Spin Crossover in [Fe(qsal-5-Brq)2]+ Complexes with a Quinoline-Substituted Qsal Ligand.

Using a quinoline substituted Qsal ligand, Hqsal-5-Brq (Hqsal-5-Brq = N-(5-bromo-8-quinolyl)salicylaldimine), four FeIII complexes, [Fe(qsal-5-Brq)2]A·CH3OH (Y = NO3- (1NO3), BF4- (2BF4), PF6- (3PF6), OTf- (4OTf), were prepared and characterized. Structure analysis revealed that complex 2BF4 contained two species (2BF4(P1̅) and 2BF4(C2/c)). In these compounds except 3PF6, the [Fe(qsal-5-Brq)2]+ cations form 1D chains through π-π interactions and other weak interactions. Adjacent chains are connected to form the 2D "Chain Layer" structures and 3D structures through various supramolecular interactions. For 3PF6, a "Dimer Chain" structure is formed from the loosely connected dimers. Magnetic studies revealed that compounds 1NO3 and 2BF4(P1̅) displayed abrupt hysteretic SCO with the transition temperature T1/2↓ = 235 K, T1/2↑ = 240 K for 1NO3 and T1/2↓ = 230 K, T1/2↑ = 235 K for 2BF4(P1̅), while compounds 3PF6 and 4OTf are in the HS state. Desolvation of the complexes significantly modifies their SCO properties: the desolvated 1NO3 and 2BF4 show a gradual SCO, desolvated 3PF6 undergoes a two-step SCO, and desolvated 4OTf exhibits a hysteretic transition. Overall, this work reported the FeIII-SCO complexes of the quinoline-substituted Hqsal ligand and highlighted the potential of these ligands for the development of interesting FeIII-SCO materials.

LILRB4 signalling in leukaemia cells mediates T cell suppression and tumour infiltration.

Immune checkpoint blockade therapy has been successful in treating some types of cancer but has not shown clinical benefits for treating leukaemia1. This result suggests that leukaemia uses unique mechanisms to evade this therapy. Certain immune inhibitory receptors that are expressed by normal immune cells are also present on leukaemia cells. Whether these receptors can initiate immune-related primary signalling in tumour cells remains unknown. Here we use mouse models and human cells to show that LILRB4, an immunoreceptor tyrosine-based inhibition motif-containing receptor and a marker of monocytic leukaemia, supports tumour cell infiltration into tissues and suppresses T cell activity via a signalling pathway that involves APOE, LILRB4, SHP-2, uPAR and ARG1 in acute myeloid leukaemia (AML) cells. Deletion of LILRB4 or the use of antibodies to block LILRB4 signalling impeded AML development. Thus, LILRB4 orchestrates tumour invasion pathways in monocytic leukaemia cells by creating an immunosuppressive microenvironment. LILRB4 represents a compelling target for the treatment of monocytic AML.

Vascular reconstruction provides short-term and long-term survival benefits for patients with hilar cholangiocarcinoma: A retrospective, multicenter study.

BACKGROUND: In patients with hilar cholangiocarcinoma (HCCA), radical resection can be achieved by resection and reconstruction of the vasculature. However, whether vascular reconstruction (VR) improves long-term and short-term prognosis has not been demonstrated comprehensively. METHODS: This was a retrospective multicenter study of patients who received surgery for HCCA with or without VR. Variables associated with overall survival (OS) and recurrence-free survival (RFS) were identified based on Cox regression. Kaplan-Meier curves were used to explore the impact of VR. Restricted mean survival time (RMST) was used for comparisons of short-term survival between the groups. Patients' intraoperative and postoperative characteristics were compared. RESULTS: Totally 447 patients were enrolled. We divided these patients into 3 groups: VR with radical resections (n = 84); non-VR radical resections (n = 309) and non-radical resection (we pooled VR-nonradical and non-VR nonradical together, n = 54). Cox regression revealed that carbohydrate antigen 242 (CA242), vascular invasion, lymph node metastasis and poor differentiation were independent risk factors for OS and RFS. There was no significant difference of RMST between the VR and non-VR radical groups within 12 months after surgery (10.18 vs. 10.76 mon, P = 0.179), although the 5-year OS (P < 0.001) and RFS (P < 0.001) were worse in the VR radical group. The incidences of most complications were not significantly different, but those of bile leakage (P < 0.001) and postoperative infection (P = 0.009) were higher in the VR radical group than in the non-VR radical group. Additionally, the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) up to 7 days after surgery tended to decrease in all groups. There was no significant difference in the incidence of postoperative liver failure between the VR and non-VR radical groups. CONCLUSIONS: Radical resection can be achieved with VR to improve the survival rate without worsening short-term survival compared with resection with non-VR. After adequate assessment of the patient's general condition, VR can be considered in the resection.

Syntheses, Structures, and Magnetic Properties of Three Cyano-Bridged FeII-MoIII Single-Molecule Magnets.

Three new cyano-bridged FeII-MoIII complexes assembled from the [MoIII(CN)7]4- unit, FeII ions, and three pentadentate N3O2 ligands, namely {[Fe2H3(dapab)2][Mo(CN)6]}n·2H2O·3.5MeCN (1), [Fe(H2dapb)(H2O)][Fe(Hdapb)(H2O)][Mo(CN)6]·4H2O·3MeCN (2), and [Fe(H2dapba)(H2O)]2[Mo(CN)7]·6H2O (3) (H2dapab = 2,6-diacetylpyridine bis(2-aminobenzoylhydrazone), H2dapb = 2,6-diacetylpyridine bis(benzoylhydrazone), H2dapba = 2,6-diacetylpyridine bis(4-aminobenzoylhydrazone)), have been synthesized and characterized. Single-crystal structure analyses suggest that complex 1 contains a one-dimensional (1D) chain structure where two FeII ions are bridged by the in situ generated [MoIII(CN)6]3- unit through two trans-cyanide groups into trinuclear Fe2IIMoIII clusters that are further linked by the amino of the ligand into an infinite chain. Complexes 2 and 3 are cyano-bridged Fe2IIMoIII trinuclear clusters with two FeII ions connected by the [MoIII(CN)6]3- and [MoIII(CN)7]4- units, respectively. Direct current magnetic studies confirmed the ferromagnetic interactions between the cyano-bridged FeII and MoIII centers and significant easy-axis magnetic anisotropy for all three complexes. Furthermore, complexes 1-3 exhibit slow magnetic relaxation under a zero dc field, with relaxation barriers of 42.3, 21.6, and 14.4 K, respectively, making them the first examples of cyano-bridged FeII-MoIII single-molecule magnets.

The epithelial-mesenchymal transition generates cells with properties of stem cells.

The epithelial-mesenchymal transition (EMT) is a key developmental program that is often activated during cancer invasion and metastasis. We here report that the induction of an EMT in immortalized human mammary epithelial cells (HMLEs) results in the acquisition of mesenchymal traits and in the expression of stem-cell markers. Furthermore, we show that those cells have an increased ability to form mammospheres, a property associated with mammary epithelial stem cells. Independent of this, stem cell-like cells isolated from HMLE cultures form mammospheres and express markers similar to those of HMLEs that have undergone an EMT. Moreover, stem-like cells isolated either from mouse or human mammary glands or mammary carcinomas express EMT markers. Finally, transformed human mammary epithelial cells that have undergone an EMT form mammospheres, soft agar colonies, and tumors more efficiently. These findings illustrate a direct link between the EMT and the gain of epithelial stem cell properties.

Hypoxia induces heart regeneration in adult mice.

The adult mammalian heart is incapable of regeneration following cardiomyocyte loss, which underpins the lasting and severe effects of cardiomyopathy. Recently, it has become clear that the mammalian heart is not a post-mitotic organ. For example, the neonatal heart is capable of regenerating lost myocardium, and the adult heart is capable of modest self-renewal. In both of these scenarios, cardiomyocyte renewal occurs via the proliferation of pre-existing cardiomyocytes, and is regulated by aerobic-respiration-mediated oxidative DNA damage. Therefore, we reasoned that inhibiting aerobic respiration by inducing systemic hypoxaemia would alleviate oxidative DNA damage, thereby inducing cardiomyocyte proliferation in adult mammals. Here we report that, in mice, gradual exposure to severe systemic hypoxaemia, in which inspired oxygen is gradually decreased by 1% and maintained at 7% for 2 weeks, results in inhibition of oxidative metabolism, decreased reactive oxygen species production and oxidative DNA damage, and reactivation of cardiomyocyte mitosis. Notably, we find that exposure to hypoxaemia 1 week after induction of myocardial infarction induces a robust regenerative response with decreased myocardial fibrosis and improvement of left ventricular systolic function. Genetic fate-mapping analysis confirms that the newly formed myocardium is derived from pre-existing cardiomyocytes. These results demonstrate that the endogenous regenerative properties of the adult mammalian heart can be reactivated by exposure to gradual systemic hypoxaemia, and highlight the potential therapeutic role of hypoxia in regenerative medicine.

Gastroduodenal artery disconnection during liver transplantation decreases non-anastomotic stricture incidence.

BACKGROUND: The hepatic artery is the only blood source nourishing the biliary duct and associated with biliary complication after liver transplantation (LT). Gastroduodenal artery (GDA) disconnection increased proper hepatic artery flow. Whether this procedure attenuates biliary non-anastomotic stricture (NAS) is not clear. METHODS: A total of 241 patients with LT were retrospectively analyzed. The patients were divided into the GDA disconnection (GDA-) and GDA preservation (GDA+) groups. Propensity score matching (PSM) was administrated to reduce bias. Logistic regression was conducted to analyze risk factors for biliary NAS before and after PSM. Postoperative complications were compared. Kaplan-Meier survival analysis and log-rank tests were performed to compare overall survival. RESULTS: In all, 99 patients (41.1%) underwent GDA disconnection, and 49 (20.3%) developed NAS. Multivariate logistic regression revealed that GDA preservation (OR = 2.24, 95% CI: 1.11-4.53; P = 0.025) and model for end-stage liver disease (MELD) score > 15 (OR = 2.14, 95% CI: 1.12-4.11; P = 0.022) were risk factors for biliary NAS. PSM provided 66 pairs using 1:2 matching method, including 66 GDA disconnection and 99 GDA preservation patients. Multivariate logistic regression after PSM also showed that GDA preservation (OR = 3.15, 95% CI: 1.26-7.89; P = 0.014) and MELD score > 15 (OR = 2.41, 95% CI: 1.08-5.36; P = 0.031) were risk factors for NAS. When comparing complications between the two groups, GDA preservation was associated with a higher incidence of biliary NAS before and after PSM (P = 0.031 and 0.017, respectively). In contrast, other complications including early allograft dysfunction (P = 0.620), small-for-size graft syndrome (P = 0.441), abdominal hemorrhage (P = 1.000), major complications (Clavien-Dindo grade ≥ 3, P = 0.318), and overall survival (P = 0.088) were not significantly different between the two groups. CONCLUSIONS: GDA disconnection during LT ameliorates biliary NAS incidence and may be recommended for application in clinical practice.

A perspective on LILRBs and LAIR1 as immune checkpoint targets for cancer treatment.

Immunosuppressive myeloid cells in the tumor microenvironment inhibit anti-tumor immunity and support tumor development. The leukocyte Ig-like receptor subfamily B (LILRB) proteins and the related receptor LAIR1 are immune checkpoint receptors that support the immunosuppressive activity of myeloid cells. All LILRBs and LAIR1 have intracellular immunoreceptor tyrosine-based inhibitory motifs in their signaling domains, but the individual proteins have different functions. The determinants of the distinct functions of these inhibitory receptors likely rest in their interactions with different ligands and other surface proteins, characteristic signaling domains, and expression dynamics in different cell types regulated by various extrinsic cues and transcription factors. Significant advancement of immuno-oncology therapeutic products based on targeting or reprogramming of LILRB- and LAIR1-mediated signaling is anticipated.

Anion Modified Spin Crossover in [Fe(qsal-4-F)]+ Complexes with a 4-Position Substituted Qsal Ligand.

Four iron(III) complexes, [Fe(qsal-4-F)2]Y·sol (Hqsal-4-F = 4-fluoro-N-(8-quinolyl)salicylaldimine; Y = NO3-, sol = 0.91MeOH·0.57H2O (1NO3); Y = PF6- (2PF6); Y = BF4- (3BF4); Y = OTf-, sol =1.5MeOH (4OTf)), with a new 4-position substituted qsal type ligand Hqsal-4-F have been synthesized and structurally and magnetically characterized. Complexes 1NO3-3BF4 consist of 1D chains formed by the [Fe(qsal-4-F)2]+ cations connected by π-π and C-H···O interactions, which are further linked by more weak interactions to form 2D layers and 3D networks. On the other hand, complex 4OTf has a structure of nearly isolated 1D column where the [Fe(qsal-4-F)2]+ cations are connected by π-π, C-H···π, and C-F···π interactions. Magnetic studies revealed the occurrence of two-step symmetry-breaking SCO in 1NO3 and two-step gradual SCO in 2PF6. Complex 3BF4 undergoes a gradual SCO, whereas 4OTf remains almost high-spin. The smaller anions tend to stabilize the low-spin state, while larger anions tend to stabilize the high-spin state. In addition, the intermediate spin state of 1NO3 could be thermally trapped by quenching from the high temperature, thereby kinetically suppressing the spin transition to the full low-spin state. This work represents a good example that the position of the substituent and the anions plays critical roles in the preparation of SCO materials with tunable properties.

Bone transport combined with bone graft and internal fixation versus simple bone transport in the treatment of large bone defects of lower limbs after trauma.

BACKGROUND: Bone transport has been successfully applied for the management of large segmental bone defects. However, its main shortcoming is the long-lasting consolidation period, which may cause lots of related complications. To overcome this shortcoming, we developed bone transport combined with bone graft and internal fixation technique. The purpose of this study was to compare the clinical effects of this modified technique with simple bone transport in the treatment of large segmental bone defects of lower limbs after trauma. METHODS: Eighty-four patients with large segmental bone defects treated in our institution from January 2014 to January 2017 were selected for retrospective study. A total of 77 cases were completely followed. Among them, 35 patients were treated by bone transport combined with bone graft and internal fixation technique (Group A), and 42 by simple bone transport technique (Group B). Patients with open injuries were classified according to Gustilo-Anderson (GA) classification. The general data of Group A and B were compared. The time in external fixator, total cure time and operation times of two groups were recorded. Ennecking score was used to evaluate the recovery of limb functions while self-rating anxiety scale (SAS) for the postoperative anxiety evaluation. In addition, the total complication incidence was compared between Group A and B. RESULTS: There was no significant difference in demographic data between Group A and B (p > 0.05). The time in external fixator of Group A and B was (4.8 ± 1.6) and (18.2 ± 3.9) months, respectively (p < 0.05). The total cure time was (17.6 ± 2.2) and (20.4 ± 2.8) months in Group A and B (p < 0.05). The number of operations in Group A and B was (4.9 ± 1.2) and (4.8 ± 1.0) (p > 0.05). Ennecking score of Group A and B was 84.7 and 75.7% (p < 0.05). SAS score and total complication incidence in Group A were significantly lower than those in Group B (p < 0.05). CONCLUSIONS: The clinical effects of bone transport combined with bone graft and internal fixation technique were better than that of simple bone transport technique, including shorter time in external fixator, shorter total cure time, lower anxiety score and better limb functions.

Hypoxia fate mapping identifies cycling cardiomyocytes in the adult heart.

Although the adult mammalian heart is incapable of meaningful functional recovery following substantial cardiomyocyte loss, it is now clear that modest cardiomyocyte turnover occurs in adult mouse and human hearts, mediated primarily by proliferation of pre-existing cardiomyocytes. However, fate mapping of these cycling cardiomyocytes has not been possible thus far owing to the lack of identifiable genetic markers. In several organs, stem or progenitor cells reside in relatively hypoxic microenvironments where the stabilization of the hypoxia-inducible factor 1 alpha (Hif-1α) subunit is critical for their maintenance and function. Here we report fate mapping of hypoxic cells and their progenies by generating a transgenic mouse expressing a chimaeric protein in which the oxygen-dependent degradation (ODD) domain of Hif-1α is fused to the tamoxifen-inducible CreERT2 recombinase. In mice bearing the creERT2-ODD transgene driven by either the ubiquitous CAG promoter or the cardiomyocyte-specific α myosin heavy chain promoter, we identify a rare population of hypoxic cardiomyocytes that display characteristics of proliferative neonatal cardiomyocytes, such as smaller size, mononucleation and lower oxidative DNA damage. Notably, these hypoxic cardiomyocytes contributed widely to new cardiomyocyte formation in the adult heart. These results indicate that hypoxia signalling is an important hallmark of cycling cardiomyocytes, and suggest that hypoxia fate mapping can be a powerful tool for identifying cycling cells in adult mammals.

FBXW10 promotes hepatocarcinogenesis in male patients and mice.

Hepatocellular carcinoma (HCC) is reported to associate with abnormal expression of SCF E3 ubiquitin ligases. FBXW10, an F-box protein of the E3 ubiquitin ligases, was abnormally regulated in HCC patients. However, whether FBXW10 is associated with HCC has not yet been evaluated. Here, we analyzed the associations between overall survival and various risk factors in 191 HCC tissues. Univariate and multivariate analyses demonstrated that FBXW10 was an independent risk factor related to HCC prognosis. The results showed that FBXW10, gender and tumor state were strongly associated with overall survival in HCC patients. Furthermore, high expression of FBXW10 was associated with poor survival among male HCC patients but not female HCC patients. FBXW10 was more highly expressed in male HCC tissues and more strongly related to vascular invasion in male HCC patients. Consistent with these findings, the male FBXW10-Tg(+) mice were more susceptible to tumorigenesis, changes in regenerative capacity, and liver injury and inflammation but not changes in liver function than FBXW10-Tg(-) mice. FBXW10 promoted cell proliferation and migration in HCC cell lines. Our findings reveal that FBXW10, an independent risk factor for HCC, promotes hepatocarcinogenesis in male patients, and is also a potential prognostic marker in male patients with HCC.

Impact of body mass index on postoperative outcomes in patients undergoing radical resection for hilar cholangiocarcinoma.

BACKGROUND: Body mass index (BMI) has been widely used as a prognostic indicator. The association between preoperative BMI and postoperative morbidity in patients with hilar cholangiocarcinoma (HCCA) has not been proved. This study aimed to identify the association between preoperative BMI and postoperative morbidity following radical resection of HCCA. METHODS: Patients were divided into three groups according to preoperative BMI: low BMI (≤18.4 kg/m2 ), normal BMI (18.4-24.9 kg/m2 ), and high BMI (≥24.9 kg/m2 ). Baseline characteristics, operative variables, postoperative 30-day mortality, and morbidity were compared. Risk factors associated with postoperative morbidity were assessed using univariable and multivariable logistic analyses. RESULTS: Among 260 patients, 183 (70.4%) had normal BMI, 32 (12.3%) had low BMI, and 45 (17.3%) had high BMI. Compared to the patients with normal-BMI, both low and high BMI patients exhibited a significantly higher postoperative morbidity (87.5% and 82.2% vs 63.9%, P = .019 and P = .025, respectively). Additionally, the multivariable analysis revealed that both low and high BMI patients remained independently associated with an increased risk of postoperative morbidity. (OR: 3.707, 95% CI: 1.080-12.725, P = .037; and OR: 2.858, 95% CI: 1.167-7.002, P = .022, respectively). CONCLUSION: BMI is an independent risk factor for higher postoperative morbidity in patients who undergo surgical treatment of hilar cholangiocarcinoma.

Glatiramer Acetate Enhances Myeloid-Derived Suppressor Cell Function via Recognition of Paired Ig-like Receptor B.

Glatiramer acetate (GA; Copaxone) is a copolymer therapeutic that is approved by the Food and Drug Administration for the relapsing-remitting form of multiple sclerosis. Despite an unclear mechanism of action, studies have shown that GA promotes protective Th2 immunity and stimulates release of cytokines that suppress autoimmunity. In this study, we demonstrate that GA interacts with murine paired Ig-like receptor B (PIR-B) on myeloid-derived suppressor cells and suppresses the STAT1/NF-κB pathways while promoting IL-10/TGF-ß cytokine release. In inflammatory bowel disease models, GA enhanced myeloid-derived suppressor cell-dependent CD4+ regulatory T cell generation while reducing proinflammatory cytokine secretion. Human monocyte-derived macrophages responded to GA by reducing TNF-α production and promoting CD163 expression typical of alternative maturation despite the presence of GM-CSF. Furthermore, GA competitively interacts with leukocyte Ig-like receptors B (LILRBs), the human orthologs of PIR-B. Because GA limited proinflammatory activation of myeloid cells, therapeutics that target LILRBs represent novel treatment modalities for autoimmune indications.

Impact of iatrogenic biliary injury during laparoscopic cholecystectomy on surgeon's mental distress: a nationwide survey from China.

BACKGROUND: Iatrogenic biliary injury (IBI) following laparoscopic cholecystectomy (LC) is the most serious iatrogenic complications. Little is known whether LC-IBI would lead to surgeon's severe mental distress (SMD). METHODS: A cross-sectional survey in the form of electronic questionnaire was conducted among Chinese general surgeons who have caused LC-IBI. The six collected clinical features relating to mental distress included: 1) feeling burnout, anxiety, or depression, 2) avoiding performing LC, 3) having physical reactions when recalling the incidence, 4) having the urge to quit surgery, 5) taking psychiatric medications, and 6) seeking professional psychological counseling. Univariable and multivariable analyses were performed to identify risk factors of SMD, which was defined as meeting ≥3 of the above-mentioned clinical features. RESULTS: Among 1466 surveyed surgeons, 1236 (84.3%) experienced mental distress following LC-IBI, and nearly half (49.7%, 614/1236) had SMD. Multivariable analyses demonstrated that surgeons from non-university affiliated hospitals (OR:1.873), patients who required multiple repair operations (OR:4.075), patients who required hepaticojejunostomy/partial hepatectomy (OR:1.859), existing lawsuit litigation (OR:10.491), existing violent doctor-patient conflicts (OR:4.995), needing surgeons' personal compensation (OR:2.531), and additional administrative punishment by hospitals (OR:2.324) were independent risk factors of surgeon's SMD. CONCLUSION: Four out of five surgeons experienced mental distress following LC-IBI, and nearly half had SMD. Several independent risk factors of SMD were identified, which could help to make strategies to improve surgeons' mental well-being.

[An MRI Study of the Relationship Between Duration of Untreated Psychosis and Morphology of Cerebral Cortex in First-episode Schizophrenia].

OBJECTIVE: We analyzed the brain structure of schizophrenia patients from multiple perspectives to explore the relationship between the duration of untreated psychosis (DUP) and clinical outcomes. METHODS: For 85 patients and 86 controls, clinical symptoms and cognitive function were evaluated, magnetic resonance imaging (MRI) and free surfer analysis were used to extract the cortical indicator, such as brain cortex thickness, surface area, volume, and so on. The patients were divided into four subgroups according to the boundary of March, June and two year due to the distribution and median of DUP. Finally multi-group comparison and correlation analysis for above indicators were analysed. RESULTS: DUP was associated with the surface area of the left insula, parsorbitalis, right hippocampus, superior frontal gyrus, frontal pole, and temporal pole; DUP mainly influenced the cortical thickness of left posterior cingulate gyrus, postcentral gyrus, right lateral occipital cortex, parsopercularis, medial orbitofrontal cortex, and the bilateral precentral gyrus. For cortical volume, DUP significantly affected left postcentral gyrus, right precuneus, lateral occipital cortex, parsopercularis, lingual gyrus, superior temporal gyrus, bilateral cuneus, pericalcarine cortex, precentral gyrus,superior parietal lobule, and insula.The first three months after onset is a critical period for the deterioration of cortical morphology and clinical function. CONCLUSION: DUP in first-episode schizophrenia is associated with cortical morphological changes of temporal lobe, precentral, orbitofrontal cortex and the majority of medial regions of occipital lobe, it is very important to conduct early intervention for patients.

Chemotherapeutic paclitaxel and cisplatin differentially induce pyroptosis in A549 lung cancer cells via caspase-3/GSDME activation.

Gasdermin E (GSDME) has an important role in inducing secondary necrosis/pyroptosis. Upon apoptotic stimulation, it can be cleaved by activated caspase-3 to generate its N-terminal fragment (GSDME-NT), which executes pyroptosis by perforating the plasma membrane. GSDME is expressed in many human lung cancers including A549 cells. Paclitaxel and cisplatin are two representative chemotherapeutic agents for lung cancers, which induce apoptosis via different action mechanisms. However, it remains unclear whether they can induce GSDME-mediated secondary necrosis/pyroptosis in lung A549 cancer cells. Here we showed that both paclitaxel and cisplatin evidently induced apoptosis in A549 cells as revealed by the activation of multiple apoptotic markers. Notably, some of the dying cells displayed characteristic morphology of secondary necrosis/pyroptosis, by blowing large bubbles from the cellular membrane accompanied by caspase-3 activation and GSDME-NT generation. But the ability of cisplatin to induce this phenomenon was much stronger than that of paclitaxel. Consistent with this, cisplatin triggered much higher activation of caspase-3 and generation of GSDME-NT than paclitaxel, suggesting that the levels of secondary necrosis/pyroptosis correlated with the levels of active caspase-3 and GSDME-NT. Supporting this, caspase-3 specific inhibitor (Ac-DEVD-CHO) suppressed cisplatin-induced GSDME-NT generation and concurrently reduced the secondary necrosis/pyroptosis. Besides, GSDME knockdown significantly inhibited cisplatin- but not paclitaxel-induced secondary necrosis/pyroptosis. These results indicated that cisplatin induced higher levels of secondary necrosis/pyroptosis in A549 cells than paclitaxel, suggesting that cisplatin may provide additional advantages in the treatment of lung cancers with high levels of GSDME expression.

ATP induces caspase-3/gasdermin E-mediated pyroptosis in NLRP3 pathway-blocked murine macrophages.

ATP acts as a canonical activator to induce NLRP3 (NOD-like receptor family, pyrin domain containing 3) inflammasome activation in macrophages, leading to caspase-1/gasdermin D (GSDMD)-mediated pyroptosis. It remains unclear whether ATP can induce pyroptosis in macrophages when the NLRP3 pathway is blocked by pathogenic infection. In this study, we used cellular models to mimic such blockade of NLRP3 activation: bone marrow-derived macrophages (BMDMs) treated with NLRP3-specific inhibitor MCC950 and RAW264.7 cells deficient in ASC (apoptosis-associated speck-like protein containing a caspase recruitment domain) expression. The results showed that ATP treatment induced lytic cell death morphologically resembling canonical pyroptosis in both MCC950-treated BMDMs and RAW264.7 cells, but did not cause the activation of caspase-1 (by detecting caspase-1p10 and mature interleukin-1ß) and cleavage of GSDMD. Instead, both apoptotic initiator (caspase-8 and -9) and executioner (caspase-3 and -7) caspases were evidently activated and gasdermin E (GSDME) was cleaved to generate its N-terminal fragment (GSDME-NT) which executes pyroptosis. The GSDME-NT production and lytic cell death induced by ATP were diminished by caspase-3 inhibitor. In BMDMs without MCC950 treatment, ATP induced the formation of ASC specks which were co-localized with caspase-8; with MCC950 treatment, however, ATP did not induced the formation of ASC specks. In RAW264.7 cells, knockdown of GSDME by small interfering RNA attenuated ATP-induced lytic cell death and HMGB1 release into culture supernatants. Collectively, our results indicate that ATP induces pyroptosis in macrophages through the caspase-3/GSDME axis when the canonical NLRP3 pathway is blocked, suggestive of an alternative mechanism for combating against pathogen evasion.

NK cell-mediated anti-leukemia cytotoxicity is enhanced using a NKG2D ligand MICA and anti-CD20 scfv chimeric protein.

NK cells are important innate cytotoxic lymphocytes that have potential in treatment of leukemia. Engagement of NKG2D receptor on NK cells enhances the target cytotoxicity. Here, we produced a fusion protein consisting of the extracellular domain of the NKG2D ligand MICA and the anti-CD20 single-chain variable fragment (scfv). This recombinant protein is capable of binding both NK cells and CD20+ tumor cells. Using a human NKG2D reporter cell system we developed, we showed that this fusion protein could decorate CD20+ tumor cells with MICA extracellular domain and activate NK through NKG2D. We further demonstrated that this protein could specifically induce the ability of a NK cell line (NKL) and primary NK cells to lyse CD20+ leukemia cells. Moreover, we found that downregulation of surface HLA class I expression in the target cells improved NKL-mediated killing. Our results demonstrated that this recombinant protein specifically lyses leukemia cells by NK cells, which may lead to development of a novel strategy for treating leukemia and other tumors.