Favorable Metabolic Properties Research Articles

AGCM-22, a novel cetuximab-based EGFR-targeting antibody-drug-conjugate with highly selective anti-glioblastoma efficacy

The epidermal growth factor receptor (EGFR) has received significant attention as a potential target for glioblastoma (GBM) therapeutics in the past two decades. However, although cetuximab, an antibody that specifically targets EGFR, exhibits a high affinity for EGFR, it has not yet been applied in the treatment of GBM. Antibody-drug conjugates (ADCs) utilize tumor-targeting antibodies for the selective delivery of cytotoxic drugs, resulting in improved efficacy compared to conventional chemotherapy drugs. However, the effectiveness of cetuximab as a targeted antibody for ADCs in the treatment of GBM remains uncertain. In this study, we synthesized AGCM-22, an EGFR-targeted ADC derived from cetuximab, by conjugating it with the tubulin inhibitor monomethyl auristatin E (MMAE) using our Valine-Alanine Cathepsin B cleavable linker. In vitro experiments demonstrated that AGCM-22 effectively inhibited GBM cell proliferation through increased levels of apoptosis and autophagy-related cell death, whereas cetuximab alone had no anti-GBM effects. Additionally, both mouse and human orthotopic tumor models exhibited the selective tumor-targeting efficacy of AGCM-22, along with favorable metabolic properties and superior anti-GBM activity compared to temozolomide (TMZ). In summary, this study presents a novel ADC for GBM therapy that utilizes cetuximab as the tumor-targeting antibody, resulting in effective delivery of the cytotoxic drug payload.

Abstract 13007: Ketone Bodies for Right Ventricular Failure: A Unique Therapeutic Opportunity

Introduction: Right ventricular failure (RVF) is the leading cause of death in pulmonary arterial hypertension (PAH), but effective therapies for RVF are lacking. Ketones exert therapeutic effects through suppression of the NLRP3 (nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3) inflammasome and exhibit favorable metabolic properties in LVF. However, the relationships among serum ketone bodies, RV inflammasome activation, and RV function in preclinical and human RVF are unexplored. Hypothesis: Serum ketones correlate with RV function and induction of therapeutic ketosis ameliorates RV dysfunction. Methods: 51 PAH patients were dichotomized into preserved or impaired RV function based on a cardiac index of 2.2 L/min/m 2 . Serum ketone bodies acetoacetate (AcAc) and β-hydroxybutyrate (BOHB) were quantified using ultra performance liquid chromatography and mass spectrometry. The relationships between AcAc and BOHB and clinical measures of RV function were evaluated. In rodent studies, male Sprague Dawley rats were assigned to three groups: control (saline injection), monocrotaline (MCT) standard chow diet (MCT-SD), and MCT ketogenic diet (MCT-KD). Immunoblots and confocal microscopy probed macrophage NLRP3 activation in RV extracts and sections. RV fibrosis was determined by Picrosirus Red. Echocardiography evaluated RV function. Results: Human RVF patients lacked a compensatory ketosis as serum AcAc and BOHB levels were not associated with hemodynamic or echocardiographic measures of RV function. In rodent studies, AcAc and BOHB levels were also not elevated in MCT-mediated RVF, but the ketogenic diet significantly increased AcAc and BOHB levels. MCT-KD exhibited suppressed NLRP3 activation with a reduction in NLRP3, ASC (apoptosis-associated speck-like protein), pro-caspase-1, and interleukin-1 beta on immunoblots. Moreover, the number of ASC-positive macrophage in RV sections was reduced, RV fibrosis was blunted, and RV function was augmented in MCT-KD rats. Conclusions: Our preclinical and clinical data suggests therapeutic ketosis could combat RVF, and patients with RVF are uniquely primed for ketogenic interventions due to a lack of effective ketosis.

Lead optimization of novel quinolone chalcone compounds by a structure\u2013activity relationship (SAR) study to increase efficacy and metabolic stability

Many agents targeting the colchicine binding site in tubulin have been developed as potential anticancer agents. However, none has successfully made it to the clinic, due mainly to dose limiting toxicities and the emergence of multi-drug resistance. Chalcones targeting tubulin have been proposed as a safe and effective alternative. We have shown previously that quinolone chalcones target tubulin and maintain potent anti-proliferative activity vis-à-vis colchicine, while also having high tolerability and low toxicity in mouse models of cancer and refractivity to multi-drug resistance mechanisms. To identify the most effective anticancer chalcone compound, we synthesized 17 quinolone–chalcone derivatives based on our previously published CTR-17 and CTR-20, and then carried out a structure–activity relationship study. We identified two compounds, CTR-21 [((E)-8-Methoxy-3-(3-(2-methoxyphenyl)-3-oxoprop-1-enyl) quinolin-2(1H)-one)] and CTR-32 [((E)-3-(3-(2-ethoxyphenyl)-3-oxoprop-1-enyl) quinolin-2(1H)-one)] as potential leads, which contain independent moieties that play a significant role in their enhanced activities. At the nM range, CTR-21 and CTR-32 effectively kill a panel of different cancer cells originated from a variety of different tissues including breast and skin. Both compounds also effectively kill multi-drug resistant cancer cells. Most importantly, CTR-21 and CTR-32 show a high degree of selectivity against cancer cells. In silico, both of them dock near the colchicine-binding site with similar energies. Whereas both CTR-21 and CTR-32 effectively prevents tubulin polymerization, leading to the cell cycle arrest at G2/M, CTR-21 has more favorable metabolic properties. Perhaps not surprisingly, the combination of CTR-21 and ABT-737, a Bcl-2 inhibitor, showed synergistic effect in killing cancer cells, since we previously found the “parental” CTR-20 also exhibited synergism. Taken together, CTR-21 can potentially be a highly effective and relatively safe anticancer drug.

Modulation of insulin resistance by renin angiotensin system inhibitors: implications for cardiovascular prevention.

Insulin resistance (IR) and the related hyperinsulinamia play a key role in the genesis and progression of the continuum of cardiovascular (CV) disease. Thus, it is reasonable to pursue in primary and secondary CV prevention, the pharmacological strategies that are capable to interfere with the development of IR. The renin-angiotensin-aldosterone system (RAAS) plays an important role in the pathogenesis of IR. In particular, angiotensin II (Ang II) through the generation of reactive oxygen species, induces a low grade of inflammation, which impairs the insulin signal transduction. The angiotensin converting enzyme (ACE) inhibitors are effective not only as blood pressure-lowering agents, but also as modulators of metabolic abnormalities. Indeed, experimental evidence indicates that in animal models of IR, ACE inhibitors are capable to ameliorate the insulin sensitivity. The Ang II receptor blockers (ARBs) modulate the peroxisome proliferator-activated receptor (PPAR)-γ activity. PPARâ€"γ is a transcription factor that controls the gene expression of several key enzymes of glucose metabolism. A further mechanism that accounts for the favorable metabolic properties of ARBs is the capability to modulate the hypothalamicâ€"pituitary-adrenal (HPA) axis. The available clinical evidence is consistent with the concept that both ACE inhibitors and ARBs are able to interfere with the development of IR and its consequences like type 2 diabetes. In addition, pharmacological inhibition of the RAAS has favourable effects on dyslipidaemias, metabolic syndrome and obesity. Therefore, the pharmacological antagonism of the RAAS, nowadays, represents the first choice in the prevention of cardio-metabolic diseases.

The Glycaemic and Insulinaemic Response of Pasta in Chinese and Indians Compared to Asian Carbohydrate Staples: Taking Spaghetti Back to Asia.

In this study, we compared the metabolic properties of the Asian staples rice and noodles, which are typically high in glycaemic index (GI), to two types of spaghetti. It is hypothesised that pasta can be a healthy replacement, particularly amongst the Asian population. Thirty Chinese and Indian subjects (17 men, 13 women; BMI: 18.5–25 kg/m2) participated in this randomised crossover trial. On seven occasions, they consumed a glucose reference drink (3 times), white rice, wheat-based mee pok noodles, semolina spaghetti and wholegrain spaghetti. Blood samples were taken to measure glucose and insulin response over a period of 3 h. The current evaluation showed that semolina spaghetti and wholegrain spaghetti can be classified as low GI products, with a GI of 53 and 54, respectively, significantly lower than wheat based mee pok noodles (74) and rice (80) (p < 0.005). In addition, both spaghettis had a lower insulin response compared to rice (p < 0.05). Furthermore, there was no difference in glucose or insulin response between semolina and wholegrain spaghetti. After controlling for gender, ethnicity, fat and fat free mass (kg), the glucose and insulin results did not change. In conclusion, wheat-based pasta can be helpful to modify the carbohydrate-rich Asian diet. Notably, there was no effect of gender, ethnicity and body composition on the glycaemic and insulinaemic response. We speculate that the starch-protein structure as a result of the spaghetti production process is a major driver of its favourable metabolic properties.

HIGH DOSE INSULIN AND VA ECMO FOR POISON-INDUCED CARDIOGENIC SHOCK

SESSION TITLE: Critical Care 2 SESSION TYPE: Med Student/Res Case Report PRESENTED ON: 10/09/2018 05:00 PM - 06:00 PM INTRODUCTION: High dose insulin therapy (HDI) is an emerging and increasingly well described intervention for poison-induced cardiogenic shock (PICS). PICS due to beta-blocker or calcium channel blocker overdose is both frequent and life-threatening [1]. When traditional therapies such as fluid resuscitation, cardiac pacing, atropine, calcium, glucagon, vasopressors and inotropes fail to provide hemodynamic stability, HDI can be effective [2-7]. While the current literature is limited to case series and animal models [2-7], we present a case of successful HDI in a patient with beta-blocker toxicity. CASE PRESENTATION: We report a 36-year-old female who presented in cardiogenic shock secondary to polypharmacy overdose, including significant amounts of propranolol. She suffered cardiopulmonary arrest shortly after arrival to the hospital. Despite aggressive resuscitation, she required emergent venoarterial extracorporeal membrane oxygenation (VA ECMO) support to achieve hemodynamic stability. HDI was subsequently initiated by assessing hemodynamic responsiveness to progressively increased bolus doses, starting with 1 unit per kilogram. HDI was continued with an insulin infusion at 15 units/kilogram/hour. She demonstrated an excellent response, and was successfully transitioned off VA ECMO support and all vasoactive medications. The following day, the insulin drip was carefully weaned to avoid large potassium shifts. The patient was eventually discharged to home, neurologically intact with normal biventricular function by echocardiogram. DISCUSSION: This patient demonstrated a rapid and robust response to HDI in the setting of profound cardiogenic shock. Despite requiring escalation of care to VA ECMO, HDI allowed for rapid discontinuation of this salvage therapy. Several mechanisms of action have been postulated for HDI, including a direct positive inotropic effect and multiple favorable metabolic properties [3,5,8-12]. HDI also induces vasodilation, which improves both microcirculation and systemic perfusion [5,11]. While evidence for specific dosing regimens remains limited, the doses used in this case are consistent with previously described values including bolus doses of 1 unit per kilogram and infusions of 10 units/kilogram/hour or more [13-15]. CONCLUSIONS: In patients with PICS due to either calcium channel blockers or beta-blockers, HDI can be a definitive and life-saving treatment. While large clinical trials are lacking, sufficient evidence exists to consider this therapy in patients with PICS refractory to traditional treatment [16]. Note: All sixteen references available in uploaded document Reference #1: DeWitt CR, et al. Pharmacology, pathophysiology and management of calcium channel blocker and beta blocker toxicity. Toxicol Rev 2004, 23:223-38 Reference #2: Yuan TH, Kerns WP, Tomaszewski CA, Ford MD, Kline JA. Insulin-glucose as adjunctive therapy of severe calcium channel antagonist poisoning. J Toxicol Clin Toxicol 1999, 37:463-74 Reference #3: Megarbane B, et al. The role of insulin and glucose (hyperinsulinemia/euglycemia) therapy in acute calcium channel antagonist and beta-blocker poisoning. Toxicol Rev 2004, 23:215-22 DISCLOSURES: No relevant relationships by Benjamin Abrams, source=Web Response No relevant relationships by David Douin, source=Web Response No relevant relationships by Scott Wolf, source=Web Response

Structure-Based Discovery of a Series of 5H-Pyrrolo[2,3-b]pyrazine FGFR Kinase Inhibitors.

Fibroblast growth factor receptors (FGFRs), a subfamily of receptor tyrosine kinases, are aberrant in various cancer types, and considered to be promising targets for cancer therapy. We started with a weak-active compound that was identified from our internal hepatocyte growth factor receptor (also called c-Met) inhibitor project, and optimized it with the guidance of a co-crystal structure of compound 8 with FGFR1. Through rational design, synthesis, and the biological evaluation of a series of 5H-pyrrolo[2,3-b]pyrazine derivatives, we discovered several potent FGFR kinase inhibitors. Among them, compound 13 displayed high selectivity and favorable metabolic properties, demonstrating a promising lead for further development.

Design, synthesis and biological evaluation of 4-amidobenzimidazole acridine derivatives as dual PARP and Topo inhibitors for cancer therapy

PARP-1 could repair the DNA damages induced by Topo inhibitors, therefore inhibiting Topo and PARP-1 simultaneously might be able to overcome resistance and improve outcomes. In this study a series of 4-amidobenzimidazole acridines were designed and synthesized as dual Topo and PARP-1 inhibitors. Compound 11l displayed good inhibitory activities against Topo and PARP-1, as well as significantly inhibited cancer cells proliferation. Further mechanistic evaluations indicated that 11l treatment in MCF-7 cells induced accumulated DNA double-strand breaks, prompted remarkable apoptosis, and caused prominent G0/G1 cell cycle arrest. Moreover, 11l greatly suppressed tumor growth in mice, and displayed favorable metabolic properties in liver microsomes. Our study suggested that single agents inhibiting Topo and PARP concurrently might be an alternative for cancer therapy and 11l represented a potential lead compound for development of antitumor agents.

The proportion and metabolic effects of adiponectin multimeric isoforms in patients with chronic kidney disease on maintenance hemodialysis

Adiponectin circulates at least in three major forms of oligomeric complexes in plasma: a low-molecular-weight (LMW) trimer, a middle-molecular-weight (MMW) hexamer, and high-molecular-weight (HMW) adiponectin. Although it has been reported that adiponectin has the favorable metabolic properties for humans, the roles of these multimers in the patients with the end-stage renal disease (ESRD) were unidentified. We determined the level of total and multimeric adiponectin in 71 patients with nondiabetic ESRD treated with hemodialysis (HD) using a commercially available kit of enzyme-linked immunosorbent assay (ELISA). Correlations between metabolic variables and total and multimeric adiponectin were examined by Spearman's correlations analysis. Forward stepwise multiple linear regression analysis was also performed to determine the factors independently associated with them. Female patients had significantly higher total, HMW, and MMW levels than male patients did. According to homeostasis model of assessment of insulin resistance (HOMA-IR), value was associated not only with HMW but also with MMW and LMW. In multivariate analyses, HMW showed independently and positively associated with high-density lipoprotein cholesterol (HDL-C), body mass index (BMI), and sex as total adiponectin did. Unexpectedly, LMW adiponectin was independently and negatively correlated with TG and high-sensitive C-reactive protein (hs-CRP). Not only HMW adiponectin but also LMW adiponectin track with favorable metabolic effects in the patient with the ESRD.

Angiotensin II Blockade and Total Cardiovascular Risk

Hypertension is one of the world's largest public health problems and it is both a disease and a risk factor for cardiovascular disease (CVD). The heart, the endothelium and the kidneys are the target organs of hypertension. Recently, several antihypertensive drugs have been introduced to the market; therefore, the choice is mainly determined by the patients' features. In particular, ACE inhibitors and angiotensin II type 1 receptor antagonists (angiotensin receptor blockers [ARBs]) demonstrate a larger reduction in cardiovascular risk than other antihypertensive treatments because of the existence of blood pressure-independent effects. In fact, the angiotensin II pathway plays a major role in metabolic, haemodynamic and endothelial homeostasis. For these reasons, ACE inhibitors and ARBs have primary indications in patients with obesity, hypercholesterolaemia and diabetes mellitus because of their favourable metabolic properties. Furthermore, several large trials have demonstrated that they have favourable effects also in patients with left ventricular dysfunction or systolic heart failure, as well as other forms of heart disease. Drugs affecting the angiotensin II pathway may reduce endothelial dysfunction through several mechanisms including reduction of vascular permeability and oxidative stress. Another important effect of these drugs is neuroprotection. This is an important effect because in the near future, due to an aging population, an important goal for optimal antihypertensive treatment will be the prevention of cognitive decline. ACE inhibitors and ARBs are very important drugs in the modern management of the total cardiovascular risk in hypertensive patients.

A Metabolic Screening Study of Trichostatin A (TSA) and TSA-Like Histone Deacetylase Inhibitors in Rat and Human Primary Hepatocyte Cultures

Hydroxamic acid (HA)-based histone deacetylase (HDAC) inhibitors, with trichostatin A (TSA) as the reference compound, are potential antitumoral drugs and show promise in the creation of long-term primary cell cultures. However, their metabolic properties have barely been investigated. TSA is rapidly inactivated in rodents both in vitro and in vivo. We previously found that 5-(4-dimethylaminobenzoyl)aminovaleric acid hydroxyamide or 4-Me2N-BAVAH (compound 1) is metabolically more stable upon incubation with rat hepatocyte suspensions. In this study, we show that human hepatocytes also metabolize TSA more rapidly than compound 1 and that similar pathways are involved. Furthermore, structural analogs of compound 1 (compounds 2-9) are reported to have the same favorable metabolic properties. Removal of the dimethylamino substituent of compound 1 creates a very stable but 50% less potent inhibitor. Chain lengthening (4 to 5 carbon spacer) slightly improves both potency and metabolic stability, favoring HA reduction to hydrolysis. On the other hand, Calpha-unsaturation and spacer methylation not only reduce HDAC inhibition but also increase the rate of metabolic inactivation approximately 2-fold, mainly through HA reduction. However, in rat hepatocyte monolayer cultures, compound 1 is shown to be extensively metabolized by phase II conjugation. In conclusion, this study suggests that simple structural modifications of amide-linked TSA analogs can improve their phase I metabolic stability in both rat and human hepatocyte suspensions. Phase II glucuronidation, however, can compensate for their lower phase I metabolism in rat hepatocyte monolayers and could play a yet unidentified role in the determination of their in vivo clearance.

Is there a rationale for angiotensin blockade in the management of obesity hypertension?

Obesity, currently affecting >20% of the adult population in most Western countries, is a major risk factor for the development of hypertension. Hypertension in obese patients is, in the majority of instances, further complicated by the concomitant presence of dyslipidemia and insulin resistance. The latter is reflected by derangement of glucose homeostasis, ranging from hyperinsulinemia to frank type 2 diabetes. Hypertension in obese patients is also associated with an increased risk for left ventricular hypertrophy, endothelial dysfunction, renal hyperfiltration, microalbuminuria, and elevated markers of inflammation. Sodium retention, volume expansion, and increased cardiac output are common findings in obese individuals. These changes are largely attributable to increased activity of the sympathetic nervous system and insufficient suppression of the renin-angiotensin system. Recent data show increased expression of angiotensin II-forming enzymes in adipose tissue, and increased activity of the renin-angiotensin system has recently been implicated in the development of insulin resistance and type 2 diabetes. Accordingly, antihypertensive agents that block the renin-angiotensin system might be a beneficial strategy for treatment of obesity-related hypertension. Both angiotensin-converting enzyme inhibitors and angiotensin type-1 receptor blockers have been associated with favorable metabolic properties and end-organ protection in addition to their antihypertensive effects. Data from ongoing large trials will provide an indication of the protective and preventive effects of these treatment strategies while offering insights into the mechanisms linking obesity, hypertension, and other facets of the metabolic syndrome.

In vitro high throughput screening of compounds for favorable metabolic properties in drug discovery.

Drug metabolism can have profound effects on the pharmacological and toxicological profile of therapeutic agents. In the pharmaceutical industry, many in vitro techniques are in place or under development to screen and optimize compounds for favorable metabolic properties in the drug discovery phase. These in vitro technologies are meant to address important issues such as: (1) is the compound a potent inhibitor of drug metabolising enzymes (DMEs)? (2) does the compound induce the expression of DMEs? (3) how labile is the compound to metabolic degradation? (4) which specific enzyme(s) is responsible for the compound's biotransformation? and (5) to which metabolites is the compound metabolized? Answers to these questions provide a basis for judging whether a compound is likely to have acceptable pharmacokinetic properties in vivo. To address these issues on the increasing number of compounds inundating the drug discovery programs, high throughput assays are essential. A combination of biochemical advances in the understanding of the function and regulation of DMEs (in particular, cytochromes P450, CYPs) and automated analytical technologies are revolutionizing drug metabolism research. Automated LC-MS based metabolic stability, fluorescence, radiometric and LC-MS based CYP inhibition assays are now in routine use. Automatible models for studying CYP induction based on enzyme activity, quantitative RT-PCR and reporter gene systems are being developed. We will review the utility and limitations of these HTS approaches and highlight on-going developments and emerging technologies to answer metabolism questions at the different stages of the drug discovery process.

Effects of very long chain versus long chain triglycerides on gastrointestinal motility and hormone release in humans.

Fish oil (a very long chain triglycerides, VLCT) has received much attention because of its favorable metabolic properties; however, its effect on gastrointestinal function has not been studied. We investigated the effects of intraduodenally administered VLCT on gut-hormone release [cholecystokinin (CCK), neurotensin, peptide YY (PYY)], gallbladder emptying, antroduodenal motility, and small bowel transit time (SBTT) in comparison to intraduodenal administration of saline and long chain triglycerides (LCT, corn oil) in nine healthy volunteers. Gallbladder contraction duration was significantly shorter after VLCT than after LCT (138 +/- 16 min vs 233 +/- 38 min, P < 0.05). Both fats induced a fed motility pattern, while SBTT was not significantly altered. CCK secretion was significantly reduced after VLCT compared to LCT (36 +/- 12 pM x 120 min vs 78 +/- 15 pM x 120 min, P < 0.05), whereas PYY and neurotensin release were not significantly different. In conclusion, effects of triglycerides on CCK and gallbladder motility appear to be chain-length dependent, in contrast to the effects on distal gut-hormone release and intestinal motility and transit, which appear to be chain-length independent.

Tauroursodeoxycholic acid for the treatment of chronic hepatitis: a multicentre dose-response study

Ursodeoxycholic acid (UDCA) improves the biochemical expression of chronic liver disease. Tauroursodeoxycholic acid (TUDCA) was recently shown to have more favourable metabolic properties. We designed a multicenter, randomized, controlled study, aimed at assessing the efficacy of TUDCA for the treatment of chronic hepatitis. One hundred and fifty-five patients with chronic hepatitis were randomly assigned to receive TUDCA at the daily doses of 250, 500 and 1000 mg, or no treatment for 6 months. Aminotransferase and gamma-glutamyl transpeptidase (GGT) serum levels decreased with each dose of TUDCA compared with controls ( P<0.001). The 1000 mg dose was followed by more marked improvement compared with 250 mg ( P<0.05). A progressive improvement of alanine aminotransferase (ALT) with time ( P<0.05) was found only with the two higher doses. TUDCA improves the biochemical expression of chronic hepatitis and daily doses of at least 500 mg are recommended.