Propofol Treatment Inhibits Constitutive Apoptosis in Human Primary Neutrophils and Granulocyte-Differentiated Human HL60 Cells

Sepsis in elderly patients: the role of neutrophils in pathophysiology and therapy

Sepsis is among the most important causes of mortality, particularly within the elderly population. Sepsis prevalence is on the rise due to different factors, including increasing average population age and the concomitant rise in the prevalence of frailty and chronic morbidities. Recent investigations have unveiled a "trimodal" trajectory for sepsis-related mortality, with the ultimate zenith occurring from 60 to 90 days until several years after the original insult. This prolonged temporal course ostensibly emanates from the sustained perturbation of immune responses, persevering beyond the phase of clinical convalescence. This phenomenon is particularly associated with the aging immune system, characterized by a broad dysregulation commonly known as "inflammaging." Inflammaging associates with a chronic low-grade activation of the innate immune system preventing an appropriate response to infective agents. Notably, during the initial phases of sepsis, neutrophils-essential in combating pathogens-may exhibit compromised activity. Paradoxically, an overly zealous neutrophilic reaction has been observed to underlie multi-organ dysfunction during the later stages of sepsis. Given this scenario, discovering treatments that can enhance neutrophil activity during the early phases of sepsis while curbing their overactivity in the later phases could prove beneficial in fighting pathogens and reducing the detrimental effects caused by an overactive immune system. This narrative review delves into the potential key role of neutrophils in the pathological process of sepsis, focusing on how the aging process impacts their functions, and highlighting possible targets for developing immune-modulatory therapies. Additionally, the review includes tables that outline the principal potential targets for immunomodulating agents.

Dexamethasone Sensitizes Acute Monocytic Leukemia Cells to Ara-C by Upregulating FKBP51

In this study, we demonstrated that the expression of FK506 binding protein 51 (FKBP51) is upregulated in acute monocytic leukemia (AML-M5) cells by dexamethasone and aimed to investigate the possible effects of FKBP51 on the growth and cytarabine sensitivity of AML-M5 cells. THP-1 and U937cells were used to establish AML-M5 cell models with FKBP51 overexpression and knockdown, respectively. Cell proliferation, apoptosis and response to cytarabine were investigated by cell cycle, CCK-8 and Flow cytometry analyses. The mice experiment was conducted to detect the role of FKBP51 on AML-M5 cells proliferation and antileukemia effect of Ara-C/Dexamethasone co-therapy in vivo. Western blots were employed to determine protein expression levels. FKBP51 upregulation significantly attenuated THP-1 cell proliferation and sensitized the cells to cytarabine treatment which was further enhanced by dexamethasone. These effects were indicated by decreases in cell viability, S-G2/M phase cell cycle distribution, cytarabine 50% inhibitory concentration (IC50) values and increases in apoptosis and were supported by decreased phosphorylation levels of AKT, GSK3β and FOXO1A and decreased levels of BCL-2 and increased levels of P21 and P27. In contrast, FKBP51 knockdown led to excessive U937 cell proliferation and cytarabine resistance, as indicated by increased cell viability and S-G2/M phase cell cycle distribution, decreased apoptosis, increased phosphorylation levels of AKT, GSK3β and FOXO1A, and increased BCL-2 and decreased P21 and P27 expression. In addition, an AKT inhibitor blocked cell cycle progression and reduced cell viability in all groups of cells. Furthermore, SAFit2, a specific FKBP51 inhibitor, increased U937 cell viability and cytarabine resistance as well as AKT phosphorylation. In conclusion, FKBP51 decelerates proliferation and improves the cytarabine sensitivity of AML-M5 cells by inhibiting AKT pathways, and dexamethasone in combination with Ara-C improves the chemosensitivity of AML-M5.

GSK3 modulation in acute lung injury, myocarditis and polycystic kidney disease-related aneurysm

GSK3 are involved in different physical and pathological conditions and inflammatory regulated by macrophages contribute to significant mechanism. Infection stimuli may modulate GSK3 activity and influence host cell adaption, immune cells infiltration or cytokine expressions. To further address the role of GSK3 modulation in macrophages, the signal transduction of three major organs challenged by endotoxin, virus and genetic inherited factors are briefly introduced (lung injury, myocarditis and autosomal dominant polycystic kidney disease). As a result of pro-inflammatory and anti-inflammatory functions of GSK3 in different microenvironments and stages of macrophages (M1/M2), the rational resolution should be considered by adequately GSK3.

Blue light-induced apoptosis of human promyelocytic leukemia cells via the mitochondrial-mediated signaling pathway

Acute promyelocytic leukemia is frequently associated with dizziness, fever, nausea, hematochezia and anemia. Blue light, or light with wavelengths of 400–480 nm, transmits high levels of energy. The aim of the present study was to determine the pro-apoptotic effects of blue light (wavelength, 456 nm; radiation power, 0.25 mW/cm²) and the underlying mechanisms in a human promyelocytic leukemia cell line (HL60). Blue light reduced the viability and enhanced the mortality of HL60 cells in a time-dependent manner. Exposure to blue light for 24 h caused depolarization of the mitochondrial membrane potential and the overproduction of reactive oxygen species in HL60 cells. In a nude mouse model, 9-day exposure to blue light markedly suppressed the growth of HL60-xenografted tumors; however, it had no effect on hepatic and renal tissues. In addition, blue light abrogated the expression of B-cell lymphoma (Bcl)-2 and Bcl extra-long, while enhancing the levels of Bcl-2-associated X protein, cytochrome c, and cleaved caspases-3 and −9 in tumor tissues. The results suggested that the pro-apoptotic effects of blue light in human promyelocytic leukemia cells may be associated with the mitochondrial apoptosis signaling pathway.

High performance mass spectrometry based proteomics reveals enzyme and signaling pathway regulation in neutrophils during the early stage of surgical trauma

PURPOSE

In clinical conditions trauma is associated with high mortality and morbidity. Neutrophils play a key role in the development of multiple organ failure after trauma EXPERIMENTAL DESIGN: To have a detailed understanding of the neutrophil activation at primary stages after trauma, neutrophils are isolated from control and surgical trauma rats in this study. Extracted proteins are analyzed using nano liquid chromatography coupled with tandem mass spectrometry.

RESULTS

A total of 2924 rat neutrophil proteins are identified in our analysis, of which 393 are found differentially regulated between control and trauma groups. By using functional pathways analysis of the 190 proteins up-regulated in surgical trauma, we found proteins related to transcription initiation and protein biosynthesis. On the other hand, among the 203 proteins down-regulated in surgical trauma we found enrichment for proteins of the immune response, proteasome degradation and actin cytoskeleton. Overall, enzyme prediction analysis revealed that regulated enzymes are directly involved in neutrophil apoptosis, directional migration and chemotaxis. Our observations are then confirmed by in silico protein-protein interaction analysis.

CONCLUSIONS AND CLINICAL RELEVANCE

Collectively, our results reveal that neutrophils drastically regulate their biochemical pathways after the early stages of surgical trauma, showing lower activity. This implies higher susceptibility of the trauma patients to infection and bystander tissues damage.

Propofol Suppressed Hypoxia/Reoxygenation-Induced Apoptosis in HBVSMC by Regulation of the Expression of Bcl-2, Bax, Caspase3, Kir6.1, and p-JNK

Recent studies have found that propofol may protect brain from cerebral ischemic-reperfusion injury. However, the underlying mechanism remains unclear. The effects of propofol were evaluated in HBVSMC after hypoxia/reoxygenation (H/R). Cell viability and levels of SOD, LDH, and MDA were measured. Apoptosis was detected by flow cytometry. The levels of Bax, Bcl-2, Caspase3, Sur2b, Kir6.1, JNK, p-JNK, mTOR, and p-mTOR proteins were measured by western blotting. H/R decreased cell viability and SOD activity and increased LDH leakage and MDA content in HBVSMC, all of which were significantly reversed by propofol. Propofol suppressed the levels of H/R-induced apoptosis. The expression of Bcl-2 and p-mTOR was significantly downregulated and the expression levels of Bax, Caspase3, Kir6.1, and p-JNK were upregulated following H/R injury. The ratio of p-JNK/JNK was increased; however, that of p-mTOR/mTOR decreased correspondingly. The effects on the expression of these proteins were reversed by propofol treatment. SP600125 enhanced and Everolimus attenuated the effect of propofol. These findings suggested that the protective effect of propofol against H/R injury in the HBVSMC was through the inhibition of apoptosis by inducing the expression of Bcl-2 and p-mTOR as well as inhibiting the expression levels of Bax, Caspase3, Kir6.1, and p-JNK.