Insulin-like growth factor-1 in myocardial tissue: interaction with tumor necrosis factor

Enhancing myocardial repair with CardioClusters

Cellular therapy to treat heart failure is an ongoing focus of intense research, but progress toward structural and functional recovery remains modest. Engineered augmentation of established cellular effectors overcomes impediments to enhance reparative activity. Such 'next generation' implementation includes delivery of combinatorial cell populations exerting synergistic effects. Concurrent isolation and expansion of three distinct cardiac-derived interstitial cell types from human heart tissue, previously reported by our group, prompted design of a 3D structure that maximizes cellular interaction, allows for defined cell ratios, controls size, enables injectability, and minimizes cell loss. Herein, mesenchymal stem cells (MSCs), endothelial progenitor cells (EPCs) and c-Kit⁺ cardiac interstitial cells (cCICs) when cultured together spontaneously form scaffold-free 3D microenvironments termed CardioClusters. scRNA-Seq profiling reveals CardioCluster expression of stem cell-relevant factors, adhesion/extracellular-matrix molecules, and cytokines, while maintaining a more native transcriptome similar to endogenous cardiac cells. CardioCluster intramyocardial delivery improves cell retention and capillary density with preservation of cardiomyocyte size and long-term cardiac function in a murine infarction model followed 20 weeks. CardioCluster utilization in this preclinical setting establish fundamental insights, laying the framework for optimization in cell-based therapeutics intended to mitigate cardiomyopathic damage.

Carvacrol and Thymol Modulate the Cross-Talk between TNF-α and IGF-1 Signaling in Radiotherapy-Induced Ovarian Failure

Premature ovarian failure (POF) is a common cause of infertility in premenopausal women who are unavoidably exposed to cytotoxic therapy. Radiotherapy is one of the most effective cytotoxic treatments. However, the radiosensitivity of ovarian tissues limits its therapeutic outcome and results in the depletion of the primordial follicle and loss of fertility. Therefore, the need for an effective radioprotective therapy is evident especially when none of the current clinically used modalities for radioprotection succeeds efficiently. The present study investigated the potential radioprotective effect of carvacrol (CAR) (80 mg) or thymol (80 mg) on gamma- (γ-) irradiation-induced ovarian damage as well as their role in the cross-talk between IGF-1 and TNF-α signaling and antioxidative activity. In immature female Wister rats, a single dose of whole-body irradiation (3.2 Gy, LD₂₀) produced considerable ovarian damage, which was evident by histopathological findings and hormonal changes. Interestingly, pretreatment with CAR or thymol significantly enhanced the follicular development and restored the anti-Mullerian hormone (AMH), E2, and FSH levels. Both essential oils improved the irradiation-mediated oxidative stress and reduction in proliferating cell nuclear antigen (PCNA) expression. Moreover, irradiated rats exhibited an inverse relationship between IGF-1 and TNF-α levels two days post irradiation, which was further inverted by the pretreatment with CAR and thymol and ought to contribute in their radioprotective mechanisms. In conclusion, CAR and thymol showed a radioprotective effect and rescued the ovarian reserve mainly through counteracting oxidative stress and the dysregulated cross-talk between IGF-1 and TNF-α.

Impact of adult growth hormone deficiency on metabolic profile and cardiovascular risk [Review]

Adult growth hormone deficiency (GHD) is a well defined clinical condition, which is characterized by abnormal body composition, impaired physical activity and decreased quality of life. In addition, in recent years, growing interest has been shown towards cardiovascular risks in adult patients affected by GHD. In this regard, GHD is widely known to be associated with increased mortality, likely due to the increase of risk factors, such as central obesity, impaired lipid and glucose profiles and other less-known risk factors, such as inflammatory cytokines, endothelial dysfunction and oxidative stress. However, very few papers have recently discussed this topic. In this review, the aim is to clarify this issue by discussing evidence regarding the effects of adult GHD on metabolic and cardiovascular profiles.

Vasculogenic conditioning of peripheral blood mononuclear cells promotes endothelial progenitor cell expansion and phenotype transition of anti-inflammatory macrophage and T lymphocyte to cells with regenerative potential

Background

Cell‐based therapies involving mononuclear cells (MNCs) have been developed for vascular regeneration to treat ischemic diseases; however, quality control of therapeutic MNCs has not been evaluated. We investigated the therapeutic potential of peripheral blood (PB) MNCs, operated by recently developed quality and quantity (QQ) culture of endothelial progenitor cells (EPCs).

Methods and Results

PBs were collected from healthy volunteers; peripheral blood mononuclear cells (PBMNCs) isolated from these PBs were subjected to QQ culture for 7 days with medium containing stem cell factor, thrombopoietin, Flt‐3 ligand, vascular endothelial growth factor, and interleukin‐6. The resulting cells (QQMNCs) in EPC colony‐forming assay generated significantly more definitive EPC colonies than PBMNCs. In flow cytometry, macrophages and helper T lymphocytes of QQMNCs became phenotypically polarized into angiogenic, anti‐inflammatory, and regenerative subsets: classical M1 to alternative M2; T helper (Th)1 to Th2; angiogenic or regulatory T‐cell expansion. Quantitative real‐time polymerase chain reaction (qRT‐PCR) assay revealed the predominant proangiogenic gene expressions in QQMNCs versus PBMNCs. Using murine ischemic hindlimb models, the efficacy of QQMNC intramuscular transplantation (Tx) was compared to that of PBMNCTx, cultured “early EPC” Tx (eEPCTx), and granulocyte colony‐stimulating factor mobilized CD34⁺ cell Tx (GmCD34Tx). Laser Doppler imaging revealed the blood perfusion recovery in ischemic hindlimbs after QQMNCTx superior to after PBMNCTx and eEPCTx, but also earlier than after GmCD34Tx. Histological evaluations and qRT‐PCR assays in ischemic hindlimbs demonstrated that QQMNCTx, similarly to GmCD34Tx, enhanced angiovasculogenesis and myogenesis, whereas it preponderantly inhibited inflammation and fibrosis versus PBMNCTx and eEPCTx.

Conclusions

QQ culture potentiates the ability of PBMNCs to promote regeneration of injured tissue; considering the feasible cell preparation, QQ culture‐treated PBMNCs may provide a promising therapeutic option for ischemic diseases.

Clinical Trial Registration

URL: irb.med.u-tokai.ac.jp/d/2/monthly/2010.html; IRB No.: 10R‐020.

URL: irb.med.u-tokai.ac.jp/d/2/monthly/201312.html; IRB No.: 13R228.

Insulin-like growth factor-1 abrogates microglial oxidative stress and TNF-α responses to spreading depression

Spreading depression (SD), the most likely cause of migraine aura and perhaps migraine, occurs with increased oxidative stress (OS). SD increases reactive oxygen species (ROS), and ROS, in turn, can signal to increase neuronal excitability,which includes increased SD susceptibility. SD also elevates tumor necrosis factor-α (TNF-α), which increases neuronal excitability. Accordingly, we probed for the cellular origin of OS from SD and its relationship to TNF-α, which might promote SD, using rat hippocampal slice cultures. We observed significantly increased OS from SD in astrocytes and microglia but not in neurons or oligodendrocytes. Since insulin-like growth factor-1 (IGF-1) mitigates OS from SD, we determined the cell types responsible for this effect. We found that IGF-1 significantly decreased microglial but not astrocytic OS from SD. We also show that IGF-1 abrogated the SD-induced TNF-α increase. Furthermore, TNF-α application increased microglial but not astrocytic OS, an effect abrogated by IGF-1. Next,we showed that SD increased SD susceptibility, and does so via TNF-α. This work suggests that microglia promote SD via increased and interrelated ROS and TNF-α signaling. Thus, IGF-1 mitigation of microglial ROS and TNF-α responses maybe targets for novel therapeutics development to prevent SD, and perhaps migraine.

How Institut Georges Lopez preservation solution protects nonsteatotic and steatotic livers against ischemia-reperfusion injury

The Institut Georges Lopez preservation solution (IGL-1) is a serum-free organ preservative that has been shown to protect steatotic livers against hepatic ischemia-reperfusion injury. Although several hypotheses have been proposed to explain the graft protection mechanisms induced by IGL-1 solution, they have not been fully investigated. This review assessed possible IGL-1 mechanisms responsible for the increased liver tolerance of ischemia-reperfusion injury with special emphasis on vasodilatator mediators such as nitric oxide, on oxidative stress prevention, on protection against mitochondrial damage, and finally on induction of cytoprotective factors.

Insulin like growth factor-1 increases fatty liver preservation in IGL-1 solution

AIM: To investigate the benefits of insulin like growth factor-1 (IGF-1) supplementation to serum-free institut georges lopez-1 (IGL-1)^® solution to protect fatty liver against cold ischemia reperfusion injury.

METHODS: Steatotic livers were preserved for 24 h in IGL-1^® solution supplemented with or without IGF-1 and then perfused “ex vivo” for 2 h at 37°C. We examined the effects of IGF-1 on hepatic damage and function (transaminases, percentage of sulfobromophthalein clearance in bile and vascular resistance). We also studied other factors associated with the poor tolerance of fatty livers to cold ischemia reperfusion injury such as mitochondrial damage, oxidative stress, nitric oxide, tumor necrosis factor-α (TNF-α) and mitogen-activated protein kinases.

RESULTS: Steatotic livers preserved in IGL-1^® solution supplemented with IGF-1 showed lower transaminase levels, increased bile clearance and a reduction in vascular resistance when compared to those preserved in IGL-1^® solution alone. These benefits are mediated by activation of AKT and constitutive endothelial nitric oxide synthase (eNOS), as well as the inhibition of inflammatory cytokines such as TNF-α. Mitochondrial damage and oxidative stress were also prevented.

CONCLUSION: IGL-1^® enrichment with IGF-1 increased fatty liver graft preservation through AKT and eNOS activation, and prevented TNF-α release during normothermic reperfusion.

Regulation of IRS-2 signaling by IGF-1 receptor in the diabetic rat heart

Cardiovascular disease involves changes in inflammatory markers. Since insulin/insulin-like growth factor 1 receptor (IGF-1R) can activate vascular endothelial growth factor to promote vascular growth, reduced IGF-1R signaling in the type I diabetic heart could be detrimental, leading to reduced, collateral blood vessel growth. This study assessed whether diabetes can induce an inflammatory phenotype to regulate molecules in the IGF-1 signaling cascade, thus mediating apoptosis. Rats were made diabetic using streptozotocin (to render them type I diabetic) for 2 months with no insulin treatment. At 2 months, rats were sacrificed under anesthesia, and the left ventricle was immediately removed and placed into cold lysis buffer for protein analyses. Western blotting, immunoprecipitation, and enzyme-linked immunosorbent assay analyses were completed to evaluate protein levels. Diabetes increased TNF-α, interleukin-6 (IL-6), and IL-1α levels in the heart. JNK and p42/p44 activity was significantly increased in the diabetic heart, while IGF-1R phosphorylation, IRS-2 tyrosine phosphorylation, and Akt activities were reduced. A significant increase in Bad protein levels and the cleavage of caspase 3 was observed in the diabetic heart. These results suggest that diabetes activates multiple inflammatory markers in the heart, which then signal a decrease in the activities of key players in the insulin-signaling cascade, namely IGF-1R, IRS-2, and Akt, to regulate apoptosis.