PERK is a critical metabolic hub for immunosuppressive function in macrophages.

Chronic inflammation triggers compensatory immunosuppression to stop inflammation and minimize tissue damage. Studies have demonstrated that endoplasmic reticulum (ER) stress augments the suppressive phenotypes of immune cells; however, the molecular mechanisms underpinning this process and how it links to the metabolic reprogramming of immunosuppressive macrophages remain elusive. In the present study, we report that the helper T cell 2 cytokine interleukin-4 and the tumor microenvironment increase the activity of a protein kinase RNA-like ER kinase (PERK)-signaling cascade in macrophages and promote immunosuppressive M2 activation and proliferation. Loss of PERK signaling impeded mitochondrial respiration and lipid oxidation critical for M2 macrophages. PERK activation mediated the upregulation of phosphoserine aminotransferase 1 (PSAT1) and serine biosynthesis via the downstream transcription factor ATF-4. Increased serine biosynthesis resulted in enhanced mitochondrial function and α-ketoglutarate production required for JMJD3-dependent epigenetic modification. Inhibition of PERK suppressed macrophage immunosuppressive activity and could enhance the efficacy of immune checkpoint programmed cell death protein 1 inhibition in melanoma. Our findings delineate a previously undescribed connection between PERK signaling and PSAT1-mediated serine metabolism critical for promoting immunosuppressive function in M2 macrophages.

DNA-DISK: Automated end-to-end data storage via enzymatic single-nucleotide DNA synthesis and sequencing on digital microfluidics.

In the age of information explosion, the exponential growth of digital data far exceeds the capacity of current mainstream storage media. DNA is emerging as a promising alternative due to its higher storage density, longer retention time, and lower power consumption. To date, commercially mature DNA synthesis and sequencing technologies allow for writing and reading of information on DNA with customization and convenience at the research level. However, under the disconnected and nonspecialized mode, DNA data storage encounters practical challenges, including susceptibility to errors, long storage latency, resource-intensive requirements, and elevated information security risks. Herein, we introduce a platform named DNA-DISK that seamlessly streamlined DNA synthesis, storage, and sequencing on digital microfluidics coupled with a tabletop device for automated end-to-end information storage. The single-nucleotide enzymatic DNA synthesis with biocapping strategy is utilized, offering an ecofriendly and cost-effective approach for data writing. A DNA encapsulation using thermo-responsive agarose is developed for on-chip solidification, not only eliminating data clutter but also preventing DNA degradation. Pyrosequencing is employed for in situ and accurate data reading. As a proof of concept, DNA-DISK successfully stored and retrieved a musical sheet file (228 bits) with lower write-to-read latency (4.4 min of latency per bit) as well as superior automation compared to other platforms, demonstrating its potential to evolve into a DNA Hard Disk Drive in the future.

Micro but mighty-Micronutrients in the epigenetic regulation of adaptive immune responses.

Micronutrients are essential small molecules required by organisms in minute quantity for survival. For instance, vitamins and minerals, the two major categories of micronutrients, are central for biological processes such as metabolism, cell replication, differentiation, and immune response. Studies estimated that around two billion humans worldwide suffer from micronutrient deficiencies, also known as "hidden hunger," linked to weakened immune responses. While micronutrients affect the immune system at multiple levels, recent studies showed that micronutrients potentially impact the differentiation and function of immune cells as cofactors for epigenetic enzymes, including the 2-oxoglutarate-dependent dioxygenase (2OGDD) family involved in histone and DNA demethylation. Here, we will first provide an overview of the role of DNA methylation in T cells and B cells, followed by the micronutrients ascorbate (vitamin C) and iron, two critical cofactors for 2OGDD. We will discuss the emerging evidence of these micronutrients could regulate adaptive immune response by influencing epigenetic remodeling.

Persistent ER stress causes GPI anchor deficit to convert a GPI-anchored prion protein into pro-PrP via the ATF6-miR449c-5p-PIGV axis.

Endoplasmic reticulum (ER) stress and unfolded protein response are cells' survival strategies to thwart disruption of proteostasis. Tumor cells are continuously being challenged by ER stress. The prion protein, PrP, normally a glycosylphosphatidylinositol (GPI)-anchored protein exists as a pro-PrP retaining its GPI-peptide signal sequence in human pancreatic ductal cell adenocarcinoma (PDAC). Higher abundance of pro-PrP indicates poorer prognosis in PDAC patients. The reason why PDAC cells express pro-PrP is unknown. Here, we report that persistent ER stress causes conversion of GPI-anchored PrP to pro-PrP via a conserved ATF6-miRNA449c-5p-PIGV axis. Mouse neurons and AsPC-1, a PDAC cell line, express GPI-anchored PrP. However, continuous culture of these cells with the ER stress inducers thapsigargin or brefeldin A results in the conversion of a GPI-anchored PrP to pro-PrP. Such a conversion is reversible; removal of the inducers allows the cells to re-express a GPI-anchored PrP. Mechanistically, persistent ER stress increases the abundance of an active ATF6, which increases the level of miRNA449c-5p (miR449c-5p). By binding the mRNA of PIGV at its 3'-UTRs, miR449c-5p suppresses the level of PIGV, a mannosyltransferase pivotal in the synthesis of the GPI anchor. Reduction of PIGV leads to disruption of the GPI anchor assembly, causing pro-PrP accumulation and enhancing cancer cell migration and invasion. The importance of ATF6-miR449c-5p-PIGV axis is recapitulated in PDAC biopsies as the higher levels of ATF6 and miR449c-5p and lower levels of PIGV are markers of poorer outcome for patients with PDAC. Drugs targeting this axis may prevent PDAC progression.

Ocular toxicity associated with anti-HER2 agents in breast cancer: A pharmacovigilance analysis using the FAERS database.

Anti-human epidermal growth factor receptor 2 (HER2) agents have exhibited pronounced tumor-inhibitory activity, yet the accompanying ocular toxicity has frequently been underestimated. We aim to conduct a comprehensive comparative analysis of ocular toxicity risk related to various anti-HER2 agents. We executed a retrospective pharmacovigilance investigation based on the FDA Adverse Event Reporting System (FAERS) database, covering the period from Q2 2018 to Q1 2023. The disproportionality analysis was performed to assess ocular toxicity risk. Multivariate logistic regression was implemented to mitigate potential biases. Moreover, the time to onset of ocular toxicity was also evaluated. A total of 3467 ocular adverse event (AE) reports concerning anti-HER2 agents were collected. At the preferred term (PT) level, there were 69 positive signals, among which excessive eye blinking, abnormal sensation in the eye, and asthenopia presented a significant risk. In comparison to tyrosine kinase inhibitors (TKIs), antibody drugs were associated with a broader range of ocular disorders at Standardized MedDRA Queries (SMQ)levels, including conjunctival disorders, corneal disorders, ocular infections, ocular motility disorders, optic nerve disorders, and retinal disorders. In terms of onset time, pertuzumab displayed an earlier onset at 21.5 days, while trastuzumab deruxtecan had the latest at 91.5 days. In summary, our study reveals varying degrees of ocular toxicity related to anti-HER2 agents, with a significantly higher risk observed in antibody drugs. Additionally, novel ocular toxicity signals, not documented in product labels, have been detected. In the future, further research will be necessary to validate our findings.

Kinetics Conditioning of (Electro) Chemically Stable Zn Anode with pH Regulation Toward Long-Life Zn-Storage Devices.

The safety, low cost, and high power density of aqueous Zn-based devices (AZDs) appeal to large-scale energy storage. Yet, the presence of hydrogen evolution reaction (HER) and chemical corrosion in the AZDs leads to local OH- concentration increasement and the formation of ZnxSOy(OH)z•nH2O (ZHS) by-products at the Zn/electrolyte interface, causing instability and irreversibility of the Zn-anodes. Here, a strategy is proposed to regulate OH- by introducing a bio-sourced/renewable polypeptide (ɛ-PL) as a pH regulator in electrolyte. The consumption of OH- species is evaluated through in vitro titration and cell in vivo in situ attenuated total reflection surface-enhanced infrared absorption spectroscopy at a macroscopic and molecular level. The introduction of ɛ-PL is found to significantly suppress the formation of ZHS and associated side reactions, and reduce the local coordinated H2O of the Zn2+ solvation shell, widening electrochemical stable window and suppressing OH- generation during HER. As a result, the inclusion of ɛ-PL improves the cycle time of Zn/Zn symmetrical cells from 15 to 225 h and enhances the cycle time of aqueous Zn- I2 cells to 1650 h compared to those with pristine electrolytes. This work highlights the potential of kinetical OH- regulation for by-product and dendrite-free AZDs.

Boosting the Energy Density of Bowl-Like MnO2@Carbon Through Lithium-Intercalation in a High-Voltage Asymmetric Supercapacitor with "Water-In-Salt" Electrolyte.

Highly concentrated "'water-in-salt"' (WIS) electrolytes are promising for high-performance energy storage devices due to their wide electrochemical stability window. However, the energy storage mechanism of MnO2 in WIS electrolytes-based supercapacitors remains unclear. Herein, MnO2 nanoflowers are successfully grown on mesoporous bowl-like carbon (MBC) particles to generate MnO2/MBC composites, which not only increase electroactive sites and inhibit the pulverization of MnO2 particles during the fast charging/discharging processes, but also facilitate the electron transfer and ion diffusion within the whole electrode, resulting in significant enhancement of the electrochemical performance. An asymmetric supercapacitor, assembled with MnO2/MBC and activated carbon (AC) and using 21 m LiTFSI solution as the WIS electrolyte, delivers an ultrahigh energy density of 70.2 Wh kg-1 at 700 W kg-1, and still retains 24.8 Wh kg-1 when the power density is increased to 28 kW kg-1. The ex situ XRD, Raman, and XPS measurements reveal that a reversible reaction of MnO2 + xLi+ + xe-↔LixMnO2 takes place during charging and discharging. Therefore, the asymmetric MnO2/MBC//AC supercapacitor with LiTFSI electrolyte is actually a lithium-ion hybrid supercapacitor, which can greatly boost the energy density of the assembled device and expand the voltage window.

Kill Two Birds with One Stone: Dual-Metal MOF-Nanozyme-Decorated Hydrogels with ROS-Scavenging, Oxygen-Generating, and Antibacterial Abilities for Accelerating Infected Diabetic Wound Healing.

Diabetic wounds tend to develop into nonhealing wounds associated with the complex inflammatory microenvironment of uncontrollable bacterial infection, reactive oxygen species (ROS) accumulation, and chronic hypoxia. Damaged blood vessels hinder metabolic circulation, aggravating hypoxia, and ROS accumulation and further exacerbating the diabetic wound microenvironment. However, existing treatments with a single functionality have difficulty healing complicated diabetic wounds. Therefore, developing an integrative strategy to improve the hostility of the diabetic wound microenvironment is urgently needed. Herein, multifunctional genipin (GP)-crosslinked chitosan (CS)-based hydrogels decorated with the biomimetic metal-organic framework (MOF)-nanozymes and the natural antibacterial agent chlorogenic acid (CGA), which is named MOF/CGA@GP-CS (MCGC), are prepared. With catalase (CAT)-like activity, these dual-metal MOF-nanozymes are promising bioreactors for simultaneously alleviating ROS accumulation and hypoxia by converting elevated endogenous H2O2 into dissolved oxygen in diabetic wounds. In addition, the other component of natural polyphenolic CGA acts as a mild antibacterial agent, efficiently inhibiting wound infection and avoiding antibiotic resistance. Impressively, the MCGC hydrogels accelerate infected diabetic wound healing by eliminating oxidative stress, increasing oxygenation, and reversing bacterial infection in vivo. In this work, an effective strategy based on multifunctional hydrogel wound dressings is successfully developed and applied in diabetic wound management.

A gene-encoded aldehyde tag repurposed from RiPP cyclophane-forming pathway.

Gene-encoded aldehyde tag technology has been widely utilized in protein bioorthogonal chemistry and biotechnological application. Herein, we report utilization of the promiscuous rSAM cyclophane synthase SjiB involved in triceptide biosynthesis as a dedicated and highly efficient formylglycine synthase. The new aldehyde tag sequence in this system, YQSSI, is biosynthetically orthogonal to the known aldehyde tag (C/S)x(P/A)xR. The potential use of SjiB/YQSSI aldehyde tag system was further validated in fluorescent labelling of model proteins.

Enhanced Visible-Light H2O2 Production over Pt/g-C3N4 Schottky Junction Photocatalyst.

Photocatalytic for hydrogen peroxide (H2O2) production is thought as a promising technology owing to its clean and green properties with the cheap and easily available raw materials of H2O and O2. Herein, Pt/g-C3N4 Schottky junction photocatalysts with ultralow Pt contents (0.025-0.1 wt %) were successfully fabricated by an impregnation-reduction method. It can efficiently reduce O2 to generate H2O2 without a sacrificial agent under visible-light irradiation. The yield of H2O2 produced over Pt0.05/g-C3N4 with the optimal 0.05 wt % Pt reached 31.82 µM, which was 2.46 times that of g-C3N4 and higher than most of those in the literature. It also showed good stability in three repeated tests. The deposition of highly dispersed metal Pt nanoparticles with low and limited content can expose enough active Pt atoms, significantly enhance the separation efficiency of photogenerated carriers, and reduce its negative effect on H2O2 decomposition, resulting in improved and outstanding efficiency of H2O2 production. The ·O2- radicals were found to be the main active species. The mechanism of photocatalytic H2O2 production was confirmed to be a two-step single electron route (O2 + e-→ ·O2- → H2O2).

Dynamic Number and Function of IL-10-Producing Regulatory B Cells in the Immune Microenvironment at Distinct Stages of Type 1 Diabetes.

The critical role of IL-10-producing B cells (B10 cells) with a unique CD1dhiCD5+ phenotype in suppressing autoimmune responses and relieving inflammation has been demonstrated in several models of autoimmune diseases. However, the regulatory role of B10 cells in T cell-mediated autoimmune responses during the natural history of type 1 diabetes is unclear. In this study, we used the NOD mouse model of autoimmune diabetes to clarify the changes and potential mechanisms of B10 cells for disease. Compared with B10 cells present in the 4-wk-old normoglycemic NOD mice, the frequency of B10 cells was increased in the insulitis and diabetic NOD mice, with the highest proportion in the insulitis NOD mice. The changes in the relative number of B10 cells were most pronounced in the pancreas-draining lymph nodes. The pathogenic T cells, including Th1 and Th17 cells, remarkably increased. The assays in vitro showed that B10 cells in the NOD mice did not inhibit the proliferation of CD4+CD25- T cells. They also had no regulatory effect on IFN-γ and IL-4 secretion or on Foxp3 expression of T cells. B10 cells suppressed T cell-mediated autoimmune responses via an IL-10-dependent pathway. In contrast, B10 cells in the NOD mice exhibited a significant reduction in IL-10 production. In summary, a defect in the number and function of B10 cells may participate in the development and progression of type 1 diabetes.

Exploring the heterogeneity of brain structure in autism spectrum disorder based on individual structural covariance network.

Autism spectrum disorder (ASD) is characterized by highly structural heterogeneity. However, most previous studies analyzed between-group differences through a structural covariance network constructed based on the ASD group level, ignoring the effect of between-individual differences. We constructed the gray matter volume-based individual differential structural covariance network (IDSCN) using T1-weighted images of 207 children (ASD/healthy controls: 105/102). We analyzed structural heterogeneity of ASD and differences among ASD subtypes obtained by a K-means clustering analysis based on evidently different covariance edges relative to healthy controls. The relationship between the distortion coefficients (DCs) calculated at the whole-brain, intra- and interhemispheric levels and the clinical symptoms of ASD subtypes was then examined. Compared with the control group, ASD showed significantly altered structural covariance edges mainly involved in the frontal and subcortical regions. Given the IDSCN of ASD, we obtained 2 subtypes, and the positive DCs of the 2 ASD subtypes were significantly different. Intra- and interhemispheric positive and negative DCs can predict the severity of repetitive stereotyped behaviors in ASD subtypes 1 and 2, respectively. These findings highlight the crucial role of frontal and subcortical regions in the heterogeneity of ASD and the necessity of studying ASD from the perspective of individual differences.

Dysregulated dynamic time-varying triple-network segregation in children with autism spectrum disorder.

One of the remarkable characteristics of autism spectrum disorder (ASD) is the dysregulation of functional connectivity of the triple-network, which includes the salience network (SN), default mode network (DMN), and central executive network (CEN). However, there is little known about the segregation of the triple-network dynamics in ASD. This study used resting-state functional magnetic resonance imaging data including 105 ASD and 102 demographically-matched typical developing control (TC) children. We compared the dynamic time-varying triple-network segregation and triple-network functional connectivity states between ASD and TC groups, and examined the relationship between dynamic triple-network segregation alterations and clinical symptoms of ASD. The average dynamic network segregation value of the DMN with SN and the DMN with CEN in ASD was lower but the coefficient of variation (CV) of dynamic network segregation of the DMN with CEN was higher in ASD. Furthermore, partially reduced triple-network segregation associated with the DMN was found in connectivity states analysis of ASD. These abnormal average values and CV of dynamic network segregation predicted social communication deficits and restricted and repetitive behaviors in ASD. Our findings indicate abnormal dynamic time-varying triple-network segregation of ASD and highlight the crucial role of the triple-network in the neural mechanisms underlying ASD.

An individual-level weighted artificial neural network method to improve the systematic bias in BrainAGE analysis.

BrainAGE is a commonly used machine learning technique to measure the accelerated/delayed development pattern of human brain structure/function with neuropsychiatric disorders. However, recent studies have shown a systematic bias ("regression toward mean" effect) in the BrainAGE method, which indicates that the prediction error is not uniformly distributed across Chronological Ages: for the older individuals, the Brain Ages would be under-estimated but would be over-estimated for the younger individuals. In the present study, we propose an individual-level weighted artificial neural network method and apply it to simulation datasets (containing 5000 simulated subjects) and a real dataset (containing 135 subjects). Results show that compared with traditional machine learning methods, the individual-level weighted strategy can significantly reduce the "regression toward mean" effect, while the prediction performance can achieve the comparable level with traditional machine learning methods. Further analysis indicates that the sigmoid active function for artificial neural network shows better performance than the relu active function. The present study provides a novel strategy to reduce the "regression toward mean" effect of BrainAGE analysis, which is helpful to improve accuracy in exploring the atypical brain structure/function development pattern of neuropsychiatric disorders.

The association between serum magnesium and chronic kidney disease in Chinese adults: a cross-sectional study.

BACKGROUND: Magnesium (Mg) is both an essential macro-element and a known catalyst, and it plays a vital role in various physiological activities and mechanisms in relation to chronic kidney disease (CKD). However, epidemiological evidence involving this is limited and not entirely consistent. This study aims to explore the association of serum Mg concentrations with the risk of CKD among general Chinese adults. METHODS: A total of 8,277 Chinese adults were included in the wave of 2009 from the China Health and Nutrition Survey (CHNS). The primary outcome was the risk of CKD, which was defined as the estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2. Multivariable logistic regression model was used to examine the relationship of serum Mg concentrations with the risk of CKD. RESULTS: Included were 8,277 individuals, with an overall CKD prevalence of 11.8% (n = 977). Compared with the first quartile of serum Mg, the multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for participants in the second, third, and fourth quartiles of serum Mg were 0.74 (0.58, 0.93), 0.87 (0.69, 1.11) and 1.29 (1.03, 1.61), respectively. Similar results were observed in our several sensitivity analyses. Restricted cubic spline analysis demonstrated a nonlinear (similar "J"-shaped) association between serum Mg concentrations and the risk of CKD (Pnonlinearity <0.001), with a threshold at around a serum Mg value of 2.2 mg/dL. CONCLUSIONS: Our results suggested a similar "J"-shaped association between serum Mg concentration and the risk of CKD among Chinese adults. Further large prospective studies are needed to verify these findings.

Collagen prolyl 4-hydroxylase subunit α member-induced head and neck squamous cell carcinoma aggressiveness is antagonized by LLGL2 via reduced expression of occludin.

There are three isoforms of human collagen prolyl 4-hydroxylases (C-P4Hs), each of which has been reported to play an important role in regulating the progression of a variety of human cancers. By analyzing TGCA datasets on human head and neck squamous cell carcinoma (HNSC), we find that a higher expression of all three C-P4HAs (the α subunit of C-P4Hs) is a superior prognostic indicator than a higher expression of two or a single C-P4HA. Unexpectedly, some patients with higher levels of three C-P4HAs survive longer than patients whose tumors have lower expression of C-P4HAs. Therefore, there may be molecule(s) that can negate the deleterious effects of overexpressing C-P4HAs during cancer progression. By constructing a functional protein interaction network of C-P4HAs and analyzing molecules whose expressions are correlated significantly with that of C-P4HAs, we identify scribble cell polarity complex component 2 (LLGL2) as a factor that antagonizes the effects of overexpressed C-P4HAs on HNSC. Silencing of LLGL2 in the human oral squamous cell line Cal-27 upregulates the expression of occludin and increases cancer cell invasion and migration. In contrast, knocking down C-P4HA alone inhibits cell migration and invasion. Furthermore, simultaneously downregulating three C-P4HAs has more pronounced effects on inhibiting cell migration and invasion. Accordingly, high LLGL2 expression is also a marker indicating improved prognosis in patients with HNSC. These results suggest that the interplay between LLGL2 and C-P4HAs may be targeted to mitigate HNSC tumorigenesis and progression.

Triazine herbicide reduced the toxicity of the harmful dinoflagellate Karenia mikimotoi by impairing its photosynthetic systems.

Triazine herbicides are common contaminants in coastal waters, and they are recognized as inhibitors of photosystem II, causing significant hinderance to the growth and reproduction of phytoplankton. However, the influence of these herbicides on microalgal toxin production remains unclear. This study aimed to examine this relationship by conducting a comprehensive physiological and 4D label-free quantitative proteomic analysis on the harmful dinoflagellate Karenia mikimotoi in the presence of the triazine herbicide dipropetryn. The findings demonstrated a significant decrease in photosynthetic activity and pigment content, as well as reduced levels of unsaturated fatty acids, reactive oxygen species (ROS), and hemolytic toxins in K. mikimotoi when exposed to dipropetryn. The proteomic analysis revealed a down-regulation in proteins associated with photosynthesis, ROS response, and energy metabolism, such as fatty acid biosynthesis, chlorophyll metabolism, and nitrogen metabolism. In contrast, an up-regulation of proteins related to energy-producing processes, such as fatty acid ß-oxidation, glycolysis, and the tricarboxylic acid cycle, was observed. This study demonstrated that dipropetryn disrupts the photosynthetic systems of K. mikimotoi, resulting in a notable decrease in algal toxin production. These findings provide valuable insights into the underlying mechanisms of toxin production in toxigenic microalgae and explore the potential effect of herbicide pollution on harmful algal blooms in coastal environments.

Association of urinary and seminal plasma vanadium concentrations with semen quality: A repeated-measures study of 1135 healthy men.

Although animal studies have shown the reproductive toxicity of vanadium, less is known about its effects on semen quality in humans. Among 1135 healthy men who were screened as potential semen donors, we investigated the relationships of semen quality with urinary and seminal plasma vanadium levels via inductively coupled plasma-mass spectrometry (ICP-MS). Spearman rank correlation tests and linear regression models were used to assess the correlations between average urinary and within-individual pooled seminal plasma vanadium concentrations (n = 1135). We utilized linear mixed-effects models to evaluate the associations of urinary and seminal plasma vanadium levels (n = 1135) with repeated sperm quality parameters (n = 5576). Seminal plasma vanadium concentrations were not significantly correlated with urinary vanadium concentrations (r = 0.03). After adjusting for possible confounders, we observed inverse relationships of within-individual pooled seminal plasma vanadium levels with total count, semen volume, and sperm concentration (all P values for trend < 0.05). Specifically, subjects in the highest (vs. lowest) tertile of seminal plasma vanadium concentrations had - 11.3% (-16.4%, -5.9%), - 11.1% (-19.1%, -2.4%), and - 20.9% (-29.0%, -11.8%) lower sperm volume, concentration, and total count, respectively; moreover, urinary vanadium levels appeared to be negatively associated with sperm motility. These relationships showed monotonically decreasing dose-response patterns in the restricted cubic spline analyses. Our results demonstrated a poor correlation between urinary and seminal plasma levels of vanadium, and elevated vanadium concentrations in urine and seminal plasma may be adversely related to male semen quality.

Anatomic versus Low Tibial Tunnel in Double-Bundle Posterior Cruciate Ligament Reconstruction: Clinical and Radiologic Outcomes with a Minimum 2-Year Follow-Up.

There is currently no consensus on the optimal placement of the tibial tunnel for double-bundle posterior cruciate ligament (PCL) reconstruction. The purpose of this study was to compare the clinical and radiologic outcomes of double-bundle PCL reconstruction utilizing anatomic versus low tibial tunnels. We conducted a retrospective cohort study involving patients who underwent double-bundle PCL reconstruction between Jan 2019 and Jan 2022, with a minimum follow-up of 2 years (n = 36). Based on the tibial tunnel position on postoperative computed tomography, patients were categorized into two groups: anatomic placement (group A; n = 18) and low tunnel placement (group L; n = 18). We compared the range of motion, stability test, complications, and side-to-side differences in tibial posterior translation using kneeling stress radiography between the two groups. There were no significant differences between the groups regarding clinical outcomes or complication rates. No significant differences in the posterior drawer test and side-to-side difference on kneeling stress radiography (2.5 ± 1.2 mm in group A vs. 3.7 ± 2.0 mm in group L; p = 0.346). In conclusion, the main findings of this study indicate that both anatomic tunnel and low tibial tunnel placements in double-bundle PCL reconstruction demonstrated comparable and satisfactory clinical and radiologic outcomes, with similar overall complication rates at the 2-year follow-up.

Substrate-Controlled Catalysis in the Ether Cross-Link-Forming Radical SAM Enzymes.

Darobactin is a heptapeptide antibiotic featuring an ether cross-link and a C-C cross-link, and both cross-links are installed by a radical S-adenosylmethionine (rSAM) enzyme DarE. How a single DarE enzyme affords the two chemically distinct cross-links remains largely obscure. Herein, by mapping the biosynthetic landscape for darobactin-like RiPP (daropeptide), we identified and characterized two novel daropeptides that lack the C-C cross-link present in darobactin and instead are solely composed of ether cross-links. Phylogenetic and mutagenesis analyses reveal that the daropeptide maturases possess intrinsic multifunctionality, catalyzing not only the formation of ether cross-link but also C-C cross-linking and Ser oxidation. Intriguingly, the different chemical outcomes are controlled by the exact substrate motifs. Our work not only provides a roadmap for the discovery of new daropeptide natural products but also offers insights into the regulatory mechanisms that govern these remarkably versatile ether cross-link-forming rSAM enzymes.