Hypoxic Air Inhalation and Ischemia Interventions Both Elicit Preconditioning Which Attenuate Subsequent Cellular Stress In vivo Following Blood Flow Occlusion and Reperfusion

Abstract

Ischemic preconditioning (IPC) is valid technique which elicits reductions in femoral blood flow occlusion mediated reperfusion stress (oxidative stress, Hsp gene transcripts) within the systemic blood circulation and/or skeletal muscle. It is unknown whether systemic hypoxia, evoked by hypoxic preconditioning (HPC) has efficacy in priming the heat shock protein (Hsp) system thus reducing reperfusion stress following blood flow occlusion, in the same manner as IPC. The comparison between IPC and HPC being relevant as a preconditioning strategy prior to orthopedic surgery. In an independent group design, 18 healthy men were exposed to 40 min of (1) passive whole-body HPC (FiO2 = 0.143; no ischemia. N = 6), (2) IPC (FiO2 = 0.209; four bouts of 5 min ischemia and 5 min reperfusion. n = 6), or (3) rest (FiO2 = 0.209; no ischemia. n = 6). The interventions were administered 1 h prior to 30 min of tourniquet derived femoral blood flow occlusion and were followed by 2 h subsequent reperfusion. Systemic blood samples were taken pre- and post-intervention. Systemic blood and gastrocnemius skeletal muscle samples were obtained pre-, 15 min post- (15PoT) and 120 min (120PoT) post-tourniquet deflation. To determine the cellular stress response gastrocnemius and leukocyte Hsp72 mRNA and Hsp32 mRNA gene transcripts were determined by RT-qPCR. The plasma oxidative stress response (protein carbonyl, reduced glutathione/oxidized glutathione ratio) was measured utilizing commercially available kits. In comparison to control, at 15PoT a significant difference in gastrocnemius Hsp72 mRNA was seen in HPC (−1.93-fold; p = 0.007) and IPC (−1.97-fold; p = 0.006). No significant differences were observed in gastrocnemius Hsp32 and Hsp72 mRNA, leukocyte Hsp72 and Hsp32 mRNA, or oxidative stress markers (p > 0.05) between HPC and IPC. HPC provided near identical amelioration of blood flow occlusion mediated gastrocnemius stress response (Hsp72 mRNA), compared to an established IPC protocol. This was seen independent of changes in systemic oxidative stress, which likely explains the absence of change in Hsp32 mRNA transcripts within leukocytes and the gastrocnemius. Both the established IPC and novel HPC interventions facilitate a priming of the skeletal muscle, but not leukocyte, Hsp system prior to femoral blood flow occlusion. This response demonstrates a localized tissue specific adaptation which may ameliorate reperfusion stress.

The childbirth experience: obstetric and psychological predictors in Italian primiparous women

“…Labor and childbirth information was then obtained from the maternal birth records. These data included: [1] duration of dilatation phase (i.e., first stage of labor), defined as the beginning of frequent contractions (≥3 contractions per 10 min and a cervix dilation of approximately 4 cm) [2]; duration of the expulsive phase (i.e., second stage of labor) [3]; induction of labor (for pregnancies beyond the 41 + 5th week), which included amniotomy, endocervical placement of a catheter, and oxytocin or prostaglandin administration (selected on the basis of the clinical evaluation of the woman) [4]; use of epidural analgesia during labor (started at any time during labor); and [5] mode of childbirth: spontaneous vaginal childbirth, instrumental vaginal childbirth (with vacuum assistance), or emergency caesarean section (CS).…”

“…The woman’s emotional and cognitive experience of birth is recognized as having a significant impact on her postpartum physical and psychological state [1] and on her first interactions with the infant [2]. A positive childbirth experience can improve maternal well-being and facilitate mother-infant bonding, while a negative experience can lead to a condition of psychological distress as well as to severe forms of disease such as postpartum depression [3] or post-traumatic stress symptoms [4], often connected with the level of pain perceived during childbirth [5]. These conditions have inevitable long-term consequences on the relationship with the child in addition to its well-being and development [6].…”

Exosomal circHIPK3 Released from Hypoxia-Pretreated Cardiomyocytes Regulates Oxidative Damage in Cardiac Microvascular Endothelial Cells via the miR-29a/IGF-1 Pathway

“…Hypoxic preconditioning (HPC) is widely used to simulate in vivo ischemic preconditioning (IPC) in cell culture models. HPC may enhance cellular tolerance to ROS [17]. As shown in our previous studies, miR-214, also known as “exosomal shuttle RNA,” is shuttled between cells following HPC and regulates apoptosis in target cells [13, 18].…”

miR‑133b‑5p contributes to hypoxic preconditioning‑mediated cardioprotection by inhibiting the activation of caspase‑8 and caspase-3 in cardiomyocytes

“…In addition, inhaled hypoxic air preconditioning including intermittent hypoxia has been suggested a potential non-pharmacological therapeutic intervention to improve some cardiovascular diseases such as hypertension, myocardial infarction. Such HPC may enhance cellular tolerance to subsequent hypoxia-induced oxidative stress, simulating the protective effects of IPC, taking advantage of convenient and non-invasive intervention ( 3 , 4 ). In recent years, HPC has been extensively studied and established to be cardioprotective against H/R injury, which involves many factors including oxygen transport, energy metabolism, redox balance, stress protein and protein kinase signaling, adenosine release, ATP-sensitive potassium channels, mitochondrial function, control of calcium levels, and nitric oxide production ( 5 – 7 ).…”