Acid Peptide Research Articles

Adipose‑derived stem cell‑mediated alphastatin targeting delivery system inhibits angiogenesis and tumor growth in glioma.

Malignant glioma is a highly vascularized tumor. Therefore, inhibition of angiogenesis is an effective treatment strategy for it. Alphastatin is a 24‑amino acid peptide that has been demonstrated to inhibit glioma angiogenesis and tumor growth. Adipose‑derived stem cells (ADSCs) are considered an ideal targeted drug delivery system for glioma therapy due to their targeted tropism for cancer and the intrinsic attribute of autologous transplantation. The aim of the present study was to construct an ADSC‑mediated alphastatin targeted delivery system and investigate its effects on angiogenesis in glioma. The sequence encoding the human neurotrophin‑4 signal peptide and alphastatin fusion gene fragment was transferred into ADSCs using a lentiviral vector to construct the ADSC‑mediated alphastatin targeted delivery system (Al‑ADSCs). Flow cytometry was used to detect the stem cell surface markers of Al‑ADSCs. Western blot analysis and ELISA were used to detect the expression and secretion of alphastatin peptide in Al‑ADSCs. Cell migration assay was used to detect the tendency of Al‑ADSCs to target CD133+ glioma stem cells (GSCs). The effects of Al‑ADSCs on angiogenesis invitro were detected by tube formation assay. A Cell Counting Kit‑8 assay was used to detect the effects of Al‑ADSCs on endothelial cell (EC) proliferation. Wound healing assay was used to examine the effects of Al‑ADSCs on EC migration. Intracranial xenograft models were constructed and invivo fluorescence imaging was used to examine the effects of Al‑ADSCs on glioma growth. Fluorescence microscopy was used to detect the distribution of Al‑ADSCs in glioma tissue and CD133 immunofluorescence staining was used to detect the effects of Al‑ADSCs on GSCs in glioma tissue. The results revealed that ADSCs exhibited more marked tropism to GSCs than to other types of cells (P<0.01). Al‑ADSCs maintained the surface markers of ADSCs and there was no significant difference between the ADSCs and Al‑ADSCs regarding tropism to GSCs (P=0.639 for GSCs‑SHG44 cells; and P=0.386 for GSCs‑U87 cells). Al‑ADSCs were able to successfully secrete and express alphastatin peptide and inhibited EC‑mediated angiogenesis (P<0.01) and EC migration (P<0.01) and proliferation (P<0.01) invitro. Invivo, Al‑ADSCs were detected in glioma tissue and were able to inhibit tumor growth. In addition, the Al‑ADSCs reduced the number of GSCs and microvascular density (P<0.01) in the tumors. Overall, the results of the present study indicated that the Al‑ADSCs were able to target glioma tissue and inhibit glioma angiogenesis and tumor growth. This anti‑angiogenic targeted therapy system may provide a new strategy for the treatment of glioma.

Structure guided mimicry of an essential P. falciparum receptor-ligand complex enhances cross neutralizing antibodies

Invasion of human erythrocytes by Plasmodium falciparum (Pf) merozoites relies on the interaction between two parasite proteins: apical membrane antigen 1 (AMA1) and rhoptry neck protein 2 (RON2). While antibodies to AMA1 provide limited protection against Pf in non-human primate malaria models, clinical trials using recombinant AMA1 alone (apoAMA1) yielded no protection due to insufficient functional antibodies. Immunization with AMA1 bound to RON2L, a 49-amino acid peptide from its ligand RON2, has shown superior protection by increasing the proportion of neutralizing antibodies. However, this approach relies on the formation of a complex in solution between the two vaccine components. To advance vaccine development, here we engineered chimeric antigens by replacing the AMA1 DII loop, displaced upon ligand binding, with RON2L. Structural analysis confirmed that the fusion chimera (Fusion-FD12) closely mimics the binary AMA1-RON2L complex. Immunization studies in female rats demonstrated that Fusion-FD12 immune sera, but not purified IgG, neutralized vaccine-type parasites more efficiently compared to apoAMA1, despite lower overall anti-AMA1 titers. Interestingly, Fusion-FD12 immunization enhanced antibodies targeting conserved epitopes on AMA1, leading to increased neutralization of non-vaccine type parasites. Identifying these cross-neutralizing antibody epitopes holds promise for developing an effective, strain-transcending malaria vaccine.

Microvascular Endothelial Function Assessed Using Peripheral Arterial Tonometry in Adolescents with Repaired Congenital Heart Disease.

Atherosclerosis can develop in adult patients with congenital heart disease (CHD) and should be given attention. Endothelial function is well known as a predictor of the development of atherosclerosis but has not been well investigated in patients with repaired CHD. This study aimed to clarify the endothelial function and its relationship with clinical backgrounds and parameters in adolescents with various types of repaired CHDs. Endothelial function was evaluated using peripheral arterial tonometry (PAT). The reactive hyperemia index (RHI) was evaluated and compared between adolescents with repaired CHD and those in the control group. The relationship between the clinical background and parameters was also investigated in patients with repaired CHD. Forty-eight patients with repaired CHD (age 14.0 ± 3.3 years) and 114 healthy volunteers were included in this study. Patients with repaired CHD comprised 16 with repaired non-cyanotic CHD, 14 with repaired tetralogy of Fallot, and 18 who underwent the Fontan procedure. RHI in the repaired CHD group was significantly lower than in the control group. There was no significant correlation between the RHI and blood biochemical markers, such as uric acid, creatine, and brain natriuretic peptide levels. The RHI was significantly higher in patients taking angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) than in those not taking them. Endothelial function was impaired in adolescents with repaired CHD compared to that in the control group. Microvascular endothelial dysfunction developed even in adolescents with simple non-cyanotic CHD.

Long-Circulating Lipid Nanospheres Loaded with Flurbiprofen Axetil for Targeted Rheumatoid Arthritis Treatment.

Flurbiprofen axetil (FA) is a non-steroidal anti-inflammatory drug with good analgesic and anti-inflammatory effects. However, it suffers from poor solubility, short circulation time, and off-target binding profile, which significantly limit its clinical application. Here, we loaded FA into stealth lipid microspheres modified with the arginine-glycine-aspartic acid (RGD) peptide (cRGD-FA-SLM), and examined the therapeutic potential of the resulting platform for the treatment of rheumatoid arthritis (RA). cRGD-FA-SLM was prepared by high pressure homogenization, and its toxicity and uptake by macrophages were examined using cultures of RAW264.7 cells. Hemolysis and hepatotoxicity tests were performed to assess the safety of the developed platform, while its pharmacokinetics, biodistribution, and therapeutic efficacy were investigated in a collagen-induced arthritis rat model. cRGD-FA-SLM showed homogeneous spherical morphology and efficient encapsulation of FA. The developed platform was non-toxic to normal macrophages and was selectively internalized by lipopolysaccharide-activated macrophages in vitro, while it distributed mainly to arthritic joints and significantly prolonged FA in circulation in vivo. cRGD-FA-SLM also significantly reduced the expression of prostaglandin E2 and alleviated joint edema and bone erosion, showing prolonged analgesic effects in arthritic rats. cRGD-FA-SLM shows good inflammation-targeting ability and prolongs drug circulation in vivo, suggesting promise as an anti-inflammatory and analgesic agent for targeted RA treatment.

Student Competition (Knowledge Generation) ID 1987946

Background/Objectives NX210c is a 12-amino acid peptide derived from conserved thrombospondin type 1 repeat sequences in the subcommissural organ-spondin, which has a unique multifunctional mechanism of action to ameliorate outcomes following neurological injuries. The aim of this study was to evaluate the efficacy of NX210c to promote functional recovery and tissue repair in a cervical traumatic spinal cord injury (SCI) model. Methods/Overview Adult female Wistar rats were subjected to a C6/C7 clip compression-contusion injury and treated once daily with intraperitoneal injections of NX210c (8 mg/kg) or its vehicle for 8 weeks, beginning 4 hours (h) or 8h post-injury (n=16-17/group), with concurrent neurobehavioural tests. Results Earlier NX210c administration at 4h increased forelimb grip strength (p&amp;lt;0.05) and improved several static and dynamic aspects of locomotion including regularity index and base of support of the forelimbs (CatWalk) (p&amp;lt;0.05). Delaying initial administration of NX210c to 8h, promoted weight gain, accelerated bladder control recovery from 14 to 9 days post-injury, and improved trunk balance (inclined plane) as early as one-week post-injury (p&amp;lt;0.05). 94% of NX210c-treated rats compared to 75% of vehicle controls observed weight support at the delayed initial injection timepoint. Histology (n=6/group) demonstrated greater white matter preservation and reduced cavity size at the injury epicenter, and higher neuronal soma counts caudally, with NX210c starting 8h post-injury compared to the vehicle (p&amp;lt;0.05). Conclusions NX210c targets various aspects of SCI, improving motor function, bladder control, white matter preservation, and neuronal counts, with more benefits observed at the later initial injection timepoint.

Intranasal neuropeptide Y1 receptor antagonism improves motor deficits in symptomatic SOD1 ALS mice.

Neuropeptide Y (NPY) is a 36 amino acid peptide widely considered to provide neuroprotection in a range of neurodegenerative diseases. In the fatal motor neuron disease amyotrophic lateral sclerosis (ALS), recent evidence supports a link between NPY and ALS disease processes. The goal of this study was to determine the therapeutic potential and role of NPY in ALS, harnessing the brain-targeted intranasal delivery of the peptide, previously utilised to correct motor and cognitive phenotypes in other neurological conditions. To confirm the association with clinical disease characteristics, NPY expression was quantified in post-mortem motor cortex tissue of ALS patients and age-matched controls. The effect of NPY on ALS cortical pathophysiology was investigated using slice electrophysiology and multi-electrode array recordings of SOD1G93A cortical cultures in vitro. The impact of NPY on ALS disease trajectory was investigated by treating SOD1G93A mice intranasally with NPY and selective NPY receptor agonists and antagonists from pre-symptomatic and symptomatic phases of disease. In the human post-mortem ALS motor cortex, we observe a significant increase in NPY expression, which is not present in the somatosensory cortex. In vitro, we demonstrate that NPY can ameliorate ALS hyperexcitability, while brain-targeted nasal delivery of NPY and a selective NPY Y1 receptor antagonist modified survival and motor deficits specifically within the symptomatic phase of the disease in the ALS SOD1G93A mouse. Taken together, these findings highlight the capacity for non-invasive brain-targeted interventions in ALS and support antagonism of NPY Y1Rs as a novel strategy to improve ALS motor function.

Characterization and Classification In Silico of Peptides with Dual Activity (Antimicrobial and Wound Healing).

The growing challenge of chronic wounds and antibiotic resistance has spotlighted the potential of dual-function peptides (antimicrobial and wound healing) as novel therapeutic strategies. The investigation aimed to characterize and correlate in silico the physicochemical attributes of these peptides with their biological activity. We sourced a dataset of 207 such peptides from various peptide databases, followed by a detailed analysis of their physicochemical properties using bioinformatic tools. Utilizing statistical tools like clustering, correlation, and principal component analysis (PCA), patterns and relationships were discerned among these properties. Furthermore, we analyzed the peptides' functional domains for insights into their potential mechanisms of action. Our findings spotlight peptides in Cluster 2 as efficacious in wound healing, whereas Cluster 1 peptides exhibited pronounced antimicrobial potential. In our study, we identified specific amino acid patterns and peptide families associated with their biological activities, such as the cecropin antimicrobial domain. Additionally, we found the presence of polar amino acids like arginine, cysteine, and lysine, as well as apolar amino acids like glycine, isoleucine, and leucine. These characteristics are crucial for interactions with bacterial membranes and receptors involved in migration, proliferation, angiogenesis, and immunomodulation. While this study provides a groundwork for therapeutic development, translating these findings into practical applications necessitates additional experimental and clinical research.

A Multifunctional Delivery System for Remodulating Cell Behaviors of Circulating Malignant Cells to Prevent Cell Fusion.

Cell fusion plays a critical role in cancer progression and metastasis. However, effective modulation of the cell fusion behavior and timely evaluation on the cell fusion to provide accurate information for personalized therapy are facing challenges. Here, it demonstrates that the cancer cell fusion behavior can be efficiently modulated and precisely detected through employing a multifunctional delivery vector to realize cancer targeting delivery of a genome editing plasmid and a molecular beacon-based AND logic gate. The multifunctional delivery vector decorated by AS1411 conjugated hyaluronic acid and NLS-GE11 peptide conjugated hyaluronic acid can specifically target circulating malignant cells (CMCs) of cancer patients to deliver the genome editing plasmid for epidermal growth factor receptor (EGFR) knockout. The cell fusion between CMCs and endothelial cells can be detected by the AND logic gate delivered by the multifunctional vector. After EGFR knockout, the edited CMCs exhibit dramatically inhibited cell fusion capability, while unedited CMCs can easily fuse with human umbilical vein endothelial cells (HUVEC) to form hybrid cells. This study provides a new therapeutic strategy for preventing cancer progression and a reliable tool for evaluating cancer cell fusion for precise personalized therapy.

Alveolar epithelial cell growth hormone releasing hormone receptor in alveolar epithelial inflammation

Purpose: Growth hormone-releasing hormone (GHRH) is a 44-amino acid peptide that regulates growth hormone (GH) secretion. We hypothesized that GHRH receptor (GHRH-R) in alveolar type 2 (AT2) cells could modulate pro-inflammatory and possibly subsequent pro-fibrotic effects of lipopolysaccharide (LPS) or cytokines, such that AT2 cells could participate in lung inflammation and fibrosis. Methods: We used human alveolar type 2 (iAT2) epithelial cells derived from induced pluripotent stem cells (iPSC) to investigate how GHRH-R modulates gene and protein expression. We tested iAT2 cells’ gene expression in response to LPS or cytokines, seeking whether these mechanisms caused endogenous production of pro-inflammatory molecules or mesenchymal markers. Quantitative real-time PCR (RT-PCR) and Western blotting were used to investigate differential expression of epithelial and mesenchymal markers. Result: Incubation of iAT2 cells with LPS increased expression of IL1-β and TNF-α in addition to mesenchymal genes, including ACTA2, FN1 and COL1A1. Alveolar epithelial cell gene expression due to LPS was significantly inhibited by GHRH-R peptide antagonist MIA-602. Incubation of iAT2 cells with cytokines like those in fibrotic lungs similarly increased expression of genes for IL1-β, TNF-α, TGFβ-1, Wnt5a, smooth muscle actin, fibronectin and collagen. Expression of mesenchymal proteins, such as N-cadherin and vimentin, were also elevated after prolonged exposure to cytokines, confirming epithelial production of pro-inflammatory molecules as an important mechanism that might lead to subsequent fibrosis. Conclusion: iAT2 cells clearly expressed the GHRH-R. Exposure to LPS or cytokines increased iAT2 cell production of pro-inflammatory factors. GHRH-R antagonist MIA-602 inhibited pro-inflammatory gene expression, implicating iAT2 cell GHRH-R signaling in lung inflammation and potentially in fibrosis.

Semenogelins Armed in Zn(II) and Cu(II): May Bioinorganic Chemistry Help Nature to Cope with Enterococcus faecalis?

Proteolytic degradation of semenogelins, the most abundant proteins from human semen, results in the formation of 26- and 29-amino acid peptides (SgIIA and SgI-29, respectively), which share a common 15 amino acid fragment (Sg-15). All three ligands are effective Zn(II) and Cu(II) binders; in solution, a variety of differently metalated species exist in equilibrium, with the [NH2, 3Nim] donor set prevailing at physiological pH in the case of both metals. For the first time, the Cu(II)-induced antimicrobial activity of Sg-15 against Enterococcus faecalis is shown. In the case of the two native semenogelin fragment metal complexes, the strong local positive charge in the metal-bound HH motif correlates well with their antimicrobial activity. A careful analysis of semenogelins' metal coordination behavior reveals two facts: (i) The histamine-like Cu(II) binding mode of SgI-29 strongly increases the stability of such a complex below pH 6 (with respect to the non-histamine-like binding of SgIIA), while in the case of the SgI-29 Zn(II)-histamine-like species, the stability enhancement is less pronounced. (ii) The HH sequence is a more tempting site for Cu(II) ions than the HXH one.

GV1001 Inhibits the Severity of the Ligature-Induced Periodontitis and the Vascular Lipid Deposition Associated with the Periodontitis in Mice.

GV1001, a 16 amino acid peptide derived from the catalytic segment of human telomerase reverse transcriptase, was developed as an anti-cancer vaccine. Subsequently, it was found to exhibit anti-inflammatory and anti-Alzheimer's disease properties. Periodontitis is a risk factor for a variety of systemic diseases, including atherosclerosis, a process in which chronic systemic and vascular inflammation results in the formation of plaques containing lipids, macrophages, foam cells, and tissue debris on the vascular intima. Thus, we investigated the effect of GV1001 on the severity of ligature-induced periodontitis, vascular inflammation, and arterial lipid deposition in mice. GV1001 notably reduced the severity of ligature-induced periodontitis by inhibiting gingival and systemic inflammation, alveolar bone loss, and vascular inflammation in wild-type mice. It also significantly lowered the amount of lipid deposition in the arterial wall in ApoE-deficient mice receiving ligature placement without changing the serum lipid profile. In vitro, we found that GV1001 inhibited the Receptor Activator of NF-κB ligand (RANKL)-induced osteoclast formation and tumor necrosis factor-α (TNF-α)-induced phenotypic changes in endothelial cells. In conclusion, our study suggests that GV1001 prevents the exacerbation of periodontitis and atherosclerosis associated with periodontitis partly by inhibiting local, systemic, and vascular inflammation and phenotypic changes of vascular endothelial cells.

Abstract P3183: Cardiac Troponin I Directly Binds Mitochondrial Proteins And Inhibits Mitochondrial Functions

The heart relies on mitochondria for its extensive energetic demands, and some cytoskeletal elements can regulate mitochondrial function. Cardiac troponin I (cTnI) is a structural protein involved in sarcomeric contraction. Here we demonstrate that some cTnI localizes to mitochondria, inhibits mitochondrial functions, and increases opening of the mitochondrial permeability transition pore under oxidative stress. Purified cTnI directly binds immune-captured ATP synthase in saturable fashion and doubles "reverse" F 1 F 0 -ATPase activity in vitro , whereas skeletal troponin I (ssTnI) does not. Relevant to human disease, several pathogenic variants of cTnI associated with hypertrophic cardiomyopathy do not increase F 1 F 0 -ATPase activity. Using a rational search, we identified the d subunit of ATP synthase as a potential cTnI-binding partner, and a ten-amino acid peptide inhibitor of cTnI’s interaction with ATP synthase, peptide P888, inhibited cTnI binding to ATP synthase and abolished the cTnI-induced increase in ATPase activity. P888 treatment greatly reduced cardiac LDH release and improved fractional shortening in vivo after transient coronary artery occlusion in rats, indicating that mitochondrial cTnI exacerbates cardiac ischemia-reperfusion injury. We explore the mechanisms governing cTnI’s mitochondrial localization and additional mitochondrial binding partners for cTnI. Together, our studies suggest that mitochondria-associated cTnI inhibits ATP synthase under basal conditions. Preventing cTnI from binding to ATP synthase during cardiac ischemia may increase the reservoir of functional mitochondria to mitigate post-ischemic cardiac injury. We also suggest that cTnI has additional roles in regulating mitochondrial functions. Finally, pathogenic cTnI mutations associated with hypertrophic cardiomyopathy do not affect ATP synthase activity, suggesting a potential mechanism that contributes to the diverse pathologies associated with these mutations.

Use of Chitosan from Southern King Crab to Develop Films Functionalized with RGD Peptides for Potential Tissue Engineering Applications.

Southern King Crab (SKC) represents an important fishery resource that has the potential to be a natural source of chitosan (CS) production. In tissue engineering, CS is very useful to generate biomaterials. However, CS has a lack of signaling molecules that facilitate cell-substrate interaction. Therefore, RGD (arginine-glycine-aspartic acid) peptides corresponding to the main integrin recognition site in extracellular matrix proteins have been used to improve the CS surface. The aim of this study was to evaluate in vitro cell adhesion and proliferation of CS films synthesized from SKC shell wastes functionalized with RGD peptides. The FTIR spectrum of CS isolated from SKC shells (SKC-CS) was comparable to commercial CS. Thermal properties of films showed similar endothermic peaks at 53.4 and 53.0 °C in commercial CS and SKC-CS, respectively. The purification and molecular masses of the synthesized RGD peptides were confirmed using HPLC and ESI-MS mass spectrometry, respectively. Mouse embryonic fibroblast cells showed higher adhesion on SKC-CS (1% w/v) film when it was functionalized with linear RGD peptides. In contrast, a cyclic RGD peptide showed similar adhesion to control peptide (RDG), but the highest cell proliferation was after 48 h of culture. This study shows that functionalization of SKC-CS films with linear or cyclic RGD peptides are useful to improve effects on cell adhesion or cell proliferation. Furthermore, our work contributes to knowledge of a new source of CS to synthesize constructs for tissue engineering applications.

Self-assembled and Zn(II)-coordinated dipeptide nanoparticles with membrane-rupturing action on bacteria.

Metal ion-coordinated self-assembled short-chain amino acid peptide molecules with multi-photon excitation wavelengths and their photoluminescence properties are advantageous for fluorescence-based diagnostics and treatments of biological diseases based on their extra features of antibacterial agents. We have designed a novel strategy based on tryptophan molecule coordinated with Zn(II) ions in the form of biocompatible spherical nanoparticles of diameter 30-80nm which have been used for antibacterial treatments against different kinds of pathogenic bacteria (Escherichia coli, Salmonella typhimurium, and Pseudomonas). Preferably, we have used tryptophan-phenylalanine (Trp-Phe), a dipeptide molecule having tryptophan as principal material against E. coli strains as antimicrobial agents for surface rupturing and killing purposes. Furthermore, based on single amino acid, tryptophan, self-assembled and Zn(II)-coordinated dipeptide nanoparticles (Zn-DPNPs) were studied against three types of multi-drug-resistant bacteria as an active antimicrobial agent. These antibacterial efficient nanoparticles may have best alternative of antibiotic drugs for clinical applications. The capability of self-assembled fluorescence behavior of Zn-coordinated dipeptide molecules and higher hydrophobicity against bacterial cell wall will perform as antimicrobial fluorescent agents. KEY POINTS: • Zn(II) and Cu(II) better coordinated into self-assembled NPs. • Fluorescence signals showed interaction of NPs with gram-ve cell wall. • Significant surface-damaging effects were observed in the case of Cu-DPNPs and Zn-DPNPs.

Optimizing animal models of autoimmune encephalitis using active immunization.

Encephalitis is a devastating neurologic disorder with high morbidity and mortality. Autoimmune causes are roughly as common as infectious ones. N-methyl-D-aspartic acid receptor (NMDAR) encephalitis (NMDARE), characterized by serum and/or spinal fluid NMDAR antibodies, is the most common form of autoimmune encephalitis (AE). A translational rodent NMDARE model would allow for pathophysiologic studies of AE, leading to advances in the diagnosis and treatment of this debilitating neuropsychiatric disorder. The main objective of this work was to identify optimal active immunization conditions for NMDARE in mice. Female C57BL/6J mice aged 8 weeks old were injected subcutaneously with an emulsion of complete Freund's adjuvant, killed and dessicated Mycobacterium tuberculosis, and a 30 amino acid peptide flanking the NMDAR GluN1 subunit N368/G369 residue targeted by NMDARE patients' antibodies. Three different induction methods were examined using subcutaneous injection of the peptide emulsion mixture into mice in 1) the ventral surface, 2) the dorsal surface, or 3) the dorsal surface with reimmunization at 4 and 8 weeks (boosted). Mice were bled biweekly and sacrificed at 2, 4, 6, 8, and 14 weeks. Serum and CSF NMDAR antibody titer, mouse behavior, hippocampal cell surface and postsynaptic NMDAR cluster density, and brain immune cell entry and cytokine content were examined. All immunized mice produced serum and CSF NMDAR antibodies, which peaked at 6 weeks in the serum and at 6 (ventral and dorsal boosted) or 8 weeks (dorsal unboosted) post-immunization in the CSF, and demonstrated decreased hippocampal NMDAR cluster density by 6 weeks post-immunization. In contrast to dorsally-immunized mice, ventrally-induced mice displayed a translationally-relevant phenotype including memory deficits and depressive behavior, changes in cerebral cytokines, and entry of T-cells into the brain at the 4-week timepoint. A similar phenotype of memory dysfunction and anxiety was seen in dorsally-immunized mice only when they were serially boosted, which also resulted in higher antibody titers. Our study revealed induction method-dependent differences in active immunization mouse models of NMDARE disease. A novel ventrally-induced NMDARE model demonstrated characteristics of AE earlier compared to dorsally-induced animals and is likely suitable for most short-term studies. However, boosting and improving the durability of the immune response might be preferred in prolonged longitudinal studies.

Lithio Tris(methylthio)methane as Hydroxy/Thio/Aminocarbonyl Anion Equivalent: Asymmetric Synthesis of α-Amino Acid Esters, Thioesters, Amides, and Peptides.

The use of lithio tris(methylthio)methane as a hydroxy/thio/amino carbonyl anion equivalent in the synthesis of α-amino acids is reported. Addition of the reagent to nonracemic sulfinimines furnished the α-sulfinamido trithioformates in excellent diastereoselectivity. Unmasking the trithioformates to diverse functionalities, such as α-amino acid thioesters, esters, anilides, amides, and di/tri peptides, without epimerization of chiral centers was accomplished.

Alternative splicing of TaHSFA6e modulates heat shock protein-mediated translational regulation in response to heat stress in wheat.

Heat stress greatly threatens crop production. Plants have evolved multiple adaptive mechanisms, including alternative splicing, that allow them to withstand this stress. However, how alternative splicing contributes to heat stress responses in wheat (Triticum aestivum) is unclear. We reveal that the heat shock transcription factor gene TaHSFA6e is alternatively spliced in response to heat stress. TaHSFA6e generates two major functional transcripts: TaHSFA6e-II and TaHSFA6e-III. TaHSFA6e-III enhances the transcriptional activity of three downstream heat shock protein 70 (TaHSP70) genes to a greater extent than does TaHSFA6e-II. Further investigation reveals that the enhanced transcriptional activity of TaHSFA6e-III is due to a 14-amino acid peptide at its C-terminus, which arises from alternative splicing and is predicted to form an amphipathic helix. Results show that knockout of TaHSFA6e or TaHSP70s increases heat sensitivity in wheat. Moreover, TaHSP70s are localized in stress granule following exposure to heat stress and are involved in regulating stress granule disassembly and translation re-initiation upon stress relief. Polysome profiling analysis confirms that the translational efficiency of stress granule stored mRNAs is lower at the recovery stage in Tahsp70s mutants than in the wild types. Our finding provides insight into the molecular mechanisms by which alternative splicing improves the thermotolerance in wheat.

Potential of Negative-Ion-Mode Proteomics: An MS1-Only Approach.

Current proteomics approaches rely almost exclusively on using the positive ionization mode, resulting in inefficient ionization of many acidic peptides. This study investigates protein identification efficiency in the negative ionization mode using the DirectMS1 method. DirectMS1 is an ultrafast data acquisition method based on accurate peptide mass measurements and predicted retention times. Our method achieves the highest rate of protein identification in the negative ion mode to date, identifying over 1000 proteins in a human cell line at a 1% false discovery rate. This is accomplished using a single-shot 10 min separation gradient, comparable to lengthy MS/MS-based analyses. Optimizing separation and experimental conditions was achieved by utilizing mobile buffers containing 2.5 mM imidazole and 3% isopropanol. The study emphasized the complementary nature of data obtained in positive and negative ion modes. Combining the results from all replicates in both polarities increased the number of identified proteins to 1774. Additionally, we analyzed the method's efficiency using different proteases for protein digestion. Among the four studied proteases (LysC, GluC, AspN, and trypsin), trypsin and LysC demonstrated the highest protein identification yield. This suggests that digestion procedures utilized in positive-mode proteomics can be effectively applied in the negative ion mode. Data are deposited to ProteomeXchange: PXD040583.

Comprehensive Phytochemical Analysis and Bioactivity Evaluation of Padina boergesenii: Unveiling Its Prospects as a Promising Cosmetic Component.

Marine macroalgae, such as Padina boergesenii, are gaining recognition in the cosmetics industry as valuable sources of natural bioactive compounds. This study aimed to investigate the biochemical profile of P. boergesenii and evaluate its potential as a cosmetic ingredient. Fourier-transform infrared (FTIR), gas chromatography-mass spectrometry (GCMS), and high-resolution liquid chromatography-mass spectrometry quadrupole time-of-flight (HRLCMS QTOF) analyses were employed to assess the functional groups, phycocompounds, and beneficial compounds present in P. boergesenii. Pigment estimation, total phenol and protein content determination, DPPH antioxidant analysis, and tyrosinase inhibition assay were conducted to evaluate the extracts' ability to counteract oxidative stress and address hyperpigmentation concerns. Elemental composition and amino acid quantification were determined using inductively coupled plasma atomic emission spectrometry (ICP-AES) and HRLCMS, respectively. FTIR spectroscopy confirmed diverse functional groups, including halo compounds, alcohols, esters, amines, and acids. GCMS analysis identified moisturizing, conditioning, and anti-aging compounds such as long-chain fatty alcohols, fatty esters, fatty acids, and hydrocarbon derivatives. HRLCMS QTOF analysis revealed phenolic compounds, fatty acid derivatives, peptides, terpenoids, and amino acids with antioxidant, anti-inflammatory, and skin-nourishing properties. Elemental analysis indicated varying concentrations of elements, with silicon (Si) being the most abundant and copper (Cu) being the least abundant. The total phenol content was 86.50 µg/mL, suggesting the presence of antioxidants. The total protein content was 113.72 µg/mL, indicating nourishing and rejuvenating effects. The ethanolic extract exhibited an IC50 value of 36.75 μg/mL in the DPPH assay, indicating significant antioxidant activity. The methanolic extract showed an IC50 value of 42.784 μg/mL. Furthermore, P. boergesenii extracts demonstrated 62.14% inhibition of tyrosinase activity. This comprehensive analysis underscores the potential of P. boergesenii as an effective cosmetic ingredient for enhancing skin health. Given the increasing use of seaweed-based bioactive components in cosmetics, further exploration of P. boergesenii's potential in the cosmetics industry is warranted to leverage its valuable properties.

New perspective into possible mechanism in growth promotion of potassium diformate (KDF) on the juvenile grass carp (Ctenopharyngodon idella)

The present study was mainly designed to evaluate the effect of potassium diformate (KDF) on growth performance, digestion and absorption capacity and intestinal microbes of juvenile grass carp (Ctenopharyngodon idella). Six experimental diets with KDF 0.0, 1.5, 3.0, 4.5, 6.0 and 7.5 g/kg were respectively fed to 1620 fish (5.73 ± 0.01 g) for 70 days. Results indicated that dietary KDF addition improved growth performance, intestinal growth and development, digestive enzymes and brush border enzymes activity. Additionally, mRNA levels of most amino acid transporters (AATs) and peptide transporter 1 (PepT1), and protein expressions of SLC7A1, SLC1A5 and SLC15A1 in intestine were up-regulated with addition of 3.0 g/kg KDF, which might be related to the activated TOR signaling pathway, as evident by the up-regulated mRNA levels of TOR and S6K1, the increased protein expression of phosphorylation TORSer2448, as well as the down-regulated mRNA level of 4EBP1. Furthermore, the 16S rRNA sequencing revealed that low dose of KDF addition enriched the abundances of Fusobacteria and Cetobacterium, and reduced the abundances of Proteobacteria and Ralstonia, which might be related to the reduced pH of intestine. In a word, this study using grass carp as a model provided novel evidence on the positive role and possible mechanisms of KDF in promoting fish growth.