Role of Phytomolecules in the Treatment of Obesity: Targets, Mechanisms and Limitations.

Obesity has become a worldwide health problem. It triggers additional co-morbidities like cardiovascular diseases, cancer, depression, sleep disorders, gastrointestinal problems and many more. Excess accumulation of fat in obesity could be caused by many factors like sedentary lifestyle, consumption of high-fat diet, genetic predisposition, etc. Imbalanced energy metabolism i.e., greater energy consumption than utilisation, invariably underlies obesity. Considering the high prevalence and continuous, uncontrolled increase of this major public health issue, there is an urgent need to find appropriate therapeutic agents with minimal or no side effects. The high prevalence of obesity in recent years has led to a surge in the number of drugs available in the market that claim to control obesity. Although there is a long list of medicines and management strategies that are available, selecting the right therapeutic intervention and feasible management of obesity is a challenge. Several phytochemicals like hydroxycitric acid, flavonoids, tannins, anthocyanins, phytohaemagglutinin, thymoquinone and epigallocatechin gallate have been shown to possess promising anti-obesity properties. However, studies providing information on how various phytochemicals exert their anti-obesity effects are inadequate. This calls for more experimentation in this less explored area of research. Additionally, the complication of obesity arises when it is a result of multiple factors and associated with a number of co-morbidities. In order to handle such complexities, combinatorial therapeutic interventions become effective. In this review, we have described the medicinal chemistry of different highly effective phytochemicals which can be used in the effective treatment and management of obesity.

The complex role of adipokines in obesity, inflammation, and autoimmunity.

The global obesity epidemic is a major contributor to chronic disease and disability in the world today. Since the discovery of leptin in 1994, a multitude of studies have characterized the pathological changes that occur within adipose tissue in the obese state. One significant change is the dysregulation of adipokine production. Adipokines are an indispensable link between metabolism and optimal immune system function; however, their dysregulation in obesity contributes to chronic low-grade inflammation and disease pathology. Herein, I will highlight current knowledge on adipokine structure and physiological function, and focus on the known roles of these factors in the modulation of the immune response. I will also discuss adipokines in rheumatic and autoimmune diseases.

Zinc-α2-glycoprotein as an inhibitor of amine oxidase copper-containing 3.

Zinc-α2-glycoprotein (ZAG) is a major plasma protein whose levels increase in chronic energy-demanding diseases and thus serves as an important clinical biomarker in the diagnosis and prognosis of the development of cachexia. Current knowledge suggests that ZAG mediates progressive weight loss through ß-adrenergic signalling in adipocytes, resulting in the activation of lipolysis and fat mobilization. Here, through cross-linking experiments, amine oxidase copper-containing 3 (AOC3) is identified as a novel ZAG binding partner. AOC3-also known as vascular adhesion protein 1 (VAP-1) and semicarbazide sensitive amine oxidase (SSAO)-deaminates primary amines, thereby generating the corresponding aldehyde, H2O2 and NH3. It is an ectoenzyme largely expressed by adipocytes and induced in endothelial cells during inflammation. Extravasation of immune cells depends on amine oxidase activity and AOC3-derived H2O2 has an insulinogenic effect. The observations described here suggest that ZAG acts as an allosteric inhibitor of AOC3 and interferes with the associated pro-inflammatory and anti-lipolytic functions. Thus, inhibition of the deamination of lipolytic hormone octopamine by AOC3 represents a novel mechanism by which ZAG might stimulate lipolysis. Furthermore, experiments involving overexpression of recombinant ZAG reveal that its glycosylation is co-regulated by oxygen availability and that the pattern of glycosylation affects its inhibitory potential. The newly identified protein interaction between AOC3 and ZAG highlights a previously unknown functional relationship, which may be relevant to inflammation, energy metabolism and the development of cachexia.

An MRM-Based Multiplexed Quantification Assay for Human Adipokines and Apolipoproteins.

Adipokines and apolipoproteins are key regulators and potential biomarkers in obesity and associated diseases and their quantitative assessment is crucial for functional analyses to understand disease mechanisms. Compared to routinely used ELISAs, multiple reaction monitoring (MRM)-based mass spectrometry allows multiplexing and detection of proteins for which antibodies are not available. Thus, we established an MRM method to quantify 9 adipokines and 10 apolipoproteins in human serum. We optimized sample preparation by depleting the two most abundant serum proteins for improved detectability of low abundant proteins. Intra-day and inter-day imprecision were below 16.5%, demonstrating a high accuracy. In 50 serum samples from participants with either normal weight or obesity, we quantified 8 adipokines and 10 apolipoproteins. Significantly different abundances were observed for five adipokines (adipsin, adiponectin, chemerin, leptin, vaspin) and four apolipoproteins (apo-B100/-C2/-C4/-D) between the body mass index (BMI) groups. Additionally, we applied our MRM assay to serum samples from normal weight children and human adipocyte cell culture supernatants to proof the feasibility for large cohort studies and distinct biological matrices. In summary, this multiplexed assay facilitated the investigation of relationships between adipokines or apolipoproteins and phenotypes or clinical parameters in large cohorts, which may contribute to disease prediction approaches in the future.

MicroRNA-199a regulates myocardial fibrosis in rats by targeting SFRP5.

OBJECTIVE: Myocardial fibrosis seriously affects normal heart function. This study focused on the role of microRNA-199a in regulating rat myocardial fibrosis by targeting secreted frizzled-related protein 5 (SFRP5). MATERIALS AND METHODS: The in vitro myocardial fibrosis model was established by 10 µM isoproterenol (ISO) induction in cardiac fibroblasts (CFs) for 24 h. Expression levels of microRNA-199a, collagen I and α smooth muscle actin (α-SMA) were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Protein levels of SFRP5 and transforming growth factor-ß1 (TGF-ß1) in CFs were detected by Western blot. The binding condition between microRNA-199a and SFRP5 was verified by luciferase reporter gene assay. After transfection of microRNA-199a inhibitor or SFRP5 overexpression plasmid, proliferative and migratory rates of CFs were determined by cell counting kit-8 (CCK-8) and transwell assay, respectively. RESULTS: ISO treatment remarkably upregulated microRNA-199a expression in CFs. Transfection of microRNA-199a inhibitor could inhibit proliferation, migration and cardiac fibroblast-to-myofibroblast transformation (CMT) of CFs. Luciferase reporter gene assay confirmed the binding of microRNA-199a to SFRP5 3'UTR. Moreover, SFRP5 overexpression reversed the effects of microRNA-199a inhibitor on proliferation, migration, and CMT of CFs. CONCLUSIONS: MicroRNA-199a deficiency can inhibit the proliferative and migratory potentials of CFs, as well as CMT by targeting SFRP5, thus exerting the protective effect on myocardial fibrosis.

N-Linked Glycosylation-Dependent and -Independent Mechanisms Regulating CTRP12 Cleavage, Secretion, and Stability.

C1q/TNF-related protein 12 (CTRP12) is a secreted regulator of glucose and lipid metabolism. It circulates in plasma as a full-length protein or as a cleaved isoform generated by furin/PCSK3 cleavage. These isoforms preferentially activate different signaling pathways, and their ratio in plasma is altered in obesity and diabetes. Here, we show that three conserved asparagine residues (Asn-39, Asn-287, and Asn-297) play important roles in modulating CTRP12 cleavage, secretion, and stability. Mass spectrometry analysis provided direct evidence of Asn-39 glycosylation. When N-linked glycosylation was inhibited by tunicamycin or abolished by the N39Q, N39A, or T41A mutation, CTRP12 cleavage was enhanced. Complex-type N-glycans on CTRP12 blocked cleavage by the Golgi-localized furin. In N-acetylglucosaminyltransferase I (GnTI)-deficient cells that could not form hybrid and complex-type N-glycans in the Golgi, CTRP12 cleavage was enhanced, and re-expressing GnTI reduced cleavage. Replacing the nonglycosylated Asn-297 with glutamine or alanine also increased CTRP12 cleavage. Both Asn-39 and Asn-297 contributed independently to CTRP12 cleavage: maximum cleavage was observed in the double mutant. In addition, CTRP12 cleavage was abolished in furin-deficient cells and restored by furin re-expression. Replacing the nonglycosylated Asn-287 with glutamine or alanine resulted in protein misfolding and aggregation, leading to retention in the endoplasmic reticulum. Cycloheximide chase analyses indicated reduced protein stability for N39Q, T41A, and N297Q mutants. Lastly, we show that increasing the flux through the hexosamine biosynthesis pathway by exogenous glucosamine, known to disrupt protein glycosylation, also promoted CTRP12 cleavage. Combined, these data highlight glycosylation-dependent and -independent mechanisms regulating CTRP12 cleavage, secretion, and protein stability.

Identification of Novel Natural Substrates of Fibroblast Activation Protein-alpha by Differential Degradomics and Proteomics.

Fibroblast activation protein-alpha (FAP) is a cell-surface transmembrane-anchored dimeric protease. This unique, constitutively active serine protease has both dipeptidyl aminopeptidase and endopeptidase activities and can hydrolyze the post-proline bond. FAP expression is very low in adult organs but is upregulated by activated fibroblasts in sites of tissue remodeling, including fibrosis, atherosclerosis, arthritis and tumors. To identify the endogenous substrates of FAP, we immortalized primary mouse embryonic fibroblasts (MEFs) from FAP gene knockout embryos and then stably transduced them to express either enzymatically active or inactive FAP. The MEF secretomes were then analyzed using degradomic and proteomic techniques. Terminal amine isotopic labeling of substrates (TAILS)-based degradomics identified cleavage sites in collagens, many other extracellular matrix (ECM) and associated proteins, and lysyl oxidase-like-1, CXCL-5, CSF-1, and C1qT6, that were confirmed in vitro In addition, differential metabolic labeling coupled with quantitative proteomic analysis also implicated FAP in ECM-cell interactions, as well as with coagulation, metabolism and wound healing associated proteins. Plasma from FAP-deficient mice exhibited slower than wild-type clotting times. This study provides a significant expansion of the substrate repertoire of FAP and provides insight into the physiological and potential pathological roles of this enigmatic protease.

Adipokines expression profile in liver, adipose tissue and muscle during chicken embryo development.

In broiler chickens, the intense genetic selection for rapid growth has resulted in an increase in growth rate and fat deposition. Adipose tissue is now recognized as an important endocrine organ that secretes a variety of factors including adipokines. However, the expression pattern of these adipokines is unclear in chicken embryo development. In the present study, we determined the expression profile of three novel adipokines, NAMPT, RARRES2 and ADIPOQ, and their cognate receptors in metabolic tissues (liver, muscles and adipose tissue) of chicken embryo/chicks from 15 days of incubation (E15) to hatching (D0). From E15 to hatching, embryos gradually gained weight and started to develop subcutaneous adipose tissue at E15. We conducted western blot and RT-qPCR tests and found that ADIPOQ expression increased over time and was positively correlated with adipose tissue weight. In addition, NAMPT expression increased only in muscles. By using a new homemade chicken RARRES2 specific antibody we showed that RARRES2 protein levels increased specifically at hatching in adipose tissue, liver and pectoralis major and this was associated with an increase in the weight of embryo. Taken together, these results support a potential involvement of adipokines in metabolic regulation during chicken embryo development.

Adipokines and Myokines: A Pivotal Role in Metabolic and Cardiovascular Disorders.

Obesity induces an imbalance in the expression and secretion of several cytokines, which contributes to the development of metabolic and cardiovascular disorders. On the contrary, skeletal muscle is known to have a role in reversing the detrimental impact of obesity. It has been established that adipose tissue acts as an endocrine organ that secretes proinflammatory and anti-inflammatory adipokines. Similarly, skeletal muscle produces secretory molecules, called myokines, from contracting muscle fibers. Myokines were recently recognized as beneficial modulators of obesity, metabolic syndrome, and type 2 diabetes. Furthermore, adipokines and myokines play a crucial role in the communication between adipose tissue, skeletal muscle and other organs. It could be beneficial to find novel adipokines and myokines, and to explore their signaling pathways to identify targets for the treatment and prevention of cardiometabolic disorders. In this review, we summarize recent studies on cross-talk between skeletal muscle and adipose tissue. In particular, we concentrate on the major action mechanisms of adipokines and myokines, such as adiponectin, adipocyte fatty acid binding protein, C1q/TNF-related proteins, interleukin- 6, irisin, and fibroblast growth factor 21.

Adipose derived delivery vehicle for encapsulated adipogenic factors.

Hydrogels derived from adipose tissue extracellular matrix (AdECM) have shown potential in the ability to generate new adipose tissue in vivo. To further enhance adipogenesis, a composite adipose derived delivery system (CADDS) containing single- and double-walled dexamethasone encapsulated microspheres (SW and DW Dex MS) has been developed. Previously, our laboratory has published the use of Dex MS as an additive to enhance adipogenesis and angiogenesis in adipose tissue grafts. In the current work, AdECM and CADDS are extensively characterized, in addition to conducting in vitro cell culture analysis. Study results indicate the AdECM used for the CADDS has minimal cellular and lipid content allowing for gelation of its collagen structure under physiological conditions. Adipose-derived stem cell (ASC) culture studies confirmed biocompatibility with the CADDS, and adipogenesis was increased in experimental groups containing the hydrogel scaffold. In vitro studies of AdECM hydrogel containing microspheres demonstrated a controlled release of dexamethasone from SW and DW formulations. The delivery of Dex MS via an injectable hydrogel scaffold combines two biologically responsive components to develop a minimally, invasive, off-the-shelf biomaterial for adipose tissue engineering. STATEMENT OF SIGNIFICANCE: Scientists and doctors have yet to develop an off-the-shelf product for patients with soft tissue defects. Recently, the use of adipose derived extracellular matrix (adECM) to generate new adipose tissue in vivo has shown great promise but individually, adECM still has limitations in terms of volume and consistency. The current work introduces a novel composite off-the-shelf construct comprised of an adECM-based hydrogel and dexamethasone encapsulated microspheres (Dex MS). The hydrogel construct serves not only as an injectable protein-rich scaffold but also a delivery system for the Dex MS for non-invasive application to the defect site. The methods and results presented are a progressive step forward in the field of adipose tissue engineering.

Progranulin, a New Adipokine at the Crossroads of Metabolic Syndrome, Diabetes, Dyslipidemia and Hypertension.

BACKGROUND: Progranulin is a multifunctional regulatory protein with growth-promoting, neuroprotective and antiinflammatory activities. Recent studies indicate that progranulin is one of the adipose tissue hormones (adipokines). Progranulin expression in visceral adipose tissue and circulating progranulin concentration are increased in obesity and hyperprogranulinemia is involved in the pathogenesis of obesity-associated insulin resistance. Progranulin impairs insulin signaling and reduces insulin-induced glucose uptake both in vitro and in vivo whereas progranulin deficiency protects from high fat diet-induced insulin resistance. Several studies, including some prospective ones, have demonstrated the association between high progranulin and type 2 diabetes and its complications such as nephro- and retinopathy as well as non-alcoholic fatty liver disease. It is quite well established that progranulin contributes to insulin resistance and resulting deterioration of carbohydrate metabolism. In addition, progranulin may be associated with the development of diabetic microangiopathy, fatty liver disease and possibly with the increased risk of cancer in subjects with the metabolic syndrome. On the other hand, progranulin augments vasorelaxation, inhibits inflammatory reaction, is neuroprotective and reduces ischemiareperfusion injury. CONCLUSION: Progranulin has both detrimental and beneficial effects. More clinical studies including prospective ones are needed to clarify the role of progranulin in obesity-associated pathologies such as diabetes, hyperlipidemia, hypertension and atherosclerosis.

Identification of Putative Receptors for the Novel Adipokine CTRP3 Using Ligand-Receptor Capture Technology.

METHODS: We used Ligand-receptor glycocapture technology with TriCEPS™-based ligand-receptor capture (LRC-TriCEPS; Dualsystems Biotech AG). The LRC-TriCEPS experiment with CTRP3-FLAG protein as ligand and insulin as a control ligand was performed on the H4IIE rat hepatoma cell line. RESULTS: Initial analysis demonstrated efficient coupling of TriCEPS to CTRP3. Further, flow cytometry analysis (FACS) demonstrated successful oxidation and crosslinking of CTRP3-TriCEPS and Insulin-TriCEPS complexes to cell surface glycans. Demonstrating the utility of TriCEPS under these conditions, the insulin receptor was identified in the control dataset. In the CTRP3 treated cells a total enrichment of 261 peptides was observed. From these experiments 5 putative receptors for CTRP3 were identified with two reaching statistically significance: Lysosomal-associated membrane protein 1 (LAMP-1) and Lysosome membrane protein 2 (LIMP II). Follow-up Co-immunoprecipitation analysis confirmed the association between LAMP1 and CTRP3 and further testing using a polyclonal antibody to block potential binding sites of LAMP1 prevented CTRP3 binding to the cells. CONCLUSION: The LRC-TriCEPS methodology was successful in identifying potential novel receptors for CTRP3. RELEVANCE: The identification of the receptors for CTRP3 are important prerequisites for the development of small molecule drug candidates, of which none currently exist, for the treatment NAFLD.

Cloning and Expression of SFRP5 in Tibetan Chicken and its Relationship with IMF Deposition.

Secreted frizzled related protein 5 (SFRP5), an anti-inflammatory adipokine, is relevant to the adipocyte differentiation. In order to clarify its role in regulating intramuscular fat (IMF) deposition in Tibetan chicken, the full-length sequence of the Tibetan chicken SFRP5 gene was cloned. The relative expression of SFRP5 gene was detected using quantitative RT-PCR in various tissues of 154 days old Tibetan chicken, as well as in breast muscle, thigh muscle, and adipose tissue at different growth stages. The results showed that SFRP5 gene was expressed in all examined tissues but highly enriched in adipose tissue. Temporal expression profile showed that the expression of SFRP5 was gradually decreased in breast muscle, but was fluctuated in thigh muscle and adipose tissue with the growth of Tibetan chicken. Furthermore, correlation analysis demonstrated that the expression of SFRP5 in breast muscle, thigh muscle and adipose tissue was correlated with IMF content at different levels. The results indicated that Tibetan chicken SFRP5 is involved in IMF deposition.

Role of chitinase-like proteins in cancer.

Chitinase-like proteins (CLPs) are lectins combining properties of cytokines and growth factors. Human CLPs include YKL-40, YKL-39 and SI-CLP that are secreted by cancer cells, macrophages, neutrophils, synoviocytes, chondrocytes and other cells. The best investigated CLP in cancer is YKL-40. Serum and plasma levels of YKL-40 correlate with poor prognosis in breast, lung, prostate, liver, bladder, colon and other types of cancers. In combination with other circulating factors YKL-40 can be used as a predictive biomarker of cancer outcome. In experimental models YKL-40 supports tumor initiation through binding to RAGE, and is able to induce cancer cell proliferation via ERK1/2-MAPK pathway. YKL-40 supports tumor angiogenesis by interaction with syndecan-1 on endothelial cells and metastatic spread by stimulating production of pro-inflammatory and pro-invasive factors MMP9, CCL2 and CXCL2. CLPs induce production of pro- and anti-inflammatory cytokines and chemokines, and are potential modulators of inflammatory tumor microenvironment. Targeting YKL-40 using neutralizing antibodies exerts anti-cancer effect in preclinical animal models. Multifunctional role of CLPs in regulation of inflammation and intratumoral processes makes them attractive candidates for tumor therapy and immunomodulation. In this review we comprehensively analyze recent data about expression pattern, and involvement of human CLPs in cancer.

C-peptide modifies leptin and visfatin secretion in human adipose tissue.

OBJECTIVE: The effects of C-peptide on adipose tissue, an organ involved in the development of obesity and insulin resistance, are not yet well known. The aim of this study was to determine whether C-peptide could be involved in the regulation of the adipocytokine synthesis in human visceral adipose tissue. METHODS: The association between C-peptide and different serum adipocytokines, with an intravenous glucose tolerance test (IVGTT), and in an in vitro study in subjects without obesity and in subjects with morbid obesity were analyzed. RESULTS: In different multiple regression analysis models, C-peptide and C-peptide increase above basal levels during total IVGTT and between 0 and 10 min were associated positively with leptin and negatively with visfatin. Rhodamine-labeled C-peptide binds to human adipocytes, and this binding was blocked with excess of unlabeled C-peptide. Exposure of human visceral explants and adipocytes from subjects with morbid obesity to C-peptide at 1 and 10 nM induced a significant increase in leptin and a decrease in visfatin secretion. In subjects without obesity, these C-peptide effects were found mainly at 10 nM. These effects can be inhibited by phosphatidylinositol 3-kinase (PI3K) or protein kinase B (PKB) inhibitors. CONCLUSIONS: C-peptide may be involved in the regulation of leptin and visfatin secretion, molecules intimately involved in energy homeostasis processes, through PI3K or PKB pathways.

Two novel tyrosine-containing peptides (Tyr(4)) of the adipokinetic hormone family in beetles of the families Coccinellidae and Silphidae.

Novel members of the adipokinetic hormone family of peptides have been identified from the corpora cardiaca (CC) of two species of beetles representing two families, the Silphidae and the Coccinellidae. A crude CC extract (0.3 gland equivalents) of the burying beetle, Nicrophorus vespilloides, was active in mobilizing trehalose in a heterologous assay using the cockroach Periplaneta americana, whereas the CC extract (0.5 gland equivalents) of the ladybird beetle, Harmonia axyridis, exhibited no hypertrehalosemic activity. Primary sequences of one adipokinetic hormone from each species were elucidated by liquid chromatography coupled to electrospray mass spectrometry (LC-MS). The multiple MS(N) electrospray mass data revealed an octapeptide with an unusual tyrosine residue at position 4 for each species: pGlu-Leu-Thr-Tyr-Ser-Thr-Gly-Trp amide for N. vespilloides (code-named Nicve-AKH) and pGlu-Ile-Asn-Tyr-Ser-Thr-Gly-Trp amide for H. axyridis (code-named Harax-AKH). Assignment of the correct sequences was confirmed by synthesis of the peptides and co-elution in reversed-phase high-performance liquid chromatography with fluorescence detection or by LC-MS. Moreover, synthetic peptides were shown to be active in the heterologous cockroach assay system, but Harax-AKH only at a dose of 30 pmol, which explains the negative result with the crude CC extract. It appears that the tyrosine residue at position 4 can be used as a diagnostic feature for certain beetle adipokinetic peptides, because this feature has not been found in another order other than Coleoptera.

Adipokines and their receptors: potential new targets in cardiovascular diseases.

Adipose tissue is an 'endocrine organ' that influences diverse physiological and pathological processes via adipokines secretion. Strong evidences suggest that epicardial and perivascular adipose tissue can directly regulate heart and vessels' structure and function. Indeed, in obesity there is a shift toward the secretion of adipokines that promote a pro-inflammatory status and contribute to obesity cardiomyopathy. The prospect of modulating adipokines and/or their receptors represents an attractive perspective to the treatment of cardiovascular diseases. In this paper, we described the most important actions of certain adipokines and their receptors that are capable of influencing cardiovascular physiology as well as their possible use as therapeutic targets.

Structure-activity relationship of adipokinetic hormone analogs in the striped hawk moth, Hippotion eson.

We showed previously that the sphingid moth Hippotion eson synthesizes the highest number of adipokinetic hormones (AKHs) ever recorded, viz. five, in its corpus cardiacum: two octa-, two nona- and one decapeptide. Further, the endogenous decapeptide (Manse-AKH-II) and the other four AKHs are all active in lipid mobilization, whereas a non-lepidopteran decapeptide (Lacsp-AKH, five amino acid substitutions compared with Manse-AKH-II), was inactive in H. eson. We tested the decapeptide, Lacol-AKH, from a noctuid moth for the first time in a bioassay and it shows a maximal AKH effect in H. eson. Lacol-AKH differs from Manse-AKH-II in three places and from Lacsp-AKH in four places. We, thus, used Lacol-AKH as a lead peptide on which a series of AKH analogs are based to represent: (a) single amino acid replacements (according to the substitutions in Lacsp-AKH), (b) shorter chain lengths, (c) modified termini, and (d) a replacement of Trp in position 8. These analogs, as well as a few naturally occurring AKHs from other lepidopterans were tested in in vivo adipokinetic assays to gain insight into the ligand-receptor interaction in H. eson. Our results show that the second and third amino acids are important for biological activity in the sphingid moth. Analogs with an N-[acetylated]Glu(1) (instead of a pyroGlu), or a free C-terminus, or Ala(8) were not active in the bioassays, while shortened Lacol-AKH analogs and the undecapeptide, non-amidated Vanca-AKH showed very reduced activity (below 25%). This information is important for the consideration of peptide mimetics to combat specific lepidopteran pest insects.

A novel adipokinetic peptide from the corpus cardiacum of the primitive caeliferan pygmy grasshopper Tetrix subulata (Caelifera, Tetrigidae).

The basal caeliferan family Tetrigidae is investigated to identify neuropeptides belonging to the adipokinetic hormone (AKH) family. The pygmy grasshopper Tetrix subulata contains in its corpus cardiacum two octapeptides as revealed by liquid chromatography coupled to electrospray ionization mass spectrometry. The less abundant peptide is the well-known Schgr-AKH-II (pELNFSTGW amide) which is suggested to be the ancestral AKH of Caelifera and Ensifera. The second peptide, Tetsu-AKH (pEFNFTPGW amide), is novel and quite unusual with its third aromatic residue at position 2. It is thought to be autapomorphic for Caelifera. Tetsu-AKH has hyperlipemic activity in T. subulata and in Schistocerca gregaria.