Acute hypobaric hypoxic brain damage is a potentially fatal high-altitude sickness. Autophagy plays a critical role in ischemic brain injury, but its role in hypobaric hypoxia (HH) remains unknown. Here we used an HH chamber to demonstrate that acute HH exposure impairs autophagic activity in both the early and late stages of the mouse brain, and is partially responsible for HH-induced oxidative stress, neuronal loss, and brain damage. The autophagic agonist rapamycin only promotes the initiation of autophagy. By proteome analysis, a screen showed that protein dynamin2 (DNM2) potentially regulates autophagic flux. Overexpression of DNM2 significantly increased the formation of autolysosomes, thus maintaining autophagic flux in combination with rapamycin. Furthermore, the enhancement of autophagic activity attenuated oxidative stress and neurological deficits after HH exposure. These results contribute to evidence supporting the conclusion that DNM2-mediated autophagic flux represents a new therapeutic target in HH-induced brain damage.
Mice ; Animals ; Hypoxia ; Oxidative Stress ; Autophagy ; Cognition ; Sirolimus/therapeutic use*

In the tumor microenvironment, metabolic reprogramming can impact metabolic characteristics of T cells, thus inducing immunosuppression to promote tumor immune escape. The mammalian target of rapamycin (mTOR) signaling pathway plays an important role in regulating diverse functions of various immune cells. This review mainly focuses on the molecular mechanism of mTOR signaling in regulating cellular energy metabolism process, and the activation status of mTOR signaling under different nutritional environments. In addition, it also summarizes the role of the mTOR signaling in regulatory T cell (Tregs) metabolism and function in current studies, and evaluates the potential of mTOR as a clinical immunotherapeutic target and its current application challenges.
Immunosuppression Therapy ; Metabolic Reprogramming ; Signal Transduction ; Sirolimus ; T-Lymphocytes, Regulatory ; TOR Serine-Threonine Kinases ; Humans

Klippel-Trenaunay syndrome (KTS) is a rare slow-flow congenital vascular disorder with an incidence of 1:100,000. 1 , 2 KTS is classically characterized by a clinical triad of capillary malformation, venous malformation, and bony or soft tissue hypertrophy. RAD50 and POLE genes act directly on deoxyribonucleicacid (DNA) and genome stability. Although distinct from the more studiedphosphatidylinositol-4,5-bisphosphate3-kinase catalytic subunit alpha (PIK3CA)gene, RAD50 and POLE genes coexist as a deficient gene in few vascular malformations and papillary thyroid carcinoma (PTC).

This is a case of a 7-month-old Filipino female patient clinically and radiologically diagnosed as KTS presenting with multiple capillary malformations and left limb length-girth discrepancies. Dermoscopy showed various vessel patterns in all affected areas. Soft tissue ultrasound and magnetic resonance imaging/angiography (MRI/MRA) of the left extremities revealed subcutaneous capillary malformations, hypertrophy of the subcutaneous structures and compartment muscles. Strong family history of PTC was elicited and genetic sequencing revealed detected RAD50 and POLE genes. She was treated using the mammalian target of rapamycin inhibitor sirolimus with careful monitoring of trough levels and radiographic tests. A significant outcome one year post-sirolimus revealed no abnormal vessels on ultrasound, a lesser degree of hypertrophy and capillary malformations were no longer appreciated in MRI/MRA of left extremities. Port-wine stains (PWS) and affected limbs showed a decrease in erythema and growth rate during the treatment period.

KTS detected with RAD50 and POLE genes successfully treated with sirolimus with trough-level monitoring. Radiographic evaluation and regular anthropometric assessment remain valuable in the diagnosis and monitoring.

This paper aimed to investigate the role and potential mechanism of p53 on primordial follicle activation. Firstly, the p53 mRNA expression in the ovary of neonatal mice at 3, 5, 7 and 9 days post-partum (dpp) and the subcellular localization of p53 were detected to confirm the expression pattern of p53. Secondly, 2 dpp and 3 dpp ovaries were cultured with p53 inhibitor Pifithrin-μ (PFT-μ, 5 μmol/L) or equal volume of dimethyl sulfoxide for 3 days. The function of p53 in primordial follicle activation was determined by hematoxylin staining and whole ovary follicle counting. The proliferation of cell was detected by immunohistochemistry. The relative mRNA levels and protein levels of the key molecules involved in the classical pathways associated with the growing follicles were examined by immunofluorescence staining, Western blot and real-time PCR, respectively. Finally, rapamycin (RAP) was used to intervene the mTOR signaling pathway, and ovaries were divided into four groups: Control, RAP (1 μmol/L), PFT-μ (5 μmol/L), PFT-μ (5 μmol/L) + RAP (1 μmol/L) groups. The number of follicles in each group was determined by hematoxylin staining and whole ovary follicle counting. The results showed that the expression of p53 mRNA was decreased with the activation of primordial follicles in physiological condition. p53 was expressed in granulosa cells and oocyte cytoplasm of the primordial follicles and growing follicles, and the expression of p53 in the primordial follicles was higher than that in the growing follicles. Inhibition of p53 promoted follicle activation and reduced the primordial follicle reserve. Inhibition of p53 promoted the proliferation of the granulosa cells and oocytes. The mRNA and protein expression levels of key molecules in the PI3K/AKT signaling pathway including AKT, PTEN, and FOXO3a were not significantly changed after PFT-μ treatment, while the expression of RPS6/p-RPS6, the downstream effectors of the mTOR signaling pathway, was upregulated. Inhibition of both p53 and mTOR blocked p53 inhibition-induced primordial follicle activation. Collectively, these findings suggest that p53 may inhibit primordial follicle activation through the mTOR signaling pathway to maintain the primordial follicle reserve.
Female ; Animals ; Mice ; Tumor Suppressor Protein p53/metabolism* ; Proto-Oncogene Proteins c-akt/metabolism* ; Phosphatidylinositol 3-Kinases/metabolism* ; Hematoxylin ; Signal Transduction/physiology* ; TOR Serine-Threonine Kinases ; Sirolimus ; RNA, Messenger

OBJECTIVES: The phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway is one of the main signaling pathways related to autophagy. Autophagy plays a key role in the formation of silicosis fibrosis. The phenotypic transformation of lung fibroblasts into myofibroblasts is a hallmark of the transition from the inflammatory phase to the fibrotic phase in silicosis. This study aims to investigate whether the PI3K/Akt/mTOR pathway affects the phenotypic transformation of silicosis-induced lung fibroblasts into myofibroblasts via mediating macrophage autophagy. METHODS: The human monocytic leukemia cell line THP-1 cells were differentiated into macrophages by treating with 100 ng/mL of phorbol ester for 24 h. Macrophages were exposed to different concentrations (0, 25, 50, 100, 200, 400 μg/mL) and different times (0, 6, 12, 24, 48 h) of SiO₂ dust suspension. The survival rate of macrophages was measured by cell counting kit-8 (CCK-8) method. Enzyme linked immunosorbent assay (ELISA) was used to measure the contents of transforming growth factor-β1 (TGF-β1) and tumor necrosis factor-α (TNF-α) in the cell supernatant. The co-culture system of macrophages and HFL-1 cells was established by transwell. A blank control group, a SiO₂ group, a LY294002 group, a SC79 group, a LY294002+SiO₂ group, and a SC79+SiO₂ group were set up in this experiment. Macrophages in the LY294002+SiO₂ group were pretreated with LY294002 (PI3K inhibitor) for 18 hours, and macrophages in the SC79+SiO₂ group were pretreated with SC79 (Akt activator) for 24 hours, and then exposed to SiO₂ (100 μg/mL) dust suspension for 12 hours. The expression of microtubule-associated protein 1 light chain 3 (LC3) protein in macrophages was detected by the immunofluorescence method. The protein expressions of PI3K, Akt, mTOR, Beclin-1, LC3 in macrophages, and collagen III (Col III), α-smooth muscle actin (α-SMA), fibronectin (FN), matrix metalloproteinase-1 (MMP-1), tissue metalloproteinase inhibitor-1 (TIMP-1) in HFL-1 cells were measured by Western blotting. RESULTS: After the macrophages were exposed to SiO₂ dust suspension of different concentrations for 12 h, the survival rates of macrophages were gradually decreased with the increase of SiO₂ concentration. Compared with the 0 μg/mL group, the survival rates of macrophages in the 100, 200, and 400 μg/mL groups were significantly decreased, and the concentrations of TGF-β1 and TNF-α in the cell supernatant were obviously increased (all P<0.05). When 100 μg/mL SiO₂ dust suspension was applied to macrophages, the survival rates of macrophages were decreased with the prolonged exposure time. Compared with the 0 h group, the survival rates of macrophages were significantly decreased (all P<0.05), the concentrations of TGF-β1 and TNF-α in the cell supernatant were significantly increased, and the protein expression levels of Beclin-1 and LC3II were increased markedly in the 6, 12, 24, and 48 h groups (all P<0.05). Immunofluorescence results demonstrated that after exposure to SiO₂ (100 μg/mL) dust for 12 h, LC3 exhibited punctate aggregation and significantly higher fluorescence intensity compared to the blank control group (P<0.05). Compared with the blank control group, the protein expressions of Col III, FN, α-SMA, MMP-1, and TIMP-1 in HFL-1 cells were up-regulated in the SiO₂ group (all P<0.05). Compared with the SiO₂ group, the protein expressions of PI3K, Akt, and mTOR were down-regulated and the protein expressions of LC3II and Beclin-1 were up-regulated in macrophages (all P<0.05), the contents of TNF-α and TGF-β1 in the cell supernatant were decreased (both P<0.01), and the protein expressions of Col III, FN, α-SMA, MMP-1, and TIMP-1 in HFL-1 cells were down-regulated (all P<0.05) in the LY294002+SiO₂ group. Compared with the SiO₂ group, the protein expressions of PI3K, Akt, and mTOR were up-regulated and the protein expressions of LC3II and Beclin-1 were down-regulated in macrophages (all P<0.05), the contents of TNF-α and TGF-β1 in the cell supernatant were increased (both P<0.01), and the protein expressions of Col III, FN, α-SMA, MMP-1, and TIMP-1 in HFL-1 cells were up-regulated (all P<0.05) in the SC79+SiO₂ group. CONCLUSIONS Silica dust exposure inhibits the PI3K/Akt/mTOR pathway, increases autophagy and concentration of inflammatory factors in macrophages, and promotes the phenotype transformation of HFL-1 cells into myofibroblasts. The regulation of the PI3K/Akt/mTOR pathway can affect the autophagy induction and the concentration of inflammatory factors of macrophages by silica dust exposure, and then affect the phenotype transformation of HFL-1 cells into myofibroblasts induced by silica dust exposure.
Humans ; Proto-Oncogene Proteins c-akt/metabolism* ; Transforming Growth Factor beta1/metabolism* ; Silicon Dioxide/metabolism* ; Phosphatidylinositol 3-Kinases/metabolism* ; Matrix Metalloproteinase 1/metabolism* ; Tissue Inhibitor of Metalloproteinase-1 ; Sirolimus ; Beclin-1/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Dust ; TOR Serine-Threonine Kinases/metabolism* ; Lung/metabolism* ; Fibroblasts/metabolism* ; Silicosis/metabolism* ; Macrophages/metabolism* ; Autophagy

BACKGROUND: The HELIOS stent is a sirolimus-eluting stent with a biodegradable polymer and titanium oxide film as the tie-layer. The study aimed to evaluate the safety and efficacy of HELIOS stent in a real-world setting. METHODS: The HELIOS registry is a prospective, multicenter, cohort study conducted at 38 centers across China between November 2018 and December 2019. A total of 3060 consecutive patients were enrolled after application of minimal inclusion and exclusion criteria. The primary endpoint was target lesion failure (TLF), defined as a composite of cardiac death, non-fatal target vessel myocardial infarction (MI), and clinically indicated target lesion revascularization (TLR) at 1-year follow-up. Kaplan-Meier methods were used to estimate the cumulative incidence of clinical events and construct survival curves. RESULTS: A total of 2998 (98.0%) patients completed the 1-year follow-up. The 1-year incidence of TLF was 3.10% (94/2998, 95% closed interval: 2.54-3.78%). The rates of cardiac death, non-fatal target vessel MI and clinically indicated TLR were 2.33% (70/2998), 0.20% (6/2998), and 0.70% (21/2998), respectively. The rate of stent thrombosis was 0.33% (10/2998). Age ≥60 years, diabetes mellitus, family history of coronary artery disease, acute myocardial infarction at admission, and device success were independent predictors of TLF at 1 year. CONCLUSION: The 1-year incidence rates of TLF and stent thrombosis were 3.10% and 0.33%, respectively, in patients treated with HELIOS stents. Our results provide clinical evidence for interventional cardiologists and policymakers to evaluate HELIOS stent. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov, NCT03916432.
Humans ; Middle Aged ; Sirolimus/therapeutic use* ; Drug-Eluting Stents/adverse effects* ; Prospective Studies ; Cohort Studies ; Treatment Outcome ; Risk Factors ; Time Factors ; Percutaneous Coronary Intervention/adverse effects* ; Cardiovascular Agents/therapeutic use* ; Coronary Artery Disease/therapy* ; Myocardial Infarction/etiology* ; Thrombosis/complications* ; Polymers ; Registries

Human induced pluripotent stem cells (hiPSCs) are promising in regenerative medicine. However, the pluripotent stem cells (PSCs) may form clumps of cancerous tissue, which is a major safety concern in PSCs therapies. Rapamycin is a safe and widely used immunosuppressive pharmaceutical that acts through heterodimerization of the FKBP12 and FRB fragment. Here, we aimed to insert a rapamycin inducible caspase 9 (riC9) gene in a safe harbor AAVS1 site to safeguard hiPSCs therapy by drug induced homodimerization. The donor vector containing an EF1α promoter, a FRB-FKBP-Caspase 9 (CARD domain) fusion protein and a puromycin resistant gene was constructed and co-transfected with sgRNA/Cas9 vector into hiPSCs. After one to two weeks screening with puromycin, single clones were collected for genotype and phenotype analysis. Finally, rapamycin was used to induce the homodimerization of caspase 9 to activate the apoptosis of the engineered cells. After transfection of hiPSCs followed by puromycin screening, five cell clones were collected. Genome amplification and sequencing showed that the donor DNA has been precisely knocked out at the endogenous AAVS1 site. The engineered hiPSCs showed normal pluripotency and proliferative capacity. Rapamycin induced caspase 9 activation, which led to the apoptosis of all engineered hiPSCs and its differentiated cells with different sensitivity to drugs. In conclusion, we generated a rapamycin-controllable hiPSCs survival by homodimerization of caspase 9 to turn on cell apoptosis. It provides a new strategy to guarantee the safety of the hiPSCs therapy.
Humans ; Induced Pluripotent Stem Cells ; Sirolimus/metabolism* ; Caspase 9/metabolism* ; RNA, Guide, CRISPR-Cas Systems ; Pluripotent Stem Cells/metabolism* ; Cell Differentiation ; Puromycin/metabolism*

Intraosseous hemangioma is a benign, rare neoplasm that accounts to 0.5 - 1% of all benign tumors of bones.1, 2 While most hemangiomas arise from soft tissues, it is uncommon for it to arise from bones.2 The most common sites of growth are in the vertebral body and the calvarium with frontal bone making up approximately 45% of calvarial cases.2,3 However, they are also encountered in the head and neck with sites such as the skull (53%), mandible (10.7%), nasal bones (9%), and cervical spine (6%).4 In the mandible, the body is mostly affected and 65% are found in the molar and premolar region.1 They are more common in adult females with peaks at the second and fifth decades of life.1-3 Hemangioma of the mandible is difficult to diagnose due to its nonspecific clinical presentation and radiographic features. It mimics various mass lesions in the mandible such as giant cell granuloma, fibrous dysplasia, multiple myeloma, osteosarcoma, ameloblastoma and keratocysts. Therefore, a comprehensive history taking and physical examination plus examination of the imaging studies available and tissue biopsy all play important roles in arriving at the final diagnosis.5 We present the case of an aggressive mandibular hemangioma in a young boy and our management involving a failed fibular free flap reconstruction.
Sirolimus ; Sirolimus

Objective To explore the role of autophagy, apoptosis of neutrophils and neutrophils extracellular traps (NET) formation in systemic lupus erythematosus (SLE). Methods Thirty-six patients with SLE were recruited as research subjects, and 32 healthy controls matched accordingly were enrolled as control subjects. The expression levels of microtubule associated protein 1 light chain 3B (LC3B), autophagy-related gene5(ATG5), P62, B-cell lymphoma 2(Bcl2), Bcl2-related X protein (BAX) in neutrophils were detected by Western blot analysis. Flow cytometry was employed to analyze the expression of LC3B on neutrophils. The expression level of myeloperoxidase(MPO) in plasma was estimated by ELISA. Furthermore, neutrophils were cultured in vitro and stimulated by 100 nmol/L rapamycin and 10 μg/mL lipopolysaccharide (LPS) for 6 hours, respectively. And then, the expression levels of LC3B, ATG5, P62, Bcl2 and BAX in neutrophils were detected by Western blot analysis. The level of MPO in culture supernatant was detected by ELISA. The change of fluorescence intensity of NET in culture supernatant was assayed by Sytox^TM Green staining combined with fluorescence spectrophotometry. Results Compared with healthy controls, the levels of autophagy and apoptosis of neutrophils and NET formation in SLE patients were increased. The level of apoptosis and NET formation was positively associated with neutrophil autophagy. The level of autophagy showed an increase but had no effect on apoptosis and NET formation for neutrophil stimulated by rapamycin. The levels of autophagy and NET formation also increased with no significant effect on apoptosis for neutrophil induced by LPS. Conclusion The autophagy, apoptosis and NET formation of neutrophils increase in SLE patients. The activation of autophagy and NET in neutrophils possibly result from the inflammatory internal environment in SLE patients.
Humans ; Neutrophils ; Extracellular Traps/metabolism* ; Lipopolysaccharides/pharmacology* ; bcl-2-Associated X Protein/metabolism* ; Sirolimus/pharmacology* ; Lupus Erythematosus, Systemic ; Autophagy

Mammalian target of rapamycin (mTOR) controls cellular anabolism, and mTOR signaling is hyperactive in most cancer cells. As a result, inhibition of mTOR signaling benefits cancer patients. Rapamycin is a US Food and Drug Administration (FDA)-approved drug, a specific mTOR complex 1 (mTORC1) inhibitor, for the treatment of several different types of cancer. However, rapamycin is reported to inhibit cancer growth rather than induce apoptosis. Pyruvate dehydrogenase complex (PDHc) is the gatekeeper for mitochondrial pyruvate oxidation. PDHc inactivation has been observed in a number of cancer cells, and this alteration protects cancer cells from senescence and nicotinamide adenine dinucleotide (NAD^+‍) exhaustion. In this paper, we describe our finding that rapamycin treatment promotes pyruvate dehydrogenase E1 subunit alpha 1 (PDHA1) phosphorylation and leads to PDHc inactivation dependent on mTOR signaling inhibition in cells. This inactivation reduces the sensitivity of cancer cells' response to rapamycin. As a result, rebooting PDHc activity with dichloroacetic acid (DCA), a pyruvate dehydrogenase kinase (PDK) inhibitor, promotes cancer cells' susceptibility to rapamycin treatment in vitro and in vivo.
Humans ; Sirolimus/pharmacology* ; Dichloroacetic Acid/pharmacology* ; Pyruvate Dehydrogenase Complex ; TOR Serine-Threonine Kinases ; Mechanistic Target of Rapamycin Complex 1 ; Neoplasms/drug therapy*