Dual role of Nrf2/HO-1 pathway in Z-ligustilide-induced ferroptosis against AML cells

BACKGROUND

The scarcity of drugs targeting AML cells poses a significant challenge in AML management. Z-Ligustilide (Z-LIG), a phthalide compound, shows promising pharmacological potential as a candidate for AML therapy. However, its precise selective mechanism remains unclear.

PURPOSE

In order to assess the selective inducement effects of Z-LIG on ferroptosis in AML cells and explore the possible involvement of the Nrf2/HO-1 pathway in the regulation of ferroptosis.

METHODS

Through in vitro cell proliferation and in vivo tumor growth tests, the evaluation of Z-LIG's anticancer activity was conducted. Ferroptosis was determined by the measurement of ROS and lipid peroxide levels using flow cytometry, as well as the observation of mitochondrial morphology. To analyze the iron-related factors, western blot analysis was employed. The up-regulation of the Nrf2/HO-1 axis was confirmed through various experimental techniques, including CRISPR/Cas9 gene knockout, fluorescent probe staining, and flow cytometry. The efficacy of Z-LIG in inducing ferroptosis was further validated in a xenograft nude mouse model.

RESULTS

Our study revealed that Z-LIG specifically triggered lipid peroxidation-driven cell death in AML cells. Z-LIG downregulated the total protein and nuclear entrance levels of IRP2, resulting in upregulation of FTH1 and downregulation of TFR1. Z-LIG significantly increased the susceptibility to ferroptosis by upregulating ACSL4 levels and simultaneously suppressing the activity of GPX4. Notably, the Nrf2/HO-1 pathway displayed a twofold impact in the ferroptosis induced by Z-LIG. Mild activation suppressed ferroptosis, while excessive activation promoted it, mainly driven by ROS-induced labile iron pool (LIP) accumulation in AML cells, which was not observed in normal human cells. Additionally, Nrf2 knockout and HO-1 knockdown reversed iron imbalance and mitochondrial damage induced by Z-LIG in HL-60 cells. Z-LIG effectively inhibited the growth of AML xenografts in mice, and Nrf2 knockout partially weakened its antitumor effect by inhibiting ferroptosis.

CONCLUSION

Our study presents biological proof indicating that the selective initiation of ferroptosis in leukemia cells is credited to the excessive activation of the Nrf2/HO-1 pathway triggered by Z-LIG.

[A study on the first-order interaction of diagnostic performance of coronary CT angiography-derived fractional flow reserve]

Objective: To investigate the effect of image quality, degree of stenosis, calcification, and their first-order interactions on diagnostic performance of coronary computed tomography (CT) angiography-derived fractional flow reserve (CT-FFR). Methods: This is a reanalysis of data from a multi-center retrospective cross-sectional study of CT-FFR in China. A total of 522 patients with suspected or known coronary heart disease [mean age: 61.6 (34.0-83.0) years, 71.8% (354/493) were male] from 11 medical centers including the General Hospital of Eastern Theater Command from May 2015 to October 2019 were enrolled. All patients underwent coronary CT angiography (CCTA), CT-FFR, and invasive FFR examination. Subjective image quality scores of target vessels were recorded on CCTA images, and stenosis was visually assessed at the lesion level. Calcification arc and calcification remodeling index (CRI) were recorded for each lesion. Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) were compared. Two-way analysis of variance was used to analyze the first-order interaction effects of image quality, degree of stenosis, and calcification. Results: A total of 493 patients with 629 lesions with invasive FFR as a reference were included in the study. The overall sensitivity, specificity, and accuracy of CT-FFR were 80.4%, 93.8%, and 88.6%, respectively. The specificity (95.0% vs. 87.3%, χ2=4.11, P=0.043); accuracy (90.1% vs. 81.9%, χ2=6.22, P=0.013); and NPV (89.7% vs. 80.9%, χ2=4.25, P=0.039) of the group with image quality ≥3 was higher than the group with image quality <3. The degree of stenosis affected the sensitivity, PPV, and NPV of CT-FFR and the calcification arc affected the specificity of CT-FFR (all P>0.05). The specificity (95.8% vs. 90.5%, χ2=4.23, P=0.040); accuracy (91.0% vs. 86.1%, χ2=4.01, P=0.045); and NPV (91.1% vs. 83.8%, χ2=5.10, P=0.024) of the group with CRI<1 were higher than that of the group with CRI≥1. In the subgroup of mild and severe stenosis, no calcification, and CRI<1, the accuracy of CT-FFR with image quality ≥3 points were higher than that with image quality <3 points. The accuracy of CT-FFR in the moderate stenosis group was mainly affected by CRI; the accuracy of CT-FFR in the group with CRI<1 was higher than that in the group with CRI≥1 (after Bonferroni correction, P values between groups were statistically significant). Conclusion: Subjective image quality, degree of stenosis, calcification of lesions, and their first-order interactions can all negatively affect the diagnostic performance of CT-FFR.

Z-ligustilide preferentially caused mitochondrial dysfunction in AML HL-60 cells by activating nuclear receptors NUR77 and NOR1

BACKGROUND

Nuclear receptors NUR77 and NOR1 were identified as critical targets in acute myeloid leukemia (AML) therapy. Previously, we showed that Z-ligustilide (Z-LIG) selectively targeted AML by restoring NUR77 and NOR1. However, its downstream mechanisms are yet to be elucidated.

METHODS

SRB staining assay was used to measure cell viability. Cell apoptosis, mitochondrial membrane potential and mitochondrial reactive oxygen species were analyzed using flow cytometry. The potential targets of Z-LIG in AML HL-60 cells were evaluated by RNA sequencing. Changes in RNA levels were measured using quantitative RT-qPCR and western blot analysis was used to detect the expression of proteins.

RESULTS

Z-LIG preferentially induced mitochondrial dysfunction in HL-60 cells compared with 293T cells. Furthermore, RNA sequencing revealed that mitochondrial transcription and translation might be potential Z-LIG targets inhibiting HL-60 cells. NUR77/NOR1 overexpression significantly reduced the mitochondrial ATP and mitochondrial membrane potential and increased mitochondrial reactive oxygen species in HL-60 cells but not in 293T cells. Moreover, Z-LIG induced mitochondrial dysfunction by restoring NUR77 and NOR1 in HL-60 cells. Compared with HL-60 cells, the apoptosis-inducing activities of NUR77/NOR1 and Z-LIG were significantly reduced in HL-60 ρ0 cells depleted in mitochondrial DNA (mt-DNA). Moreover, NUR77/NOR1 and Z-LIG downregulated mitochondrial transcription and translation related proteins in HL-60 cells. Notably, Z-LIG remarkably reduced mitochondrial ATP in primary AML cells and showed anti-AML activity in mouse models of human AML.

CONCLUSIONS

Collectively, our findings suggested that Z-LIG selectively induces mitochondrial dysfunction in AML HL-60 cells by restoring NUR77 and NOR1, a process associated with interference in mtDNA transcription.

Neutralization sensitivity, fusogenicity, and infectivity of Omicron subvariants

BACKGROUND

The emergence of SARS-CoV-2 Omicron subvariants has raised questions regarding resistance to immunity by natural infection or immunization. We examined the sensitivity of Delta and Omicron subvariants (BA.1, BA.1.1, BA.2, BA.2.12.1, BA.4/5, and BA.3) to neutralizing antibodies from BBIBP-CorV-vaccinated and BBIBP-CorV- or ZF2001-boosted individuals, as well as individuals with Delta and BA.1 breakthrough infections, and determined their fusogenicity and infectivity.

METHODS

In this cross-sectional study, serum samples from two doses of BBIBP-CorV-vaccinated individuals 1 (n = 36), 3 (n = 36), and 7 (n = 37) months after the second dose; BBIBP-CorV- (n = 25) or ZF2001-boosted (n = 30) individuals; and fully vaccinated individuals with Delta (n = 30) or BA.1 (n = 26) infection were collected. The serum-neutralizing reactivity and potency of bebtelovimab were assessed against D614G, Delta, and Omicron subvariants (BA.1, BA.1.1, BA.2, BA.2.12.1, BA.4/5, and BA.3) through a pseudovirus neutralization assay. The fusogenicity and infectivity of D614G, Delta, and Omicron subvariants were determined by cell-cell fusion assay and pseudovirus infection assay, respectively.

RESULTS

Omicron subvariants markedly escaped vaccine-elicited neutralizing antibodies after two doses of BBIBP-CorV with comparable efficiency. A third dose vaccination of BBIBP-CorV or ZF2001 increased neutralizing antibody titers and breadth against Delta and three Omicron subvariants. Delta and BA.1 breakthrough infections induced comparable neutralizing antibody titers against D614G and Delta variants, whereas BA.1 breakthrough infections elicited a stronger and broader antibody response against three Omicron subvariants than Delta breakthrough infections. BA.2.12.1 and BA.4/5 are more resistant to immunity induced by breakthrough infections. Bebtelovimab had no significant loss of potency against the Delta and Omicron subvariants. Cell culture experiments showed Omicron subvariants to be less fusogenic and have higher infectivity than D614G and Delta with comparable efficiency.

CONCLUSIONS

These findings have important public health implications and highlight the importance of repeated exposure to SARS-CoV-2 antigens to broaden the neutralizing antibody response against Omicron subvariants.

Retroperitoneal tumor finally diagnosed as a bronchogenic cyst: A case report and review of literature

BACKGROUND

Retroperitoneal bronchogenic cyst (RBC) is an extremely rare developmental abnormality. Most are benign tumors but malignant transformation is possible. Because of their anatomical position, RBCs are easily misdiagnosed as adrenal or pancreatic solid tumors on radiological evaluation. Here, we report a case of RBC, review the literature, and summarize some important features.

CASE SUMMARY

A 49-year-old woman was incidentally found to have a retroperitoneal tumor during a physical examination. Enhanced computed tomography and laboratory evaluations, including routine blood examination, blood biochemistry, 24-h urine 17 ketones, 17 hydroxyls, adrenocortical hormone, serum potassium concentration, serum amylase, lipase, and epithelial tumor markers, revealed a moderate density, 54 mm × 40 mm mass with a clear boundary near the left adrenal gland. The were no abnormalities in the blood and urine values. Because the patient had a history of hypertension and the location of the mass was adjacent to the adrenal gland, it was initially diagnosed as a left adrenal tumor and was resected by retroperitoneal laparoscopy. However, the pathological examination after surgery confirmed it to be a bronchogenic cyst.

CONCLUSION

Retroperitoneal laparoscopic surgery can be prioritized for symptomatic RBC patients. Conservative treatment is feasible for selected patients.

Persistence of Antibody and Cellular Immune Responses in COVID-19 patients over Nine Months after Infection

Background

The duration of humoral and T and cell response after the infection of SARS-CoV-2 remains unclear.

Methods

We performed a cross-sectional study to assess the virus-specific antibody and memory T and B cell responses in COVID-19 patients up to 343 days after infection. Neutralizing antibodies and antibodies against the receptor-binding domain, spike, and nucleoprotein of SARS-CoV-2 were measured. Virus-specific memory T and B cell responses were analyzed.

Results

We enrolled 59 COVID-19 patients, including 38 moderate, 16 mild, and five asymptomatic patients; 31 (52.5%) were men, and 28 (47.5%) were women. The median age was 41 (interquartile range [IQR]: 30–55). The median day from symptom onset to enrollment was 317 days (range 257 to 343 days). We found that approximately 90% of patients still have detectable IgG antibodies against spike and nucleocapsid proteins and neutralizing antibodies against pseudovirus, whereas ~60% of patients had detectable IgG antibodies against receptor binding domain and surrogate virus-neutralizing antibodies. SARS-CoV-2-specific IgG ⁺ memory B cell and IFN-γ secreting T cell responses were detectable in over 70% of patients.

Conclusions

SARS-CoV-2-specific immune memory response persists in most patients nearly one year after infection, which provides a promising sign for prevention from reinfection and vaccination strategy.

Effects of irrigation fluid temperature during flexible ureteroscopic holmium laser lithotripsy on postoperative fever and shivering: a randomized controlled trial

Background

Flexible ureteroscopic holmium laser lithotripsy is used to treat urinary tract calculi, but postoperative complications include shivering, fever and infection. To investigate the effects of irrigation fluid temperature on postoperative complications.

Methods

This randomized controlled trial included 120 consecutive patients undergoing flexible ureteroscopic holmium laser lithotripsy at the Urology Department, Suining Central Hospital, Sichuan, China between January 2017 and July 2019. Patients were randomized 1:1:1 into three groups (17 °C, 27 °C or 37 °C). Primary outcome was fever incidence (body temperature > 37.5 °C) within 48 h after surgery. Secondary outcomes included shivering incidence during recovery from anesthesia, white blood cell count (WBC), serum procalcitonin (PCT) and incidence of suspected infection (temperature > 38.5 °C and PCT > 0.5 µg/L).

Results

There were 108 patients, (17 °C group, n = 36; 27 °C group, n = 35; 37 °C group, n = 37), received flexible ureteroscopic holmium laser lithotripsy and analyzed. Age, gender distribution, body mass index, ASA grade, stone burden, preoperative creatinine, preoperative core temperature and irrigation fluid volume did not differ significantly between groups. 17 °C, 27 °C and 37 °C groups exhibited significant differences in the incidences of postoperative fever (38.9% vs. 17.1% vs. 13.5%) and shivering (22.2% vs. 5.7% vs. 2.7%) (p < 0.05 for all pairwise comparisons). There was no significant difference of WBC, PCT and incidence of suspected infection in 37 °C or 27 °C group compared with 17 °C group. One case each of flash pulmonary edema and bleeding occurred in 37 °C group.

Conclusion

Warming the irrigation fluid can reduce the incidence of postoperative fever and shivering, but further studies are needed to determine the optimal temperature.

Trial registration The trial was registered at the Chinese Clinical Trials Registry and allocated as ChiCTR2000031683. The trial was registered on 07/04/2020 and this was a retrospective registration.

[The 482nd case: vomiting, paroxysmal dizziness and anhidrosis]

A 31-year-old woman was admitted to Peking Union Medical College Hospital presented with intermittent vomiting and abdominal pain for 2 years, and recurrence with paroxysmal dizziness for 1 month. This patient was diagnosed with systemic lupus erythematosus (SLE) 2 years ago with involvement of gastrointestinal and urinary tracts. One month ago, repeated vomiting and nausea recurred. No laboratory and imaging abnormalities were found in central nervous system and gastrointestinal evaluation. Orthostatic hypotension and fluctuation of blood pressure were recorded during hospitalization. Combined with sexual dysfunction, left adie pupil, anhidrosis and abnormal sympathetic skin response, autonomic nerve dysfunction related to SLE was diagnosed. After treated with pulse glucocorticoids and intravenous immunoglobulin, the patient's symptoms improved remarkably. Orthostatic hypotension in SLE patients may link to autonomic nerve dysfunction.

Identification of warm day and cool night conditions induced flowering-related genes in a Phalaenopsis orchid hybrid by suppression subtractive hybridization

The influence of warm day and cool night conditions on induction of spikes in Phalaenopsis orchids has been studied with respect to photosynthetic efficiency, metabolic cycles and physiology. However, molecular events involved in spike emergence induced by warm day and cool night conditions are not clearly understood. We examined gene expression induced by warm day and cool night conditions in the Phalaenopsis hybrid Fortune Saltzman through suppression subtractive hybridization, which allowed identification of flowering-related genes in warm day and cool night conditions in spikes and leaves at vegetative phase grown under warm daily temperatures. In total, 450 presumably regulated expressed sequence tags (ESTs) were identified and classified into functional categories, including metabolism, development, transcription factor, signal transduction, transportation, cell defense, and stress. Furthermore, database comparisons revealed a notable number of Phalaenopsis hybrid Fortune Saltzman ESTs that matched genes with unknown function. The expression profiles of 24 genes (from different functional categories) have been confirmed by quantitative real-time PCR in induced spikes and juvenile apical leaves. The results of the real-time PCR showed that, compared to the vegetative apical leaves, the transcripts of genes encoding flowering locus T, AP1, AP2, KNOX1, knotted1-like homeobox protein, R2R3-like MYB, adenosine kinase 2, S-adenosylmethionine synthetase, dihydroflavonol 4-reductase, and naringenin 3-dioxygenase accumulated significantly higher levels, and genes encoding FCA, retrotransposon protein Ty3 and C3HC4-type RING finger protein accumulated remarkably lower levels in spikes of early developmental stages. These results suggested that the genes of two expression changing trends may play positive and negative roles in the early floral transition of Phalaenopsis orchids. In conclusion, spikes induced by warm day and cool night conditions were complex in Phalaenopsis orchids; nevertheless, several molecular flowering pathway-related genes were found. The acquired data form the basis for a molecular understanding of spike induction by warm day and cool night conditions in Phalaenopsis orchids.

[Application of superparamagnetic iron oxide labeled antisense oligodeoxynucleotide probe in cellular magnetic resonance imaging]

OBJECTIVE

To prepare the superparamagnetic iron oxide (SPIO)-labeled antisense oligodeoxynucleotide (ASODN) probe and evaluate the application of this probe in cellular magnetic resonance imaging (MRI).

METHODS

We prepared the SPIO-labeled ASODN probe using chemical cross linking method to conjugate SPIO to ASODN, detected its configuration by atomic force microscopy, determined the conjugating rate and biology activation by high performance liquid chromatography, and detected the stability by polyacrylamide gel electrophoresis. After that, we transfected the SK-Br3 oncocytes which had over-expression of the c-erbB2 oncogene by this probes, observed the intracellular iron distribution by optical microscope, measured iron content by atomic absorption spectroscopy, and observed the signal change by MRI.

RESULTS

Atomic force microscope showed that the SPIO-labeled ASODN probe was mostly spherical and well-distributed, with a diameter of 25-40 nm and a conjugating rate of 100%. This probe had inhered biological activity and stability. In addition, light microscopy revealed an intracellular uptake of iron oxides in the transfected SK-Br3 oncocyte, and the iron content of the group of transfected SK-Br3 oncocytes was significantly higher than those of other contrast groups (all P < 0.01). MRI showed that transfected SK-Br3 oncocyte had the lowest signal among all other cells (all P < 0.05).

CONCLUSIONS

We prepared the SPIO-labeled ASODN probe successfully. It can effectively transfect SK-Br3 oncocyte and enter SK-Br3 oncocyte, and thus reduce the signal intension in MRI.

[Clinical evaluation of HBV, HCV and HDV serum markers in patients with liver cirrhosis (LC) and hepatocellular carcinoma (HCC)]

11 kinds of HBV, HCV and HDV serum markers were investigated in 46 patients with HCC, 48 patients with LC, and 52 controls without liver disease. The prevalence of one out of HBV or HCV or HDV markers (M) in HCC and LC was 91.3% and 95.8% respectively, significantly higher than that in controls (17.3%). Positivity of HBV-M in HCC and LC was remarkably higher than those of HCV-M and HDV-M (P < 0.05). Prevalence of HCV-M in HBV-M negative HCC and LC was 66.7% and 75.0% respectively, significantly higher than that in HBV-M positive cases (P < 0.05). Frequency of viral replication in HCC and LC was significantly higher than that in controls (P < 0.01). The co-occurrence of two or three kinds of viral markers in HCC was more prevalent than that in LC (38% vs 14%, P < 0.05). Patients with coinfection from both HBV and HDV had a significantly younger age than those infected by HBV alone or infected by HCV (more than 10 years earlier). Among HCC and LC, 36% of HBV seronegative cases had HBV DNA detectable in their serum. Our data suggest that HCC and LC have a close association with the infection of HBV HCV and HDV especially HBV. Active viral replication and coinfection of several kinds of virus play on important role in the determination of HCC or LC development, and HDV appears to provide an additional risk for HCC and LC. In HBV-M negative cases, HCV infection may be more important for HCC and LC development than HBV.

[Serum anti-hepatitis C virus and hepatitis C virus RNA in patients with hepatocellular carcinoma]

Serum anti-HCV and HCV RNA (RT-PCR), possible association to the markers of hepatitis B virus (HBV-M) including HBsAg were evaluated in 48 patients with hepatocellular carcinoma (HCC). The results indicated that 13 were anti-HCV positive in HCC group and 5 in other cancers (control group, P < 0.05). Serum HCV RNA was detected in 11 patients with HCC (23%). The positive rate of HCV RNA and/or anti-HCV (HCV-M) was 38% in all HCC cases, 80% (12/15) in HBV-M (-) HCC, 58% (14/24) in HBsAg(-), 18% (6/33) in HBV-M(+), and 15% (4/24) in HBsAg(+). HBV-M and/or HCV-M was found positive in 45 patients with HCC (93.8%). Our study shows that both HBV and HCV infections are related to the development of HCC. HCV-M was found positive mostly in HBV-M negative HCC patients and serum HCV RNA replication existed in some of HCC cases.