Cleavage-independent activation of ancient eukaryotic gasdermins and structural mechanisms.

Gasdermins (GSDMs) are pore-forming proteins that execute pyroptosis for immune defense. GSDMs are two-domain proteins activated by proteolytic removal of the inhibitory domain. In this work, we report two types of cleavage-independent GSDM activation. First, TrichoGSDM, a pore-forming domain-only protein from the basal metazoan Trichoplax adhaerens, is a disulfides-linked autoinhibited dimer activated by reduction of the disulfides. The cryo-electron microscopy (cryo-EM) structure illustrates the assembly mechanism for the 44-mer TrichoGSDM pore. Second, RCD-1-1 and RCD-1-2, encoded by the polymorphic regulator of cell death-1 (rcd-1) gene in filamentous fungus Neurospora crassa, are also pore-forming domain-only GSDMs. RCD-1-1 and RCD-1-2, when encountering each other, form pores and cause pyroptosis, underlying allorecognition in Neurospora. The cryo-EM structure reveals a pore of 11 RCD-1-1/RCD-1-2 heterodimers and a heterodimerization-triggered pore assembly mechanism. This study shows mechanistic diversities in GSDM activation and indicates versatile functions of GSDMs.

Comparative transcriptome and metabolome profiles of the leaf and fruits of a Xianjinfeng litchi budding mutant and its mother plant.

Background: Litchi (Litchi chinensis) is an important sub-tropical fruit in the horticulture market in China. Breeding for improved fruit characteristics is needed for satisfying consumer demands. Budding is a sustainable method for its propagation. During our ongoing breeding program, we observed a litchi mutant with flat leaves and sharp fruit peel cracking in comparison to the curled leaves and blunt fruit peel cracking fruits of the mother plant. Methods: To understand the possible molecular pathways involved, we performed a combined metabolome and transcriptome analysis. Results: We identified 1,060 metabolites in litchi leaves and fruits, of which 106 and 101 were differentially accumulated between the leaves and fruits, respectively. The mutant leaves were richer in carbohydrates, nucleotides, and phenolic acids, while the mother plant was rich in most of the amino acids and derivatives, flavonoids, lipids and organic acids and derivatives, and vitamins. Contrastingly, mutant fruits had higher levels of amino acids and derivatives, carbohydrates and derivatives, and organic acids and derivatives. However, the mother plant's fruits contained higher levels of flavonoids, scopoletin, amines, some amino acids and derivatives, benzamidine, carbohydrates and derivatives, and some organic acids and derivatives. The number of differentially expressed genes was consistent with the metabolome profiles. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway-enriched gene expressions showed consistent profiles as of metabolome analysis. Conclusion: These results provide the groundwork for breeding litchi for fruit and leaf traits that are useful for its taste and yield.

How is intergenerational emotional cohesion linked to depression among older internal migrants in China: the mediating roles of loneliness and perceived stress.

BACKGROUND: Late-life internal migration is frequently associated with a higher risk of depression in older parents. This research delves into the impact of intergenerational emotional cohesion (IEC) on depression in older internal migrants and the underlying mechanisms within the contemporary Chinese context. METHODS: Obtained from a cross-sectional survey in Nanjing, China, the research involved 654 older internal migrants (66.97% female; mean age = 66.05 years; SD = 4.67). Variables were assessed using the Intergenerational Solidarity Inventory, 3-item R-UCLA Loneliness Scale, Perceived Stress Scale, and 9-item Patient Health Questionnaire (PHQ-9). For mediation exploration, a serial mediation model was utilized, and the Bootstrap method was employed to test the signifcance of these mediation effects. RESULTS: IEC demonstrates a negative correlation with depression. Through IEC, three significant mediation pathways were identified that directly affect depression: (1) loneliness (ß=-0.06; Ratio=17.14%), (2) perceived stress (ß=-0.09; Ratio=25.71%), and (3) loneliness and perceived stress (ß=-0.03; Ratio=8.57%). CONCLUSIONS: IEC can impact the depression of older internal migrants by mitigating negative psychological emotions during the migration process. This finding provides valuable theoretical insights for the prevention of mental health problems among this demographic.

Analysis of correlative risk factors for radiation-induced hypothyroidism in head and neck tumors.

OBJECTIVE: The aim of the study is to identify clinical and dosimetric factors that could predict the risk of radiation-induced hypothyroidism(RIHT) in head and neck cancer(HNC) patients following intensity-modulated radiotherapy(IMRT). METHODS: A total of 103 HNC patients were included in our study. General clinical characteristic and dosimetric data of all recruited patients were analyzed, respectively. The univariate and multivariate logistic regression anlalysis were successively conducted to identify optimal predictors, which aim to construct the nomogram. And the joint prediction was performed. RESULTS: The incidence of patients with HNC was 36.9% (38/103). Among the clinical factors, gender, N stage, chemotherapy, frequency of chemotherapy and surgery involving the thyroid were related to RIHT. Logistic regression analysis showed that thyroid volume, Dmean, VS45, VS50, VS60 and V30,60 were independent predictors of RIHT, which were also incorporated in the nomogram. An AUC of 0.937 (95%CI, 0.888-0.958) also was showed outstanding resolving ability of the nomogram. When the volume of the thyroid was greater than 10.6 cm3, the incidence of RIHT was 14.8%, and when the volume of the thyroid was equal to or smaller than 10.6 cm3, the incidence was 72.5%. The incidence rates of RIHT in the group with VS60≦8.4cm3 and VS60 > 8.4cm3 were 61.4% and 19.3%, respectively. CONCLUSIONS: Thyroid volume and thyroid VS60 are independent predictors of RIHT in patients with HNC. Moreover, more attention should be paid to patients with thyroid volume ≤ 10.6cm3. Thyroid VS60 > 8.4cm3 may be a useful threshold for predicting the development of RIHT. The nomogram conducted by the research may become a potential and valuable tool that could individually predict the risk of RIHT for HNC patients.

Recognition and maturation of IL-18 by caspase-4 noncanonical inflammasome.

The canonical (caspase-1) and noncanonical (comprising caspases 4, 5 and 11; hereafter, caspase-4/5/11) inflammasomes both cleave gasdermin D (GSDMD) to induce pyroptosis1,2. Whereas caspase-1 processes IL-1ß and IL-18 for maturation3-6, no cytokine target has been firmly established for lipopolysaccharide-activated caspase-4/5/117-9. Here we show that activated human caspase-4, but not mouse caspase-11, directly and efficiently processes IL-18 in vitro and during bacterial infections. Caspase-4 cleaves the same tetrapeptide site in pro-IL-18 as caspase-1. The crystal structure of the caspase-4-pro-IL-18 complex reveals a two-site (binary) substrate-recognition mechanism; the catalytic pocket engages the tetrapeptide, and a unique exosite that critically recognizes GSDMD10 similarly binds to a specific structure formed jointly by the propeptide and post-cleavage-site sequences in pro-IL-18. This binary recognition is also used by caspase-5 as well as caspase-1 to process pro-IL-18. In caspase-11, a structural deviation around the exosite underlies its inability to target pro-IL-18, which is restored by rationally designed mutations. The structure of pro-IL-18 features autoinhibitory interactions between the propeptide and the post-cleavage-site region, preventing recognition by the IL-18Rα receptor. Cleavage by caspase-1, -4 or -5 induces substantial conformational changes of IL-18 to generate two critical receptor-binding sites. Our study establishes IL-18 as a target of lipopolysaccharide-activated caspase-4/5. The finding is paradigm shifting in the understanding of noncanonical-inflammasome-mediated defences and also the function of IL-18 in immunity and disease.

[Network Meta-analysis of Chinese patent medicines in treatment of idiopathic membranous nephropathy].

This study aimed to systematically evaluate the efficacy and safety of different Chinese patent medicines in the treatment of idiopathic membranous nephropathy. The relevant randomized controlled trial(RCT) was retrieved from PubMed, EMbase, Cochrane Library, CNKI, SinoMed, Wanfang, and VIP with the time interval from database inception to December 2022. The Cochrane risk of bias assessment tool was employed to evaluate the quality of the included RCT, and Stata 15.0 and GEMTC to perform the Bayesian network Meta-analysis. Finally, 51 RCTs were included, involving 9 Chinese patent medicines and 3 591 patients. The results of network Meta-analysis showed that in terms of the total effective rate and the increase in plasma albumin, the top three interventions were Zhengqing Fengtongning Sustained Release Tablets + conventional western medicine, Bailing Capsules + conventional western medicine, and Tripterygium Glycosides Tablets + conventional western medicine. In terms of reducing 24-hour urine total protein, the top three interventions were Zhengqing Fengtongning Sustained Release Tablets + conventional western medicine, Shenfukang Capsules +conventional western medicine, and Huangkui Capsules + conventional western medicine. In terms of reducing serum creatinine, the top three interventions were Shenfukang Capsules + conventional western medicine, Bailing Capsules + conventional western medicine, and Zhengqing Fengtongning Sustained Release Tablets + conventional western medicine. In terms of safety, Chinese patent medicines combined with conventional western medicine had fewer adverse reactions than the control group. The results suggest that Chinese patent medicines combined with conventional western medicine can improve the therapeutic effect on idiopathic membranous nephropathy, and differentiated medications can be adopted according to the specific symptoms of patients in clinical treatment. Further validation needs to be carried out in the future with multi-center, large-sample, and high-quality RCT.

Flagellar brake protein YcgR interacts with motor proteins MotA and FliG to regulate the flagellar rotation speed and direction.

In E. coli and related species, flagellar brake protein YcgR responds to the elevated intracellular c-di-GMP, decreases the flagellar rotation speed, causes a CCW rotation bias, and regulates bacterial swimming. Boehm et al. suggested that c-di-GMP-activated YcgR directly interacted with the motor protein MotA to curb flagellar motor output. Paul et al. proposed that YcgR disrupted the organization of the FliG C-terminal domain to bias the flagellar rotation. The target proteins are controversial, and the role of motor proteins remains unclear in flagellar rotation speed and direction regulation by YcgR. Here we assayed the motor proteins' affinity via a modified FRET biosensor and accessed the role of those key residue via bead assays. We found that YcgR could interact with both MotA and FliG, and the affinities could be enhanced upon c-di-GMP binding. Furthermore, residue D54 of YcgR-N was needed for FliG binding. The mutation of the FliG binding residue D54 or the MotA binding ones, F117 and E232, restored flagellar rotation speed in wild-type cells and cells lacking chemotaxis response regulator CheY that switched the flagellar rotation direction and decreased the CCW ratio in wild-type cells. We propose that c-di-GMP-activated YcgR regulated the flagellar rotation speed and direction via its interaction with motor proteins MotA and FliG. Our work suggest the role of YcgR-motor proteins interaction in bacterial swimming regulation.

Comparison of structures and emulsifying properties between water-extracted pectins from Fructus aurantii.

The structural characteristics of two water-extracted pectic polysaccharides from Fructus aurantii were investigated, and the impacts of their structures on the emulsifying stability were evaluated. FWP-60 (extracted by cold water and followed 60 % ethanol precipitation) and FHWP-50 (extracted by hot water and followed 50 % ethanol precipitation) were both high methyl-esterified pectins, which were composed of homogalacturonan (HG) and highly branched rhamnogalacturonan I (RG-I) regions. The weight-average molecular weight, methyl-esterification degree (DM) and HG/RG-I ratio of FWP-60 were 1200 kDa, 66.39 % and 4.45, respectively, which were 781 kDa, 79.10 % and 1.95 for FHWP-50. The methylation and NMR analysis of FWP-60 and FHWP-50 demonstrated that the main backbone consisted of different molar ratios of →4)-α-GalpA-(1 â†’ and →4)-α-GalpA-6-O-methyl-(1 →, and the side chains contained arabinan and galactan. Moreover, the emulsifying properties of FWP-60 and FHWP-50 were discussed. Compared with FHWP-50, FWP-60 had better emulsion stability. Overall, pectin had a linear HG domain and a small number of RG-I domain with short side chains to facilitate the stabilization of emulsions in Fructus aurantii. A comprehensive knowledge of the structure characteristic and emulsifying property would enable us to provide more information and theoretical guidance for the structure and emulsion preparation of Fructus aurantii pectic polysaccharides.

A Latent Class Analysis of Intergenerational Relationships Among the Elderly Migrants in Nanjing, China.

Objective: This study aimed to identify (1) different types of intergenerational relationships among the elderly migrants, (2) factors influencing each type of relationship, and (3) the types significantly associated with psychological well-being of the elderly migrants. Methods: Data were collected from 654 elderly migrants in Nanjing, China. Incorporating ten solidarity conflict indicators, the latent class analysis (LCA) was performed to classify intergenerational relationships. Logistic regression were used to analyze influencing factors, and ordinary least squares (OLS) regression was used to analyze the relationship of each type of intergenerational relationship with depression and life satisfaction. Results: Three types of intergenerational relationships were classified: tight-knit (65%), conflicting (25%), distant intimate (10%). Gender, marital status, education level, annual income, subjective health, number of children and parentage were influencing factors for the three types. The tight-knit type predicted a healthy mental status. Discussion: Three intergenerational relationships exist between elderly migrants and their children in Nanjing, China. A closer relationship predicts a better mental health in the elderly migrants.

Structural mechanisms for regulation of GSDMB pore-forming activity.

Cytotoxic lymphocyte-derived granzyme A (GZMA) cleaves GSDMB, a gasdermin-family pore-forming protein1,2, to trigger target cell pyroptosis3. GSDMB and the charter gasdermin family member GSDMD4,5 have been inconsistently reported to be degraded by the Shigella flexneri ubiquitin-ligase virulence factor IpaH7.8 (refs. 6,7). Whether and how IpaH7.8 targets both gasdermins is undefined, and the pyroptosis function of GSDMB has even been questioned recently6,8. Here we report the crystal structure of the IpaH7.8-GSDMB complex, which shows how IpaH7.8 recognizes the GSDMB pore-forming domain. We clarify that IpaH7.8 targets human (but not mouse) GSDMD through a similar mechanism. The structure of full-length GSDMB suggests stronger autoinhibition than in other gasdermins9,10. GSDMB has multiple splicing isoforms that are equally targeted by IpaH7.8 but exhibit contrasting pyroptotic activities. Presence of exon 6 in the isoforms dictates the pore-forming, pyroptotic activity in GSDMB. We determine the cryo-electron microscopy structure of the 27-fold-symmetric GSDMB pore and depict conformational changes that drive pore formation. The structure uncovers an essential role for exon-6-derived elements in pore assembly, explaining pyroptosis deficiency in the non-canonical splicing isoform used in recent studies6,8. Different cancer cell lines have markedly different isoform compositions, correlating with the onset and extent of pyroptosis following GZMA stimulation. Our study illustrates fine regulation of GSDMB pore-forming activity by pathogenic bacteria and mRNA splicing and defines the underlying structural mechanisms.

How is grandparenting linked to life satisfaction among community-dwelling older migrants in Nanjing, China: The mediating role of loneliness and self-esteem.

Grandparenting is a crucial part of family child care. This study aims to examine the effect of grandparenting on the life satisfaction of community-dwelling older migrants, and attempts to explore the psychological mechanisms linking them. A total of 723 participants were recruited. The PROCESS Model 6 was used to complete the mediation analysis. The mediating effect was significant if the 95%CI did not contain zero. Results indicated that grandparenting was positively associated with migrants' life satisfaction (r=0.223, p<0.001). Loneliness and self-esteem significantly mediated this relationship, with mediating effects of 0.287 (95%CI: 0.072, 0.563) and 1.127 (95%CI: 0.648, 1.622), respectively. Grandparenting affects life satisfaction either directly, or indirectly by reducing loneliness and enhancing self-esteem.

Structural mechanisms of calmodulin activation of Shigella effector OspC3 to ADP-riboxanate caspase-4/11 and block pyroptosis.

The caspase-4/11-GSDMD pyroptosis axis recognizes cytosolic lipopolysaccharide for antibacterial defenses. Shigella flexneri employs an OspC3 effector to block pyroptosis by catalyzing NAD+-dependent arginine ADP-riboxanation of caspase-4/11. Here, we identify Ca2+-free calmodulin (CaM) that binds and stimulates OspC3 ADP-riboxanase activity. Crystal structures of OspC3-CaM and OspC3-caspase-4 binary complexes reveal unique CaM binding to an OspC3 N-terminal domain featuring an ADP-ribosyltransferase-like fold and specific recognition of caspase-4 by an OspC3 ankryin repeat domain, respectively. CaM-OspC3-caspase-4 ternary complex structures show that NAD+ binding reorganizes the catalytic pocket, in which D231 and D177 activate the substrate arginine for initial ADP-ribosylation and ribosyl 2'-OH in the ADP-ribosylated arginine, respectively, for subsequent deamination. We also determine structures of unmodified and OspC3-ADP-riboxanated caspase-4. Mechanisms derived from this series of structures covering the entire process of OspC3 action are supported by biochemical analyses in vitro and functional validation in S. flexneri-infected mice.

Self-Rated Health and Life Satisfaction among Elderly Migrants in China: A Moderated Mediation Model of Resilience and Upward Intergenerational Support.

OBJECTIVE: This study aimed to test whether resilience mediates the association between self-rated health and life satisfaction and the moderated effect of upward intergenerational support among elderly migrants in China. METHOD: We used self-reported data collected from 654 elderly migrants in Nanjing. The regression analysis using bootstrapping methods was conducted to explore the mediating and moderating effects. RESULTS: Resilience mediated the relationship between self-rated health and life satisfaction among elderly migrants in China. The moderated mediation analysis indicated that the upward intergenerational support moderated the path between self-rated health and resilience. Specifically, compared with those with a low level of emotional support, the self-rated health of elderly migrants with a high level of emotional support has a stronger effect on resilience. Moreover, the self-rated health of elderly migrants with a low level of financial support has a stronger effect on resilience than those with a higher level of financial support. CONCLUSION: Resilience could partially mediate the effect of self-rated health on life satisfaction among elderly migrants in China, and upward intergenerational support moderated the indirect relationship between self-rated health and life satisfaction via resilience.

Perceived stress and life satisfaction among elderly migrants in China: A moderated mediation model.

Objective: Our study aims to test whether anxiety mediated the association between perceived stress and life satisfaction and whether the mediating effect was moderated by resilience among elderly migrants in China. Methods: We used self-reported data collected from 654 elderly migrants in Nanjing. Regression analyses using bootstrapping methods were conducted to explore the mediating and moderating effects. Results: The results showed that anxiety mediated the relationship between perceived stress and life satisfaction (indirect effect = -0.040, CI [-0.066, -0.017]). Moreover, moderated mediated analysis indicated that resilience moderated the path between anxiety and life satisfaction (moderating effect = 0.034, 95% CI [0.021, 0.048]). In particular, anxiety had a negative impact on life satisfaction only for Chinese elderly migrants with lower resilience. Conclusion: Our study suggests that perceived stress could reduce life satisfaction among elderly migrants as their anxiety levels increase. Fortunately, elderly migrants' resilience could undermine this negative effect.

Chinese elderly migrants' loneliness, anxiety and depressive symptoms: The mediation effect of perceived stress and resilience.

Elderly migrants who face the dual challenges of aging and migration are more likely to suffer psychological disorders. Existing research has demonstrated a link between loneliness and psychological disorders in the general elderly population. However, we know little about the relationships among elderly migrants, and the psychological mechanisms linking them. This study aims to examine the effects of loneliness on anxiety and depressive symptoms among Chinese elderly migrants, and explore the mediating roles of perceived stress and resilience. All 654 participants were recruited in Nanjing, Jiangsu Province, China. Results showed that loneliness was significantly correlated with anxiety and depressive symptoms (p < 0.001). Perceived stress and resilience mediated the relationship between loneliness and anxiety symptoms. The mediating effect of perceived stress was 0.128 (Bootstrap 95% CI: 0.092-0.168, Ratio = 37.4%). Resilience was 0.026 (Bootstrap 95% CI: 0.005-0.049, Ratio = 7.6%). Furthermore, perceived stress and resilience also mediated the relationship between loneliness and depressive symptoms. The mediating effects were 0.111 and 0.043, respectively (Bootstrap 95% CI: 0.073-0.151, Ratio = 27.9%; Bootstrap 95% CI: 0.020-0.069, Ratio = 10.8%). All the mediating effects were significant because the bootstrap 95% CIs did not contain zero. Overall, our findings suggested that loneliness not only can directly influence elderly migrants' anxiety and depressive symptoms but also by increasing perceived stress or decreasing resilience.

[Study on the indication of concurrent chemoradiotherapy for locally advanced laryngeal carcinoma].

Laryngeal cancer is one of the most common malignant cancer of the head and neck. Concurrent chemoradiotherapy is considered by the NCCN guideline to be the most effective organ protection strategy for locally advanced laryngeal cancer, which can preserve the larynx without reducing the survival rate of patients. Patients with non-T4 （T1-3） and high lymph node burden （N2-3） laryngeal cancer can benefit from concurrent chemoradiotherapy, which are more suitable for concurrent chemoradiotherapy than locally advanced laryngeal cancer with other stages. The indications of concurrent chemoradiotherapy were further discussed in this paper.

Calmodulin Binding Activates Chromobacterium CopC Effector to ADP-Riboxanate Host Apoptotic Caspases.

Blocking host cell death is an important virulence strategy employed by many bacterial pathogens. We recently reported that Shigella flexneri inhibits host pyroptosis by delivering a type III secretion system (T3SS) effector OspC3 that catalyzes a novel arginine ADP-riboxanation modification on caspase-4/11. Here, we investigated the OspC3 homologue CopC from Chromobacterium violaceum, an opportunistic but sometimes deadly bacterial pathogen. CopC bears the same arginine ADP-riboxanase activity as OspC3, but with a different substrate specificity. Through proteomic analysis, we first identified host calmodulin (CaM) as a binding partner of CopC. The analyses additionally revealed that CopC preferably modifies apoptotic caspases including caspase-7, -8 and -9. This results in suppression of both extrinsic and intrinsic apoptosis programs in C. violaceum-infected cells. Biochemical reconstitution showed that CopC requires binding to CaM, specifically in the calcium-free state, to achieve efficient ADP-riboxanation of the caspases. We determined crystal structure of the CaM-CopC-CASP7 ternary complex, which illustrates the caspase recognition mechanism and a unique CaM-binding mode in CopC. Structure-directed mutagenesis validated the functional significance of CaM binding for stimulating CopC modification of its caspase substrates. CopC adopts an ADP-ribosyltransferase-like fold with a unique His-Phe-Glu catalytic triad, featuring two acidic residues critical for site-specific arginine ADP-riboxanation. Our study expands and deepens our understanding of the OspC family of ADP-riboxanase effectors. IMPORTANCE Programmed cell death is a suicidal defense mechanism for eukaryotes to combat pathogen infection. In the evolutionary arms race with the host, bacteria are endowed with ingenious tactics to block host cell death to facilitate their replication. Here, we report that the C. violaceum effector CopC ADP-riboxanates caspase-7/8/9, enabled by interacting with the host factor calmodulin, to block host cell apoptosis, illustrating a unique and sophisticated strategy adopted by the pathogen to counteract host defense.

Metabolite profiling and transcriptome analyses provide insight into the regulatory network of graft incompatibility in litchi.

Litchi is an important commercial fruit crop widely grown in the world. Graft incompatibility between rootstocks and scions is a major constraint for large-scale cultivation of litchi orchards, popularization of new and excellent litchi varieties, and associated industrial development. Further, the genetic mechanism of graft incompatibility is still unclear in litchi. To reduce the incompatibility problems, this study investigated metabolic and transcriptomic differences between graft compatible and incompatible rootstock-scion combinations of litchi. The result of metabolomics analysis showed that incompatible rootstock-scion interaction modified the profiles of several metabolic substances. However, various compounds of flavonoids, phenolic acids, and lignin predominantly exhibited significantly altered abundance in graft incompatible combinations. Transcriptome analysis identified that graft incompatibility induces dynamic gene differences. The majority of these differentially expressed genes were enriched in biosynthetic pathways of phenylpropanoids. The differential expressions of genes in these pathways could be linked to the differential abundance levels of flavonoids, phenolic acids, and lignin compounds. Integrated metabolomic and transcriptomic analyses revealed a strong relationship between differential genes and differential metabolites identified in this study. In addition, identified hub genes and metabolites were closely associated with graft incompatibility of litchi. This study characterized the abundance of metabolites and genes in graft incompatible combinations and further discussed the genetic mechanism of graft incompatibility in litchi. Our results provide a platform to dissect the molecular mechanisms of graft incompatibility in the litchi fruit.

Rapid efficacy of percutaneous kyphoplasty (PKP) in treating thoracolumbar fractures in elderly patients.

OBJECTIVE: This study aims to investigate the effects of percutaneous kyphoplasty (PKP) on the elderly patients with thoracolumbar fractures and its influence on their complications and quality of life. METHODS: Totally 175 elderly patients with thoracolumbar fractures admitted to our hospital from June 2017 to January 2019 were selected as the research participants. Seventy patients in the control group (CG) were treated with conventional therapy, and 105 in the research group (RG) were treated by percutaneous kyphoplasty (PKP). The surgical indications (time of hospitalization and ground exercise), pressure injury and pain (VAS score) of patients in both groups were tested and compared. The ODI score, quality of life GQOLI-74 scale score, height of anterior vertebral border and cobb angle of patients were compared, and their total effective and complication rates were statistically analyzed. RESULTS: The surgical indications of patients in the RG were better than those in the CG. Those with pressure injury in stages 1 and 2 were fewer, and VAS and ODI scores were lower; GQOLI-74 scale score was higher, height of anterior vertebral border was higher than that in the CG, and the cobb angle was smaller The total effective rate was higher and the incidence of complications was lower than that in the CG. CONCLUSION: PKP is more effective and faster in treating thoracolumbar fractures in elderly patients with fewer postoperative complications, and can promote the recovery of function and quality of life.

Structural and Biochemical Analysis Reveals a Distinct Catalytic Site of Salicylate 5-Monooxygenase NagGH from Rieske Dioxygenases.

Rieske nonheme iron oxygenases (ROs) catalyze the oxidation of a wide variety of substrates and play important roles in aromatic compound degradation and polycyclic aromatic hydrocarbon degradation. Those Rieske dioxygenases that usually act on hydrophobic substrates have been extensively studied and structurally characterized. Here, we report the crystal structure of a novel Rieske monooxygenase, NagGH, the oxygenase component of a salicylate 5-monooxygenase from Ralstonia sp. strain U2 that catalyzes the hydroxylation of a hydrophilic substrate salicylate (2-hydroxybenzoate), forming gentisate (2, 5-dihydroxybenzoate). The large subunit NagG and small subunit NagH share the same fold as that for their counterparts of Rieske dioxygenases and assemble the same α3ß3 hexamer, despite that they share low (or no identity for NagH) sequence identities with these dioxygenase counterparts. A potential substrate-binding pocket was observed in the vicinity of the nonheme iron site. It featured a positively charged residue Arg323 that was surrounded by hydrophobic residues. The shift of nonheme iron atom caused by residue Leu228 disrupted the usual substrate pocket observed in other ROs. Residue Asn218 at the usual substrate pocket observed in other ROs was likewise involved in substrate binding and oxidation, yet residues Gln316 and Ser367, away from the usual substrate pocket of other ROs, were shown to play a more important role in substrate oxidation than Asn218. The unique binding pocket and unusual substrate-protein hydrophilic interaction provide new insights into Rieske monooxygenases.IMPORTANCE Rieske oxygenases are involved in the degradation of various aromatic compounds. These dioxygenases usually carry out hydroxylation of hydrophobic aromatic compounds and supply substrates with hydroxyl groups for extradiol/intradiol dioxygenases to cleave rings, and have been extensively studied. Salicylate 5-hydroxylase NagGH is a novel Rieske monooxygenase with high similarity to Rieske dioxygenases, and also shares reductase and ferredoxin similarity with a Rieske dioxygenase naphthalene 1,2-dioxygenase (NagAcAd) in Ralstonia sp. strain U2. The structure of NagGH, the oxygenase component of salicylate 5-monooxygenase, gives a representative of those monooxygenases and will help us understand the mechanism of their substrate binding and product regio-selectivity.