GRK-Biased Activation Via β2-Adrenergic Receptors in Human Skeletal Muscle (GAIN)
G Protein-Coupled Receptor Kinase (GRK)-Biased Signaling Via β2-Adrenergic Receptors and Downstream Activation and Its Role for Protein Synthesis-Regulating Kinases, Function and Receptor Desensitization in Human Skeletal Muscle
This longitudinal mechanistic physiological study examines biased β2-adrenergic receptor (β2-AR) signaling in human skeletal muscle, with emphasis on G protein-coupled receptor kinase (GRK)-mediated pathways. Participants will receive daily oral dosing of the GRK-selective long-acting β2-agonist ATR-258 for 8 weeks. Muscle biopsies and physiological measurements will quantify GRK-, cAMP/PKA-, and β-arrestin-related up- and downstream signaling, fiber-type specificity, and potential receptor desensitization with repeated stimulation along with functional read-outs, tissue distribution, cardiovascular response and tolerability.
調査の概要
状態
状態
条件
条件
介入・治療
介入・治療
詳細な説明
Healthy men with overweight/obesity will complete an 8-week intervention with daily oral ATR-258 (0.5-2.5 mg/day). On experimental days (Days 1, 15, 29, and 56), β2-AR signaling sensitivity will be assessed before and after stimulation (1-2, 4, and 8 hours) using blood biomarkers, hemodynamics, indirect calorimetry, and lower extremity muscle function/power testing. Muscle biopsies (vastus lateralis) will be obtained at rest and 4 hours after stimulation on Days 1, 29, and 56 to quantify downstream signaling (GRK, cAMP/PKA, β-arrestin), phosphorylation of rpS6/mTOR/Akt, β2-AR content, and muscle fiber morphology.
研究の種類
研究の種類
入学 (実際)
入学
段階
段階
- フェーズ2
連絡先と場所
研究場所
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-
-
Copenhagen、デンマーク、2100
- University of Copenhagen, August Krogh Section for Human & Molecular Physiology
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参加基準
適格基準
適格基準
就学可能な年齢
健康ボランティアの受け入れ
受講資格のある性別
説明
Inclusion Criteria:
- Healthy men
- Age 21-45 years
- BMI 25-35 kg/m^2
- Body fat percentage 25-40%
- Lean Mass Index 14-22
Exclusion Criteria:
- Regular use of or allergy to β2-agonists
- Serious adverse reactions to β2-agonists
- Current smoker
- Regular use of medication (except OTC allergy or analgesics)
- Abnormal ECG before or after β2-AR stimulation
- Hypertension
- Reduced kidney function (eGFR < 90 ml/min/1.73m^2)
- Cardiovascular, metabolic, gastrointestinal, renal, or pulmonary disease
- Psychiatric or neurological disorders affecting compliance/safety reporting
- Cancer history within the last 5 years
- Substance abuse or alcohol intake >14 units/week
研究計画
研究はどのように設計されていますか?
デザインの詳細
- 主な目的:基礎科学
- 割り当て:なし
- 介入モデル:単一グループの割り当て
- マスキング:なし(オープンラベル)
アーム数
武器と介入
参加者グループ / アーム参加者グループ / アーム |
介入・治療介入・治療 |
|---|---|
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実験的:ATR-258
Daily oral ATR-258 |
Daily oral ATR-258 for 8 weeks with repeated experimental assessment days (Days 1, 15, 29, 56). |
この研究は何を測定していますか?
主要な結果の測定
主要な結果の測定
結果測定 |
メジャーの説明 |
時間枠 |
|---|---|---|
|
Intensity of β2-AR downstream signaling pathways (e.g. GRK, cAMP/PKA, β-arrestin, rpS6) in type I and type II muscle fibers
時間枠:Before and 4 hours after ATR-258 ingestion on day 1, 29, and 56.
|
Assessed in vastus lateralis biopsies at rest |
Before and 4 hours after ATR-258 ingestion on day 1, 29, and 56.
|
二次結果の測定
二次結果の測定
結果測定 |
メジャーの説明 |
時間枠 |
|---|---|---|
|
Phosphorylation of rpS6, mTOR, and Akt in type I and type II muscle fibers
時間枠:Day 1, 29 and, 56.
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In response to ATR-258 ingestion |
Day 1, 29 and, 56.
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Lean/fat mass
時間枠:Day 1, 15, 29, and 56
|
Measured by DXA scan |
Day 1, 15, 29, and 56
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|
Muscle function
時間枠:Pre and post 8 weeks of daily ATR-258 ingestion. Post visit conducted 2-5 days after last day of ATR-258 ingestion.
|
Participants will perform lower extremity peak exercise and a one-legged knee-extensor exercise protocol to exhaustion before and after the full intervention to assess muscle power and endurance |
Pre and post 8 weeks of daily ATR-258 ingestion. Post visit conducted 2-5 days after last day of ATR-258 ingestion.
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|
Peripheral glucose clearance including OGTT-derived outcomes
時間枠:Pre and post 8 weeks of daily ATR-258 ingestion. Post visit conducted 2-5 days after last day of ATR-258 ingestion.
|
Pre and post 8 weeks of daily ATR-258 ingestion. Post visit conducted 2-5 days after last day of ATR-258 ingestion.
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|
|
β2-adrenergic receptor content in type I and type II muscle fibers
時間枠:On day 1, 29 and 56
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Measured by western blotting |
On day 1, 29 and 56
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Resting metabolic rate (incl. carbohydrate and fat oxidation)
時間枠:Before and 1, 2, 4 and 8 hours after ATR-258 ingestion on day 1, 15, 29, and 56.
|
Measured by indirect calorimetry |
Before and 1, 2, 4 and 8 hours after ATR-258 ingestion on day 1, 15, 29, and 56.
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Femoral arterial blood flow
時間枠:Before and 1, 2, 4 and 8 hours after ATR-258 ingestion on day 1, 15, 29, and 56.
|
Measured by Doppler. |
Before and 1, 2, 4 and 8 hours after ATR-258 ingestion on day 1, 15, 29, and 56.
|
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Continous ECG and heart rate
時間枠:A 5-day baseline period, and day 1-5, day 15-20, and day 29-34 of ATR-258 administration.
|
Participants will wear a Holter-device for 4 x 5 days to continuously measure ECG and heart rate. The periods will be after the screening (baseline period), and after trial days on Day 1, 15, and 29. |
A 5-day baseline period, and day 1-5, day 15-20, and day 29-34 of ATR-258 administration.
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|
Muscle fiber cross-sectional area (type I and type II)
時間枠:Day 1, 29, and 56
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Measured by histochemical analysis |
Day 1, 29, and 56
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Maximal electrically-stimulated muscle force development and relaxation
時間枠:Pre and post 8 weeks of daily ATR-258 ingestion. Post visit conducted 2-5 days after last day of ATR-258 ingestion.
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Isometric quadriceps. Measured seated with leg in 90 degree angle and attached to strain gauge. |
Pre and post 8 weeks of daily ATR-258 ingestion. Post visit conducted 2-5 days after last day of ATR-258 ingestion.
|
協力者と研究者
協力者
協力者
研究記録日
主要日程の研究
研究開始 (実際)
研究開始
一次修了 (推定)
一次修了
研究の完了 (推定)
研究の完了
試験登録日
最初に提出
最初に提出
QC基準を満たした最初の提出物
QC基準を満たした最初の提出物
最初の投稿 (実際)
最初の投稿
学習記録の更新
投稿された最後の更新 (実際)
投稿された最後の更新
QC基準を満たした最後の更新が送信されました
QC基準を満たした最後の更新が送信されました
最終確認日
最終確認日
詳しくは
本研究に関する用語
その他の研究ID番号
その他の研究ID番号
- ATR
- H-25045258 (その他の識別子:Danish Ethics Board)
個々の参加者データ (IPD) の計画
個々の参加者データ (IPD) を共有する予定はありますか?
医薬品およびデバイス情報、研究文書
米国FDA規制医薬品の研究
米国FDA規制機器製品の研究
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