β-Blockade in Heart Failure

Controlled clinical trials performed in more than 13 000 patients have, to date, consistently shown the beneficial effects of long term β-adrenoceptor antagonist (β-blocker) therapy in patients with chronic heart failure. It is not clear whether this represents a class effect or whether it is specific only to some agents. Beneficial effects on the prognosis of patients with mild to moderate heart failure have been shown with metoprolol, bisoprolol, and carvedilol. These β-blockers, however, differ in their pharmacologic characteristics. Metoprolol and bisoprolol are selective for β₁-adrenergic receptors and are devoid of ancillary properties. Carvedilol, at a dosage of 50 mg/day, blocks all β₁-, β₂-, and α₁-adrenergic receptors, and it has associated antiproliferative and antioxidant activities. These differences cause a varied acute hemodynamic response, with a reduction in cardiac output and a tendency toward a rise in pulmonary wedge pressure with selective agents and no change in cardiac output and a slight decrease in pulmonary pressures with carvedilol. Accordingly, when the therapy is started, the most frequent adverse effects are worsening heart failure with metoprolol and bisoprolol, and hypotension and dizziness with carvedilol. It remains controversial whether these differences also influence the long term effects of therapy. Carvedilol may provide a more comprehensive blockade of the cardiac adrenergic drive than selective β-blockers because it does not upregulate β₁-adrenergic receptors, blocks all adrenergic receptors and decreases cardiac norepinephrine release. These properties may lead to a larger increase in left ventricular function and a lack of improvement in maximal exercise capacity with carvedilol, compared with selective β-blockers. It is, however, unclear whether these differences also influence patient outcome. The long term effects of different β-blockers on prognosis are currently being compared in the Carvedilol or Metoprolol European Trial (COMET) in which more than 3000 patients with chronic heart failure have been randomized in a 1 : 1 ratio to receive metoprolol or carvedilol.     

β-Adrenergic receptors in guinea-pig myocardial tissue

Summary Stereospecific binding sites for (–) [³H]-alprenolol, a -adrenergic antagonist, have been identified in guinea-pig myocardial broken cell preparations. The concentration of the sites was 0.3 pmoles per mg of protein and the dissociation constant (at 37°C) 10^–8 M. A close correlation between the ability of various -adrenergic antagonists to compete with tracer alprenolol binding and to block the response of isoprenaline-stimulated myocardial adenylate cyclase has been found. Low affinity sites for the labelled -adrenergic antagonist in contrast to stereospecific sites are heat stable and do not discriminate between the (–) and the (+) forms of the -adrenergic antagonists. Adenylate cyclase in guineapig myocardial tissue is poorly stimulated by isoprenaline or 5-guanylylimidodiphosphate. This is attributed to a high basal activity which could be lowered by a preincubation at 37°C.     

TGF-β2 signaling in high-grade gliomas

High-grade gliomas are the most common primary tumors in the central nervous system (CNS) in adults. Despite efforts to improve treatment by combination therapies (neurosurgery, radio- and chemotherapy), high-grade glioma patients still have a grim prognosis, indicating an urgent need for new therapeutic approaches. The molecular processes of gliomagenesis are being unraveled, and novel targeted therapeutic strategies to defy high-grade gliomas are emerging. Transforming growth factor-beta (TGF-β), in particular the TGF-β2 isoform, has been identified as a key factor in the progression of malignant gliomas. TGF-β2, originally described as "glioblastoma-derived T-cell suppressor factor", is associated with the immuno-suppressed status of patients with glioblastoma, and is therefore responsible for loss of tumor immune surveillance. Elevated TGF-β2 levels in tumors and in the plasma of patients have been associated with advanced disease stage and poor prognosis. Consequently, a targeted strategy to modulate TGF-β2 signaling is highly promising. The antisense oligonucleotide trabedersen (AP 12009) that specifically blocks TGF-β2 mRNA will be the main focus of this review. In three phase I/II studies and a randomized, active-controlled dose-finding phase IIb study, trabedersen treatment of high-grade glioma patients with recurrent or refractory tumor disease led to long-lasting tumor responses and so far promising survival data. On the basis of these data the currently ongoing phase III study SAPHIRRE was initiated.     

β-Adrenergic Receptor Subtypes in the Urinary Tract

Within the urinary tract, β-adrenergic receptors (AR) are found largely on smooth muscle cells but are also present, at least in the bladder, in the urothelium and on afferent nerves. Our understanding of β-AR subtype expression and function is hampered by a lack of well-validated tools, particularly with regard to β(3)-AR. Moreover, the β-AR subtypes involved in a specific function may differ between species. In the ureter, β-AR can modulate pacemaker activity and smooth muscle tone involving multiple subtypes. In the human bladder, β-AR promote urine storage. Bladder smooth muscle relaxation primarily involves β(3)-AR, and the agonists selective for this subtype are in clinical development to treat bladder dysfunction. While prostate and urethra also express β-AR, the overall physiological role in these tissues remains unclear.     

Influence of hydroxypropyl-β-cyclodextrin and dimethyl-β-cyclodextrin on diphenhydramine intestinal absorption in a rat in situ model

The influence of complexation of diphenhydramine (DPHA) with hydroxypropyl-β-cyclodextrin (HPβCD) and dimethyl-β-cyclodextrin (DMβCD) on intestinal absorption of DPHA has been investigated on an in situ model in rats. The mean apparent stability constants of the complexes formed at 23°C between DPHA and the cyclodextrins DMβCD and HPβCD were 4988 and 1635 M⁻¹, respectively. At 37°C, the apparent stability constants were smaller: 895 and 494 M⁻¹ for the complexes formed between DPHA and the cyclodextrins DMβCD and HPβCD, respectively. Complexation of DPHA with DMβCD led to a significant decrease (−36%) in the percentage of DPHA absorbed (30.6±12.0 vs. 22.5±6.9%, P=0.018). On the other hand, complexation of DPHA with HPβCD only slightly decreased (−8%) the extent of absorption (43.2±9.0 vs. 40.0±7.7%, P=0.16). These data suggest that the magnitude of the apparent stability constant of drug–cyclodextrin complexes should be considered when complexes are used to increase the oral absorption of drugs.     

Advances in targeting the WNT/β-catenin signaling pathway in cancer

WNT/β-catenin signaling orchestrates various physiological processes, including embryonic development, growth, tissue homeostasis, and regeneration. Abnormal WNT/β-catenin signaling is associated with various cancers and its inhibition has shown effective antitumor responses. In this review, we discuss the pathway, potential targets for the development of WNT/β-catenin inhibitors, available inhibitors, and their specific molecular interactions with the target proteins. We also discuss inhibitors that are in clinical trials and describe potential new avenues for therapeutically targeting the WNT/β-catenin pathway. Furthermore, we introduce emerging strategies, including artificial intelligence (AI)-assisted tools and technology-based actionable approaches, to translate WNT/β-catenin inhibitors to the clinic for cancer therapy.     

β-Amyloid therapies in Alzheimer’s disease

Neurones in the brain produce β-amyloid (Aβ) fragments from a larger precursor molecule termed the amyloid precursor protein (APP). When released from the cell, these protein fragments may accumulate in extracellular amyloid plaques and consequently hasten the onset and progression of Alzheimer’s disease (AD). β-Amyloid fragments are generated through the action of specific proteases within the cell. Two of these enzymes, β- and γ-secretase, are particularly important in the formation of Aβ as they cleave within the APP protein to give rise to the N-terminal and C-terminal ends of the Aβ fragment, respectively. Consequently, many researchers are investigating therapeutic approaches that inhibit either β- or γ-secretase activity, with the ultimate goal of limiting Aβ production. An alternative AD therapeutic approach that is being investigated is to employ anti-Aβ antibodies to dissolve plaques that have already formed. Both of these approaches focus on the possibility that accrual of Aβ leads to neuronal degeneration and cognitive impairment characterised by AD and test the hypothesis that limiting Aβ deposition in neuritic plaques may be an effective treatment for AD.     

Gender differences in response to chronic treatment with 17β-oestradiol and 17β-aminoestrogen pentolame on hemostasis in rats

Objectives:

This work evaluated chronic treatment with 17β-oestradiol (E₂) and 17β-aminoestrogen pentolame (AEP) on prothrombin time (PT), activated partial thromboplastin time (aPTT), thrombin time (TT), and fibrinogen concentration (FIB). Male (M) and ovariectomized (Ovx) Wistar rats were used to explore gender differences in the pharmacological response.

Materials and Methods:

Rats (n = 12-18) were treated every third day during three months with E₂ (1, 10, 100 μg/kg), AEP (1, 10, 100, 500 μg/kg) or vehicle (propylenglycol 1 ml/ kg). PT, aPTT, TT, and FIB were measured using standardized techniques.

Results:

Chronic treatment with E₂ in male rats increased PT (4-7%; P < 0.05), decreased aPTT (9%; 100 μg/kg; P < 0.05) and decreased TT (5% at 100 μg/Kg; P < 0.05). Chronic treatment with E₂ in ovariectomized female rats decreased PT (3-4%; P < 0.05), did not induce significant changes on aPTT and decreased TT in a dose dependent manner (12-27%; P < 0.05). Chronic treatment with AEP in male rats did not alter PT, increased aPTT in a dose dependent manner (5-16%; P < 0.05), and decreased TT (5%; 500 μg/Kg; P < 0.05) while in female ovariectomized rats it decreased PT (5-9%; P < 0.05), increased aPTT (8-13%; P < 0.05) and decreased TT (6-13%; P < 0.05). E₂ and AEP decreased FIB in M and Ovx animals. Decreases in FIB by E₂ were more pronounced in male (15-18% P < 0.05) than in ovariectomized rats (10-14% P < 0.05). E₂ showed more potency than AEP, lowering FIB at 1 and 10 μg/kg doses. Both estrogens decreased FIB in ovariectomized animals (E₂, 10-14%, P < 0.05; AEP, 9% P < 0.05) and were reverted by increasing dosage.

Conclusions:

Gender influenced response to chronic treatment with E₂ and AEP on hemostatic parameters. PT and aPTT were the most affected parameters, demonstrating non-equivalence in the pharmacological response of M and Ovx rats.KEY WORDS: 17β-aminoestrogens, gender, hemostasis, oestradiol, rat     

Strain differences in age-associated change in testosterone 6β-hydroxylation in Wistar and Dark Agouti rats

This study examines strain differences in testosterone (T)-hydroxylations between Wistar and Dark Agouti (DA) rats of both genders. The DA rat, an animal model, is a poor metabolizer of such drugs as debrisoquine, which are metabolized by cytochrome P450 (CYP) 2D. T-16α-, 2α-hydroxylations, which are linked to CYP2C11, were catalyzed at similar rates by the microsomes of both strains. In contrast, the liver microsomes from mature male DA rats catalyzed T-6β-hydroxylation, the CYP3A mediated activity, at higher rates (～ 2-fold) than Wistar rat liver microsomes did. There was no difference between immature male DA and Wistar rats for T-6β-hydroxylation, indicating that the activity in male DA rat increases with maturation. Polyclonal antibodies raised against rat liver microsomal CYP3A2 and a CYP3A inhibitor, troleandomycin (TAO), effectively inhibited T-6β-hydroxylation by liver microsomes from both strains of rats. The level of T-6β- hydroxylation activity correlated well with the amount of CYP3A protein in the microsomes in mature as well as in immature male and female Wistar and DA rats. Northern blot analysis repeatedly indicated that the cellular contents of CYP3A2 mRNA are slightly (～ 20%) higher in the liver of mature DA rats than in that of mature Wistar rats. These results indicate that the increased levels of CYP3A are responsible for the increased T-6β-hydroxylation activity and protein in DA rat.     

β-endorphin-sensitive opioid receptors in the rat tail artery

Summary Isolated tail arteries of rats were perfused and field-stimulated every 2 min with 2 pulses at 1 Hz. Different opioid peptides depressed the contractile responses to stimulation; their concentration-response curves showed a maximum at about 40% inhibition. The rank order of potency of the peptides was -endorphin (IC₅₀ = 97 nmol/1) BAM-22P > FK-33824 > DAGO > [d-Ala²,d-Leu⁵]-enkephalin metorphamide > dynorphin A-(1-13) [Met⁵]enkephalin. All these substances have in common a certain activity at opioid -receptors, although the enkephalins are preferential -, and the dynorphins preferential -agonists. However, the selective -agonist [d-Pen²,l-Pen⁵]enkephalin was ineffective at up to 10 mol/l, and the -agonists ethylketocyclazocine and U-50488 acted only at concentrations higher than 3 mol/l. Whereas the effects of -endorphin, DAGO and [d-Ala²,d-Leu⁵]enkephalin could be reduced by the -preferential antagonist naloxone, the effects of ethylketocyclazocine and U-50488 were not changed. The -selective antagonist ICI 174864 did not influence the action of [d-Ala²,d-Leu⁵]enkephalin. Naloxone in a concentration (1 mol/l) which nearly abolished the effect of DAGO 3 mol/l, slightly enhanced responses to stimulation. Neither -endorphin nor DAGO influenced vasoconstriction evoked by the application of noradrenaline or adenosine triphosphate; U-50488 reduced it. In arteries preincubated with [³H]noradrenaline DAGO depressed, whereas naloxone enhanced the tritium overflow and vasoconstriction evoked by field stimulation (0.4 Hz, 24 pulses every 14 min). In addition, naloxone antagonized the effect of DAGO. We suggest that the axon terminals of postganglionic sympathetic neurones in the rat tail artery possess -endorphin-sensitive opioid receptors of the -type. The activation of these receptors by exogenous or endogenous opioids inhibits the release of the neuroeffector transmitter.This work was supported by the Deutsche Forschungsgemeinschaft (SFB 325) Send offprint requests to P. Illes at the above address     

17β-estradiol decreases methylmercury-induced neurotoxicity in male mice

There is increasing evidence that health effects of toxic metals, including methylmercury (MeHg), differ in prevalence or are manifested differently in men and women. The present study was aimed at investigating the potential differential susceptibility of male and female Swiss mice against MeHg-induced neurotoxicity, which was evaluated by biochemical (cerebellar oxidative stress-related parameters) and behavioral (locomotor activity and motor performance) variables. We also aimed to evaluate the potential protective effects of 17β-estradiol against such toxicity in MeHg-exposed male animals. MeHg exposure (40mg/L, diluted in tap water, during 2 weeks) decreased locomotor activity and motor performance in both male and female animals, but such phenomena were higher in males. 17β-estradiol co-treatment (10μg/animal, in alternate days) prevented MeHg-induced locomotor deficits in males. MeHg exposure caused a significant increase (60%) in cerebellar lipid peroxidation in male mice, but did not in females. In close agreement, MeHg exposure decreased (43%) cerebellar glutathione peroxidase activity in males, but did not in females. These events were prevented by 17β-estradiol administration. Cerebellar GR activity was increased (25%) in MeHg-exposed males and such event was partially prevented by 17β-estradiol administration. These results indicate that the low susceptibility of female mice to the neurotoxicity elicited by MeHg is linked to neuroprotective effects of sex steroids, which appear to modulate the activities of glutathione-related enzymes. Our experimental observation corroborates previous epidemiological studies showing the greater developmental effects in male than in female humans exposed to MeHg.     

Nasal Absorption Enhancement of 17β-Estradiol by Dimethyl-β-Cyclodextrin in Rabbits and Rats

A new formulation for nasal administration containing 17-estradiol (E₂) with dimethyl--cyclodextrin (DMC) as a solubilizer and absorption enhancer is described. Nasal administration of this E₂-DMC formulation gave a significantly higher E₂ absorption than an E₂ suspension in both rabbits and rats. Relative to an intravenous injection of the E₂-DMC formulation, absolute bioavailabilities of 94.6 and 67.2% were calculated for the nasal E₂-DMC formulation in rabbits and rats, respectively. Differences in bioavailability may have resulted from differences in experimental animal conditions. The effects on human nasal ciliary activity of the E₂-DMC formulation were studied with an in vitro method. The formulation was found to exert only a minor effect on ciliary beat frequency. Thus, nasal delivery of E₂, using a cyclodextrin inclusion formulation, may have potential for clinical application, e.g., in the therapy of postmenopausal disorders.     

The expression and clinical significance of P-GSK3βandβ-catenin in endometrial carcinoma

目的 检测子宫内膜癌组织中P-GSK3β蛋白和β-catenin蛋白表达并探讨其意义.方法 采用微波EliVisionTM免疫组织化学法检测60例子宫内膜癌,32例正常子宫内膜组织中P-GSK3β蛋白和β-catenin蛋白的表达.结果 正常子宫内膜组织中β-catenin蛋白表达正常,子宫内膜癌组织中β-catenin发生异位表达.子宫内膜癌组织中P-GSK3β和异位表达的β-catenin分别定位于细胞浆和细胞核,两者表达明显高于癌旁正常组织(P<0.05).两者的表达与肌层浸润程度、淋巴结转移、临床分期及病理分期有关 (P<0.05);两者之间表达呈正相关(P<0.05).结论 P-GSK3β表达和β-catenin异位表达在子宫内膜癌呈高表达,且与子宫内膜癌的发生、发展和转移密切相关.     

β-adrenergic antagonists attenuate withdrawal anxiety in cocaine-and morphine-dependent rats

Rats were treated chronically with either cocaine (20 mg/kg/day, 14 days), morphine (incrementing doses of 10 mg/kg/day to 80 mg/kg, 11 days) or saline. During morphine or cocaine abstinence (48 h), dependent rats showed increased anxiety-like behavior in a conditioned defensive burying paradigm as evidenced by significantly shorter latencies to begin burying as well as a 4-fold increase in burying duration relative to salinetreated animals. This withdrawal-induced increase in burying behavior was blocked by pretreatment with either the -adrenergic antagonist propranolol (5 mg/kg) or the lipophobic selective ₁-antagonist, atenolol (5 mg/kg). These results are consistent with the possibility that activation of peripheral ₁ receptors may substantially contribute to withdrawal-induced anxiety and that -adrenergic antagonists could be useful in treating in cocaine and morphine dependent addicts.     

Eine Oestradiol-17β-Dehydrogenase in den Erythrocyten der Ratte

Zusammenfassung In Fortsetzung einer Untersuchungsreihe über Steroidfermente wird in der vorliegenden Arbeit über eine Oestradiol-17-Dehydrogenase in den roten Blutzellen der Ratte berichtet. Intakte Zellen reduzieren Oestron zu Oestradiol-17 und dehydrogenieren Oestradiol-17, dagegen nicht das 17-Epimere, zu Oestron. Zwischen den beidem Reaktionen stellt sich ein Gleichgewicht her, das unter physiologischen Bedingungen auf seiten des Reduktionsprodukts liegt. Die unter wechselnden Bedingungen angetroffene Gleichgewichtseinstellung wird vor allem von dem Verhältnis TPNH:TPN bestimmt. Dieses Verhältnis wiederum hängt vorwiegend von der Aktivität der Glucose-6-phosphat-Dehydrogenase ab. — Nebenreaktionen, insbesondere die Bildung von Oestradiol-17, lassen sich nicht nachweisen. Zwischen dem Blut von Ratten verschiedenen Geschlechts sind keine Aktivitätsdifferenzen. Die Erythrocyten von Ratten mit fortgeschrittenem Hepatom oder Yoshida-Sarkom enthalten weniger Ferment. praktisch der gesamte Gehalt des Bluts an Oestradiol-17-Dehydrogenase fällt auf die roten Blutzellen. Darstellung und Eigenschaften eines rohen Fermentpräparats aus Erythrocyten werden beschrieben. Die Ergebnisse werden unter den Gesichtspunkten Gleichgewichts-Einstellung mit Erythrocyten sowie Stereo- und Pyridin-nucleotid-Spezifität des Ferments diskutiert.Mit 5 TextabbildungenEin Teil der Ergebnisse wurde auf der Tagung der Gesellschaft für Physiologische Chemie am 24. September 1959 in Berlin vorgetragen.Meinem verehrten Lehrer, Herrn Professor P. Wels, in Dankbarkeit zum 70. Geburtstag gewidmet.     

C-Kit controls IL-1β-induced effector functions in HMC-cells

The receptor tyrosine kinase c-Kit is important for mast cell differentiation, proliferation, and cytokine release. Recently, we reported that c-Kit acts as an intermediate signalling molecule regulating IL-33-induced signalling and effector functions in mast cells. Here, we investigated the influence of c-Kit on the IL-1β-induced signalling and effector functions in HMC mast cell lines. HMC-cells were stimulated with IL-1β and the resulting signalling and cytokine responses were analysed. Furthermore, we used pharmacological inhibitors to investigate the relevance of several signalling molecules for the IL-1β-induced signalling and cytokine responses. Treatment of HMC-cells with the c-Kit inhibitor STI571 blocked the IL-1β-induced activation of Erk1/2 and JNK1/2 but not p38 and NFκB. Furthermore, inhibition of these signalling pathways blocked the IL-6 production in HMC-cells. These findings indicate that IL-1β-induced signalling in mast cells branches into c-Kit- dependent and -independent pathways, both relevant for IL-6 release. Therefore, c-Kit is an important regulator of IL-1 receptor 1-induced signalling and effector functions in HMC-cells.     

Transforming growth factor-β/Smad signalling in diabetic nephropathy

Diabetic nephropathy (DN) is a major diabetic complication that is mediated by transforming growth factor (TGF)-β1 via Smad-dependent and -independent signalling pathways. Under diabetic conditions, many profibrotic factors, such as advanced glycation end-products and angiotensin II, can also activate the Smad signalling pathway via the extracellular signal-regulated kinase/p38 mitogen-activated protein kinase-Smad signalling cross-talk pathway. Thus, Smads act as signal integrators and interact with other signalling pathways to mediate DN. In the context of renal fibrosis, Smad3 is pathogenic, but Smad2 is protective. Deletion of Smad3 inhibits, whereas disruption of Smad2 upregulates, connective tissue growth factor and vascular endothelial growth factor expression and promotes both epithelial-myofibroblast and endothelial-myofibroblast transition. Smad7 plays a protective role in DN because deletion of Smad7 enhances, whereas overexpression of Smad7 inhibits, Smad3-mediated renal fibrosis and nuclear factor-κB-driven renal inflammation. Transforming growth factor-β1 activates Smad3 to regulate microRNAs that mediate renal fibrosis. Of these, miR-21 and miR-192 are upregulated, whereas the miR-29 and miR-200 families are downregulated. Targeting downstream TGF-β/Smad signalling by overexpressing Smad7- or Smad3-dependent microRNA related to fibrosis may represent a novel and effective strategy for the treatment of DN.