Use of sedoheptulose for prevention or treatment of inflammation
09694026 · 2017-07-04
Assignee
Inventors
- Arvand Haschemi (Vienna, AT)
- Oswald Wagner (Vienna, AT)
- Csörsz Nagy (Vienna, AT)
- Rodrig Marculescu (Altenberg, AT)
Cpc classification
A61P1/04
HUMAN NECESSITIES
A61P29/00
HUMAN NECESSITIES
A61P1/02
HUMAN NECESSITIES
A61P9/10
HUMAN NECESSITIES
A61P43/00
HUMAN NECESSITIES
A61K31/7004
HUMAN NECESSITIES
A61K2300/00
HUMAN NECESSITIES
A61K2300/00
HUMAN NECESSITIES
A61P1/16
HUMAN NECESSITIES
A61P35/00
HUMAN NECESSITIES
A61K45/06
HUMAN NECESSITIES
A61K31/7004
HUMAN NECESSITIES
Y02A50/30
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
A01N1/126
HUMAN NECESSITIES
A61P25/28
HUMAN NECESSITIES
A61P37/06
HUMAN NECESSITIES
International classification
A61K31/7004
HUMAN NECESSITIES
Abstract
The invention discloses sedoheptulose for use in the prevention or treatment of inflammation.
Claims
1. A method of treating inflammation comprising: obtaining sedoheptulose; and administering said sedoheptulose to a subject; wherein inflammation is treated in the subject and the inflammation is further defined as: a systemic inflammatory response syndrome (SIRS) or sepsis; involved, causally or otherwise, in pathogenesis of adiposity, Crohn's disease, multiple sclerosis, diabetic polyneuropathy, Lyme disease, rheumatoid arthritis, ankylosing spondylitis, autoimmune connective tissue disorders, myositis, psoriasis, or atopic dermatitis; involved in pathogenesis of cancer comprising cancer causation, progression, metastasis, resistance to therapy, relapse after therapy, or a cancer manifestation; or involved in acute or chronic transplant rejection or in acute or chronic graft-versus-host disease following autologous, syngeneic or allogeneic bone marrow, peripheral blood stem cell (PBSC) or cord blood transplantation.
2. The method of claim 1, wherein the inflammation is a systemic inflammatory response syndrome (SIRS) or sepsis.
3. The method of claim 2, wherein the inflammation is in response to polytrauma, in response to infection, includes organ-specific manifestations, acute respiratory distress syndrome (ARDS) and/or multiple organ dysfunction syndrome (MODS).
4. The method of claim 1, wherein the inflammation is involved, causally or otherwise, in the pathogenesis of adiposity, Crohn's disease, multiple sclerosis, diabetic polyneuropathy, Lyme disease, rheumatoid arthritis, ankylosing spondylitis, autoimmune connective tissue disorders, myositis, psoriasis, or atopic dermatitis.
5. The method of claim 1, wherein the inflammation is involved in the pathogenesis of cancer comprising cancer causation, progression, metastasis, resistance to therapy, relapse after therapy, or a cancer manifestation.
6. The method of claim 5, wherein the cancer manifestation comprises cancer-related cachexia, anemia, fatigue, or depression.
7. The method of claim 1, wherein the inflammation is involved in acute or chronic transplant rejection or in acute or chronic graft-versus-host disease following autologous, syngeneic or allogeneic bone marrow, peripheral blood stem cell (PBSC) or cord blood transplantation.
8. The method of claim 7, wherein the inflammation is involved in acute or chronic transplant rejection of an allogeneic lung, liver, kidney, heart, intestine, or pancreatic islet cell transplant.
9. The method of claim 1, wherein the sedoheptulose is administered in an amount of 0.001 to 300 g per daily dosage.
10. A method for storage of organs for transplantation purposes comprising: obtaining an organ to be transplanted to a patient; and storing the organ in a storage solution comprising sedoheptulose.
11. The method of claim 10, wherein the storage solution comprises sedoheptulose in a concentration of 0.001 to 500 mg/ml, defined as the concentration of all liquid material attached to or covering the organ to be transplanted.
Description
(1) The present invention is further described in the following examples and the figures, yet without being restricted thereto.
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EXAMPLES
Materials and Methods
(8) Carbohydrates
(9) Glucose and fructose were purchased from Sigma Aldrich. Sedoheptulose was isolated from the plant sedum Spectabile or sedum telephium (Haschemi et al., Cell Metab. 15 (2012), 813-826) and was further purified by chromatography.
(10) Glucose and Sedoheptulose Measurements in Carrots and Human Serum
(11) Fresh carrots with an Austrian organic-certificate were sliced into small pieces and snap-frozen in liquid nitrogen. The same procedure was applied to leaves freshly harvested from indoor-grown Sedum Spectabile plants. Three samples of each tissue were pooled and homogenized to powder by glass-beads. The carbohydrate rich fractions of the samples were isolated by 20% H.sub.2O and 80% MeOH extraction solution spiked with 13C standards and processed for standard gas-chromatography coupled to mass spectrometry (GC-MS). Glucose and sedoheptulose were identified by their individual masses and their relative amount was derived from the peak area of each individual analyte normalized to 13C content. Glucose and sedoheptulose were also measured in equal volumes of serum from overnight fasted or carrot fed individuals. The carrots were steamed and some olive-oil, salt and pepper were used for flavour. Two hours before and two hours after the carrot containing meal human serum was prepared in VACUETTE Z Serum Sep tubes from blood. Serum samples were processed as previously described and also analyzed by GC-MS as detailed above and in Ruiz-Matute A I et al., Chromatogr B Analyt Technol Biomed Life Sci. (2011) May 15 879(17-18).
(12) Glucose, Fructose and Sedoheptulose Concentration in Beverages
(13) Indicated beverages were purchased from a local grocery store and were all pre-packed. From each beverage 1 ml (for each of four technical replicates) was aliquoted and vacuum concentrated on a SpeedVac. This was followed by MeOH/H2O (80:20) precipitation and a centrifugation step to clear the carbohydrate fraction in the supernatant from precipitate. Each supernatant was again lyophilized in a SpeedVac, rehydrated in equal volumes of water and technical replicates were pooled. For carbohydrate analysis a Dionex ICS-3000 DC metal-free system was used with a CarboPac PA1 column (2504 mm) and a CarboPac PA1 guard column (both from Dionex) at a flow rate of 1 mL min-1. Elution was carried out isocratically with 16 mM NaOH for the first 20 min. Then a linear gradient to 100 mM NaOH was applied from 20 to 40 min followed by an increase over two minutes to 200 mM hold until 47 min. The starting condition with 16 mM NaOH was reached again at 49 min and kept until 70 min. Parameters of the pulsed amperometric detection are exactly as recommended in the Technical Note 21 (Optimal Settings for Pulsed Amperometric Detection of Carbohydrates Using the Dionex ED40 Electrochemical Detector) from Dionex. Chromatograms were evaluated according to chromatograms of authentic glucose, fructose and sedoheptulose standards, each 100 M.
(14) Human Adipocyte Culture
(15) Stromal vascular fraction cells (SVFs) from subcutaneous white adipose tissue of a patient undergoing abdominal surgery were isolated as described before (Lindroos et al, Cell Metab. (2013), Jul. 2; 18(1):62-74.). Briefly, adipose tissue was digested with Collagenase II (Worthington) and filtered. SVFs were separated from mature adipocytes by centrifugation, followed by the lysis of erythrocytes in the SVF-fraction (Buffer EL, Qiagen). The purified SVFs were cultured in DMEM/F12, 10% FBS (Gibco, Life Technologies). As soon as the cells reached confluence, they were washed with DMEM/F12 w/o glucose (Biowest) and the medium was replaced by DMEM/F12 with a total carbohydrate load of 3 g/L, containing 1.5 g/L glucose and fructose or 1 g/L each of glucose, fructose, and sedoheptulose, respectively. Two days after confluence (day 0), differentiation was induced by adding 1 M dexamethasone, 1.74 M insulin, 5 M troglitazone, 0.5 M IBMX, 17 M pantothenic acid and 33 M biotin. After two days, IBMX and dexamethasone were omitted, while insulin and troglitazone were removed on day 4. 50% of the medium was replaced on day 6. Two days later, the cells were harvested for RNA isolation (RNeasy mini kit, Qiagen).
(16) Mature Murine Adipocytes Ceiling Culture
(17) Anterior and posterior subcutaneous adipose tissue and epididymal white adipose tissue was isolated from transgenic CARKL-mice and wild-type littermate controls. Adipose tissue was digested as described above for the human sample. After centrifugation, the layer of floating mature adipocytes was removed and re-centrifuged at 100 rcf for 10 minutes. 150 L of packed adipocytes were cultured under a floating coverslip in six-well plates, in DMEM/F12, 15% calf serum (PAA). 24 hours after isolation, the wells were washed twice with PBS and the medium was exchanged to DMEM/F12 with a total carbohydrate load of 3 g/L, containing 1.5 g/L glucose and fructose, or 1 g/L each of glucose, fructose and sedoheptulose, respectively. Three days later, the cells were harvested for RNA isolation using TRIreagent (Sigma).
(18) Hepatocyte Culture
(19) Hepatocytes were isolated from male wild-type and CARKL overexpressing mice after the mice were sacrificed by hepatic in situ collagenase perfusion. After perfusion, the liver was quickly removed, minced, and filtered through a cell strainer (Fisher Scientific, Inc) into a 50 ml sterile tube. Hepatocytes in the resulting filtrate were purified from the nonparenchymal cells by centrifugation steps. The isolated hepatocytes were seeded into plates at a concentration of 0.2510^6/ml in respective DMEM-media containing 10% FBS and indicated carbohydrate mixes at 3 g/L (glucose and fructose (GF), or glucose, fructose and sedoheptulose (GFS)) at least two days before experiments were performed.
(20) Bone Marrow Derived Macrophages and Osteoclasts Culture
(21) Mouse bones were isolated from male wild-type and CARKL overexpressing mice and bone marrow wash flushed, washed and cleared from redblood cells by lysis, and subsequently differentiated in DMEM containing 25 mM glucose and 20 ng/ml M-CSF. After 4 days, cells for osteoclast differentiation were harvested and seeded in corning osteo assay plates with differentiation media (see below), and for primary bone marrow derived macrophages (BMDM) the medium was renewed and further supplemented with M-SCF for two days. Differentiated BMDM were then seeded in respective DMEM-media containing 10% FBS and indicated carbohydrate mixes at 3 g/L (glucose and fructose (GF), or glucose, fructose and sedoheptulose (GFS)) at least two days before experiments were performed.
(22) In Vitro Bone Resorption Assay
(23) Osteoclast precursor cells (bone marrow cells treated with 20 ng/ml M-CSF for 4 days) were plated in 24-well Corning Osteo Assay plate in the presence of 10 ng/ml M-CSF and 100 ng/ml RANKL in alpha-MEM medium containing 10% FBS and 3 g/L either glucose and fructose (GF), or glucose, fructose, and sedoheptulose (GFS). The Medium was renewed every third day. After 7 days, cells were removed with bleach and washed three times with water before Von Kossa staining according to standard protocols from Corning (technical review) was performed to enhance contrast between the intact assay surface and resorption pit. Each well was entirely photographed by TissueFax with an 20 objective and all visible resorption pits were counted and analysed blinded.
(24) Extracellular Acidification Rates and Oxygen Consumption Rates
(25) The XF-Analyzer (Seahorse Bio.) was used to measure changes in cellular metabolism induced by different carbohydrates. Extracellular acidification rates (ECAR, mpH/min) and oxygen consumption rates (OCR, pmoles/min) were recorded in primary human adipocytes and primary murine hepatocytes according to the manufacture instructions. Briefly, cells were seeded in seahorse cell plates at a density of 10^4 cells per well for adipocytes and 0.510^5 cells per well for hepatocytes. At the day of experiments the cells were washed with carbohydrate free media and incubated for one hour in indicated media containing carbohydrate mixes at a concentration of 3 g/L (glucose and fructose (GF), or glucose, fructose and sedoheptulose (GFS)). To measure glucose-induced ECAR, cells were starved for one hour in carbon free media before glucose (1 g/L) was added to the well per automatic injection. Glucose-induced ECAR was normalized to respective ECAR before glucose addition (basal=100%). Changes induced by the different carbohydrate sources were expressed as relative change in % to illustrate the effect of each carbon source.
(26) Gene Expression Analysis
(27) Briefly, total RNA was extracted and reverse-transcribed using commercial kits (QIAGEN, Applied Biosystems). Quantitative real-time PCRs were performed on an AbiPRISM 7900HT real-time cycler using iTaq SYBR Green Supermix with ROX (BioRad) to measure CARKL, adiponectin, UCP-1, TNFa, IL-6, MCP-1, and beta-actin expression as previously described (Haschemi et al., Cell Metab. 15 (2012), 813-826). Expression of target gene was normalized to beta-actin expression. Relative expression of target gene was calculated by the delta-delta CT method.
(28) Sedoheptulose Kinase Assay
(29) The ADP Quest Assay (DiscoveRx) was used to indirectly measure S7P formation by ADP accumulation over time according to the manufacture instructions. Recombinant sedoheptulose kinase was previously produced in E. coli and purified by affinity purification (Haschemi et al., Cell Metab. 15 (2012), 813-826).
(30) Indirect Calorimetry
(31) The respiratory quotient (VCO2 production/VO2 consumption) and energy expenditure (EE, kcal/day/kg^0.75) per activity of mice were measured in metabolic cages (Harvard Apperatus) by indirect calorimetry. Either one CARKL transgenic mouse or a wild-type littermate, was housed per cage for one day before it was started to record mean respiratory quotient and energy expenditure per activity during day (8 am to 4 pm) and night (8 pm to 4 am).
(32) Insulin Tolerance Test
(33) Four hours pre-starved female CARKL-transgenic mice and wild type littermate controls were i.p. injected with 0.75 U insulin/kg body weight. Blood glucose was measured before the injection and 15, 30, 45 and 60 minutes after injection by using one-touch glucose strips (Accu Check, Roche).
(34) Oil Red Staining
(35) Briefly, hepatocytes were cultured as indicated before the medium was removed and cells were fixed by 10% formalin. After a wash with 60% isopropanol the wells were incubated with Oil Red O solution (Sigma-Aldrich) and stained for 10 min, washed 4 times with water before photographs were taken at 20 magnification.
(36) Glucose-6-Phosphate Dehydrogenase Activity Assay
(37) Cells were grown on polystyrene vessel tissue culture treated glass slides, snap frozen in liquid nitrogen and kept at 80 C. The enzyme histochemical procedure was based on the tetrazolium salt method as described by Van Noorden and Frederiks. The incubation medium for the demonstration of G6PD activity contained 18% (w/v) polyvinyl alcohol (average molecular weight 70,000-100,000) in 0.1 M Tris-Maleate buffer, pH 7.5, 15 mM glucose-6-phosphate, 0.8 mM NADP, 0.4 mM magnesium chloride, 0.45 mM 1-methoxyphenazine methosulphate, 5 mM sodium azide and 5 mM tetranitroblue tetrazolium chloride. The medium was freshly prepared immediately before incubation. Control reactions additionally contained 40 mM glucosamine-6-phosphate. Cells were incubated at room temperature for 15 minutes under continuous mixing by orbital shaker. After incubation, cells were washed 35 minutes in 60 C. phosphate buffered saline, dried, and mounted in glycerol gelatin, and photographed within one day at 10 magnification.
(38) Immune Challenge and Cytokine Response Profiling In Vivo
(39) For sublethal murine in vivo endotoxemia, 7 mg/kg LPS (Sigma Aldrich) were injected intraperitoneally in male CARKL transgenic or wild-type littermates. Serum was isolated by VACUETTE mini Z Serum Sep tubes from whole blood. Cytokine were measured by milliplex map mouse cytokine profiler according to manufactures instructions (Millipore). All animal experiments were carried out according to an ethical animal license protocol and contract approved by the Medical University Vienna (BMWF-66.009/0140-II/10b/2010).
(40) CARKL Single Nucleotide Polymorphism (SNP) Association-Study with Risk of Stroke.
(41) Study Design: 578 neurologically asymptomatic patients from the Inflammation and Carotid ArteryRisk for Atherosclerosis Study (ICARAS, Schillinger et al., (2005) Circulation 111 (17):2203-2209.)), recruited until March 2003, were included into the present analysisinclusion and exclusion criteria have been published previously. Briefly, asymptomatic carotid artery disease, representing the primary inclusion criterion, was defined as the absence of transient ischemic attacks (TIA), amaurosis fugax and stroke within the last 12 months or of residual symptoms, respectively. Besides exhaustive medical examination (including anamnesis, physical status and blood testing), patients underwent sonography of the carotid arteries at baseline and at a follow-up 6-9 months after study inclusion as previously described (Schillinger et al., (2005) Circulation 111 (17):2203-2209.). Incidence of cardiovascular events was recorded until January 2006. This analysis was approved by the local ethics committee (EC-No. 1933/2012) and has been performed in accordance with the ethical standards specified by the Declaration of Helsinki and its amendments.
(42) Definitions: Arterial hypertension was defined as repetitive resting blood pressure above 140/90 mm Hg and was assumed to be present in patients with antihypertensive medication. Hyperlipidemia was diagnosed in patients with a total serum cholesterol >200 mg/dL or LDL cholesterol >130 mg/dL and was considered to be present in all patients taking lipid-lowering drugs. Diabetes mellitus was diagnosed as supposed by Expert Committee on the Diagnosis and Classification of Diabetes Mellitus. Peripheral artery disease was graded using Fontaine's classification system, coronary artery disease was defined according to the classification by the Canadian Cardiovascular Society (CCS). Anamnestic myocardial infarction was defined according to Alpert. Stroke was defined by a neurological deficit persisting >24 h and was evaluated according to the modified Rankin stroke scale. Progression of carotid artery atherosclerosis was defined as an increase in stenosis by at least one NASCET angiographic degree.
(43) Genotyping: DNA was isolated from EDTA-anticoagulated whole blood by means of spin-column based nucleic acid purification. Genotyping was done on an ABI TaqMan 7900HT fast-realtime thermocycler (Applied Biosystems, Rotkreuz, Switzerland) using the 5-Nuclease-Assay[7]. This assay includes the sequence-specific binding of labeled DNA-probes. During the annealing phase of each step, sequence-specific probes containing a fluorophore on their 5-ends bind their respective allele. The fluorescence of the fluorophore is masked by a 3-quencher, until the 5-Taq-polymerase separates these compounds by its 5-exonuclease activity during the elongation phase. End-point-measurement of the intensity of sequence-specific fluorescence indicates the presence of the corresponding allele. In the present study, rs465563 was analyzed in a total reaction volume of 10 L using a commercially available TaqMan SNP genotyping assay (Assay ID: C_717358_1_, Applied Biosystems) and TaqMan Genotyping Master Mix (Applied Biosystems) according to the standard protocol supplied by the manufacturer. The results were interpreted using SDS 2.4 sequence detection software (Applied Biosystems).
(44) Statistical Analysis: Continuous data are given with respect to its distribution as mean and standard deviation or median and interquartile range. Categorical data are presented as counts and percentage. Presence of normal distribution within subgroups was assessed by Kolmogorov-Smirnov-tests. Metric variables were compared by Mann-Whitney U tests. Connections between genotypes and study end points as well as relative risks were estimated by contingency-tables and Pearson's .sup.2-tests. Event-free survival was estimated by Kaplan-Meier-Analysis, data was compared pairwise by Log Rank (Mantel-Cox) tests. Multivariable models were calculated by means of binary logistic regression and evaluated by drawing ROC (Receiver-Operator-Characteristics) plots. Results were considered statistically significant at p<0.05 unless otherwise noted. All p-values were interpreted two-sided unless otherwise stated. All statistical calculations were done using IBM SPSS 20.0 (IBM Corporation, Armonk, USA).
(45) Results
(46) Diet-Derived Sedoheptulose Uptake in Humans
(47) To determine if nutritional sedoheptulose is absorbed from diets via the digestive tract into the human blood, which is a critical step for sedoheptulose to become a metabolic active carbohydrate, glucose (C6) and sedoheptulose (C7) levels were measured in carrots and in human serum. To determine the C6/C7 ratio of carrots plant tissue was homogenized, extracted the small molecule fractions and measured simultaneously relative glucose and sedoheptulose amounts by GC-MS (
(48) These results indicate that carrots, which are considered as healthy vegetables and constituents of diets around the world, are a natural sedoheptulose source for humans. It is interesting to mention that carrots, although they contain carbohydrates such as glucose, are suitable and well tolerated by diabetics and even protect people with common genetic risk factors for type-2 diabetes (Patel C J et al., Hum Genet. 132 (2013): 495-508).
(49) The C6/C7 Ratio in Natural and Manufactured Human Food Products
(50) Next, the concentration of glucose, fructose and sedoheptulose was measured in carbohydrate extracts from Coca-Cola, Red Bull, orange-, apple-, tomato-, and carrot-juice to establish the C6/C7 index for common beverages and thereby estimate the actual human sedoheptulose-exposure. Soft- and energy drinks contained glucose and fructose but no sedoheptulose (
(51) Sedoheptulose Kinase Oscillates and is Highly Expressed in Metabolically Active Tissue.
(52) To understand how sedoheptulose kinase CARKL and therefore sedoheptulose metabolism is distributed and controlled in various mammalian tissues, different tissues were tested for mRNA expression levels. CARKL expression, in a publicly available database for circadian expression profiles (CircaDB), was found oscillating in mouse liver (period 20.0,
(53) Sedoheptulose Metabolism is Important for the Function and Metabolic Health of Cells
(54) To investigate the metabolic consequences of exposure to sedoheptulose, human and murine cells in the culture media were exposed to either glucose in combination with fructose (GF) or to glucose, fructose and sedoheptulose (GFS), while keeping the total carbohydrate load constant. The function of adipocytes, hepatocytes and macrophages was tested to evaluate the importance of sedoheptulose in complementing nutritional carbohydrate loads. The sedoheptulose used in these experiments was isolated from sedum telephium plants.
(55) In the human body, adipocytes fulfil the crucial function to store energy in form of lipids and are therefore very important cells to maintain health. In metabolically unhealthy or in most morbidly obese patients adipocytes do not function properly, increase their cell size to account for excessive lipid loads, become inflamed (meta-inflammation, a low-grade but chronic type of inflammation) and ultimately contribute to the development of disorders like insulin resistance or cardio-vascular diseases. In human adipocytes, differentiated from subcutaneous precursor cells, an increase in sedoheptulose kinase CARKL mRNA expression was found if sedoheptulose was added to the culture media (
(56) Together, these data show that subcutaneous adipocytes maintain and improve their function (increase in adiponectin, UCP-1 and oxygen consumption) in the presence of sedoheptulose compared to a situation where only glucose and fructose are present as bio-fuel.
(57) To better define the beneficial role of sedoheptulose in preventing metabolically unhealthy states like chronic low-grade inflammation, the cytokine profiles of primary mature murine adipocytes, primary murine hepatocytes, and nave as well as lipopolysaccharide (LPS)-induced activated primary macrophages cultured in GF or GFS media were measured. Mature adipocytes, which were cultivated in sedoheptulose containing media, produced less TNFa and IL-6 mRNA than adipocytes cultivated with glucose and fructose alone (
(58) To conclude, addition of sedoheptulose to the culture media significantly enhanced subcutaneous adipocyte function and reduced the inflammatory state of cells and thereby might positively influence the pathogenesis of obesity, type II diabetes and cardiovascular diseases also summarized in part by the metabolic syndrome.
(59) Sedoheptulose Kinase CARKL Overexpression
(60) Transgenic mice overexpressing sedoheptulose kinase ubiquitously in the entire body were generated to isolate genetically engineered primary cells overexpressing CARKL and to test sedoheptulose metabolism in vivo. CARKL transgenic mice did not show any obvious phenotypes and their organ weight was not different to organ weights of WT littermate control animals (data not shown). It was hypothesized that increased sedoheptulose metabolism can either be achieved by increasing the concentration of the substrate sedoheptulose, or by elevating the level of its rate-limiting enzyme sedoheptulose kinase (CARKL). To test this in an in vitro kinase assay, a constant amount of recombinant CARKL protein was incubated with increased doses of sedoheptulose. This resulted in enhanced sedoheptulose turnover rates as measured by ADP formation (
(61) Hepatocytes were cultured in media with a C6/C7 sugar ratio of 2:1 and metabolically assessed by comparing the ECAR and OCR as more general metabolic-parameters. Hepatocytes from CARKL overexpressing mice significantly increased their metabolic rate as increased ECAR and OCR levels indicated if compared to WT control cells (
(62) These results further supported the previous data and clearly pointed out that increased sedoheptulose metabolism has distinct and beneficial effects on cells, which are important for metabolic health.
(63) Sedoheptulose Metabolism In Vivo
(64) After validating cellular phenotypes of sedoheptulose kinase overexpression in hepatocytes the metabolic effect of increased sedoheptulose turnover to an entire organism was investigated by comparing the respiratory quotient (RQ; RQ=exhaled CO.sub.2/oxygen consumption), as well as energy expenditure per physical activity of control and sedoheptulose kinase transgenic mice, measured by indirect calorimetry during day and night as systemic indicators of metabolism (
(65) Together, these experiments showed that increased sedoheptulose metabolism does not only alter metabolism in vitro but also in vivo. The lower RQ values observed in CARKL mice combined with the by trend lower EE per physical activity and the increased insulin sensitivity are indicative for a more efficient and sustainable metabolic program, which can be induced by increasing sedoheptulose metabolism.
(66) Hepatic Lipid Deposition is Reduced by CARKL
(67) Extensive lipid deposition in hepatocytes results in fatty liver disease and can be accompanied by inflammation (i.e. non-alcoholic steatohepatitis (NASH)) causing liver fibrosis, cirrhosis, and eventually hepatocellular carcinoma. The lipid content of hepatocytes from WT and CARKL overexpressing mice was compared and it was found that hepatocytes from CARKL mice contained less lipid droplets than their WT controls (
(68) In conclusion, high liver fat content, especially in combination with inflammation, including malfunction of adipocytes, increases risk of many diseases including type 2 diabetes or cancer, thus both, the reduction of inflammation and lipid accumulation in hepatocytes by sedoheptulose might be especially valuable for human nutrition (see vegetables, which contain high C7 levels).
(69) CARKL Regulates Glucose-6-phosphate Dehydrogenase Activity.
(70) Glucose-6-phosphate dehydrogenase (G6PD), the rate limiting enzyme of the oxidative arm of the pentose phosphate pathway (PPP) which generates C5 bodies i.e. for nucleotide synthesis and redox-equivalents, was previously shown to be directly inhibited by p53 (tumor-suppressor) (Jiang et al., Nat Cell Biol. (2011) March; 13(3):310-6). Mutation in p53, the most frequently mutated gene in human tumors, results in hyper-activation of G6PD and lipid accumulation in hepatocytes. Sedoheptulose kinase is the rate-limiting kinase of the non-oxidative arm of the PPP and was previously shown to reduce the oxidative PPP-flux, at least in macrophages. To test for a possible regulation of G6PD activity in hepatocytes by sedoheptulose metabolism, the enzyme activity of WT and CARKL overexpressing cells was compared (
(71) This data also implements sedoheptulose metabolism as a suitable target to regulate G6DP activity and for future anti-cancer strategies.
(72) Sedoheptulose and Bone Metabolism
(73) Bone is an extremely dynamic tissue. The fine balance of bone formation and resorption is essential for the proper mechanical stability of bone. Disequilibrium between bone formation and resorption is the cause of osteoporosis, a highly prevalent condition of reduced bone density and disturbed bone micro-architecture resulting in bone fragility and pathological fractures. As the osteoclasts, the cells responsible for bone resorption are derived from the monocyte lineage, whose function is strongly impacted by sedoheptulose metabolism, it was also tested whether osteoclast function may be modulated by the C6/C7 ratio.
(74) Bone marrow cells were differentiated in vitro to osteoclasts by exposing the cells to M-CSF in combination with RANKL. The cells were cultured in plates, pre-coated with a bone mineral matrix at the bottom of the well, to provide substrate for their bone-resorption activity. Analysis of the substrate resorption clearly demonstrated that both, CARKL overexpression as well as increasing C7 content in the culture media, reduced pit formation by osteoclasts (
(75) Again, this data supports the concept of the present invention that a well-balanced C6/C7 ratio is crucial to maintain health and that C7 has the potential to alleviate the pathophysiologic situations of i.e. osteoporosis in humans.
(76) Sedoheptulose Kinase Regulates the Immune Response of Animals
(77) Data of CARKL overexpression and its effects on the mouse immune-system in a model of acute immune activation and in low-grade inflammation of mature adipose tissue is presented with the present examples. In CARKL mice acute-inflammation was elicited by a sub-lethal lipopolysaccharide (LPS) injection, which resulted in a suppressed cytokine response compared to wild-type controls (
(78) This indicates that a nutritional supplement containing sedoheptulose might dampen acute and low-grade chronic inflammation. Therefore, targeting C7 metabolism, either by nutritional or clinically applied sedoheptulose appears as an effective measure to reduce inflammation and associated disorders.
(79) A single nucleotide polymorphism (SNP) in the 3-UTR of the CARKL gene is associated with the risk of stroke.
(80) 535 neurologically asymptomatic patients from the Inflammation and Carotid ArteryRisk for Atherosclerosis Study (ICARAS, Schillinger et al., (2005) Circulation 111 (17):2203-2209) were genotyped for the rs465563 [A] to [G] substitution in the 3-UTR of the CARKL gene. 33 (6.2%) patients suffered a stroke within the observation period. In those patients, the distribution of rs465563 alleles was significantly different compared to the allele frequencies of the rest of the study population (.sup.2=12.639, df=2, p=0.002, see
(81) The mechanistical background of this clinical association remains to be clarified. However, given the ability of CARKL to modulate macrophage polarization and the key role of the latter in the formation and progression of atherosclerotic plaques, it seems likely that the rs465563 polymorphism may impact on the risk of cerebrovascular events via modulation of macrophage polarization within atherosclerotic plaques. This notion is supported by the observation according to the present invention that the 3-UTR of the CARKL gene is mainly transcribed in macrophages.
(82) In conclusion, this association and the provided data on metabolism and function of adipocytes, hepatocytes, and macrophages in combination with reduced inflammation and enhanced insulin sensitivity in vitro and in vivo strongly indicates that sedoheptulose (C7-sugar) is a critical constituent for human nutrition and simultaneously a highly relevant medication to treat i.e. C7-deficiencies or other metabolic unhealthy disease states.