Molecular basis of A. thaliana KEOPS complex in biosynthesizing tRNA t6A.

In archaea and eukaryotes, the evolutionarily conserved KEOPS is composed of four core subunits-Kae1, Bud32, Cgi121 and Pcc1, and a fifth Gon7/Pcc2 that is found in fungi and metazoa. KEOPS cooperates with Sua5/YRDC to catalyze the biosynthesis of tRNA N6-threonylcarbamoyladenosine (t6A), an essential modification needed for fitness of cellular organisms. Biochemical and structural characterizations of KEOPSs from archaea, yeast and humans have determined a t6A-catalytic role for Kae1 and auxiliary roles for other subunits. However, the precise molecular workings of KEOPSs still remain poorly understood. Here, we investigated the biochemical functions of A. thaliana KEOPS and determined a cryo-EM structure of A. thaliana KEOPS dimer. We show that A. thaliana KEOPS is composed of KAE1, BUD32, CGI121 and PCC1, which adopts a conserved overall arrangement. PCC1 dimerization leads to a KEOPS dimer that is needed for an active t6A-catalytic KEOPS-tRNA assembly. BUD32 participates in direct binding of tRNA to KEOPS and modulates the t6A-catalytic activity of KEOPS via its C-terminal tail and ATP to ADP hydrolysis. CGI121 promotes the binding of tRNA to KEOPS and potentiates the t6A-catalytic activity of KEOPS. These data and findings provide insights into mechanistic understanding of KEOPS machineries.

Global, regional and national burden of male infertility in 204 countries and territories between 1990 and 2019: an analysis of global burden of disease study.

BACKGROUND: Many countries and regions have experienced male fertility problems due to various influencing factors, especially in less developed countries. Unlike female infertility, male infertility receives insufficient attention. Understanding the changing patterns of male infertility in the world, different regions and different countries is crucial for assessing the global male fertility and reproductive health. METHODS: We obtained data on prevalence, years of life lived with disability (YLD), age-standardized rates of prevalence (ASPR) and age-standardized YLD rate (ASYR) from the Global Burden of Disease Study 2019. We analyzed the burden of male infertility at all levels, including global, regional, national, age stratification and Socio-demographic Index (SDI). RESULTS: In 2019, the global prevalence of male infertility was estimated to be 56,530.4 thousand (95% UI: 31,861.5-90,211.7), reflecting a substantial 76.9% increase since 1990. Furthermore, the global ASPR stood at 1,402.98 (95% UI: 792.24-2,242.45) per 100,000 population in 2019, representing a 19% increase compared to 1990. The regions with the highest ASPR and ASYR for male infertility in 2019 were Western Sub-Saharan Africa, Eastern Europe, and East Asia. Notably, the prevalence and YLD related to male infertility peaked in the 30-34 year age group worldwide. Additionally, the burden of male infertility in the High-middle SDI and Middle SDI regions exceeded the global average in terms of both ASPR and ASYR. CONCLUSION: The global burden of male infertility has exhibited a steady increase from 1990 to 2019, as evidenced by the rising trends in ASPR and ASYR, particularly in the High-middle and Middle SDI regions. Notably, the burden of male infertility in these regions far exceeds the global average. Additionally, since 2010, there has been a notable upward trend in the burden of male infertility in Low and Middle-low SDI regions. Given these findings, it is imperative to prioritize efforts aimed at improving male fertility and reproductive health.

Structure-function analysis of an ancient TsaD-TsaC-SUA5-TcdA modular enzyme reveals a prototype of tRNA t6A and ct6A synthetases.

N 6-threonylcarbamoyladenosine (t6A) is a post-transcriptional modification found uniquely at position 37 of tRNAs that decipher ANN-codons in the three domains of life. tRNA t6A plays a pivotal role in promoting translational fidelity and maintaining protein homeostasis. The biosynthesis of tRNA t6A requires members from two evolutionarily conserved protein families TsaC/Sua5 and TsaD/Kae1/Qri7, and a varying number of auxiliary proteins. Furthermore, tRNA t6A is modified into a cyclic hydantoin form of t6A (ct6A) by TcdA in bacteria. In this work, we have identified a TsaD-TsaC-SUA5-TcdA modular protein (TsaN) from Pandoraviruses and determined a 3.2 Å resolution cryo-EM structure of P. salinus TsaN. The four domains of TsaN share strong structural similarities with TsaD/Kae1/Qri7 proteins, TsaC/Sua5 proteins, and Escherichia coli TcdA. TsaN catalyzes the formation of threonylcarbamoyladenylate (TC-AMP) using L-threonine, HCO3- and ATP, but does not participate further in tRNA t6A biosynthesis. We report for the first time that TsaN catalyzes a tRNA-independent threonylcarbamoyl modification of adenosine phosphates, leading to t6ADP and t6ATP. Moreover, TsaN is also active in catalyzing tRNA-independent conversion of t6A nucleoside to ct6A. Our results imply that TsaN from Pandoraviruses might be a prototype of the tRNA t6A- and ct6A-modifying enzymes in some cellular organisms.

Association of Sarcopenia with Cognitive Function and Dementia Risk Score: A National Prospective Cohort Study.

The relationship between skeletal muscle and cognitive disorders has drawn increasing attention. This study aims to examine the associations of sarcopenia with cognitive function and dementia risk score. Data on 1978 participants (aged 65 years and older) from the 2011 wave of the China Health and Retirement Longitudinal Study, with four follow-up waves to 2018, were used. Cognitive function was assessed by four dimensions, with a lower score indicating lower cognitive function. Dementia risk was assessed by a risk score using the Rotterdam Study Basic Dementia Risk Model (BDRM), with a higher score indicating a greater risk. Sarcopenia was defined when low muscle mass plus low muscle strength or low physical performance were met. We used generalized estimating equations to examine the associations of sarcopenia. In the fully adjusted models, sarcopenia was significantly associated with lower cognitive function (standardized, ß = -0.15; 95% CIs: -0.26, -0.04) and a higher BDRM score (standardized, ß = 0.42; 95% CIs: 0.29, 0.55). Our findings may provide a new avenue for alleviating the burden of cognitive disorders by preventing sarcopenia.

Conservation and Diversification of tRNA t6A-Modifying Enzymes across the Three Domains of Life.

The universal N6-threonylcarbamoyladenosine (t6A) modification occurs at position 37 of tRNAs that decipher codons starting with adenosine. Mechanistically, t6A stabilizes structural configurations of the anticodon stem loop, promotes anticodon-codon pairing and safeguards the translational fidelity. The biosynthesis of tRNA t6A is co-catalyzed by two universally conserved protein families of TsaC/Sua5 (COG0009) and TsaD/Kae1/Qri7 (COG0533). Enzymatically, TsaC/Sua5 protein utilizes the substrates of L-threonine, HCO3-/CO2 and ATP to synthesize an intermediate L-threonylcarbamoyladenylate, of which the threonylcarbamoyl-moiety is subsequently transferred onto the A37 of substrate tRNAs by the TsaD-TsaB -TsaE complex in bacteria or by the KEOPS complex in archaea and eukaryotic cytoplasm, whereas Qri7/OSGEPL1 protein functions on its own in mitochondria. Depletion of tRNA t6A interferes with protein homeostasis and gravely affects the life of unicellular organisms and the fitness of higher eukaryotes. Pathogenic mutations of YRDC, OSGEPL1 and KEOPS are implicated in a number of human mitochondrial and neurological diseases, including autosomal recessive Galloway-Mowat syndrome. The molecular mechanisms underscoring both the biosynthesis and cellular roles of tRNA t6A are presently not well elucidated. This review summarizes current mechanistic understandings of the catalysis, regulation and disease implications of tRNA t6A-biosynthetic machineries of three kingdoms of life, with a special focus on delineating the structure-function relationship from perspectives of conservation and diversity.

Perovskite Solar Cells Employing a PbSO4(PbO)4 Quantum Dot-Doped Spiro-OMeTAD Hole Transport Layer with an Efficiency over 22.

2,2',7,7'-Tetrakis(N,N-di-p-methoxyphenyl-amine)-9,9'-spirobifluorene (spiro-OMeTAD), the most widely used hole transport material in high-efficiency perovskite solar cells (PSCs), still has serious defects, such as moisture absorption and poor long-term conductivity, which seriously restrict further improvement of the power conversion efficiency (PCE) and stability of the cell. Herein, to overcome these problems, inorganic salt PbSO4(PbO)4 quantum dots (QDs) are incorporated into spiro-OMeTAD as the hole transport layer (HTL) for the first time. The incorporated PbSO4(PbO)4 QDs significantly hinder the agglomeration of lithium bis(trifluoromethanesulfonyl)-imide and improve the long-term conductivity through the oxidative interaction between PbSO4(PbO)4 QDs and spiro-OMeTAD and hydrophobicity of the HTL. Furthermore, the spiro-OMeTAD:PbSO4(PbO)4 composite film can effectively passivate perovskite defects at the perovskite/HTL interface, resulting in suppressed interfacial recombination. As a result, the PSC based on the spiro-OMeTAD:PbSO4(PbO)4 HTL shows an improved PCE of 22.66%, which is much higher than that (18.89%) of the control device. PbSO4(PbO)4 also significantly improves the moisture stability for 50 days at room temperature (at RH ∼ 40-50%) without encapsulation. This work indicates that inorganic PbSO4(PbO)4 QDs are crucial materials that can be employed as an additive in spiro-OMeTAD to enhance the efficiency and stability of PSCs.

Enhanced Simultaneous Nitrogen and Phosphorus Removal in A Denitrifying Biological Filter Using Waterworks Sludge Ceramsite Coupled with Iron-Carbon.

In this study, waterworks sludge ceramsite (WSC) was combined with 3% iron-carbon matrix in a denitrifying biological filter (ICWSC-DNBF) to enhance the simultaneous removal of carbon, nitrogen and phosphorus in secondary effluent of wastewater treatment plant (SE-WTP). The chemical oxygen demand (COD) and nitrogen removal, as well as phosphorus removal and the adsorbed forms of phosphorus were measured and the removal mechanism of these pollutants by the ICWSC-DNBF system for treating SE-WTP were investigated. The results showed that the ICWSC-DNBF achieved good removals of COD, NH4+-N, NO3--N, total N and total P; effluent concentrations were 17.23 mg/L, 3.72 mg/L, 14.32 mg/L, 17.38 mg/L and 0.82 mg/L, respectively. WSC enhanced the P removal due to its high specific surface area and the high number of adsorption sites. Fe-P and Al-P were the main forms of P adsorbed by WSC, accounting for 78.53% of the total adsorbed P. WSC coupled with Fe and C improved the biodegradability of SE-WTP and promoted the removal of organic matter. The removal of N was attributed to the abundant denitrifying microorganisms in the system and the electrochemical effect produced by the internal electrolysis of Fe and C.

Correction to: Decitabine plus CLAG chemotherapy as a bridge to haploidentical transplantation in the setting of acute myeloid leukemia relapse after HLA-matched sibling transplantation: a case report.

Following publication of the original article [1], the authors reported that the incorrect Fig. 2A was published in the article. The recovery times required to achieve a normal neutrophil count was omitted. The corrected Fig. 2 is given below.

Decitabine plus CLAG chemotherapy as a bridge to haploidentical transplantation in the setting of acute myeloid leukemia relapse after HLA-matched sibling transplantation: a case report.

BACKGROUND: Patients with relapsed/refractory acute myeloid leukemia after hematopoietic stem cell transplantation (HSCT) have a poor prognosis, with a 2-year survival rate of 14%. The optimal treatment for these patients remains unclear. To treat these patients, we designed a new salvage regimen consisting of decitabine, cladribine, cytarabine, and granulocyte-stimulating factor (D-CLAG). CASE PRESENTATION: Here, we describe a case of acute monocytic leukemia with a complex karyotype in a 38-year-old female patient who relapsed after her first HSCT, which was performed using a matched sibling donor. The patient did not respond to standard induction chemotherapy and subsequently achieved complete remission with the D-CLAG regimen. No severe hematological or extramedullary toxicity was observed. Subsequently, the patient received a second D-CLAG regimen as a bridge therapy and directly underwent haploidentical related HSCT. Following HSCT, the marrow showed complete hematologic and cytogenetic remission. Currently, 1 year after transplantation, the patient's general condition remains good. CONCLUSIONS: This case suggests that the D-CLAG regimen can be an option for reinduction in relapsed refractory AML patients as a bridge to transplantation. Nevertheless, further research will be required in the future as this report describes only a single case.

Antithymocyte globulin improves GVHD-free and relapse-free survival in unrelated hematopoietic stem cell transplantation.

Antithymocyte globulin (ATG) is an important component of conditioning regimens to prevent graft-versus-host disease (GVHD) in unrelated hematopoietic stem cell transplantation (HSCT), but the optimal dose of ATG remains unknown. We prospectively analyzed 205 unrelated HSCTs in patients with malignant hematological disorders. HSCTs were classified as follows: HLA-matched transplant without ATG (n = 53, group A), HLA-mismatched transplant treated with 6.0 mg/kg thymoglobulin (n = 77, group B), and HLA-matched transplant treated with 4.5 mg/kg thymoglobulin (n = 75, group C). For groups A and B, the 5-year moderate/severe chronic GVHD rates were 31.9% and 24.2%, the 5-year GVHD-free and relapse-free survival (GRFS) rates were 28.3 and 47%, and the 2-year immunosuppressive therapy (IST)-free survival rates were 8.6% and 40.2% (p = 0.0016), respectively. Furthermore, group C had lower incidences of grade II-IV acute GVHD (18.7%) and 5-year moderate/severe chronic GVHD (16.6%) than group A did. Group C had higher 5-year GRFS (52.1% vs 28.3%, p = 0.002), 2-year IST-free survival (51.7% vs 8.6%, p = 0.00004), and 5-year overall survival (OS) (68.3% vs 41.5%, p = 0.007) rates than group A did. Thus, ATG was associated with better GVHD prevention, a higher rate of IST-free survival, lower transplant-related mortality (TRM), and superior OS and GRFS in unrelated HSCTs.

Enhanced removal mechanism of iron carbon micro-electrolysis constructed wetland on C, N, and P in salty permitted effluent of wastewater treatment plant.

In this study, the combination of a constructed wetland (CW) with iron-carbon (Fe-C) system was used to enhance the simultaneous removal of carbon, nitrogen and phosphorus in salty permitted effluent of wastewater treatment plant (SPE-WTP). The removal mechanism of Fe-C micro-electrolysis CWs with different salinity (0.027, 0.308, and 0.511%) for treating SPE-WTP was investigated, including chemical oxygen demand (COD), phosphorus and nitrogen removal, the mass balance, as well as the changes in the microbial community structure. The results showed the salinity has a certain influence on the contaminant removals, and can enhance nitrogen removal under certain conditions. When the salinity increased from 0.308% to 0.511%, the removal of COD decreased from 68.20% to 62.69%, whereas the removal of total nitrogen (TN) increased from 72.02% to 81.21% in the ICCW-p system (including P. australis as the plant and gravel doped with 3% iron-carbon as the matrix). Microbial degradation, including the electrochemical effect (the degradation by iron-carbon micro-electrolysis) was the main N removal pathway in the ICCW-p system. The ICCW-p system always achieved higher removal rates (such as 81.21% TN and 62.69% COD removals at 0.511% salinity) than that in ICCW-n system (without plants and gravel doped with 3% iron-carbon as the matrix, 63.76% TN and 56.31% COD removals, respectively) and CW-n (without plants and gravel as the matrix, 14.90% TN and 22.39% COD removals, respectively). In addition, high-throughput sequencing analysis revealed that high salinity increased the abundance of N-removing bacteria in the ICCW-p system. Furthermore, with the introduction of iron-carbon in CWs, the removal methods in ICCW-p were diverse, which has enough ability to resist the impact of salinity. Fe electrolysis produced different valence states that acted as carriers for electron transport and accelerated the efficiency of biological and chemical reactions, which enhanced the simultaneous removal of carbon, nitrogen and phosphorus.

Comprehensive Analysis of Lysine Acetylome Reveals a Site-Specific Pattern in Rapamycin-Induced Autophagy.

Protein acetylation reportedly acts as a key regulator of autophagy. However, up to now, the relationship between acetylome and autophagy has remained unclear. Here stable isotope labeling of amino acids in cell culture and high-throughput quantitative mass spectrometry were used to perform an acetylome analysis of rapamycin-induced autophagy in vitro. Our data revealed that 2135 sites were quantified on 1081 proteins. During autophagy, 421 sites were significantly regulated on 296 proteins, with 80.8% of sites downregulated and 19.2% upregulated. Motif enrichment analysis revealed five main motifs. Most of the downregulated sites conformed to the classical functional motif of p300/CBP [G-AcK]. Furthermore, acetylation targeted proteins involved mainly in ribosomes, spliceosomes, and AcCoA-related metabolic process. In-depth analysis indicated that most of the acetylation sites were in the critical domain, were functional sites, or could change their enzymatic activity by acetylation, highlighting the importance of site-specific acetylation patterns. Subsequently, we demonstrated that K1549 of p300 was also a functional site that could regulate the autophagic process in vitro. In conclusion, our data reveal a deacetylation-preponderant profile with autophagy. The specificity of the related motifs and the identification of site-specific acetylation patterns will assist searches for potential targets or subsequent mechanism-focused studies to elucidate site-specific protein networks in autophagy.

Response of Aerobic Granular Sludge to the Long-Term Presence of CuO NPs in A/O/A SBRs: Nitrogen and Phosphorus Removal, Enzymatic Activity, and the Microbial Community.

The increasing use of cupric oxide nanoparticles (CuO NPs) has raised concerns about their potential environmental toxicity. Aerobic granular sludge (AGS) is a special form of microbial aggregates. In this study, the removal efficiencies of nitrogen and phosphorus, enzyme activities and microbial community of AGS under long-term exposure to CuO NPs (at concentrations of 5, 20, 50 mg/L) in aerobic/oxic/anoxic (A/O/A) sequencing batch reactors (SBRs) were investigated. The results showed the chronic toxicity caused by different concentrations of CuO NPs (5, 20, 50 mg/L) resulted in increases in the production of ROS of 110.37%, 178.64%, and 188.93% and in the release of lactate dehydrogenase (LDH) of 108.33%, 297.05%, 335.94%, respectively, compared to the control. Besides, CuO NPs decreased the activities of polyphosphate kinase (PPK) and exophosphatase (PPX), leading to lower phosphorus removal efficiency. However, the NH4+-N removal rates remained stable, and the removal efficiencies of TN increased due to the synthesis of nitrite and nitrous oxide (N2O) reductases. In addition, CuO NPs at concentrations of 0, 5, 20 mg/L increased the secretion of protein (PN) to 90, 91, 105 mg/gVSS, respectively, which could alleviate the toxicity of CuO NPs. High-throughput sequencing showed that CuO NPs increased the abundance of nitrogen-removal bacteria and reduced the abundance of phosphorus-removal bacteria, which is consistent with the results of pollutant removal upon long-term exposure to CuO NPs.