Fructose: a key factor in the development of metabolic syndrome and hypertension

Kidney consequences of obesity

Herein, we review the devastating consequences of the worldwide obesity epidemic on kidney health and outcomes. We submit that the obesity epidemic is the most pressing public health crisis facing the nephrology community today. A historical approach has been undertaken, wherein major breakthroughs in the recognition and understanding of obesity-related kidney disease (ORKD) are highlighted. We begin with a description of the worldwide obesity epidemic followed by an account of the discovery and characterization of ORKD. A detailed summary of the pathophysiology of ORKD disease is presented, wherein we set forth the following two propositions: first, ORKD is due to a maladaptive response to caloric surplus; and second, this maladaptive response causes kidney damage via hemodynamic (hyperfiltration), hormonal (adipokine dysregulation), and lipotoxic pathways. Each of these pathways is described, with particular emphasis on the relatively recent discovery that the final stage of cellular injury in ORKD is mitochondrial oxidative damage. The prevention and treatment of ORKD are then discussed, including environmental, behavioral, pharmacologic, and surgical options. Finally, we conclude with suggestions for future research to improve early recognition and treatment of ORKD.

Fructose-Induced Impairment of Liver and Skeletal Muscle Metabolism Is Prevented by Administration of Shouchella clausii Spores by Preserving Mitochondrial Function and Insulin Sensitivity

The objective of the study was to evaluate the efficacy of S. clausii spores (SF174) in counteracting the deleterious effects of dietary fructose. Thirty-days old male Wistar rats were treated for 6 weeks: control group: 0.5 mL of 10% sucrose solution (without probiotics); fructose group: 0.5 mL of 10% sucrose solution + high-fructose diet (without probiotics); SF174 group: 0.5 mL of 10% sucrose solution containing SF174 (5 × 10⁹ CFU) + high-fructose diet. Fructose intake induced an increase in proinflammatory cytokines in portal plasma, liver, and skeletal muscle, a decrease in insulin sensitivity in both tissues and a condition of hepatic steatosis. An increase in the mitochondrial activity in the liver and a decrease in skeletal muscle were evidenced, together with an increase in the thiobarbituric acid reactive substances (TBARS) levels and a decrease in the antioxidant enzyme activity. All the above alterations were counteracted by probiotic administration. We here demonstrate for the first time that S. clausii SF174 counteracts low-grade inflammation and insulin resistance induced by fructose, protects mitochondria from changes in oxidative capacity, and maintains unaltered the oxidative balance. Therefore, S. clausii SF174 administration can be an effective strategy to prevent the unhealthy consequences of dietary fructose.

Acute heat stress upregulates Akr1b3 through Nrf-2 to increase endogenous fructose leading to kidney injury

In recent years, the prevalence of extremely high-temperature climates has led to an increase in cases of acute heat stress (HS), which has been identified as a contributing factor to various kidney diseases. Fructose, the end product of the polyol pathway, has been linked to kidney conditions such as kidney stones, chronic kidney disease, and acute kidney injury. However, the relationship between acute HS and kidney injury caused by endogenous fructose remains unclear. The study found that acute HS triggers the production of reactive oxygen species, which in turn activate the Nrf-2 and Akr1b3 leading to an increase in endogenous fructose levels in kidney cells. It was further demonstrated that the elevated levels of endogenous fructose play a crucial role in causing damage to kidney cells. Moreover, inhibiting Nrf-2 effectively mitigated kidney damage induced by acute HS by reducing endogenous fructose levels. These findings underscore the detrimental impact of excessive fructose resulting from acute stress on kidney function, offering a novel perspective for future research on the prevention and treatment of acute HS-induced kidney injury.

The potential role of uric acid in women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder among women of reproductive age and is associated with a variety of multi-system complications. The prevailing treatment strategy for PCOS is to individualize the interventions based on individual symptoms and patient complaints. However, optimal efficacy in treatment necessitates a focus on addressing the underlying pathogenic mechanisms. Uric acid (UA), the end product of purine metabolism, has been suggested to be involved in the development of several diseases, including PCOS. However, the precise mechanisms by which UA may affect PCOS remain incompletely understood. This literature review aims to investigate the correlation between UA and the various clinical presentations of PCOS, such as hyperandrogenism, insulin resistance (IR), ovulation disorders, obesity, and other related manifestations, through the analysis of epidemiological and clinical studies. The purpose of this study is to improve our comprehension of how UA contributes to each aspect of PCOS and their interrelationship, thus identifying the potential role of UA as a facilitator of PCOS. Furthermore, we explore potential pathways linking UA and PCOS, and propose therapeutic interventions based on these findings to optimize the management of this condition.

Influence of different types of dietary sugars on the intestinal mucosa and hepatic lipid metabolism in germ-free mice

The excessive consumption of dietary sugar induces changes in gut microbiota, which is associated with obesity and metabolic dysregulation. This study investigated the effects of monosaccharide and fructooligosaccharide (FOS) intake on metabolic function and intestinal environment in germ-free (GF) mice lacking gut microbiota. GF mice were provided with a chow diet and administered a water solution containing 15 % glucose, fructose, or FOS for 4 weeks. Compared with FOS, glucose, and fructose induced increased hepatic lipid accumulation, increased adipocyte size in white adipose tissue, and upregulated hepatic lipogenic gene expression. FOS exhibited notably higher activation of hepatic AMP-activated protein kinase compared with those consuming glucose or fructose. Moreover, the number of goblet cells in the intestinal mucosa increased significantly with FOS consumption. Collectively, these findings indicate that while monosaccharides caused metabolic disorders in GF mice, FOS alleviated these disorders and increased the number of goblet cells in the intestinal mucosa. These results provide evidence for the occurrence of these effects independently of the gut microbiota.

Establishing a Female Animal Model of Prediabetes Using a High-Carbohydrate, High-Fat Diet

Prediabetes is a condition that often precedes the onset of type 2 diabetes and is characterized by moderate levels of insulin resistance. This condition is well established in male animal models for diabetes; however, few female models exist. There is accumulating evidence that sex variations affect the pathogenesis, treatment, and consequences of numerous diseases, such as type 2 diabetes. Therefore, we sought to develop a diet-induced prediabetic female animal model to better understand prediabetes development and its effects in females. Female Sprague Dawley rats were randomly allocated to one of two groups: the standard diet (SD) group fed a standard diet with normal drinking water, and the high-carbohydrate, high-fat (HCHF) group fed a high-carbohydrate and high-fat diet with drinking water supplemented with fructose. During induction, we measured food intake, body weight, body mass index (BMI), and oral glucose tolerance response (OGT). After the induction period, biochemical analyses were conducted to assess the levels of plasma leptin, ghrelin, insulin, and glycated hemoglobin (HbA1c). Glycogen concentrations were quantified in the liver and skeletal muscles. The HCHF diet-fed group presented higher body weight gain, food intake, and BMI levels, which were accompanied by elevated plasma insulin, ghrelin, and liver and skeletal muscle glycogen levels compared to the SD-fed group. In the HCHF diet-fed group, the HOMA-IR was above 1.9, suggesting the presence of moderate levels of insulin resistance. The OGT response was significantly higher in the HCHF-fed group versus the SD-fed group, suggesting impaired glucose tolerance, thus displaying the signs and symptoms of prediabetes. The HCHF diet with fructose led to the induction of prediabetes in female Sprague Dawley rats. This model could be used to investigate and outline the pathophysiological complications associated with prediabetes in females as a result of the prolonged ingestion of a high carbohydrate, high-fat diet with fructose. The development of this model could also serve as an effort to further bridge the gap regarding the inclusion of females in biomedical research, thus providing advancements in deriving better, specified treatment strategies for women.

Beta vulgaris L. var cicla Decreases Liver Injury Induced by Antiarrhytmic Agent, Amiodarone

Amiodarone (AMD) is an effective antiarrhythmic drug, but its long-term usage strongly forms liver toxicity due to its accumulation tendency. The chard (Beta vulgaris L. var. cicla) is a unique plant which has a blood sugar-lowering effect and powerful antioxidant activity. The aim of the current study was to investigate the possible protective effects of chard on AMD-induced liver injury. Male Sprague-Dawley rats were divided into four groups. Control group, aqueous chard extract given group 500 mg/kg/day for one week, AMD given group 100 mg/kg/day for one week, AMD+Chard given group (at the same doses and times). They were sacrificed on the 8th day. The blood and liver samples were taken. The serum and liver biochemical parameters were found to be changed in AMD treated group. Chard administration reversed these parameters in serum and liver. In histological experiments, necrotic areas, mononuclear cell infiltration, the endothelial rupture in central vein, sinusoidal dilatation, hyperemia, dark eosinophilic cells and picnotic nucleus were observed in liver tissues of AMD treated group. Chard treatment reduced liver tissue damage. Considering results, we can suggest that chard prevented AMD induced liver injury biochemically and histologically.

Walnut supplementation increases levels of UCP1 and CD36 in brown adipose tissue independently of diet type

Dietary interventions that modulate the brown adipose tissue (BAT) thermogenic activity could represent a promising therapy for metabolic disorders. In order to examine if dietary walnuts intake regulates the expression of BAT thermogenic markers levels in healthy and metabolically challenged (fructose fed) animals, rats were initially divided into the control and fructose-fed groups. After nine weeks, these groups were subdivided into the one kept on the original regimens and the other supplemented with walnuts. High-fructose diet resulted in an increased relative BAT mass and no change in UCP1 content, while the walnut supplementation increased the amount of UCP1 in BAT, but did not affect 5-HT, NA, DHPG content and DHPG/NA ratio regardless of the diet. Moreover, the CD36 levels were increased following the walnut consumption, unlike FATP1, GLUT1, GLUT4, and glycogen content which remained unchanged. Additionally, the BAT levels of activated IR and Akt were not affected by walnut consumption, while ERK signaling was decreased. Overall, we found that walnut consumption increased UCP1 and CD36 content in the BAT of both control and metabolically challenged rats, suggesting that FFAs represent the BAT preferred substrate under the previously described circumstances. This further implies that incorporating walnuts into the everyday diet may help to alleviate some symptoms of the metabolic disorder.

Hepatic glucagon action: beyond glucose mobilization

Glucagon's ability to promote hepatic glucose production has been known for over a century, with initial observations touting this hormone as a diabetogenic agent. However, glucagon receptor agonism [when balanced with an incretin, including glucagon-like peptide 1 (GLP-1) to dampen glucose excursions] is now being developed as a promising therapeutic target in the treatment of metabolic diseases, like metabolic dysfunction-associated steatotic disease/metabolic dysfunction-associated steatohepatitis (MASLD/MASH), and may also have benefit for obesity and chronic kidney disease. Conventionally regarded as the opposing tag-team partner of the anabolic mediator insulin, glucagon is gradually emerging as more than just a "catabolic hormone." Glucagon action on glucose homeostasis within the liver has been well characterized. However, growing evidence, in part thanks to new and sensitive "omics" technologies, has implicated glucagon as more than just a "glucose liberator." Elucidation of glucagon's capacity to increase fatty acid oxidation while attenuating endogenous lipid synthesis speaks to the dichotomous nature of the hormone. Furthermore, glucagon action is not limited to just glucose homeostasis and lipid metabolism, as traditionally reported. Glucagon plays key regulatory roles in hepatic amino acid and ketone body metabolism, as well as mitochondrial turnover and function, indicating broader glucagon signaling consequences for metabolic homeostasis mediated by the liver. Here we examine the broadening role of glucagon signaling within the hepatocyte and question the current dogma, to appreciate glucagon as more than just that "catabolic hormone."

Fructose Consumption Affects Placental Production of H2S: Impact on Preeclampsia-Related Parameters

H2S, a gasotransmitter that can be produced both via the transsulfuration pathway and non-enzymatically, plays a key role in vasodilation and angiogenesis during pregnancy. In fact, the involvement of H2S production on plasma levels of sFLT1, PGF, and other molecules related to preeclampsia has been demonstrated. Interestingly, we have found that maternal fructose intake (a common component of the Western diet) affects tissular H2S production. However, its consumption is allowed during pregnancy. Thus, (1) to study whether maternal fructose intake affects placental production of H2S in the offspring, when pregnant; and (2) to study if fructose consumption during pregnancy can increase the risk of preeclampsia, pregnant rats from fructose-fed mothers (10% w/v) subjected (FF) or not (FC) to a fructose supplementation were studied and compared to pregnant control rats (CC). Placental gene expression, H2S production, plasma sFLT1, and PGF were determined. Descendants of fructose-fed mothers (FC) presented an increase in H2S production. However, if they consumed fructose during their own gestation (FF), this effect was reversed so that the increase disappeared. Curiously, placental synthesis of H2S was mainly non-enzymatic. Related to this, placental expression of Cys dioxygenase, an enzyme involved in Cys catabolism (a molecule required for non-enzymatic H2S synthesis), was significantly decreased in FC rats. Related to preeclampsia, gene expression of sFLT1 (a molecule with antiangiogenic properties) was augmented in both FF and FC dams, although these differences were not reflected in their plasma levels. Furthermore, placental expression of PGF (a molecule with angiogenic properties) was decreased in both FC and FF dams, becoming significantly diminished in plasma of FC versus control dams. Both fructose consumption and maternal fructose intake induce changes in molecules that contribute to increasing the risk of preeclampsia, and these effects are not always mediated by changes in H2S production.

Glucoregulatory effect of butyrate is associated with elevated circulating VEGF and reduced cardiac lactate in high fructose fed rats

Background

High fructose diet has been linked with impaired body metabolism and cardiovascular diseases. Sodium butyrate (NaB) was documented to improve glucoregulation and cardiometabolic problems associated with high fructose diet (HFrD) but the mechanisms behind it are unclear. As a result, the purpose of this study was to look into the effects of NaB on VEGF and cardiac lactate in HFrD-induced dysmetabolism.

Methods

Twenty male Wistar rats of weight 130-140 g were assigned randomly after a week of acclimation into four groups: Control diet (CTR), High fructose drink (HFrD); 10 % (w/v), NaB (200 mg/kg bw), and HFrD + NaB (200 mg/kg bw). The animals were induced to be unconscious with 50 mg/kg of pentobarbital sodium intraperitoneally, blood samples were taken via cardiac puncture and cardiac tissue homogenates were obtained for Fasting Blood Sugar (FBS) and plasma insulin, cardiac glycogen, plasma and cardiac glycogen synthase, plasma and cardiac nitric oxide as well as vascular endothelial growth factor (VEGF).

Result

HFrD resulted in statistical elevation body and cardiac weight, plasma glucose, plasma insulin, cardiac lactate, glycogen and decreased nitric oxide level (NO) when compared with the control group. Administration of NaB reduced cardiac weight, blood glucose, plasma insulin, cardiac lactate while nitric oxide and glycogen increased (P < 0.05). NaB increased plasma glycogen synthase in normal rats, plasma and cardiac circulating VEGF in HFrD administered rats (P < 0.05) while no change was produced in plasma and cardiac glycogen synthase level of HFrD treated rats.

Conclusion

Sodium butyrate improves glucoregulation by reducing cardiac lactate and increasing circulating VEGF in HFrD-treated rats.

Early aging and premature vascular aging in chronic kidney disease

Aging is the progressive decline of body functions and a number of chronic conditions can lead to premature aging characterized by frailty, a diseased vasculature, osteoporosis, and muscle wasting. One of the major conditions associated with premature and accelerated aging is chronic kidney disease (CKD), which can also result in early vascular aging and the stiffening of the arteries. Premature vascular aging in CKD patients has been considered as a marker of prognosis of mortality and cardiovascular morbidity and therefore requires further attention. Oxidative stress, inflammation, advanced glycation end products, fructose, and an aberrant gut microbiota can contribute to the development of early aging in CKD patients. There are several key molecular pathways and molecules which play a role in aging and vascular aging including nuclear factor erythroid 2-related factor 2 (Nrf-2), AMP-activated protein kinase (AMPK), sirtuin 1 (SIRT1), and klotho. Potential therapeutic strategies can target these pathways. Future studies are needed to better understand the importance of premature aging and early vascular aging and to develop therapeutic alternatives for these conditions.

Fructose-containing food sources and blood pressure: A systematic review and meta-analysis of controlled feeding trials

Whether food source or energy mediates the effect of fructose-containing sugars on blood pressure (BP) is unclear. We conducted a systematic review and meta-analysis of the effect of different food sources of fructose-containing sugars at different levels of energy control on BP. We searched MEDLINE, Embase and the Cochrane Library through June 2021 for controlled trials ≥7-days. We prespecified 4 trial designs: substitution (energy matched substitution of sugars); addition (excess energy from sugars added); subtraction (excess energy from sugars subtracted); and ad libitum (energy from sugars freely replaced). Outcomes were systolic and diastolic BP. Independent reviewers extracted data. GRADE assessed the certainty of evidence. We included 93 reports (147 trial comparisons, N = 5,213) assessing 12 different food sources across 4 energy control levels in adults with and without hypertension or at risk for hypertension. Total fructose-containing sugars had no effect in substitution, subtraction, or ad libitum trials but decreased systolic and diastolic BP in addition trials (P<0.05). There was evidence of interaction/influence by food source: fruit and 100% fruit juice decreased and mixed sources (with sugar-sweetened beverages [SSBs]) increased BP in addition trials and the removal of SSBs (linear dose response gradient) and mixed sources (with SSBs) decreased BP in subtraction trials. The certainty of evidence was generally moderate. Food source and energy control appear to mediate the effect of fructose-containing sugars on BP. The evidence provides a good indication that fruit and 100% fruit juice at low doses (up to or less than the public health threshold of ~10% E) lead to small, but important reductions in BP, while the addition of excess energy of mixed sources (with SSBs) at high doses (up to 23%) leads to moderate increases and their removal or the removal of SSBs alone (up to ~20% E) leads to small, but important decreases in BP in adults with and without hypertension or at risk for hypertension. Trial registration: Clinicaltrials.gov: NCT02716870.

Concomitant western diet and chronic-binge alcohol dysregulate hepatic metabolism

BACKGROUND AND AIMS

There is significant overlap between non-alcoholic fatty liver disease (NAFLD) and alcohol-associated liver disease (ALD) with regards to risk factors and disease progression. However, the mechanism by which fatty liver disease arises from concomitant obesity and overconsumption of alcohol (syndrome of metabolic and alcohol-associated fatty liver disease; SMAFLD), is not fully understood.

METHODS

Male C57BL6/J mice were fed chow diet (Chow) or high-fructose, high-fat, high-cholesterol diet (FFC) for 4 weeks, then administered either saline or ethanol (EtOH, 5% in drinking water) for another 12 weeks. The EtOH treatment also consisted of a weekly 2.5 g EtOH/kg body weight gavage. Markers for lipid regulation, oxidative stress, inflammation, and fibrosis were measured by RT-qPCR, RNA-seq, Western blot, and metabolomics.

RESULTS

Combined FFC-EtOH induced more body weight gain, glucose intolerance, steatosis, and hepatomegaly compared to Chow, EtOH, or FFC. Glucose intolerance by FFC-EtOH was associated with decreased hepatic protein kinase B (AKT) protein expression and increased gluconeogenic gene expression. FFC-EtOH increased hepatic triglyceride and ceramide levels, plasma leptin levels, hepatic Perilipin 2 protein expression, and decreased lipolytic gene expression. FFC and FFC-EtOH also increased AMP-activated protein kinase (AMPK) activation. Finally, FFC-EtOH enriched the hepatic transcriptome for genes involved in immune response and lipid metabolism.

CONCLUSIONS

In our model of early SMAFLD, we observed that the combination of an obesogenic diet and alcohol caused more weight gain, promoted glucose intolerance, and contributed to steatosis by dysregulating leptin/AMPK signaling. Our model demonstrates that the combination of an obesogenic diet with a chronic-binge pattern alcohol intake is worse than either insult alone.

Fructose-induced salt-sensitive blood pressure differentially affects sympathetically mediated aortic stiffness in male and female Sprague-Dawley rats

Hypertension is the leading risk factor for major adverse cardiovascular events (MACE). Aortic stiffness and sympathoexcitation are robust predictors of MACE. Combined high fructose and sodium intake increases arterial pressure, aortic stiffness, renin, and sympathetic nerve activity in male rats. We hypothesized that activation of the renin angiotensin system (RAS) and/or the sympathetic system mediates aortic stiffness in rats with fructose-induced salt-sensitive blood pressure. Male and female Sprague-Dawley rats ingested 20% fructose or 20% glucose in drinking water with 0.4% NaCl chow for 1 week. Then, fructose-fed rats were switched to 4% NaCl chow (Fru + HS); glucose-fed rats remained on 0.4% NaCl chow (Glu + NS, controls for caloric intake). After 2 weeks, mean arterial pressure (MAP) and aortic pulsed wave velocity (PWV) were evaluated at baseline or after acute intravenous vehicle, clonidine, enalapril, losartan, or hydrochlorothiazide. Baseline global longitudinal strain (GLS) was also assessed. MAP and PWV were greater in male Fru + HS versus Glu + NS male rats (p < 0.05 and p < 0.001, respectively). PWV was similar between the female groups. Despite similarly reduced MAP after clonidine, PWV decreased in Fru + HS versus Glu + NS male rats (p < 0.01). Clonidine induced similar decreases in MAP and PWV in females on either diet. GLS was lower in Fru + HS versus Glu + NS male rats and either of the female groups. Thus, acute sympathoinhibition improved aortic compliance in male rats with fructose salt-sensitive blood pressure. Female rats retained aortic compliance regardless of diet. Acute RAS inhibition exerted no significant effects. Male rats on fructose high salt diet displayed an early deficit in myocardial function. Taken together, these findings suggest that adult female rats are protected from the impact of fructose and high salt diet on blood pressure, aortic stiffness, and early left ventricular dysfunction compared with male rats.

Snack consumption patterns and their associations with risk of incident metabolic syndrome: Tehran lipid and glucose study

AIM

Few studies considered the association between snack patterns and metabolic abnormalities. Here we aimed to characterize the major snack patterns among Iranian adults and determine their association with the risk of metabolic syndrome (MetS).

METHODS

This study was conducted on 1713 MetS-free adults who participated in the third phase of the Tehran Lipid and Glucose Study (TLGS). At baseline, dietary intake of snack was assessed using a validated 168-items food frequency questionnaire, and snack patterns were obtained by principal component analysis (PCA). Adjusted Hazard Ratios (HRs) and 95% confidence intervals (CIs) were calculated for the association of incident MetS with the extracted snack patterns.

RESULTS

PCA identified five major snack patterns, defined as "healthy pattern", "low-fructose pattern", "high-trans pattern", "high-caffeine pattern" and "high-fructose pattern". Participants in the highest tertile of the "high-caffeine pattern" had lower risk of MetS (HR = 0.80, 95% CI = 0.65-0.99, P for trend = 0.032). Other snack patterns have not shown any significant association with MetS incidence.

CONCLUSIONS

Our findings suggest that consuming a snack pattern with high loads of caffeine, defined as "High-caffeine pattern" in the present study, could reduce the risk of MetS in healthy adults. Further prospective studies are needed to more fully determine the association between snack patterns and MetS incidence.

Sugar Consumption Pattern among Cardiometabolic Risk Individuals: A Scoping Review

BACKGROUND

The global prevalence of noncommunicable diseases has risen rapidly over the past decade. Research has focused on dietary management, particularly dietary sugar, to prevent and treat noncommunicable diseases.

OBJECTIVE

This study undertakes a scoping review of research on the impacts of dietary sugar on cardiometabolic related health outcomes.

METHODS

Ovid Medline, Scopus and Web of Science Core collection databases were used to identify papers published from January 1, 2010 onwards. The included studies had to be cross-sectional or cohort studies, peered review, published in English and in adults, aged 18 years old and above. Articles had to determine the impacts of sugar intake on cardiometabolic related health outcomes. Study quality was measured using the Quality Assessment Tool for Observational Cohort and Cross-sectional Studies. In addition, a narrative synthesis of extracted information was conducted.

RESULTS

Thirty-one articles were included in this review. All studies had a large sample size, and the exposure measure was clearly defined, valid and applied consistently across all study participants. Exposure was measured using validated questionnaires. All data were statistically analysed and adjusted for critical potential confounding variables. Results showed that dietary sugar intake was significantly associated with metabolic syndrome, blood pressure, blood glucose, blood lipids, and body weight.

CONCLUSION

Dietary sugar intake significantly increased cardiometabolic risks through mechanisms dependent and independent of weight gain. It is essential to create public awareness on the topics of cardiometabolic risk management and dietary sugars intake.

The Sugar Metabolic Model of Aspergillus niger Can Only Be Reliably Transferred to Fungi of Its Phylum

Fungi play a critical role in the global carbon cycle by degrading plant polysaccharides to small sugars and metabolizing them as carbon and energy sources. We mapped the well-established sugar metabolic network of Aspergillus niger to five taxonomically distant species (Aspergillus nidulans, Penicillium subrubescens, Trichoderma reesei, Phanerochaete chrysosporium and Dichomitus squalens) using an orthology-based approach. The diversity of sugar metabolism correlates well with the taxonomic distance of the fungi. The pathways are highly conserved between the three studied Eurotiomycetes (A. niger, A. nidulans, P. subrubescens). A higher level of diversity was observed between the T. reesei and A. niger, and even more so for the two Basidiomycetes. These results were confirmed by integrative analysis of transcriptome, proteome and metabolome, as well as growth profiles of the fungi growing on the corresponding sugars. In conclusion, the establishment of sugar pathway models in different fungi revealed the diversity of fungal sugar conversion and provided a valuable resource for the community, which would facilitate rational metabolic engineering of these fungi as microbial cell factories.

A researcher's guide to preclinical mouse NASH models

Non-alcoholic fatty liver disease (NAFLD) and its inflammatory form, non-alcoholic steatohepatitis (NASH), have quickly risen to become the most prevalent chronic liver disease in the Western world and are risk factors for the development of hepatocellular carcinoma (HCC). HCC is not only one of the most common cancers but is also highly lethal. Nevertheless, there are currently no clinically approved drugs for NAFLD, and NASH-induced HCC poses a unique metabolic microenvironment that may influence responsiveness to certain treatments. Therefore, there is an urgent need to better understand the pathogenesis of this rampant disease to devise new therapies. In this line, preclinical mouse models are crucial tools to investigate mechanisms as well as novel treatment modalities during the pathogenesis of NASH and subsequent HCC in preparation for human clinical trials. Although, there are numerous genetically induced, diet-induced and toxin-induced models of NASH, not all of these models faithfully phenocopy and mirror the human pathology very well. In this Perspective, we shed some light onto the most widely used mouse models of NASH and highlight some of the key advantages and disadvantages of the various models with an emphasis on 'Western diets', which are increasingly recognized as some of the best models in recapitulating the human NASH pathology and comorbidities.

Pharmacotherapy of type 2 diabetes: An update and future directions

Type 2 diabetes (T2D) is a widely prevalent disease with substantial economic and social impact for which multiple conventional and novel pharmacotherapies are currently available; however, the landscape of T2D treatment is constantly changing as new therapies emerge and the understanding of currently available agents deepens. This review aims to provide an updated summary of the pharmacotherapeutic approach to T2D. Each class of agents is presented by mechanism of action, details of administration, side effect profile, cost, and use in certain populations including heart failure, non-alcoholic fatty liver disease, obesity, chronic kidney disease, and older individuals. We also review targets of novel therapeutic T2D agent development. Finally, we outline an up-to-date treatment approach that starts with identification of an individualized goal for glycemic control then selection, initiation, and further intensification of a personalized therapeutic plan for T2D.

New Horizons: Emerging Antidiabetic Medications

Over the past century, since the discovery of insulin, the therapeutic offer for diabetes has grown exponentially, in particular for type 2 diabetes (T2D). However, the drugs in the diabetes pipeline are even more promising because of their impressive antihyperglycemic effects coupled with remarkable weight loss. An ideal medication for T2D should target not only hyperglycemia but also insulin resistance and obesity. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and the new class of GLP1 and gastric inhibitory polypeptide dual RAs counteract 2 of these metabolic defects of T2D, hyperglycemia and obesity, with stunning results that are similar to the effects of metabolic surgery. An important role of antidiabetic medications is to reduce the risk and improve the outcome of cardiovascular diseases, including coronary artery disease and heart failure with reduced or preserved ejection fraction, as well as diabetic nephropathy, as shown by SGLT2 inhibitors. This review summarizes the main drugs currently under development for the treatment of type 1 diabetes and T2D, highlighting their strengths and side effects.

Comparison of oral administration of fructose and glucose on food intake and physiological parameters in broiler chicks

Like glucose, fructose is a monosaccharide, but the mechanisms of its absorption and metabolism in the body are very different between the 2 molecules. In this study, we investigated the effects of oral administration of glucose and fructose on food intake, diencephalic gene expression, and plasma metabolite concentrations in broiler chicks. The animals used in this study were 4-day-old male broiler chicks (Ross 308). They were given glucose, fructose (200 mg/ 0.5 mL/ bird), or a similar volume of distilled water orally after 6 h fasting. After treatment, measurements of food intake (at 0, 30, and 60 min), and blood glucose as well as insulin concentrations were measured over time; however, diencephalic (hypothalamus) gene expression and plasma metabolites were measured at 30 min. The results showed that glucose administration suppressed food intake, but fructose administration did not suppress food intake and it was at the same level as distilled water administration. In addition, fructose administration did not increase plasma glucose and insulin levels as did glucose administration. In the diencephalon, expression levels of genes related to the melanocortin system were unaffected by the treatment, while gene expression levels related to intracellular energy regulation, such as AMP-activated protein kinase were affected by the glucose treatment in the fasted chicks. These results suggest that fructose administration does not suppress feeding behavior as a result of possible reduction in the energy levels in the diencephalon and associated energy metabolism.

Maternal Fructose Intake, Programmed Mitochondrial Function and Predisposition to Adult Disease

Fructose consumption is now recognised as a major risk factor in the development of metabolic diseases, such as hyperlipidaemia, diabetes, non-alcoholic fatty liver disease and obesity. In addition to environmental, social, and genetic factors, an unfavourable intrauterine environment is now also recognised as an important factor in the progression of, or susceptibility to, metabolic disease during adulthood. Developmental trajectory in the short term, in response to nutrient restriction or excessive nutrient availability, may promote adaptation that serves to maintain organ functionality necessary for immediate survival and foetal development. Consequently, this may lead to decreased function of organ systems when presented with an unfavourable neonatal, adolescent and/or adult nutritional environment. These early events may exacerbate susceptibility to later-life disease since sub-optimal maternal nutrition increases the risk of non-communicable diseases (NCDs) in future generations. Earlier dietary interventions, implemented in pregnant mothers or those considering pregnancy, may have added benefit. Although, the mechanisms by which maternal diets high in fructose and the vertical transmission of maternal metabolic phenotype may lead to the predisposition to adult disease are poorly understood. In this review, we will discuss the potential contribution of excessive fructose intake during pregnancy and how this may lead to developmental reprogramming of mitochondrial function and predisposition to metabolic disease in offspring.

Guava Leaf Extract Suppresses Fructose Mediated Non-Alcoholic Fatty Liver Disease in Growing Rats

Purpose

Fructose is highly lipogenic, and its unhindered ingestion by children and adolescents is understood to induce hypertriglyceridemia and non-alcoholic fatty liver disease (ped-NAFLD) that is till date managed symptomatically or surgically. The aim of the present study was to investigate the potential of hydroethanolic extract of leaves of Guava (PG-HM) to suppress the alterations in the hepatic molecular signals due to unrestricted fructose (15%) drinking by growing rats.

Methods

Weaned rats (4 weeks old) in control groups had ad libitum access to fructose drinking solution (15%) for four (4FDR) or eight (8FDR) weeks, ie, till puberty or early adulthood, respectively, while treatment groups (4PGR, 8PGR) additionally received PG-HM (500 mg/kg, po).

Results

The PG-HM suppressed ped-NAFLD through hepatic signalling pathways of 1) leptin-insulin (Akt/FOX-O1/SREBP-1c), 2) hypoxia-inflammation (HIF-1ɑ/VEGF, TNF-ɑ), 3) mitochondrial function (complexes I–V), 4) oxidative stress (MDA, GSH, SOD) and 5) glycolysis/gluconeogenesis/de novo lipogenesis (hexokinase, phosphofructokinase, ketohexokinase, aldehyde dehydrogenase). Parri passu, the insulin sensitizing effect of PG-HM and its ethyl acetate fraction (PG-EA) was elucidated using HepG2 cells grown in media enhanced with fructose. Further, in murine hepatocytes cultured in fructose-rich media, PG-HM (35 µg mL-1) outperformed Pioglitazone (15 µM) and Metformin (5 mM), to suppress hepatic insulin resistance.

Conclusion

This study established that hydroethanolic extract of leaves of Guava (PG-HM) has potential to suppress hepatic metabolic alteration for the management of the pediatric NAFLD.

Akkila S, S. Ibrahim M. Adiponectin and the expression of BAX and caspase 3 in high-fructose - induced testicular injury in albino mice

Introduction and Aim: The increase in the prevalence of obesity and metabolic syndrome in recent decades has been correlated with high consumption of high-fructose and high-fat diets and has been associated with increased rates of male infertility. The aim of this study was to investigate how high fructose diet exerts its effect upon testicular morphology in addition to examine the potential effects of adiponectin treatment in restoring the architecture of seminiferous tubules through the expression of immunohistochemical markers BAX and caspase-3. Materials and Methods: Twenty-five adult albino mice were divided into three groups: In Group 1, mice fed with diet contained high concentration of fructose followed by adiponectin injection, Group 2, the mice fed with high concentration of fructose diet and received a saline placebo injection, and Group 3 (control) was nourished a regular food for 8 weeks. The parameters studied included changes in animal body weight, testicular spermatogenesis index, spermatogonia count, apoptotic index, exfoliative epithelium percentage and immunohistochemical scores for testicular BAX and caspase-3 expression. Results: Animals on high fructose diet showed increase in body weight which was markedly reduced by adiponectin treatment. High fructose diet also resulted in reduced spermatogenesis index and spermatogonia count with increased apoptotic and epithelial exfoliation indices. High fructose diet was also associated with high-fructose induced obesity and significantly associated with increased BAX and caspase-3 expression alleviated by adiponectin treatment. Conclusion: High-fructose intake induces obesity and obesity-related reduction in male fertility by reducing spermatogenesis and enhancing testicular cell apoptosis via different pathophysiological mechanisms. Such effects and mechanism can be reversed and corrected with adiponectin treatment.

Highlights of mechanisms and treatment of obesity-related hypertension

The prevalence of obesity has increased two to three times from 1975 to 2015. Large-scale epidemiological and longitudinal prospective studies link obesity with hypertension. Research suggests that excessive weight gain, particularly when associated with visceral adiposity, may account for as much as 65% to 75% of the risk of incident hypertension. Also, exercise and bariatric/metabolic surgery significantly lowers blood pressure, whereas weight gain increases blood pressure, thus establishing a firm link between these two factors. The mechanisms underpinning obesity-related hypertension are complex and multifaceted, and include, but are not limited to, renin-angiotensin-aldosterone system/sympathetic nervous system overactivation, overstimulation of adipokines, insulin resistance, immune dysfunction, structural/functional renal, cardiac, and adipocyte changes. Though weight loss is the mainstay of treatment for obesity-related hypertension, it is often not a feasible long-term solution. Therefore, it is recommended that aggressive treatment with multiple antihypertensive medications combined with diet and exercise be used to lower blood pressure and prevent complications. The research regarding the mechanisms and treatment of obesity-related hypertension has moved at a blistering pace over the past ten years. Therefore, the purpose of this expert review is two-fold: to discuss the pathophysiological mechanisms underlying obesity-related hypertension, and to revisit pharmacotherapies that have been shown to be efficacious in patients with obesity-related hypertension.

Transcriptomics of angiotensin II-induced long noncoding and coding RNAs in endothelial cells

OBJECTIVE

Angiotensin II (Ang II)-induced endothelial dysfunction plays an important role in the pathogenesis of cardiovascular diseases such as systemic hypertension, cardiac hypertrophy and atherosclerosis. Recently, long noncoding RNAs (lncRNAs) have been shown to play an essential role in the pathobiology of cardiovascular diseases; however, the effect of Ang II on lncRNAs and coding RNAs expression in endothelial cells has not been evaluated. Accordingly, we sought to evaluate the expression profiles of lncRNAs and coding RNAs in endothelial cells following treatment with Ang II.

METHODS

Human umbilical vein endothelial cells (HUVECs) were cultured and treated with Ang II (10-6 mol/l) for 24 h. The cells were then profiled for the expression of lncRNAs and mRNAs using the Arraystar Human lncRNA Expression Microarray V3.0.

RESULTS

In HUVECs following Ang II treatment, from a total of 30 584 lncRNA targets screened, 25 targets were significantly upregulated, while 69 were downregulated. In the same HUVECs samples, from 26 106 mRNA targets screened, 28 targets were significantly upregulated and 67 were downregulated. Of the differentially expressed lncRNAs, RP11-354P11.2 and RP11-360F5.1 were the most upregulated (11-fold) and downregulated (three-fold) lncRNAs, respectively. Assigning the differentially regulated genes into functional groups using bioinformatics reveals numerous genes involved in the nucleotide excision repair and ECM-receptor interaction.

CONCLUSION

This is the first study to profile the Ang II-induced differentially expressed lncRNAs and mRNAs in human endothelial cells. Our results reveal novel targets and substantially extend the list of potential candidate genes involved in Ang II-induced endothelial dysfunction and cardiovascular diseases.

Folate Deficiency Increased Lipid Accumulation and Leptin Production of Adipocytes

Imbalanced dietary habits are closely associated with poor micronutrients status and the development of obesity. Previous studies have shown that serum folate level is decreased in obese individuals. However, whether folate deficiency could result in adiposity is still unclear. The aim of this study was to investigate the effects of dietary folate on lipid accumulation and leptin production using both in vivo and in vitro studies. Male C57BL/6 mice were fed with a diet with (f1) or without (f0) folate in a high-fat (HF) diet containing high-sucrose (HFS-f1, HFS-f0) for 4.5-5 months in Experiment 1, or an HF diet (HF-f1, HF-f0) for 12 months in Experiment 2, or an HF diet containing high-fructose (HFF-f1, HFF-f0) for 12 months in Experiment 3, compared with the normal-fat (NF-f1, NF-f0) diet, respectively. The serum levels of folate and leptin, white adipose tissue (WAT), size of adipocytes, hepatic contents of triglyceride (TG), and cholesterol were measured. In vitro study, TG contents, proinflammatory cytokines, leptin, and expressions of hypoxia-inducible factor (HIF)-1α and lipogenesis-related genes of 3T3-L1 adipocytes cultured with (f1) or without (f0) folate were assayed. The results showed that folate deficiency together with a high-fat diet (HFS-f0, HF-f0, HFF-f0) had higher WAT mass, adipocyte size, serum leptin level, and hepatic TG compared to those of the folate-sufficient groups (HFS-f1, HF-f1, and HFF-f1). Folate deficiency with a high-fat high -sucrose or -fructose diet (HFS-f0, HFF-f0) significantly increased the body weight of the mice. Increased intracellular TG, leptin, monocyte chemotactic protein (MCP)-1 and interleukin (IL)-6 levels, and the expression of Hif1α and lipogenesis-related genes Cebpα, Cebpβ, Acc1, Fasn, and Fabp4 were also detected in folate-deficient 3T3-L1 adipocytes. Our results suggested that folate deficiency increased lipid accumulation and leptin production of adipocytes, and thus, inadequate folate status might be one of the risk factors for adiposity.

Trends in Antidiabetic Drug Discovery: FDA Approved Drugs, New Drugs in Clinical Trials and Global Sales

Type 2 diabetes mellitus (T2DM) continues to be a substantial medical problem due to its increasing global prevalence and because chronic hyperglycemic states are closely linked with obesity, liver disease and several cardiovascular diseases. Since the early discovery of insulin, numerous antihyperglycemic drug therapies to treat diabetes have been approved, and also discontinued, by the United States Food and Drug Administration (FDA). To provide an up-to-date account of the current trends of antidiabetic pharmaceuticals, this review offers a comprehensive analysis of the main classes of antihyperglycemic compounds and their mechanisms: insulin types, biguanides, sulfonylureas, meglitinides (glinides), alpha-glucosidase inhibitors (AGIs), thiazolidinediones (TZD), incretin-dependent therapies, sodium-glucose cotransporter type 2 (SGLT2) inhibitors and combinations thereof. The number of therapeutic alternatives to treat T2DM are increasing and now there are nearly 60 drugs approved by the FDA. Beyond this there are nearly 100 additional antidiabetic agents being evaluated in clinical trials. In addition to the standard treatments of insulin therapy and metformin, there are new drug combinations, e.g., containing metformin, SGLT2 inhibitors and dipeptidyl peptidase-4 (DPP4) inhibitors, that have gained substantial use during the last decade. Furthermore, there are several interesting alternatives, such as lobeglitazone, efpeglenatide and tirzepatide, in ongoing clinical trials. Modern drugs, such as glucagon-like peptide-1 (GLP-1) receptor agonists, DPP4 inhibitors and SGLT2 inhibitors have gained popularity on the pharmaceutical market, while less expensive over the counter alternatives are increasing in developing economies. The large heterogeneity of T2DM is also creating a push towards more personalized and accessible treatments. We describe several interesting alternatives in ongoing clinical trials, which may help to achieve this in the near future.

Dietary sugars and subclinical vascular damage in moderate-to-high cardiovascular risk adults

BACKGROUND AND AIMS

The association between dietary sugars and vascular damage has been scarcely examined out of the context of established cardiovascular disease. We aimed to investigate the association between different types of sugars with subclinical atheromatosis and arteriosclerosis, in individuals free of cardiovascular disease being, however, at moderate-to-high cardiovascular risk.

METHODS AND RESULTS

Two 24-h dietary recalls were conducted to estimate sugars intake. Subclinical atheromatosis was assessed by B-mode ultrasonography and arteriosclerosis (arterial stiffness) via tonometry (carotid-to-femoral pulse wave velocity). Multiple logistic regression analysis was performed to determine the relationship of quartiles of total sugars, monosaccharides and disaccharides with atheromatosis and arteriosclerosis, adjusting for potential confounders [Odds Ratio (95%Confidence Interval)]. In 901 participants (52.4 ± 13.8 years, 45.2% males), total sugars intake was not associated with any type of subclinical vascular damage. Subjects at 4th quartile of lactose intake (15.3 ± 5.5 g/day) had lower probability to present atheromatosis compared to those at 1st quartile (0.00 ± 0.01 g/day) even in the fully adjusted model [0.586 (0.353-0.974)]. Subjects at 3rd quartile of total disaccharides intake and particularly sucrose (15.1 ± 2.2 g/day) had higher probability to present arteriosclerosis compared to those at 1st quartile (3.0 ± 1.9 g/day) even after adjustment for all potential confounders [2.213 (1.110-4.409)].

CONCLUSIONS

Overall, the present data suggest a distinct role of each type of sugars on vascular damage. These observations highlight the need for further studies investigating not only foods rich in sugars, but sugars as separate components of food as they probably contribute via different ways on the development of arterial pathologies.

Clerodendrum trichotomum extract improves metabolic derangements in high fructose diet-fed rats

Clerodendrum trichotomum has been reported to possess beneficial properties for human health, but its effects on metabolic syndrome have not been reported. In this study, we investigated the effect of C. trichotomum leaf extract (CT) on the metabolic derangements induced by a high-fructose (HF) diet. Sprague–Dawley rats were fed with a 46% carbohydrate diet (HC group), 60% high-fructose diet (HF group), or HF diet supplemented with CT (500 mg/kg of body weight/day, CT group) via drinking water for 16 weeks. Results showed that CT alleviated HF diet-induced insulin resistance, dyslipidemia, and hepatic steatosis In liver tissues, CT affected the signaling pathways of AMP-activated protein kinase, peroxisome proliferator-activated receptor α (PPARα), and sterol regulatory element binding protein 1. CT enriched the genes that were mainly involved in cytokine-cytokine receptor interaction, PPAR, PI3K-Akt signaling pathways, and fatty acid metabolism pathway. These results suggest that CT is a promising therapeutic against metabolic disorders.

Comparative impact of dietary carbohydrates on the liver transcriptome in two strains of mice

Excessive long-term consumption of dietary carbohydrates, including glucose, sucrose, or fructose, has been shown to have significant impact on genome-wide gene expression, which likely results from changes in metabolic substrate flux. However, there has been no comprehensive study on the acute effects of individual sugars on the genome-wide gene expression that may reveal the genetic changes altering signaling pathways, subsequent metabolic processes, and ultimately physiological/pathological responses. Considering that gene expressions in response to acute carbohydrate ingestion might be different in nutrient sensitive and insensitive mammals, we conducted comparative studies of genome-wide gene expression by deep mRNA sequencing of the liver in nutrient sensitive C57BL/6J and nutrient insensitive BALB/cJ mice. Furthermore, to determine the temporal responses, we compared livers from mice in the fasted state and following ingestion of standard laboratory mouse chow supplemented with plain drinking water or water containing 20% glucose, sucrose, or fructose. Supplementation with these carbohydrates induced unique extents and temporal changes in gene expressions in a strain specific manner. Fructose and sucrose stimulated gene changes peaked at 3 h postprandial, whereas glucose effects peaked at 12 h and 6 h postprandial in C57BL/6J and BABL/cJ mice, respectively. Network analyses revealed that fructose changed genes were primarily involved in lipid metabolism and were more complex in C57BL/6J than in BALB/cJ mice. These data demonstrate that there are qualitative and antitative differences in the normal physiological responses of the liver between these two strains of mice and C57BL/6J is more sensitive to sugar intake than BALB/cJ.

Beet (Beta vulgaris) Improve Blood Glucose and AKT2 Gene Expression in High Fat and Fructose-induced Rats

ABSTRACT Background: Diet components significant effects on glucose homeostasis. A diet contains high saturated fat and fructose induces insulin resistance and enhanced blood glucose. In contrast, food containing flavonoids such as beet can improve glucose homeostasis via modulation of gene expression, e.g., AKT2, involving glucose metabolism. Aims: This study were to evaluate the benefit of beet on AKT2 gene expression and fasting glucose. Methods: Twenty wistar male was divided into five groups: Normal were fed a normal diet, group HFFD was given a diet containing high fat and fructose, and three groups (HFB1, HFB2, HFB3) were given a diet containing high fat and fructose for eight weeks and continuous fed beet-contained normal diet for six weeks. The percentage of beet in the diet for each 6%, 9%, and 12%, respectively. Results: The fasting glucose was measured before and after the intervention, whereas the gene expression of AKT2 at skeletal muscle tissue was determined after the intervention. A diet high in fat and fructose increased fasting glucose levels, and a beet-contained diet decreased it. Conclusions: The beet 9% substituted diet can improve glucose homeostasis from the effects of a high fat and fructose diet, and the expression of the AKT2 gene may have a role in the process. Keywords: AKT2, Antioxidant, Beet, Fat, Fructose.

How Perturbated Metabolites in Diabetes Mellitus Affect the Pathogenesis of Hypertension?

The presence of hypertension (HTN) in type 2 diabetes mellitus (DM) is a common phenomenon in more than half of the diabetic patients. Since HTN constitutes a predictor of vascular complications and cardiovascular disease in type 2 DM patients, it is of significance to understand the molecular and cellular mechanisms of type 2 DM binding to HTN. This review attempts to understand the mechanism via the perspective of the metabolites. It reviewed the metabolic perturbations, the biological function of perturbated metabolites in two diseases, and the mechanism underlying metabolic perturbation that contributed to the connection of type 2 DM and HTN. DM-associated metabolic perturbations may be involved in the pathogenesis of HTN potentially in insulin, angiotensin II, sympathetic nervous system, and the energy reprogramming to address how perturbated metabolites in type 2 DM affect the pathogenesis of HTN. The recent integration of the metabolism field with microbiology and immunology may provide a wider perspective. Metabolism affects immune function and supports immune cell differentiation by the switch of energy. The diverse metabolites produced by bacteria modified the biological process in the inflammatory response of chronic metabolic diseases either. The rapidly evolving metabolomics has enabled to have a better understanding of the process of diseases, which is an important tool for providing some insight into the investigation of diseases mechanism. Metabolites served as direct modulators of biological processes were believed to assess the pathological mechanisms involved in diseases.

Aqueous extract of large cardamom inhibits vascular damage, oxidative stress, and metabolic changes in fructose-fed hypertensive rats

PURPOSE

Since metabolic abnormalities such as elevated glucose level and imbalanced lipid profiles increase the risk for hypertension and cause endothelial dysfunction, we evaluated the effect of aqueous extract of large cardamom (AELC) on fructose-induced metabolic hypertension and oxidative stress.

METHODS

The male Sprague-Dawley rats were divided into 6 groups with 5 rats in each group, and each group was fed with 10% fructose in drinking water for 8 weeks. Starting from week 5, animals were treated with 50, 100, and 200 mg/kg/day AELC or Losartan (10 mg/kg/day). Systolic, diastolic, and mean arterial blood pressure was measured once in every seven days using the tail-cuff method. Vascular function, plasma nitric oxide (NO), glucose, lipid profiles, serum biochemical, and anti-oxidant parameters were also evaluated.

RESULTS

Rats fed with fructose showed higher blood pressure, serum cholesterol, and triglyceride levels, but decreased in the AELC or Losartan treatment group. Treatments with AELC prevented exaggerated plasma glucose and oxidative stress and restored the nitric oxide level in fructose-fed rats. Besides, it also reduced vascular proliferation and improved the relaxation response of acetylcholine in the aorta pre-contracted with phenylephrine.

CONCLUSION

In summary, the obtained results suggest that AELC can prevent and reverse the high blood pressure induced by fructose, probably by restoring nitric oxide level and by improving altered metabolic parameters.

High fructose induced osteogenic differentiation of human valve interstitial cells via activating PI3K/AKT/mitochondria signaling

Background

Aortic valve stenosis (AS) is a common, lethal cardiovascular disease. There is no cure except the valve replacement at last stage. Therefore, an understanding of the detail mechanism is imperative to prevent and intervene AS. Metabolic syndrome (MetS) is one of the major risk factors of AS whereas fructose overconsuming tops the list of MetS risk factors. However, whether the fructose under physiological level induces AS is currently unknown.

Methods

The human valve interstitial cells (hVICs), a crucial source to develop calcification, were co-incubated with fructose at 2 or 20 mM to mimic the serum fructose at fasting or post-fructose consumption, respectively, for 24 h. The cell proliferation was evaluated by WST-1 assays. The expressions of osteogenic and fibrotic proteins, PI3K/AKT signaling, insulin receptor substrate 1 and mitochondrial dynamic proteins were detected by Western blot analyses. The mitochondrial oxidative phosphorylation (OXPHOS) was examined by Seahorse analyzer.

Results

hVICs proliferation was significantly suppressed by 20 mM fructose. The expressions of alkaline phosphatase (ALP) and osteocalcin were enhanced concurrent with the upregulated PI3K p85, AKT, phospho(p)S473-AKT, and pS636-insulin receptor substrate 1 (p-IRS-1) by high fructose. Moreover, ATP production capacity and maximal respiratory capacity were enhanced in the high fructose groups. Synchronically, the expressions of mitochondrial fission 1 and optic atrophy type 1 were increased.

Conclusions

These results suggested that high fructose stimulated the osteogenic differentiation of hVICs via the activation of PI3K/AKT/mitochondria signaling at the early stage. These results implied that high fructose at physiological level might have a direct, hazard effect on the progression of AS.

Fructose, glucose and fat interrelationships with metabolic pathway regulation and effects on the gut microbiota

The purpose of this 30-day feeding study was to elucidate the changes, correlations, and mechanisms caused by the replacement of the starch content of the AIN-93G diet (St) with glucose (G), fructose (F) or lard (L) in body and organ weights, metabolic changes and caecal microbiota composition in rats (Wistar, SPF). The body weight gain of rats on the F diet was 12% less (P = 0.12) than in the St group. Rats on the L diet consumed 18.6% less feed, 31% more energy and gained 58.4% more than the animals on the St diet, indicating that, in addition to higher energy intake, better feed utilisation is a key factor in the obesogenic effect of diets of high nutrient and energy density. The G, F and L diets significantly increased the lipid content of the liver (St: 7.01 ± 1.48; G: 14.53 ± 8.77; F: 16.73 ± 8.77; L: 19.86 ± 4.92% of DM), suggesting that lipid accumulation in the liver is not a fructose-specific process. Relative to the St control, specific glucose effects were the decreasing serum glucagon (-41%) concentrations and glucagon/leptin ratio and the increasing serum leptin concentrations (+26%); specific fructose effects were the increased weights of the kidney, spleen, epididymal fat and the decreased weight of retroperitoneal fat and the lower immune response, as well as the increased insulin (+26%), glucagon (+26%) and decreased leptin (-25%) levels. This suggests a mild insulin resistance and catabolic metabolism in F rats. Specific lard effects were the decreased insulin (-9.14%) and increased glucagon (+40.44%) and leptin (+44.92%) levels. Relative to St, all diets increased the operational taxonomic units of the phylum Bacteroidetes. G and L decreased, while F increased the proportion of Firmicutes. F and L diets decreased the proportions of Actinobacteria, Proteobacteria and Verrucomicrobia. Correlation and centrality analyses were conducted to ascertain the positive and negative correlations and relative weights of the 32 parameters studied in the metabolic network. These correlations and the underlying potential mechanisms are discussed.

Fructose Metabolism and Cardiac Metabolic Stress

Cardiovascular disease is one of the leading causes of mortality in diabetes. High fructose consumption has been linked with the development of diabetes and cardiovascular disease. Serum and cardiac tissue fructose levels are elevated in diabetic patients, and cardiac production of fructose via the intracellular polyol pathway is upregulated. The question of whether direct myocardial fructose exposure and upregulated fructose metabolism have potential to induce cardiac fructose toxicity in metabolic stress settings arises. Unlike tightly-regulated glucose metabolism, fructose bypasses the rate-limiting glycolytic enzyme, phosphofructokinase, and proceeds through glycolysis in an unregulated manner. In vivo rodent studies have shown that high dietary fructose induces cardiac metabolic stress and functional disturbance. In vitro, studies have demonstrated that cardiomyocytes cultured in high fructose exhibit lipid accumulation, inflammation, hypertrophy and low viability. Intracellular fructose mediates post-translational modification of proteins, and this activity provides an important mechanistic pathway for fructose-related cardiomyocyte signaling and functional effect. Additionally, fructose has been shown to provide a fuel source for the stressed myocardium. Elucidating the mechanisms of fructose toxicity in the heart may have important implications for understanding cardiac pathology in metabolic stress settings.

Reproductive disorders in male rats induced by high-fructose consumption from juvenile age to puberty

There is compelling evidence that a hypercaloric, high-fructose diet can cause metabolic syndrome (MetS) and a whole range of other metabolic changes. In the context of androgen deficiency, MetS in boys merits special attention, but the effects of fructose-rich diet in youth on future male reproductive function are still poorly evidenced. The aim of this study was to address this issue and analyse the effects of high-fructose intake starting from weaning to puberty (postnatal day 23 up to 83) on the reproductive function of male rats. For this purpose juvenile male Wistar rats were divided in two groups: control and the group receiving 10 % fructose solution instead of drinking water. Reproductive function was evaluated in terms of fertility, sperm count, testes/epididymis morphology, and serum sex hormones. The fructose-treated group showed a decrease in testosterone and twofold increase in luteinising and follicle-stimulating hormone levels in the serum. This was accompanied with lower testis/epididymis weights, sperm count, and changed testis/epididymis morphology. Their fertility remained unchanged, but the fertility of females mating with these males diminished. In addition, pre-implantation and post-implantation embryonic death rate rose in these females. Our results have confirmed that high fructose consumption from early age until puberty can impair the reproductive function of male rats, and call for further animal and epidemiological investigation.

Morin alleviates fructose-induced metabolic syndrome in rats via ameliorating oxidative stress, inflammatory and fibrotic markers

Metabolic syndrome (MBS) is a widespread disease that has strongly related to unhealthy diet and low physical activity, which initiate more serious conditions such as obesity, cardiovascular diseases and type 2 diabetes mellitus. This study aimed to examine the therapeutic effects of morin, as one of the flavonoids constituents, which widely exists in many herbs and fruits, against some metabolic and hepatic manifestations observed in MBS rats and the feasible related mechanisms. MBS was induced in rats by high fructose diet feeding for 12 weeks. Morin (30 mg/kg) was administered orally to both normal and MBS rats for 4 weeks. Liver tissues were used for determination of liver index, hepatic expression of glucose transporter 2 (GLUT2) as well as both inflammatory and fibrotic markers. The fat/muscle ratio, metabolic parameters, systolic blood pressure, and oxidative stress markers were also determined. Our data confirmed that the administration of morin in fructose diet rats significantly reduced the elevated systolic blood pressure. The altered levels of metabolic parameters such as blood glucose, serum insulin, serum lipid profile, and oxidative stress markers were also reversed approximately to the normal values. In addition, morin treatment decreased liver index, serum liver enzyme activities, and fat/muscle ratio. Furthermore, morin relatively up-regulated GLUT2 expression, however, down-regulated NF-κB, TNF-α, and TGF-β expressions in the hepatic tissues. Here, we revealed that morin has an exquisite effect against metabolic disorders in the experimental model through, at least in part, antioxidant, anti-inflammatory, and anti-fibrotic mechanisms.

GLUT5 (SLC2A5) enables fructose-mediated proliferation independent of ketohexokinase

BACKGROUND

Fructose is an abundant source of carbon and energy for cells to use for metabolism, but only certain cell types use fructose to proliferate. Tumor cells that acquire the ability to metabolize fructose have a fitness advantage over their neighboring cells, but the proteins that mediate fructose metabolism in this context are unknown. Here, we investigated the determinants of fructose-mediated cell proliferation.

METHODS

Live cell imaging and crystal violet assays were used to characterize the ability of several cell lines (RKO, H508, HepG2, Huh7, HEK293T (293T), A172, U118-MG, U87, MCF-7, MDA-MB-468, PC3, DLD1 HCT116, and 22RV1) to proliferate in fructose (i.e., the fructolytic ability). Fructose metabolism gene expression was determined by RT-qPCR and western blot for each cell line. A positive selection approach was used to "train" non-fructolytic PC3 cells to utilize fructose for proliferation. RNA-seq was performed on parental and trained PC3 cells to find key transcripts associated with fructolytic ability. A CRISPR-cas9 plasmid containing KHK-specific sgRNA was transfected in 293T cells to generate KHK-/- cells. Lentiviral transduction was used to overexpress empty vector, KHK, or GLUT5 in cells. Metabolic profiling was done with seahorse metabolic flux analysis as well as LC/MS metabolomics. Cell Titer Glo was used to determine cell sensitivity to 2-deoxyglucose in media containing either fructose or glucose.

RESULTS

We found that neither the tissue of origin nor expression level of any single gene related to fructose catabolism determine the fructolytic ability. However, cells cultured chronically in fructose can develop fructolytic ability. SLC2A5, encoding the fructose transporter, GLUT5, was specifically upregulated in these cells. Overexpression of GLUT5 in non-fructolytic cells enabled growth in fructose-containing media across cells of different origins. GLUT5 permitted fructose to flux through glycolysis using hexokinase (HK) and not ketohexokinase (KHK).

CONCLUSIONS

We show that GLUT5 is a robust and generalizable driver of fructose-dependent cell proliferation. This indicates that fructose uptake is the limiting factor for fructose-mediated cell proliferation. We further demonstrate that cellular proliferation with fructose is independent of KHK.

Co-Treatment with Cefotaxime and High-Fructose Diet Inducing Nonalcoholic Fatty Liver Disease and Gut Microbial Dysbiosis in Mice

High fructose diet causes metabolic syndrome and induces host gut microbial dysbiosis and related obesity and nonalcoholic fatty liver disease (NAFLD). Several antibiotic treatments could prevent fatty liver. However, there are studies that have demonstrated that a high-fructose diet could influence the gut microbial dysbiosis and induce fatty liver. The purpose of this study was performed to partially modify the gut bacterial composition with a single cefotaxime treatment, which might affect the fructose-induced NAFLD severity. The C57BL/6JNarl male mice were divided into four groups including vehicle/chow diet (VE-CD), vehicle/high-fructose diet (VE-FD), antibiotic (cefotaxime (CF))/CD, and CF/FD. The results showed that body weight gain, moderate hepatic steatosis severity, epididymal white adipose tissue hypertrophy, and insulin resistance occurrence with NAFLD-related symptoms were observed only in the CF-FD group. The raised protein expression of hepatic lipogenesis was observed in the CF-FD group, but lipolysis protein expression was no difference. The diversity and composition of microbiota were significantly reduced in the CF-FD group. The Erysipelatoclostridium, Enterobacteriaceae, Lachnospiraceae, and Escherichia Shigella were in increased abundance in the feces of CF-FD group compared with VE-FD group. The novel model reveals that particular antibiotics such as cefotaxime co-treatment with high-fructose diet may affect the gut microbiota accelerating the NAFLD and obesity.

The Mechanism of Honey in Reversing Metabolic Syndrome

Metabolic syndrome is a constellation of five risk factors comprising central obesity, hyperglycaemia, dyslipidaemia, and hypertension, which predispose a person to cardiometabolic diseases. Many studies reported the beneficial effects of honey in reversing metabolic syndrome through its antiobesity, hypoglycaemic, hypolipidaemic, and hypotensive actions. This review aims to provide an overview of the mechanism of honey in reversing metabolic syndrome. The therapeutic effects of honey largely depend on the antioxidant and anti-inflammatory properties of its polyphenol and flavonoid contents. Polyphenols, such as caffeic acid, p-coumaric acid, and gallic acid, are some of the phenolic acids known to have antiobesity and antihyperlipidaemic properties. They could inhibit the gene expression of sterol regulatory element-binding transcription factor 1 and its target lipogenic enzyme, fatty acid synthase (FAS). Meanwhile, caffeic acid and quercetin in honey are also known to reduce body weight and fat mass. In addition, fructooligosaccharides in honey are also known to alter lipid metabolism by reducing FAS activity. The fructose and phenolic acids might contribute to the hypoglycaemic properties of honey through the phosphatidylinositol 3-kinase/protein kinase B insulin signalling pathway. Honey can increase the expression of Akt and decrease the expression of nuclear factor-kappa B. Quercetin, a component of honey, can improve vasodilation by enhancing nitric oxide production via endothelial nitric oxide synthase and stimulate calcium-activated potassium channels. In conclusion, honey can be used as a functional food or adjuvant therapy to prevent and manage metabolic syndrome.

A Sweet Story of Metabolic Innovation in the Naked Mole-Rat

The naked mole-rat's (Heterocephalus glaber) social and subterranean lifestyle imposes several evolutionary pressures which have shaped its physiology. One example is low oxygen availability in a crowded burrow system which the naked mole-rat has adapted to via several mechanisms. Here we describe a metabolic rewiring which enables the naked mole-rat to switch substrates in glycolysis from glucose to fructose thereby circumventing feedback inhibition at phosphofructokinase (PFK1) to allow unrestrained glycolytic flux and ATP supply under hypoxia. Preferential shift to fructose metabolism occurs in other species and biological systems as a means to provide fuel, water or like in the naked mole-rat, protection in a low oxygen environment. We review fructose metabolism through an ecological lens and suggest that the metabolic adaptation to utilize fructose in the naked mole-rat may have evolved to simultaneously combat multiple challenges posed by its hostile environment.

Metabolic and Appetite Effects of Fructose and Glucose in Subjects with Type 1 Diabetes: A Randomized Crossover Clinical Trial

BACKGROUND

Fructose has been widely used for producing lower post-infusion glucose increase than other carbohydrates, but it seems that it promotes an increase in post-infusion triglycerides.

OBJECTIVE

The present study investigated the effects of fructose and glucose in metabolic variables and appetite sensations in patients with type 1 diabetes mellitus (T1DM).

METHODS

This is a single-blind, randomized, and crossover study (washout of 1-5 weeks), which evaluated 16 adult T1DM patients, accompanied at University Hospital. After eight hours of overnight fasting, there was an assessment of capillary blood glucose, anthropometric variables, appetite sensations, and laboratory tests (glycemia, lipemia, leptin and glucagon) were conducted. Subsequently, they received 200mL of solutions with water and 75g of crystal fructose or glucose. Appetite sensations and capillary blood glucose were evaluated in different post-infusion times. Blood was drawn after 180 minutes for the laboratory tests.

RESULTS

Blood glucose increased after the intake of both solutions, but glucose induced a higher elevation. None of them increased triglycerides or glucagon. Glucagon maintenance was similar among the solutions. Furthermore, both solutions reduced leptin and increased fullness, but only fructose increased the lack of interest in eating sweets.

CONCLUSION

Fructose induced a smaller increase in postprandial blood glucose than glucose, without changes in triglycerides and glucagon. In addition, leptin levels and appetite sensations were similar to glucose. Other studies are needed in order to confirm these findings, especially in the long term, so that their use becomes really reliable.

DNA methylation during human adipogenesis and the impact of fructose

BACKGROUND

Increased adipogenesis and altered adipocyte function contribute to the development of obesity and associated comorbidities. Fructose modified adipocyte metabolism compared to glucose, but the regulatory mechanisms and consequences for obesity are unknown. Genome-wide methylation and global transcriptomics in SGBS pre-adipocytes exposed to 0, 2.5, 5, and 10 mM fructose, added to a 5-mM glucose-containing medium, were analyzed at 0, 24, 48, 96, 192, and 384 h following the induction of adipogenesis.

RESULTS

Time-dependent changes in DNA methylation compared to baseline (0 h) occurred during the final maturation of adipocytes, between 192 and 384 h. Larger percentages (0.1% at 192 h, 3.2% at 384 h) of differentially methylated regions (DMRs) were found in adipocytes differentiated in the glucose-containing control media compared to adipocytes differentiated in fructose-supplemented media (0.0006% for 10 mM, 0.001% for 5 mM, and 0.005% for 2.5 mM at 384 h). A total of 1437 DMRs were identified in 5237 differentially expressed genes at 384 h post-induction in glucose-containing (5 mM) control media. The majority of them inversely correlated with the gene expression, but 666 regions were positively correlated to the gene expression.

CONCLUSIONS

Our studies demonstrate that DNA methylation regulates or marks the transformation of morphologically differentiating adipocytes (seen at 192 h), to the more mature and metabolically robust adipocytes (as seen at 384 h) in a genome-wide manner. Lower (2.5 mM) concentrations of fructose have the most robust effects on methylation compared to higher concentrations (5 and 10 mM), suggesting that fructose may be playing a signaling/regulatory role at lower concentrations of fructose and as a substrate at higher concentrations.

OX-HDL: A Starring Role in Cardiorenal Syndrome and the Effects of Heme Oxygenase-1 Intervention

In this review, we will evaluate how high-density lipoprotein (HDL) and the reverse cholesterol transport (RCT) pathway are critical for proper cardiovascular-renal physiology. We will begin by reviewing the basic concepts of HDL cholesterol synthesis and pathway regulation, followed by cardiorenal syndrome (CRS) pathophysiology. After explaining how the HDL and RCT pathways become dysfunctional through oxidative processes, we will elaborate on the potential role of HDL dysfunction in CRS. We will then present findings on how HDL function and the inducible antioxidant gene heme oxygenase-1 (HO-1) are interconnected and how induction of HO-1 is protective against HDL dysfunction and important for the proper functioning of the cardiovascular-renal system. This will substantiate the proposal of HO-1 as a novel therapeutic target to prevent HDL dysfunction and, consequently, cardiovascular disease, renal dysfunction, and the onset of CRS.

Liver functions in combined models of the gentamicin induced nephrotoxicity and metabolic syndrome induced by high fat or fructose diets: a comparative study

Metabolic syndrome is one of the major risk factors that lead to various serious complications like cardiovascular abnormalities, hyperlipidemia and diabetes. Its co-incidence with other organs dysfunction results in further deterioration of the condition or precipitation of other dysfunctions. This study aimed at studying the changes in the hepatic functions after the co-incidence of the high fat or fructose diets induced metabolic syndrome along with the gentamicin induced nephrotoxicity. Briefly, six groups of male Sprague Daley rats (n = 10-12) were fed with different feeding protocols; viz; standard rodent's chow, an experimental high fat or high fructose diets feedings. For each, two groups were allocated that one of them was injected with normal saline and the other with 80 mg/kg/day I.P gentamicin during the last 24 days of the feeding period. The rats were monitored for changes in the metabolic data, glycemic control, lipid profile, renal and hepatic functions, oxidative stress and the inflammatory response. The study revealed stronger hepatic changes in the renal failure groups fed with the high fat diet rather than that in the groups fed with the high fructose diet. Although, the latter experienced a stronger deterioration in the glycemic control. The study suggests that the incidence of the hepatic changes is more linked to the incidence of the deterioration in the lipids profile that was observed after the high fat diet feeding. Overall, the co-incidence of the high fat diet induced metabolic syndrome along with the renal failure constitutes a risk factor for the hepatic dysfunction.