-3p exacerbates nonalcoholic fatty liver disease in mice

Oxidative stress and chronic inflammation are major culprits of nonalcoholic fatty liver disease (NAFLD). MicroRNA-665-3p (miR-665-3p) is implicated in regulating inflammation and oxidative stress; however, its role and molecular basis in NAFLD remain elusive. Herein, we measured a significant upregulation of miR-665-3p level in the liver and primary hepatocytes upon high fat diet (HFD) or 0.5 mmol/L palmitic acid plus 1.0 mmol/L oleic acid stimulation, and the elevated miR-665-3p expression aggravated oxidative stress, inflammation and NAFLD progression in mice. In contrast, miR-665-3p inhibition by the miR-665-3p antagomir significantly prevented HFD-induced oxidative stress, inflammation and hepatic dysfunction in vivo. Manipulation of miR-665-3p in primary hepatocytes also caused similar phenotypic alterations in vitro. Mechanistically, we demonstrated that miR-665-3p directly bound to the 3'-untranslated region of fibronectin type III domain-containing 5 (FNDC5) to downregulate its expression and inactivated the downstream AMP-activated protein kinase alpha (AMPKα) pathway, thereby facilitating oxidative stress, inflammation and NAFLD progression. Our findings identify miR-665-3p as an endogenous positive regulator of NAFLD via inactivating FNDC5/AMPKα pathway, and inhibiting miR-665-3p may provide novel therapeutic strategies to treat NAFLD.

MicroRNA-137-3p Improves Nonalcoholic Fatty Liver Disease through Activating AMPKα

Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases worldwide and can develop to nonalcoholic steatohepatitis and later hepatic cirrhosis with a high prevalence to hepatocellular carcinoma. Oxidative stress and chronic hepatic inflammation are implicated in the pathogenesis of NAFLD. MicroRNA-137-3p (miR-137-3p) are associated with oxidative stress and inflammation; however, its role and mechanism in NAFLD remain unclear. Mice were fed with a high-fat diet (HFD) for 24 weeks to establish the NAFLD model. To overexpress or suppress hepatic miR-137-3p expression, mice were intraperitoneally injected with the agomir, antagomir, or respective controls of miR-137-3p at a dose of 100 mg/kg weekly for 6 consecutive weeks before the mice were sacrificed. To validate the involvement of AMP-activated protein kinase alpha (AMPKα) or cAMP-specific phosphodiesterase 4D (PDE4D), HFD mice were intraperitoneally injected with 20 mg/kg compound C or 0.5 mg/kg rolipram every other day for 8 consecutive weeks before the mice were sacrificed. Hepatic miR-137-3p expression was significantly decreased in mice upon HFD stimulation. miR-137-3p agomir alleviated, while miR-137-3p antagomir facilitated HFD-induced oxidative stress, inflammation, and hepatic dysfunction in mice. Mechanistically, we revealed that miR-137-3p is directly bound to the 3'-untranslated region of PDE4D and subsequently increased hepatic cAMP level and protein kinase A activity, thereby activating the downstream AMPKα pathway. In summary, miR-137-3p improves NAFLD through activating AMPKα and it is a promising therapeutic candidate to treat NAFLD.

Cordycepin Decreases Ischemia/Reperfusion Injury in Diabetic Hearts via Upregulating AMPK/Mfn2-dependent Mitochondrial Fusion

Diabetes mellitus is considered to be a major risk factor for cardiovascular disease, the most common cause of death in diabetes. However, therapeutic strategies for myocardial protection in patients with diabetes are still limited. Cordycepin is a traditional Tibetan medicine with a long history of widespread use, and exerts a wide range of anti-tumor, anti-inflammatory, and anti-oxidative effects. In recent years, although the therapeutic potential of cordycepin has attracted the attention of researchers, it remains unknown whether cordycepin plays a protective role in myocardial ischemia/reperfusion (MI/R) injury in diabetic patients. Here, using a diabetic mouse model, we found that cordycepin protected diabetic hearts from MI/R injury by promoting mitochondrial fusion and Mfn2 expression. Our in vitro results showed that cordycepin enhanced Mfn2-medicated mitochondrial fusion, improved mitochondrial function, and reduced cardiomyocyte apoptosis in high-glucose/high-fat cultured simulated ischemia/reperfusion cardiomyocytes. Furthermore, we found that knockout of Mfn2 significantly blocked the cardioprotective effects of cordycepin in diabetic mice. Finally, an AMPK-dependent pathway was found to upregulate Mfn2 expression upon cordycepin treatment, indicating that cordycepin protected diabetic hearts via AMPK/Mfn2-dependent mitochondrial fusion. Collectively, our study firstly demonstrated that cordycepin could be a potential cardioprotective agent for MI/R injury, and we established a novel mechanism by which upregulated AMPK/Mfn2-dependent mitochondrial fusion contributes to the cardioprotective role of cordycepin.

miR‑351‑5p aggravates lipopolysaccharide‑induced acute lung injury via inhibiting AMPK

Inflammation and oxidative stress have indispensable roles in the development of acute lung injury (ALI). MicroRNA (miRNA/miR)‑351‑5p was initially identified as a myogenesis‑associated miRNA; however, its role in lipopolysaccharide (LPS)‑induced ALI remains unclear. The aim of the present study was to investigate the role and potential mechanisms of miR‑351‑5p in ALI. ALI was induced through a single intratracheal injection of LPS for 12 h, and miR‑351‑5p agomir, antagomir or their corresponding negative controls were injected into the tail vein before LPS stimulation. Compound C, 2',5'‑dideoxyadenosine and H89 were used to inhibit AMP‑activated protein kinase (AMPK), adenylate cyclase and protein kinase A (PKA), respectively. miR‑351‑5p levels in the lungs were significantly increased in response to LPS injection. miR‑351‑5p antagomir alleviated, while miR‑351‑5p agomir aggravated LPS‑induced oxidative stress and inflammation in the lungs. The present results also demonstrated that miR‑351‑5p antagomir attenuated LPS‑induced ALI via activating AMPK, and that the cAMP/PKA axis was required for the activation of AMPK by the miR‑351‑5p antagomir. In conclusion, the present study indicated that miR‑351‑5p aggravated LPS‑induced ALI via inhibiting AMPK, suggesting that targeting miR‑351‑5p may help to develop efficient therapeutic approaches for treating ALI.

A Systematic Review of the Biological Effects of Cordycepin

We conducted a systematic review of the literature on the effects of cordycepin on cell survival and proliferation, inflammation, signal transduction and animal models. A total of 1204 publications on cordycepin were found by the cut-off date of 1 February 2021. After application of the exclusion criteria, 791 papers remained. These were read and data on the chosen subjects were extracted. We found 192 papers on the effects of cordycepin on cell survival and proliferation and calculated a median inhibitory concentration (IC50) of 135 µM. Cordycepin consistently repressed cell migration (26 papers) and cellular inflammation (53 papers). Evaluation of 76 papers on signal transduction indicated consistently reduced PI3K/mTOR/AKT and ERK signalling and activation of AMPK. In contrast, the effects of cordycepin on the p38 and Jun kinases were variable, as were the effects on cell cycle arrest (53 papers), suggesting these are cell-specific responses. The examination of 150 animal studies indicated that purified cordycepin has many potential therapeutic effects, including the reduction of tumour growth (37 papers), repression of pain and inflammation (9 papers), protecting brain function (11 papers), improvement of respiratory and cardiac conditions (8 and 19 papers) and amelioration of metabolic disorders (8 papers). Nearly all these data are consistent with cordycepin mediating its therapeutic effects through activating AMPK, inhibiting PI3K/mTOR/AKT and repressing the inflammatory response. We conclude that cordycepin has excellent potential as a lead for drug development, especially for age-related diseases. In addition, we discuss the remaining issues around the mechanism of action, toxicity and biodistribution of cordycepin.

N-butylidenephthalide ameliorates high-fat diet-induced obesity in mice and promotes browning through adrenergic response/AMPK activation in mouse beige adipocytes

Thermogenesis (non-exercise activity) in brown adipose tissue (BAT) promotes energy expenditure because of its higher number of mitochondria than white adipose tissue (WAT). The main function of thermogenesis in BAT can counteract obesity through the dissipation of calories as heat. N-butylidenephthalide (BP) is a natural derivative from Angelica sinensis, a Chinese herb that has been used for thousands of years. In this report, we demonstrated that BP improved the metabolic profiles of mice with high fat diet-induced obesity (DIO) by preventing weight gain, improving serum blood parameters, enhancing energy expenditure, stimulating white fat browning, and reversing hepatic steatosis. Further investigations demonstrated that BP administration upregulated the mRNA expression of beige (CD137, TMEM26) and brown fat selected genes (UCP1, PRDM16, PGC-1α, PPARγ) in white adipose tissues. In vitro studies, BP treatment increased multilocular lipid droplet levels, induced β-adrenergic receptor (cAMP/PKA) and AMP-activated protein kinase (AMPK) signaling (AMPK/acetyl-CoA carboxylase/SIRT1), and increased oxygen consumption in murine differentiated beige adipocytes, and the effects of BP were blocked by an AMPK inhibitor. BP promoted the interaction of AMPK with PGC-1α in beige adipocytes. Our findings provide novel insights into the application of BP in regulating energy metabolism and suggest its utility for clinical use in the treatment of obesity and related diseases.

Non-shivering Thermogenesis Signalling Regulation and Potential Therapeutic Applications of Brown Adipose Tissue

In mammals, thermogenic organs exist in the body that increase heat production and enhance energy regulation. Because brown adipose tissue (BAT) consumes energy and generates heat, increasing energy expenditure via BAT might be a potential strategy for new treatments for obesity and obesity-related diseases. Thermogenic differentiation affects normal adipose tissue generation, emphasizing the critical role that common transcriptional regulation factors might play in common characteristics and sources. An understanding of thermogenic differentiation and related factors could help in developing ways to improve obesity indirectly or directly through targeting of specific signalling pathways. Many studies have shown that the active components of various natural products promote thermogenesis through various signalling pathways. This article reviews recent major advances in this field, including those in the cyclic adenosine monophosphate-protein kinase A (cAMP-PKA), cyclic guanosine monophosphate-GMP-dependent protein kinase G (cGMP-AKT), AMP-activated protein kinase (AMPK), mammalian target of rapamycin (mTOR), transforming growth factor-β/bone morphogenic protein (TGF-β/BMP), transient receptor potential (TRP), Wnt, nuclear factor-κ-light-chain-enhancer of activated B cells (NF-κΒ), Notch and Hedgehog (Hh) signalling pathways in brown and brown-like adipose tissue. To provide effective information for future research on weight-loss nutraceuticals or drugs, this review also highlights the natural products and their active ingredients that have been reported in recent years to affect thermogenesis and thus contribute to weight loss via the above signalling pathways.

MicroRNA-30d-5p ameliorates lipopolysaccharide-induced acute lung injury via activating AMPKα

OBJECTIVES

Acute lung injury (ALI) is a devastating lung disease characterized by uncontrolled pulmonary inflammation and oxidative stress. Currently, no effective therapeutic strategies are available for ALI and its prognosis remains poor. The present study aims to investigate the role and potential mechanism of microRNA-30d-5p (miR-30d-5p) in the progression of ALI.

METHODS

Mice were intravenously treated with miR-30d-5p agomir, antagomir or their respective controls for 3 consecutive days and then were exposed to a single intratracheal injection of lipopolysaccharide (LPS) for 12 h at a dosage of 5 mg/kg to induce ALI. To inhibit adenosine monophosphate-activated protein kinase α (AMPKα) or phosphodiesterase 4 D (PDE4D), compound C (CpC) and rolipram were used.

RESULTS

miR-30d-5p expression in the lungs was significantly inhibited by LPS treatment. miR-30d-5p agomir significantly alleviated, while miR-30d-5p antagomir aggravated pulmonary inflammation, oxidative damage, and dysfunction in ALI mice. Besides, we found that miR-30d-5p agomir ameliorated LPS-induced ALI via activating AMPKα and that the inhibition of AMPKα by CpC completely abolished these beneficial effects of miR-30d-5p agomir. Further findings validated that PDE4D downregulation was required for the activation of AMPKα by miR-30d-5p agomir.

CONCLUSION

miR-30d-5p ameliorates LPS-induced ALI via activating AMPKα and it is a valuable therapeutic candidate in the treatment of ALI.

Biochemical and immunological changes in obesity

Obesity is a syndemia that promotes high expenditures for public health, and is defined by the excess of adipose tissue that is classified according to its function and anatomical distribution. In obese people, this tissue generates oxidative stress associated with a chronic inflammatory response, in which there is an imbalance in relation to the release of hormones and adipokines that cause loss of body homeostasis and predisposition to the development of some comorbidities. The purpose of this review is to summarize the main events that occur during the onset and progression of obesity with a special focus on biochemical and immunological changes. Hypertrophied and hyperplasia adipocytes have biomarkers and release adipokines capable of regulating pathways and expressing genes that culminate in the development of metabolic changes, such as changes in energy balance and intestinal microbiota, and the development of some comorbidities, diabetes mellitus, dyslipidemias, arterial hypertension, liver disease, cancer, allergies, osteoporosis, sarcopenia and obstructive sleep apnea. Thus, it is necessary to treat and/or prevent pathology, using traditional methods based on healthy eating, and regular physical and leisure activities.

Transcriptional Factors of Thermogenic Adipocyte Development and Generation of Brown and Beige Adipocytes From Stem Cells

Brown and beige adipocytes have been widely known for their potential to dissipate excessive energy into heat form, resulting in an alleviation of obesity and other overweight-related conditions. This review highlights the origins, characteristics, and functions of the various kinds of adipocytes, as well as their anatomic distribution inside the human body. This review mainly focuses on various essential transcriptional factors such as PRDM16, FGF21, PPARα, PPARγ and PGC-1α, which exert their effects on the development and activation of thermogenic adipocytes via important pathways such as JAK-STAT, cAMP-PKA and PI3K-AKT signaling pathways. Additionally, this review will underline promising strategies to generate an unexhausted source of thermogenic adipocytes differentiated from human stem cells. These exogenous thermogenic adipocytes offer therapeutic potential for improvement of metabolic disorders via application as single cell or whole tissue transplantation. Graphical abstract Caption is required. Please provide.

Growth differentiation factor 11 mitigates cardiac radiotoxicity via activating AMPKα

Cardiac radiotoxicity largely impedes the therapeutic benefits of radiotherapy to malignancies. Growth differentiation factor 11 (GDF11) is implicated in the pathogenesis of cardiac diseases under different pathological conditions. This study aims to investigate the role and underlying mechanisms of GDF11 on cardiac radiotoxicity. Mice were injected with cardiotropic adeno-associated virus 9 carrying the full-length mouse GDF11 gene or negative control under a cTnT promoter from the tail vein, and then received a single dose of 20 Gray (Gy) whole-heart irradiation (WHI) for 16 weeks to imitate cardiac radiotoxicity. Compound C (CC, 20 mg/kg) was intraperitoneally injected every two days at 1 week before WHI stimulation to inhibit 5' AMP-activated protein kinase α (AMPKα). Cardiac GDF11 expression was significantly suppressed at both the protein and mRNA levels. GDF11 overexpression decreased oxidative stress, apoptosis, and fibrosis in radiated hearts, thereby mitigating cardiac radiotoxicity, and dysfunction. Further detection revealed that GDF11 activated AMPKα to reduce radiation-induced oxidative damage and that AMPKα inhibition by CC offset the cardioprotective effects by GDF11. GDF11 mitigates cardiac radiotoxicity via activating AMPKα and it is a promising candidate to treat cardiac radiotoxicity.

Ginsenoside Rb1 Facilitates Browning by Repressing Wnt/β-Catenin Signaling in 3T3-L1 Adipocytes

BACKGROUND The discovery of browning in white adipose tissue has provided new ideas for treating obesity. Many studies have reported that ginsenoside Rb1 (G-Rb1) has activity against diabetes, inflammation, and obesity, but further investigation is needed on the effect and mechanism of G-Rb1 on browning. MATERIAL AND METHODS We treated 3T3-L1 adipocytes with 0-200 μM G-Rb1, and 0.5 μM Compound 3f and 30 μM SKL2001 were used to activate Wnt/b-catenin signaling. Adipocyte activity was evaluated by Cell Counting Kit-8. Oil Red O staining was used to detect the lipid droplets. Quantitative real-time polymerase chain reaction was used to measure the expression of Cd-137, Cited-1, Txb-1, Prdm-16, and Ucp-1 mRNA. Western blotting was used to measure the expression of Ucp-1, pGSK-3ß (Ser 9), GSK- 3ß, and ß-catenin proteins. The expression of Ucp-1 was also detected with immunofluorescence. RESULTS Adipocyte activity was not affected by 0-100 μM G-Rb1. However, G-Rb1 dose-dependently reduced the accumulation of lipid droplets; increased the expression of Cd-137, Cited-1, Txb-1, Prdm-16, and Ucp-1 mRNA; and increased the expression of Ucp-1, pGSK-3ß (Ser 9), GSK-3ß, and ß-catenin proteins. The accumulation of lipid droplets and the expression of Ucp-1 protein decreased as b-catenin increased. CONCLUSIONS G-Rb1 at various concentrations (0-100 μM) promoted the browning of adipocytes in a dose-dependent manner. Further, we confirmed that activation of Wnt/ß-catenin signaling could inhibit browning. Therefore, the browning promoted by G-Rb1 may be associated with the inhibition of Wnt/ß-catenin signaling.

QSHY Granules Promote White Adipose Tissue Browning and Correct BCAAs Metabolic Disorder in NAFLD Mice

PURPOSE

White adipose tissue (WAT) has positive effects on peripheral metabolism parameters and liver energy metabolism. This study aimed to explain the pharmacological mechanism of Qushi Huayu (QSHY) granules in the treatment of nonalcoholic fatty liver disease (NALFD) mice based on branched-chain amino acid (BCAA) catabolism and WAT browning.

PATIENTS AND METHODS

Thirty C57BL/6J mice were randomly divided into a (Ctrl) control group, fed with a control diet, a NAFLD model group, fed with a high-fat and high-sugar (HFHS) diet, and a QSHY granules treatment (HFHS+QSHY) group, administered with QSHY granules. After 14 weeks of feeding, HFHS+QSHY group mice were administered QSHY granules through oral gavage for 6 weeks. The metabolic parameters were assessed, the circular and fecal BCAA content was observed, and liver and epididymal WAT (eWAT) were collected for pathological, quantitative real-time polymerase chain reaction, and Western blotting analyses.

RESULTS

Compared with the HFHS group, mice in the HFHS+QSHY group demonstrated restored liver histological changes, ameliorated hepatocyte steatosis, and alleviated inflammatory cell infiltration. Consistent with the pathological changes, QSHY granules significantly reduced the elevated levels of liver triglycerides, and serum alanine aminotransferase, and it relieved hypercholesterolemia and insulin resistance in mice with HFHS-induced NAFLD. Furthermore, it corrected BCAA metabolic disorders in serum and feces and promoted the expression of BCAA catabolic genes in the eWAT of HFHS mice. QSHY granules also increased the expression of phosphorylated AMP-activated protein kinase (AMPK) protein, up-regulating the protein expression of the AMPK/SIRT1/UCP-1 pathway in the eWAT.

CONCLUSION

QSHY granules improved hepatic steatosis and corrected the BCAA disorder in NAFLD mice, and the related mechanisms regulated the AMPK/SIRT1/UCP-1 pathway and promoted WAT browning.

Caffeic and Chlorogenic Acids Synergistically Activate Browning Program in Human Adipocytes: Implications of AMPK- and PPAR-Mediated Pathways

Caffeic acid (CA) and chlorogenic acid (CGA) are phenolic compounds claimed to be responsible for the metabolic effects of coffee and tea consumption. Along with their structural similarities, they share common mechanisms such as activation of the AMP-activated protein kinase (AMPK) signaling. The present study aimed to investigate the anti-obesity potential of CA and CGA as co-treatment in human adipocytes. The molecular interactions of CA and CGA with key adipogenic transcription factors were simulated through an in silico molecular docking approach. The expression levels of white and brown adipocyte markers, as well as genes related to lipid metabolism, were analyzed by real-time quantitative PCR and Western blot analyses. Mechanistically, the CA/CGA combination induced lipolysis, upregulated AMPK and browning gene expression and downregulated peroxisome proliferator-activated receptor γ (PPARγ) at both transcriptional and protein levels. The gene expression profiles of the CA/CGA-co-treated adipocytes strongly resembled brown-like signatures. Major pathways identified included the AMPK- and PPAR-related signaling pathways. Collectively, these findings indicated that CA/CGA co-stimulation exerted a browning-inducing potential superior to that of either compound used alone which merits implementation in obesity management. Further, the obtained data provide additional insights on how CA and CGA modify adipocyte function, differentiation and lipid metabolism.

Recent developments in natural products for white adipose tissue browning

Excess accumulation of white adipose tissue (WAT) causes obesity which is an imbalance between energy intake and energy expenditure. Obesity is a serious concern because it has been the leading causes of death worldwide, including diabetes, stroke, heart disease and cancer. Therefore, uncovering the mechanism of obesity and discovering anti-obesity drugs are crucial to prevent obesity and its complications. Browning, inducing white adipose tissue to brown or beige (brite) fat which is brown-like fat emerging in WAT, becomes an appealing therapeutic strategy for obesity and metabolic disorders. Due to lack of efficacy or intolerable side-effects, the clinical trials that promote brown adipose tissue (BAT) thermogenesis and browning of WAT have not been successful in humans. Obviously, more specific means still need to be developed to activate browning of white adipose tissue. In this review, we summarized seven kinds of natural products (alkaloids, flavonoids, terpenoids, long chain fatty acids, phenolic acids, else and extract) promoting white adipose tissue browning which can ameliorate the metabolic disorders, including obesity, dislipidemia, insulin resistance and diabetes. Since natural products are important drug sources and the browning property plays a significant role in not only obesity treatment but also in type 2 diabetes (T2DM) improvement, natural products of inducing browning may be an irreplaceable drug discovery orientation for obesity, diabetes and even other metabolic disorders.

MicroRNA-217 modulates inflammation, oxidative stress, and lung injury in septic mice via SIRT1

Inflammation and oxidative stress contribute to the initiation and progression of septic lung injury. MicroRNA-217 (miR-217) is proved to be involved in controlling inflammatory response and oxidative stress, yet its role and underlying mechanism in the pathogenesis of septic lung injury remain elusive. Caecal ligation and puncture surgery were performed to generate sepsis in vivo and mice were kept for 12 h to imitate septic lung injury. Next, mice were administrated with miR-217 antagomir or agomir to decrease or increase the expression of miR-217 in lung tissue. Moreover, primary peritoneal macrophages were separated and incubated with lipopolysaccharide (LPS) to further verify the role of miR-217 in vitro. miR-217 was upregulated in septic lungs and primary macrophages. miR-217 antagomir alleviated, whereas miR-217 agomir aggravated inflammation and oxidative stress in septic mice and LPS-stimulated macrophages. Further detection identified SIRT1 was responsible for miR-217 antagomir-mediated anti-inflammatory and anti-oxidant effects, and SIRT1 inhibition abolished the beneficial effects of miR-217 antagomir in vivo and in vitro. Our data defined miR-217 as a therapeutic target for treating septic lung injury.

Clinical Application Potential of Small Molecules that Induce Brown Adipose Tissue Thermogenesis by Improving Fat Metabolism

Mammalian fat comprises white and brown adipose tissue (WAT and BAT, respectively). WAT stores energy, whereas BAT is used for thermogenesis. In recent years, the incidence of obesity and its associated disorders have increased tremendously. Considering the thermogenic capacity and decreased levels of BAT with increasing age, BAT can be used as a suitable therapeutic target for the treatment of obesity and diabetes. In several studies, using positron emission tomography and computed tomography images, adult humans have been shown to have functional BAT in interscapular fat. Results of these basic research studies on BAT have shed light on the new components of transcriptional regulation and the role of hormones in stimulating BAT growth and differentiation. In this review article, we have summarized the thermogenic regulators identified in the past decades by focusing on peroxisome proliferator-activated receptor gamma/uncoupling protein 1 activators, branched-chain amino acids, fatty acids (lipokine), and adenosine monophosphate-activated protein kinase mediators. We have also presented the progress of a few ongoing clinical trials aimed at the treatment of obesity and its associated metabolic disorders. The main purpose of this review was to provide a comprehensive introduction to the latest knowledge of the representative thermogenic regulators for the treatment of obesity. The fat combustion capacity of BAT may have great potential and can be considered as a suitable target for the therapeutic application of drugs from bench-to-bed treatment of obesity and the associated diseases.

Induction of Adipose Tissue Browning as a Strategy to Combat Obesity

The ongoing obesity pandemic generates a constant need to develop new therapeutic strategies to restore the energy balance. Therefore, the concept of activating brown adipose tissue (BAT) in order to increase energy expenditure has been revived. In mammals, two developmentally distinct types of brown adipocytes exist; the classical or constitutive BAT that arises during embryogenesis, and the beige adipose tissue that is recruited postnatally within white adipose tissue (WAT) in the process called browning. Research of recent years has significantly increased our understanding of the mechanisms involved in BAT activation and WAT browning. They also allowed for the identification of critical molecules and critical steps of both processes and, therefore, many new therapeutic targets. Several non-pharmacological approaches, as well as chemical compounds aiming at the induction of WAT browning and BAT activation, have been tested in vitro as well as in animal models of genetically determined and/or diet-induced obesity. The therapeutic potential of some of these strategies has also been tested in humans. In this review, we summarize present concepts regarding potential therapeutic targets in the process of BAT activation and WAT browning and available strategies aiming at them.

Biochanin A induces a brown-fat phenotype via improvement of mitochondrial biogenesis and activation of AMPK signaling in murine C3H10T1/2 mesenchymal stem cells

In this study, we investigated the effect of Biochanin A (BioA), an O-methylated isoflavone on the brown-fat phenotype formation and on the associated thermogenic program including mitochondrial biogenesis and lipolysis in C3H10T1/2 MSCs. Our data demonstrates that Treatment with BioA in an adipogenic differentiation cocktail induced formation of brown-fat-like adipocytes from C3H10T1/2 MSCs without treatment with a known browning inducer (rosiglitazone or T3) at an early stage of differentiation. The formation of brown-fat-like adipocytes by BioA treatment was evidenced by upregulation of key thermogenic markers: Ucp1, Pgc1α, Prdm16, and Pparγ. BioA also increased the expression of beige (Cd137 and Fgf21) and brown (Elovl3 and Zic1)-specific markers. Additionally, BioA treatment promoted mitochondrial biogenesis, judging by the upregulation of genes; Cox8b, Cidea, Dio2, Sirt1, Opa1, and Fis1. BioA treatment increased the amount of mitochondrial DNA and its encoded proteins: oxidative phosphorylation complexes (I-V); this change was associated with high oxygen consumption by C3H10T1/2 MSCs. A small-interfering-RNA-induced gene knockdown and experiments with dorsomorphin-driven competitive inhibition revealed that BioA exerts the thermogenic action via activation of AMPK signaling. Our study shows the mechanism of BioA-induced promotion of a brown-fat phenotype. Nonetheless, clinical research is necessary to validate BioA as a brown-fat-like signature inducer.

Carotenoids and carotenoid conversion products in adipose tissue biology and obesity: Pre-clinical and human studies

Antiobesity activities of carotenoids and carotenoid conversion products (CCPs) have been demonstrated in pre-clinical studies, and mechanisms behind have begun to be unveiled, thus suggesting these compounds may help obesity prevention and management. The antiobesity action of carotenoids and CCPs can be traced to effects in multiple tissues, notably the adipose tissues. Key aspects of the biology of adipose tissues appear to be affected by carotenoid and CCPs, including adipogenesis, metabolic capacities for energy storage, release and inefficient oxidation, secretory function, and modulation of oxidative stress and inflammatory pathways. Here, we review the connections of carotenoids and CCPs with adipose tissue biology and obesity as revealed by cell and animal intervention studies, studies addressing the role of endogenous retinoid metabolism, and human epidemiological and intervention studies. We also consider human genetic variability influencing carotenoid and vitamin A metabolism, particularly in adipose tissues, as a potentially relevant aspect towards personalization of dietary recommendations to prevent or manage obesity and optimize metabolic health. This article is part of a Special Issue entitled Carotenoids recent advances in cell and molecular biology edited by Johannes von Lintig and Loredana Quadro.

Probing Carbon Utilization of Cordyceps militaris by Sugar Transportome and Protein Structural Analysis

Beyond comparative genomics, we identified 85 sugar transporter genes in Cordyceps militaris, clustering into nine subfamilies as sequence- and phylogenetic-based functional classification, presuming the versatile capability of the fungal growths on a range of sugars. Further analysis of the global gene expression patterns of C. militaris showed 123 genes were significantly expressed across the sucrose, glucose, and xylose cultures. The sugar transporters specific for pentose were then identified by gene-set enrichment analysis. Of them, the putative pentose transporter, CCM_06358 gene, was highest expressed in the xylose culture, and its functional role in xylose transport was discovered by the analysis of conserved structural motifs. In addition, a battery of molecular modeling methods, including homology modeling, transport pathway analysis, residue interaction network combined with molecular mechanics Poisson–Boltzmann surface area simulation (MM-PBSA), was implemented for probing the structure and function of the selected pentose transporter (CCM_06358) as a representative of sugar transportome in C. militaris. Considering the network bottlenecks and structural organizations, we further identified key amino acids (Phe38 and Trp441) and their interactions with other residues, contributing the xylose transport function, as verified by binding free energy calculation. The strategy used herein generated remarkably valuable biological information, which is applicable for the study of sugar transportome and the structure engineering of targeted transporter proteins that might link to the production of bioactive compounds derived from xylose metabolism, such as cordycepin.

Protein Arginine Methyltransferase 4 Regulates Adipose Tissue Lipolysis in Type 1 Diabetic Mice

PURPOSE

Hypertriglyceridemia is considered to be driven by increased lipolysis in type 1 diabetes mellitus (T1DM). However, information regarding the transcriptional circuitry that governs lipolysis remains incomplete in T1DM. Protein arginine methyltransferase 4 (PRMT4), a transcriptional coactivation factor, promotes autophagy and may play an important role in lipolysis. We wonder whether activated lipolysis in T1DM is regulated by PRMT4.

MATERIALS AND METHODS

Recombinant adeno-associated virus was adopted to overexpress PRMT4 in adipose tissue of mice. Streptozotocin (150 mg/kg) was injected intraperitoneally into mice to induce T1DM. Plasma insulin, triglycerides, free fatty acids (FFAs) levels were determined using commercial assay kits. Differentiated adipocytes were applied to verify the regulation of PRMT4 on lipolysis.

RESULTS

Elevated serum triglycerides and FFAs were observed in PRMT4-overexpressed T1DM mice. We also observed that PRMT4 over-expression induced the decrease of fat pads weights and adipocyte sizes. Moreover, expression levels of lipolysis-related molecules, including ATGL, HSL, and MAGL, and HSL phosphorylation levels were increased in PRMT4-overexpressed mice when compared to those of control mice. In vitro, PRMT4 promoted FFAs release and activated HSL phosphorylation, whereas PRMT4 knockdown inhibited these processes.

CONCLUSION

PRMT4 promotes lipolysis and increases serum triglyceride in T1DM.

Optimizing cultivation of Cordyceps militaris for fast growth and cordycepin overproduction using rational design of synthetic media

Cordyceps militaris is an entomopathogenic fungus which is often used in Asia as a traditional medicine developed from age-old wisdom. Presently, cordycepin from C. militaris is a great interest in medicinal applications. However, cellular growth of C. militaris and the association with cordycepin production remain poorly understood. To explore the metabolism of C. militaris as potential cell factories in medical and biotechnology applications, this study developed a high-quality genome-scale metabolic model of C. militaris, iNR1329, based on its genomic content and physiological data. The model included a total of 1329 genes, 1821 biochemical reactions, and 1171 metabolites among 4 different cellular compartments. Its in silico growth simulation results agreed well with experimental data on different carbon sources. iNR1329 was further used for optimizing the growth and cordycepin overproduction using a novel approach, POPCORN, for rational design of synthetic media. In addition to the high-quality GEM iNR1329, the presented POPCORN approach was successfully used to rationally design an optimal synthetic medium with C:N ratio of 8:1 for enhancing 3.5-fold increase in cordycepin production. This study thus provides a novel insight into C. militaris physiology and highlights a potential GEM-driven method for synthetic media design and metabolic engineering application. The iNR1329 and the POPCORN approach are available at the GitHub repository: https://github.com/sysbiomics/Cordyceps_militaris-GEM.

Asperlin Stimulates Energy Expenditure and Modulates Gut Microbiota in HFD-Fed Mice

Asperlin is a marine-derived, natural product with antifungal, anti-inflammatory and anti-atherosclerotic activities. In the present study, we showed that asperlin effectively prevented the development of obesity in high-fat diet (HFD)-fed mice. Oral administration of asperlin for 12 weeks significantly suppressed HFD-induced body weight gain and fat deposition without inhibiting food intake. Hyperlipidemia and liver steatosis were also substantially ameliorated. A respiratory metabolism monitor showed that asperlin efficiently increased energy expenditure and enhanced thermogenic gene expression in adipose tissue. Accordingly, asperlin-treated mice showed higher body temperature and were more tolerant of cold stress. Meanwhile, asperlin also increased the diversity and shifted the structure of gut microbiota. Oral administration of asperlin markedly increased the relative abundance of Bacteroidetes, leading to a higher Bacteroidetes-to-Fimicutes ratio. The HFD-induced abnormalities at both phylum and genus levels were all remarkably recovered by asperlin. These results demonstrated that asperlin is effective in preventing HFD-induced obesity and modulating gut microbiota. Its anti-obesity properties may be attributed to its effect on promoting energy expenditure.