Dual-omics reveals temporal differences in acute sympathetic stress-induced cardiac inflammation following α1 and ß-adrenergic receptors activation.

Sympathetic stress is prevalent in cardiovascular diseases. Sympathetic overactivation under strong acute stresses triggers acute cardiovascular events including myocardial infarction (MI), sudden cardiac death, and stress cardiomyopathy. α1-ARs and ß-ARs, two dominant subtypes of adrenergic receptors in the heart, play a significant role in the physiological and pathologic regulation of these processes. However, little is known about the functional similarities and differences between α1- and ß-ARs activated temporal responses in stress-induced cardiac pathology. In this work, we systematically compared the cardiac temporal genome-wide profiles of acute α1-AR and ß-AR activation in the mice model by integrating transcriptome and proteome. We found that α1- and ß-AR activations induced sustained and transient inflammatory gene expression, respectively. Particularly, the overactivation of α1-AR but not ß-AR led to neutrophil infiltration at one day, which was closely associated with the up-regulation of chemokines, activation of NF-κB pathway, and sustained inflammatory response. Furthermore, there are more metabolic disorders under α1-AR overactivation compared with ß-AR overactivation. These findings provide a new therapeutic strategy that, besides using ß-blocker as soon as possible, blocking α1-AR within one day should also be considered in the treatment of acute stress-associated cardiovascular diseases.

IMM-H007 attenuates isoprenaline-induced cardiac fibrosis through targeting TGFß1 signaling pathway.

Upon chronic stress, ß-adrenergic receptor activation induces cardiac fibrosis and leads to heart failure. The small molecule compound IMM-H007 has demonstrated protective effects in cardiovascular diseases via activation of AMP-activated protein kinase (AMPK). This study aimed to investigate IMM-H007 effects on cardiac fibrosis induced by ß-adrenergic receptor activation. Because adenosine analogs also exert AMPK-independent effects, we assessed AMPK-dependent and -independent IMM-H007 effects in murine models of cardiac fibrosis. Continual subcutaneous injection of isoprenaline for 7 days caused cardiac fibrosis and cardiac dysfunction in mice in vivo. IMM-H007 attenuated isoprenaline-induced cardiac fibrosis, diastolic dysfunction, α-smooth muscle actin expression, and collagen I deposition in both wild-type and AMPKα2-/- mice. Moreover, IMM-H007 inhibited transforming growth factor ß1 (TGFß1) expression in wild-type, but not AMPKα2-/- mice. By contrast, IMM-H007 inhibited Smad2/3 signaling downstream of TGFß1 in both wild-type and AMPKα2-/- mice. Surface plasmon resonance and molecular docking experiments showed that IMM-H007 directly interacts with TGFß1, inhibits its binding to TGFß type II receptors, and downregulates the Smad2/3 signaling pathway downstream of TGFß1. These findings suggest that IMM-H007 inhibits isoprenaline-induced cardiac fibrosis via both AMPKα2-dependent and -independent mechanisms. IMM-H007 may be useful as a novel TGFß1 antagonist.

Glibenclamide alleviates ß adrenergic receptor activation-induced cardiac inflammation.

ß-Adrenergic receptor (ß-AR) overactivation is a major pathological factor associated with cardiac diseases and mediates cardiac inflammatory injury. Glibenclamide has shown anti-inflammatory effects in previous research. However, it is unclear whether and how glibenclamide can alleviate cardiac inflammatory injury induced by ß-AR overactivation. In the present study, male C57BL/6J mice were treated with or without the ß-AR agonist isoprenaline (ISO) with or without glibenclamide pretreatment. The results indicated that glibenclamide alleviated ISO-induced macrophage infiltration in the heart, as determined by Mac-3 staining. Consistent with this finding, glibenclamide also inhibited ISO-induced chemokines and proinflammatory cytokines expression in the heart. Moreover, glibenclamide inhibited ISO-induced cardiac fibrosis and dysfunction in mice. To reveal the protective mechanism of glibenclamide, the NLRP3 inflammasome was further analysed. ISO activated the NLRP3 inflammasome in both cardiomyocytes and mouse hearts, but this effect was alleviated by glibenclamide pretreatment. Furthermore, in cardiomyocytes, ISO increased the efflux of potassium and the generation of ROS, which are recognized as activators of the NLRP3 inflammasome. The ISO-induced increases in these processes were inhibited by glibenclamide pretreatment. Moreover, glibenclamide inhibited the cAMP/PKA signalling pathway, which is downstream of ß-AR, by increasing phosphodiesterase activity in mouse hearts and cardiomyocytes. In conclusion, glibenclamide alleviates ß-AR overactivation-induced cardiac inflammation by inhibiting the NLRP3 inflammasome. The underlying mechanism involves glibenclamide-mediated suppression of potassium efflux and ROS generation by inhibiting the cAMP/PKA pathway.

α1-AR overactivation induces cardiac inflammation through NLRP3 inflammasome activation.

Acute sympathetic stress causes excessive secretion of catecholamines and induces cardiac injuries, which are mainly mediated by ß-adrenergic receptors (ß-ARs). However, α1-adrenergic receptors (α1-ARs) are also expressed in the heart and are activated upon acute sympathetic stress. In the present study, we investigated whether α1-AR activation induced cardiac inflammation and the underlying mechanisms. Male C57BL/6 mice were injected with a single dose of α1-AR agonist phenylephrine (PE, 5 or 10 mg/kg, s.c.) with or without pretreatment with α-AR antagonist prazosin (5 mg/kg, s.c.). PE injection caused cardiac dysfunction and cardiac inflammation, evidenced by the increased expression of inflammatory cytokine IL-6 and chemokines MCP-1 and MCP-5, as well as macrophage infiltration in myocardium. These effects were blocked by prazosin pretreatment. Furthermore, PE injection significantly increased the expression of NOD-like receptor protein 3 (NLRP3) and the cleavage of caspase-1 (p20) and interleukin-18 in the heart; similar results were observed in both Langendorff-perfused hearts and cultured cardiomyocytes following the treatment with PE (10 µM). Moreover, PE-induced NLRP3 inflammasome activation and cardiac inflammation was blocked in Nlrp3-/- mice compared with wild-type mice. In conclusion, α1-AR overactivation induces cardiac inflammation by activating NLRP3 inflammasomes.

IL-18 cleavage triggers cardiac inflammation and fibrosis upon ß-adrenergic insult.

Aims: Rapid over-activation of ß-adrenergic receptor (ß-AR) upon stress leads to cardiac inflammation, a prevailing factor that underlies heart injury. However, mechanisms by which acute ß-AR stimulation induce cardiac inflammation still remain unknown. Here, we set out to identify the crucial role of inflammasome/interleukin (IL)-18 in initiating and maintaining cardiac inflammatory cascades upon ß-AR insult. Methods and results: Male C57BL/6 mice were injected with a single dose of ß-AR agonist, isoproterenol (ISO, 5 mg/kg body weight) or saline subcutaneously. Cytokine array profiling demonstrated that chemokines dominated the initial cytokines upregulation specifically within the heart upon ß-AR insult, which promoted early macrophage infiltration. Further investigation revealed that the rapid inflammasome-dependent activation of IL-18, but not IL-1ß, was the critical up-stream regulator for elevated chemokine expression in the myocardium upon ISO induced ß1-AR-ROS signalling. Indeed, a positive correlation was observed between the serum levels of norepinephrine and IL-18 in patients with chest pain. Genetic deletion of IL-18 or the up-stream inflammasome component NLRP3 significantly attenuated ISO-induced chemokine expression and macrophage infiltration. In addition, IL-18 neutralizing antibodies selectively abated ISO-induced chemokines, proinflammatory cytokines and adhesion molecules but not growth factors. Moreover, blocking IL-18 early after ISO treatment effectively attenuated cardiac inflammation and fibrosis. Conclusion: Inflammasome-dependent activation of IL-18 within the myocardium upon acute ß-AR over-activation triggers cytokine cascades, macrophage infiltration and pathological cardiac remodelling. Blocking IL-18 at the early stage of ß-AR insult can successfully prevent inflammatory responses and cardiac injuries.

Long-term outcomes of patients with refractory gastroesophageal reflux disease following a minimally invasive endoscopic procedure: a prospective observational study.

BACKGROUND: Gastroesophageal reflux disease (GERD) is the most common digestive disease, affecting one third of the world's population. The minimally invasive endoscopic Stretta procedure is being increasingly used as an alternative strategy to manage refractory GERD. However, long-term benefits of this procedure have to be further evaluated in clinical settings. This prospective observational study was therefore conducted to evaluate the outcome of patients with refractory GERD 5 years after the Stretta procedure. METHODS: A total of 152 patients with refractory GERD underwent the Stretta procedure in our department between April 2007 and September 2008. They were followed up for 5 years, during which the primary outcome measures including symptom scores of heartburn, regurgitation, chest pain, cough and asthma and the secondary outcome measures including proton pump inhibitor (PPI) use and patients' satisfaction were analysed at 6, 12, 24, 36, 48 and 60 months respectively. RESULTS: Of the 152 patients, 138 completed the designated 5-year follow-up and were included in the final analysis. At the end of the 5-year follow-up, the symptom scores of heartburn (2.47 ± 1.22 vs. 5.86 ± 1.52), regurgitation (2.23 ± 1.30 vs. 5.56 ± 1.65), chest pain (2.31 ± 0.76 vs. 4.79 ± 1.59), cough (3.14 ± 1.43 vs. 6.62 ± 1.73) and asthma (3.26 ± 1.53 vs. 6.83 ± 1.46) were all significantly decreased as compared with the corresponding values before the procedure (P < 0.001). After the Stretta procedure, 59 (42.8%) patients achieved complete PPI therapy independence and 104 (75.4%) patients were completely or partially satisfied with the GERD symptom control. Moreover, no severe complications were observed except for complaint of abdominal distention in 12 (8.7%) patients after the Stretta procedure. CONCLUSION: The Stretta procedure may achieve an effective and satisfactory long-term symptom control and considerably reduce the reliance on medication without significant adverse effects in adult patients with refractory GERD, thereby having profound clinical implications.

Gastroesophageal reflux in chronic cough and cough syncope and the effect of antireflux treatment: case report and literature review.

OBJECTIVE: This study aimed to evaluate the efficacy of antireflux treatment on gastroesophageal reflux (GER)-related cough syncope. METHODS: The method used was a retrospective review of the outcomes of antireflux treatment with proton pump inhibitor (PPI), Stretta radiofrequency (SRF), or laparoscopic fundoplication (LF) of 8 patients with chronic cough and cough syncope that was clinically evaluated to be GER related over a period of 2 to 5 years. RESULTS: In the 8 selected cases, the typical GER symptoms disappeared in 7 cases and were significantly eased in 1 case. The chronic cough diminished to mild and occasional occurrence in 6 cases and was completely relieved in 2 cases. Meanwhile, the cough syncope disappeared in all cases. Seven of the patients resumed physical and social functions after the antireflux treatments, except for 1 person, who had a stroke due to other causes. CONCLUSION: For chronic cough and cough syncope of unknown cause, the GER assessment could be valuable. In treating well-selected GER-related chronic cough and cough syncope, PPI, SRF, and LF can be considered. Moreover, satisfactory restoration of physical and social functions could be achieved after effective antireflux therapy.

Extracellular matrix of mechanically stretched cardiac fibroblasts improves viability and metabolic activity of ventricular cells.

BACKGROUND: In heart, the extracellular matrix (ECM), produced by cardiac fibroblasts, is a potent regulator of heart's function and growth, and provides a supportive scaffold for heart cells in vitro and in vivo. Cardiac fibroblasts are subjected to mechanical loading all the time in vivo. Therefore, the influences of mechanical loading on formation and bioactivity of cardiac fibroblasts ECM should be investigated. METHODS: Rat cardiac fibroblasts were cultured on silicone elastic membranes and stimulated with mechanical cyclic stretch. After removing the cells, the ECMs coated on the membranes were prepared, some ECMs were treated with heparinase II (GAG-lyase), then the collagen, glycosaminoglycan (GAG) and ECM proteins were assayed. Isolated neonatal rat ventricular cells were seeded on ECM-coated membranes, the viability and lactate dehydrogenase (LDH) activity of the cells after 1-7 days of culture was assayed. In addition, the ATPase activity and related protein level, glucose consumption ratio and lactic acid production ratio of the ventricular cells were analyzed by spectrophotometric methods and Western blot. RESULTS: The cyclic stretch increased collagen and GAG levels of the ECMs, and elevated protein levels of collagen I and fibronectin. Compared with the ECMs produced by unstretched cardiac fibroblasts, the ECMs of mechanically stretched fibroblasts improved viability and LDH activity, elevated the Na⁺/K⁺-ATPase activity, sarco(endo)plasmic reticulum Ca²âº-ATPase (SERCA) activity and SERCA 2a protein level, glucose consumption ratio and lactic acid production ratio of ventricular cells seeded on them. The treatment with heparinase II reduced GAG levels of these ECMs, and lowered these metabolism-related indices of ventricular cells cultured on the ECMs. CONCLUSIONS: Mechanical stretch promotes ECM formation of cardiac fibroblasts in vitro, the ECM of mechanically stretched cardiac fibroblasts improves metabolic activity of ventricular cells cultured in vitro, and the GAG of the ECMs is involved in regulating metabolic activity of ventricular cells.

Gastroesophageal reflux in bronchiectasis and the effect of anti-reflux treatment.

BACKGROUND: Bronchiectasis is a progressive and fatal disease despite the available treatment regimens. Gastroesophageal reflux (GER) may play an important role in the progression of bronchiectasis. However, active anti-reflux intervention such as Stretta radiofrequency (SRF) and/or laparoscopic fundoplication (LF) have rarely been used to treat Bronchiectasis. CASE PRESENTATION: Seven patients' clinical outcomes for treating GER-related deteriorated bronchiectasis were retrospective reviewed. All patients were treated by SRF and/or LF, and had follow-up periods ranging from one to five years. Typical GER symptoms, respiratory symptoms, medication consumption and general health status were assessed during the follow-ups. At the latest follow-up all patients were alive. The typical GER symptoms disappeared in five people and were significantly improved in the other two. Two had complete remissions of both respiratory symptoms and bronchiectasis exacerbations; four had significantly improved respiratory symptoms to mild/moderate degrees as well as reduced or zero bronchiectasis exacerbations, which allowed them to resume the physical and social functions; one's respiratory symptoms and bronchiectasis exacerbations were not much improved, yet she was in stable condition and satisfied with the results. CONCLUSIONS: Potentially, GER plays an important role in some patients with bronchiectasis, and active anti-reflux treatments can be beneficial. Future clinical studies are suggested to clarify GER's role in bronchiectasis and to further determine whether anti-reflux interventions for GER can improve the outcomes of patients with bronchiectasis.

Cardiac fibroblast-derived extracellular matrix produced in vitro stimulates growth and metabolism of cultured ventricular cells.

Cardiac fibroblasts (CFs) produce extracellular matrix (ECM) which is a potent regulator of heart cell function and growth, and provides a supportive microenvironment for heart cells. Therefore, CF-derived ECM produced in vitro is very suitable for heart-cell culturing and cardiac tissue engineering. The aim of this study was to investigate the effect of CF-derived ECM produced in vitro on the growth and metabolism of cultured ventricular cells. CF-derived ECM-coated cell culture dishes were prepared by culturing rat CFs and then decellularizing the cultures. Isolated neonatal rat ventricular cells were seeded on ECM-coated, collagen I-coated or uncoated dishes, and the growth of cells after 1-5 days of culture was assayed with MTT reagent. In addition, cellular metabolic activity was analyzed by spectrophotometric methods and protein levels of sarco(endo)plasmic reticulum Ca(2+)-ATPase type 2a (SERCA2a) by Western blotting. The relative growth of ventricular cells was better on ECM-coated than on uncoated or collagen I-coated dishes. Furthermore, the glucose consumption ratio, lactic acid production ratio, Na(+)/K(+)-ATPase activity, SERCA activity and protein levels of SERCA2a were all higher in cells on the ECM-coated dishes. In conclusion, cardiac fi broblast-derived ECM produced in vitro stimulates the growth and metabolism of cultured ventricular cells. This study indicates that the bioactivity of the ECM supports heart cell growth in vitro, and this might be useful for cardiac tissue engineering.

Efficacy evaluation of pepsin in laparoscopic antireflux surgery for gastroesophageal reflux disease.

BACKGROUND: The false positive rate of the PPI test for the diagnosis of typical symptoms of gastroesophageal reflux disease (GERD) is extremely high. OBJECTIVE: This study aims to investigate the effect of the pepsin test on GERD and laparoscopy-assisted anti-reflux surgery for GERD. METHODS: A total of 30 GERD patients were enrolled into this study, and the pre-diagnosis of GERD was determined by symptom evaluation, impedance-pH examination, gastroscopy and pepsin test. All patients underwent surgery. RESULTS: Among the 30 GERD patients, 18 patients were male and 12 were female, and their average age was 58.2 + 12.6 years old. The patients were treated with laparoscopic fundoplication and hiatus hernia repair after preoperative assessment. A total of 28 patients were followed up, one patient developed recurrent symptoms, and one patient developed postoperative dysphagia and received non-operative treatment. Furthermore, the symptom scores were significantly lower at postoperative pepsin detection when compared to the scores before the operation (pepsin: preoperative: 148.8 ± 82.6, postoperative: 30.7 ± 24.6; t= 4.848, P= 0.000). CONCLUSIONS: Laparoscopic fundoplication and hiatus hernia repair may effectively control the symptoms of GERD. Furthermore, the detection of pepsin is non-invasive and easy to operate.

The Stretta procedure eliminates arrhythmia due to gastroesophageal reflux disease.

A significant percentage of patients with gastroesophageal reflux disease may experience extraesophageal manifestations, such as chest pain or asthma. These symptoms are more difficult to diagnose than the usual esophageal symptoms. The aim of this article is to characterize the extraesophageal manifestations in patients with gastroesophageal reflux disease and report the effects of the Stretta procedure. We report a case of a 59-year-old female patient with a history of arrhythmia. She was referred for the Stretta procedure in the gastroesophageal junction after her symptoms were documented by pH monitoring and proton-pump inhibitors treatment to be associated with acid reflux. The long-standing arrhythmia improved after the Stretta procedure. To our knowledge, this is a rare case of successful Stretta procedure treatment of a patient with cardiovascular manifestations induced by gastroesophageal reflux disease. The results indicate an underlying mechanism for extraesophageal manifestations and the success of the Stretta procedure.

Membrane nanotubes facilitate the propagation of inflammatory injury in the heart upon overactivation of the ß-adrenergic receptor.

Acute sympathetic stress quickly induces cardiac inflammation and injury, suggesting that pathogenic signals rapidly spread among cardiac cells and that cell-to-cell communication may play an important role in the subsequent cardiac injury. However, the underlying mechanism of this response is unknown. Our previous study demonstrated that acute ß-adrenergic receptor (ß-AR) signaling activates inflammasomes in the heart, which triggers the inflammatory cascade. In the present study, ß-AR overactivation induced inflammasome activation in both the cardiomyocytes and cardiac fibroblasts (CFs) of mice hearts following a subcutaneous injection of isoproterenol (ISO, 5 mg/kg body weight), a selective agonist of ß-AR. In isolated cardiac cells, ISO treatment only activated the inflammasomes in the cardiomyocytes but not the CFs. These results demonstrated that inflammasome activation was propagated from cardiomyocytes to CFs in the mice hearts. Further investigation revealed that the inflammasomes were activated in the cocultured CFs that connected with cardiomyocytes via membrane nanotubes (MNTs), a novel membrane structure that mediates distant intercellular connections and communication. Disruption of the MNTs with the microfilament polymerization inhibitor cytochalasin D (Cyto D) attenuated the inflammasome activation in the cocultured CFs. In addition, the MNT-mediated inflammasome activation in the CFs was blocked by deficiency of the inflammasome component NOD-like receptor protein 3 (NLRP3) in the cardiomyocytes, but not NLRP3 deficiency in the CFs. Moreover, ISO induced pyroptosis in the CFs cocultured with cardiomyocytes, and this process was inhibited by disruption of the MNTs with Cyto D or by the NLRP3 inhibitor MCC950 and the caspase-1 inhibitor Z-YVAD-FMK (FMK). Our study revealed that MNTs facilitate the rapid propagation of inflammasome activation among cardiac cells to promote pyroptosis in the early phase of ß-adrenergic insult. Therefore, preventing inflammasome transfer is a potential therapeutic strategy to alleviate acute ß-AR overactivation-induced cardiac injury.

Salivary Pepsin as an Intrinsic Marker for Diagnosis of Sub-types of Gastroesophageal Reflux Disease and Gastroesophageal Reflux Disease-related Disorders.

BACKGROUND/AIMS: To determine the value of salivary pepsin in discriminating sub-types of gastroesophageal reflux disease (GERD) and GERD-related disorders. METHODS: Overall, 322 patients with different sub-types of GERD and 45 healthy controls (HC) were studied. All patients took Gastroesophageal Reflux Disease Questionnaire (GerdQ) and underwent endoscopy and 24-hour esophageal pH monitoring and manometry. Salivary pepsin concentration (SPC) was detected by using colloidal gold double-antibody immunological sandwich assay. Oral esomeprazole treatment was administrated in the patients with non-erosive reflux disease (NERD) and extra-esophageal symptoms (EES). RESULTS: Compared to HC, patients with erosive esophagitis, NERD, EES, EES plus typical GERD symptoms, or Barrett's esophagus had a higher prevalence of saliva and SPC (all P < 0.001). There was no significant difference in the positive rate for pepsin in patients with functional heartburn or GERD with anxiety and depression, compared to HC. After esomeprazole treatment, the positive rate and SPC were significantly reduced in NERD (both P < 0.001) and in EES ( P = 0.001 and P = 0.002, respectively). Of the 64 NERD patients, 71.9% (n = 46) were positive for salivary pepsin, which was significantly higher than the rate (43.8%, n = 28) of pathological acid reflux as detected by 24-hour esophageal pH monitoring (P = 0.002). CONCLUSIONS: Salivary pepsin has an important significance for the diagnosis of GERD and GERD-related disorders. Salivary pepsin and 24-hour esophageal pH monitoring may complement with each other to improve the diagnostic efficiency.

Anterior thalamic nucleus stimulation modulates regional cerebral metabolism: an FDG-MicroPET study in rats.

The mechanism underlying the antiepileptic function of deep brain stimulation (DBS) of the anterior thalamic nucleus (ATN) remains unknown, presumably related to functional lesioning of target. We measured the regional normalized cerebral metabolic rate of glucose (nCMRglc) with (18)F-fluorodeoxyglucose (FDG)-MicroPET in animals receiving either ATN stimulation or lesioning. Bilateral ATN stimulation reversibly increased glucose uptake in the target region, the thalamus and hippocampus, and decreased glucose uptake in the cingulate cortex and frontal cortex. However, bilateral ATN lesioning decreased glucose uptake only in the target region. Animals with bilateral ATN lesions showed no metabolic changes after ATN stimulation. Thus, bilateral DBS of the ATN reversibly induces metabolic activation of the target area and modulates energy metabolism in remote brain regions via efferent or afferent fibers in non-epileptic rats. DBS of the ATN may work by a different mechanism than ATN lesioning.

[Delayed neuronal degeneration after intracerebral hemorrhage: the role of iron].

OBJECTIVE: To investigate the occurrence of delayed neuronal degeneration, activation of microglia and nuclear factor-kappa B after rat intracerebral hemorrhage (ICH) and the possible role of iron. METHODS: ICH model was induced by infusion of autologous whole blood into the right basal ganglia. To evaluate the possible role of iron on delayed neuron loss, an iron model by injection of FeCl(2) into hippocampus was also set up. Degeneration of neurons and the activation of microglia and NF-kappa B were detected. RESULT: Both whole blood and iron caused neuron degeneration for at least 14 days were revealed by Fluoro-jade C staining. Consistently, activated microglia and NF-kappa B positive cells were also observed in the peri-hematoma area and the ipsilateral hippocampus. CONCLUSION: The iron may participate in the delayed neuron injury followed ICH; the activated microglia and NF-kappa B may be involved in the process of delayed neuronal injury.

Mitochondria are transported along microtubules in membrane nanotubes to rescue distressed cardiomyocytes from apoptosis.

Membrane nanotubes (MNTs) act as "highways" between cells to facilitate the transfer of multiple signals and play an important role in many diseases. Our previous work reported on the transfer of mitochondria via MNTs between cardiomyocytes (CMs) and cardiac myofibroblasts (MFs); however, the elucidation of the underlying mechanism and pathophysiological significance of this transfer requires additional study. In this study, we determined that the mean movement velocity of mitochondria in MNTs between CMs and MFs was approximately 17.5 ± 2.1 nm/s. Meanwhile, treatment with microtubule polymerisation inhibitors nocodazole or colcemid in cell culture decreased mitochondrial velocity, and knockdown of the microtubule motor protein kinesin family member 5B (KIF5B) led to a similar effect, indicating that mitochondrial movement was dependent on microtubules and the motor protein KIF5B. Furthermore, we showed that hypoxia/reoxygenation-induced CM apoptosis was attenuated by coculture with intact or hypoxia/reoxygenation-treated MFs, which transferred mitochondria to CMs. This rescue was prevented either by separating the cells using Transwell culture or by impairing mitochondrial transfer with nocodazole or colcemid treatment. In conclusion, as a novel means of intercellular communication, MNTs rescue distressed CMs from apoptosis by transporting mitochondria along microtubules via KIF5B.