Isolation,purification and characterization of naturally derived Crocetin beta-d-glucosyl ester from Crocus sativus L. against breast cancer and its binding chemistry with ER-alpha/HDAC2

Saffron plant (Crocus sativus L.) is being used as a source of saffron spice and medicine to cure or prevent different types of diseases including cancers. We report the isolation, characterization of bioactive small molecule ([crocetin (β-d-glucosyl) ester] from the leaf biowastes of saffron plant of Kashmir, India. MTTC assay and Bio-autography aided approach were used to assess anti-oxidant activity and anti-cancer properties of crocin (s) against DPPH free radical and breast cancer cell line respectively. Crocetin beta-d-glucosyl ester restrained proliferation of human breast adeno-carcinoma cell model (MCF-7) without significantly affecting normal cell line (L-6). Further studies involving molecular mechanics generalized born surface area and molecular docking showed that crocetin beta-d-glucosyl ester exhibits strong affinity for estrogen receptor alpha and histone deacetylase 2 (crucial receptors involved in breast cancer signalling) as evidenced by the negative docking score and binding free energy (BFE) values. Therefore, crocetin beta-d-glucosyl ester from Crocus sativus biowastes showed antiproliferative effect possibly by inhibiting estrogen receptor alpha and HDAC2 mediated signalling cascade.     

Whole exome sequencing,in silico and functional studies confirm the association of the GJB2 mutation p.Cys169Tyr with deafness and suggest a role for the TMEM59 gene in the hearing process

The development of next generation sequencing techniques has facilitated the detection of mutations at an unprecedented rate. These efficient tools have been particularly beneficial for extremely heterogeneous disorders such as autosomal recessive non-syndromic hearing loss, the most common form of genetic deafness. GJB2 mutations are the most common cause of hereditary hearing loss. Amongst them the NM_004004.5: c.506G > A (p.Cys169Tyr) mutation has been associated with varying severity of hearing loss with unclear segregation patterns. In this study, we report a large consanguineous Emirati family with severe to profound hearing loss fully segregating the GJB2 missense mutation p.Cys169Tyr. Whole exome sequencing (WES), in silico, splicing and expression analyses ruled out the implication of any other variants and confirmed the implication of the p.Cys169Tyr mutation in this deafness family. We also show preliminary murine expression analysis that suggests a link between the TMEM59 gene and the hearing process. The present study improves our understanding of the molecular pathogenesis of hearing loss. It also emphasizes the significance of combining next generation sequencing approaches and segregation analyses especially in the diagnosis of disorders characterized by complex genetic heterogeneity.     

Anti-salmonella properties of kefir yeast isolates: An in vitro screening for potential infection control

The rise of antibiotic resistance has increased the need for alternative ways of preventing and treating enteropathogenic bacterial infection. Various probiotic bacteria have been used in animal and human. However, Saccharomyces boulardii is the only yeast currently used in humans as probiotic. There is scarce research conducted on yeast species commonly found in kefir despite its claimed potential preventative and curative effects. This work focused on adhesion properties, and antibacterial metabolites produced by Kluyveromyces lactis and Saccharomyces unisporus isolated from traditional kefir grains compared to Saccharomyces boulardii strains. Adhesion and sedimentation assay, slide agglutination, microscopy and turbidimetry assay were used to analyze adhesion of Salmonella Arizonae and Salmonella Typhimurium onto yeast cells. Salmonella growth inhibition due to the antimicrobial metabolites produced by yeasts in killer toxin medium was analyzed by slab on the lawn, turbidimetry, tube dilution and solid agar plating assays. Alcohol and antimicrobial proteins production by yeasts in killer toxin medium were analyzed using gas chromatography and shotgun proteomics, respectively. Salmonella adhered onto viable and non-viable yeast isolates cell wall. Adhesion was visualized using scanning electron microscope. Yeasts-fermented killer toxin medium showed Salmonella growth inhibition. The highest alcohol concentration detected was 1.55%, and proteins with known antimicrobial properties including cathelicidin, xanthine dehydrogenase, mucin-1, lactadherin, lactoperoxidase, serum amyloid A protein and lactotransferrin were detected in yeasts fermented killer medium. These proteins are suggested to be responsible for the observed growth inhibition effect of yeasts-fermented killer toxin medium. Kluyveromyces lactis and Saccharomyces unisporus have anti-salmonella effect comparable to Saccharomyces boulardii strains, and therefore have potential to control Salmonella infection.     

The Stability Landscape of de novo TIM Barrels Explored by a Modular Design Approach

The ability to design stable proteins with custom-made functions is a major goal in biochemistry with practical relevance for our environment and society. Understanding and manipulating protein stability provide crucial information on the molecular determinants that modulate structure and stability, and expand the applications of de novo proteins. Since the (β/⍺)₈-barrel or TIM-barrel fold is one of the most common functional scaffolds, in this work we designed a collection of stable de novo TIM barrels (DeNovoTIMs), using a computational fixed-backbone and modular approach based on improved hydrophobic packing of sTIM11, the first validated de novo TIM barrel, and subjected them to a thorough folding analysis. DeNovoTIMs navigate a region of the stability landscape previously uncharted by natural TIM barrels, with variations spanning 60 degrees in melting temperature and 22 kcal per mol in conformational stability throughout the designs. Significant non-additive or epistatic effects were observed when stabilizing mutations from different regions of the barrel were combined. The molecular basis of epistasis in DeNovoTIMs appears to be related to the extension of the hydrophobic cores. This study is an important step towards the fine-tuned modulation of protein stability by design.     

Contact toxicity and transcriptomic analysis of terpinen‐4‐ol exposure in Tribolium castaneum

The terpene, terpinen-4-ol (T4ol), exhibits contact toxicity in Tribolium castaneum. However, the molecular mechanisms underlying this toxicity have not been elucidated. This study examined changes in the expression of four classic enzymes after exposure of T. castaneum to T4ol. Acetylcholinesterase and glutathione S-transferase activities were markedly inhibited after exposure to T4ol, while that of the detoxifying enzyme cytochrome oxidase P450 increased markedly. Carboxylesterase activity did not show significant changes. Furthermore, RNA sequencing revealed 260 differentially expressed genes (DEG) between the T4ol-treated and control samples, and qRT-PCR was used to validate the RNA-Seq data. The Gene Ontology analysis classified the DEGs into 36 functional groups, including the immune system processes, response to stimulus, and developmental processes. T4ol altered the response to stimulus and the immune system process of beetles by inducing the expression of the genes Stabilin-1, Attacin 1, and Defensin 1. Furthermore, the DEGs receptor tyrosine kinase Torso-like protein (RTKTsl), Frizzled 4 (Fz4), Protein Wnt-5b, Ecdysone-induced protein 78C (E78), Zinc finger protein GLIS1 (ZFPGLIS1) were classified as participating in beetle development, and Fz4 and Protein Wnt-5b also mapped to the Wnt signaling pathway. This indicated that pathways associated with development are inhibited after exposure to T4ol. T4ol also induced CYP9Z6/GSTs7 overexpression, and RNAi targeting these genes significantly increased larvae mortality on T4ol exposure, supporting the participation of CYP9Z6/GSTs7 in the response to T4ol in T. castaneum. The results of this study will facilitate understanding of the toxic mechanisms of T4ol and provide a basis for controlling the pests of stored products.     

Psidium guajava Linn leaf ethanolic extract: In vivo giardicidal potential with ultrastructural damage,anti-inflammatory and antioxidant effects

Introduction and aimConsidering the magnitude of giardiasis problem, the side-effects of the used anti-giardia drugs and the resistance posed against them, the current study aimed to evaluate the in-vivo giardicidal effect of Psidium guajava leaf extract (PGLE).MethodsFor fulfilling this aim, five Swiss-albino mice groups were included; GI: non-infected, GII: Giardia-infected and non-treated, GIII: Giardia-infected and metronidazole-treated, GIV: Giardia-infected and PGLE-treated, and GV: Giardia-infected and treated with both metronidazole and PGLE. Treatment efficacy was assessed via; Giardia cyst viability and trophozoite count, trophozoite electron microscopic ultrastructure, duodenal histopathological scoring, immunohistochemistry for TNF-α and duodenal scanning electron microscopy. Moreover, mice serum liver enzymes, total bilirubin, albumin, lipid profile including; total cholesterol, HDL, LDL and triglycerides were assessed. Additionally, hepatic oxidative stress markers including; malondialdehyde (MDA), nitric oxide (NO), reduced glutathione (GSH) and superoxide dismutase (SOD) were measured.ResultsResults showed that PGLE whether alone or combined with metronidazole has induced significant trophozoite count reduction and major architectural changes. Duodenal histological improvement, and local protective anti-inflammatory effect were confirmed. PGLE has also helped in healing of Giardia-induced gut atrophy. Thus, offered a comprehensive therapy for both the pathogen and the resultant pathological sequalae. Serum markers showed favorable hepatoprotective effect. Total cholesterol, LDL and triglycerides levels were less in PGLE-treated group than in metronidazole-treated group. Hepatic oxidative stress markers revealed the promising extract antioxidant effect. This study highlights, the promising in-vivo giardicidal PGLE activity, that was comparable to metronidazole, thus, the extract would be an ideal strongly recommended treatment for giardiasis. When combined with metronidazole, the extract potentiated its therapeutic effect. Besides, having hepatoprotective, anti-inflammatory, and antioxidant properties, the extract can combat the major side effects of metronidazole therapy.     

Structure-Function Studies of Two Yeast Homing Endonucleases that Evolved to Cleave Identical Targets with Dissimilar Rates and Specificities

The LAGLIDADG family of homing endonucleases (LHEs) bind to and cleave their DNA recognition sequences with high specificity. Much of our understanding for how these proteins evolve their specificities has come from studying LHE homologues. To gain insight into the molecular basis of LHE specificity, we characterized I-WcaI, the homologue of the Saccharomyces cerevisiae I-SceI LHE found in Wickerhamomyces canadensis. Although I-WcaI and I-SceI cleave the same recognition sequence, expression of I-WcaI, but not I-SceI, is toxic in bacteria. Toxicity suppressing mutations frequently occur at I-WcaI residues critical for activity and I-WcaI cleaves many more non-cognate sequences in the Escherichia coli genome than I-SceI, suggesting I-WcaI endonuclease activity is the basis of toxicity. In vitro, I-WcaI is a more active and a less specific endonuclease than I-SceI, again accounting for the observed toxicity in vivo. We determined the X-ray crystal structure of I-WcaI bound to its cognate target site and found that I-WcaI and I-SceI use residues at different positions to make similar base-specific contacts. Furthermore, in some regions of the DNA interface where I-WcaI specificity is lower, the protein makes fewer DNA contacts than I-SceI. Taken together, these findings demonstrate the plastic nature of LHE site recognition and suggest that I-WcaI and I-SceI are situated at different points in their evolutionary pathways towards acquiring target site specificity.     

Impact on S. aureus and E. coli Membranes of Treatment with Chlorhexidine and Alcohol Solutions: Insights from Molecular Simulations and Nuclear Magnetic Resonance

Membranes form the first line of defence of bacteria against potentially harmful molecules in the surrounding environment. Understanding the protective properties of these membranes represents an important step towards development of targeted anti-bacterial agents such as sanitizers. Use of propanol, isopropanol and chlorhexidine can significantly decrease the threat imposed by bacteria in the face of growing anti-bacterial resistance via mechanisms that include membrane disruption. Here we have employed molecular dynamics simulations and nuclear magnetic resonance to explore the impact of chlorhexidine and alcohol on the S. aureus cell membrane, as well as the E. coli inner and outer membranes. We identify how sanitizer components partition into these bacterial membranes, and show that chlorhexidine is instrumental in this process.     

Generation of hepatoma cell lines deficient in microsomal triglyceride transfer protein

The microsomal triglyceride transfer protein (MTP) is essential for the secretion of apolipoprotein B (apoB)48- and apoB100-containing lipoproteins in the intestine and liver, respectively. Loss of function mutations in MTP cause abetalipoproteinemia. Heterologous cells are used to evaluate the function of MTP in apoB secretion to avoid background MTP activity in liver and intestine-derived cells. However, these systems are not suitable to study the role of MTP in the secretion of apoB100-containing lipoproteins, as expression of a large apoB100 peptide using plasmids is difficult. Here, we report a new cell culture model amenable for studying the role of different MTP mutations on apoB100 secretion. The endogenous MTTP gene was ablated in human hepatoma Huh-7 cells using single guide RNA and RNA-guided clustered regularly interspaced short palindromic repeats-associated sequence 9 ribonucleoprotein complexes. We successfully established three different clones that did not express any detectable MTTP mRNA or MTP protein or activity. These cells were defective in secreting apoB-containing lipoproteins and accumulated lipids. Furthermore, we show that transfection of these cells with plasmids expressing human MTTP cDNA resulted in the expression of MTP protein, restoration of triglyceride transfer activity, and secretion of apoB100. Thus, these new cells can be valuable tools for studying structure-function of MTP, roles of different missense mutations in various lipid transfer activities of MTP, and their ability to support apoB100 secretion, compensatory changes associated with loss of MTP, and in the identification of novel proteins that may require MTP for their synthesis and secretion.     

Towards Molecular Understanding of the pH Dependence Characterizing NhaA of Which Structural Fold is Shared by Other Transporters

Na⁺/H⁺ antiporters comprise a super-family (CPA) of membrane proteins that are found in all kingdoms of life and are essential in cellular homeostasis of pH, Na⁺ and volume. Their activity is strictly dependent on pH, a property that underpins their role in pH homeostasis. While several human homologues have long been drug targets, NhaA of Escherichia coli has become the paradigm for this class of secondary active transporters as NhaA crystal structure provided insight into the architecture of this molecular machine. However, the mechanism of the strict pH dependence of NhaA is missing. Here, as a follow up of a recent evolutionary analysis that identified a ‘CPA motif’, we rationally designed three E. coli NhaA mutants: D133S, I134T, and the double mutant D133S-I134T. Exploring growth phenotype, transport activity and Li⁺-binding of the mutants, we revealed that Asp133 does not participate directly in proton binding, nor does it directly dictate the pH-dependent transport of NhaA. Strikingly, the variant I134T lost some of the pH control, and the D133S-Il134T double mutant retained Li⁺ binding in a pH independent fashion. Concurrent to loss of pH control, these mutants bound Li⁺ more strongly than the WT. Both positions are in close vicinity to the ion-binding site of the antiporter, attributing the results to electrostatic interaction between these residues and Asp164 of the ion-binding site. This is consistent with pH sensing resulting from direct coupling between cation binding and deprotonation in Asp164, which applies also to other CPA antiporters that are involved in human diseases.     

CRISPR-dependent Base Editing Screens Identify Separation of Function Mutants of RADX with Altered RAD51 Regulatory Activity

RAD51 forms nucleoprotein filaments to promote homologous recombination, replication fork reversal, and fork protection. Numerous factors regulate the stability of these filaments and improper regulation leads to genomic instability and ultimately disease including cancer. RADX is a single stranded DNA binding protein that modulates RAD51 filament stability. Here, we utilize a CRISPR-dependent base editing screen to tile mutations across RADX to delineate motifs required for RADX function. We identified separation of function mutants of RADX that bind DNA and RAD51 but have a reduced ability to stimulate its ATP hydrolysis activity. Cells expressing these RADX mutants accumulate RAD51 on chromatin, exhibit replication defects, have reduced growth, accumulate DNA damage, and are hypersensitive to DNA damage and replication stress. These results indicate that RADX must promote RAD51 ATP turnover to regulate RAD51 and genome stability during DNA replication.     

Modeling Innate Antiviral Immunity in Physiological Context

An effective innate antiviral response is critical for the mitigation of severe disease and host survival following infection. In vivo, the innate antiviral response is triggered by cells that detect the invading pathogen and then communicate through autocrine and paracrine signaling to stimulate the expression of genes that inhibit viral replication, curtail cell proliferation, or modulate the immune response. In other words, the innate antiviral response is complex and dynamic. Notably, in the laboratory, culturing viruses and assaying viral life cycles frequently utilizes cells that are derived from tissues other than those that support viral replication during natural infection, while the study of viral pathogenesis often employs animal models. In recapitulating the human antiviral response, it is important to consider that variation in the expression and function of innate immune sensors and antiviral effectors exists across species, cell types, and cell differentiation states, as well as when cells are placed in different contexts. Thus, to gain novel insight into the dynamics of the host response and how specific sensors and effectors impact infection kinetics by a particular virus, the model system must be selected carefully. In this review, we briefly introduce key signaling pathways involved in the innate antiviral response and highlight how these differ between systems. We then review the application of tissue-engineered or 3D models for studying the antiviral response, and suggest how these in vitro culture systems could be further utilized to assay physiologically-relevant host responses and reveal novel insight into virus-host interactions.     

Dynamic and Reversible Aggregation of the Human CAP Superfamily Member GAPR-1 in Protein Inclusions in Saccharomyces cerevisiae

Many proteins that can assemble into higher order structures termed amyloids can also concentrate into cytoplasmic inclusions via liquid–liquid phase separation. Here, we study the assembly of human Golgi-Associated plant Pathogenesis Related protein 1 (GAPR-1), an amyloidogenic protein of the Cysteine-rich secretory proteins, Antigen 5, and Pathogenesis-related 1 proteins (CAP) protein superfamily, into cytosolic inclusions in Saccharomyces cerevisiae. Overexpression of GAPR-1-GFP results in the formation GAPR-1 oligomers and fluorescent inclusions in yeast cytosol. These cytosolic inclusions are dynamic and reversible organelles that gradually increase during time of overexpression and decrease after promoter shut-off. Inclusion formation is, however, a regulated process that is influenced by factors other than protein expression levels. We identified N-myristoylation of GAPR-1 as an important determinant at early stages of inclusion formation. In addition, mutations in the conserved metal-binding site (His54 and His103) enhanced inclusion formation, suggesting that these residues prevent uncontrolled protein sequestration. In agreement with this, we find that addition of Zn²⁺ metal ions enhances inclusion formation. Furthermore, Zn²⁺ reduces GAPR-1 protein degradation, which indicates stabilization of GAPR-1 in inclusions. We propose that the properties underlying both the amyloidogenic properties and the reversible sequestration of GAPR-1 into inclusions play a role in the biological function of GAPR-1 and other CAP family members.     

Clinical,Hormonal, and Genetic Characteristics of 5α-Reductase Type 2 Deficiency in 103 Chinese Patients

Objective5α-Reductase type 2 (5α-RD2) deficiency causes variable degrees of undervirilization in patients. The correlation between its genotype and phenotype is unclear.MethodsWe retrospectively evaluated 103 patients with 46,XY disorders of sex development who were diagnosed with 5α-RD2 deficiency.ResultsThe prevalence of female sex assignment (P = .008) and the incidences of cryptorchidism (P = .0003) and bifid scrotum (P = .0002) in the non-p.R227Q variant group were higher, but there were no significant differences in the incidences of hypospadias and isolated microphallus. The external masculinization score in the non-p.R227Q variant group was lower than that in the homozygous p.R227Q variant (P = .019) and compound heterozygous p.R227Q variant groups (P = .013). The level of anti-Mullerian hormone in the non-p.R227Q variant group was lower than that in the homozygous p.R227Q variant (P < .001) and compound heterozygous p.R227Q variant groups (P = .006). The testosterone-to-dihydrotestosterone ratio of the homozygous p.R227Q variant group was higher than that of the non-p.R227Q variant (P = .018) and compound heterozygous p.R227Q variant groups (P = .029). Twenty-three reportedly pathogenic variants and 11 novel steroid 5α-reductase 2 (SRD5A2) variants were identified.ConclusionCompared with patients without p.R227Q, patients with p.R227Q exhibited higher external masculinization scores and anti-Mullerian hormone expression, a lower prevalence of female sex assignment, and lower incidences of cryptorchidism and bifid scrotum. We identified 23 reportedly pathogenic SRD5A2 variants and 11 novel SRD5A2 variants that led to 5α-RD2 deficiency. We established a genotype-phenotype correlation, and patients with p.R227Q showed a relatively mild phenotype.     

Clinical Evaluation of BRCA1/2 Mutation in Mexican Ovarian Cancer Patients

Ovarian cancer (OC) is an important cause of gynecologic cancer-related deaths. In Mexico, around 4700 new cases of OC are diagnosed per year and it represents the second cause of gynecological cancer mortality with more than 2700 deaths. Germline mutations in BRCA1/2 genes are present in 13–18% of OC cases. Few studies have evaluated the presence of mutations in BRCA genes in a population of OC Mexican patients and their relationship with clinical response and survival rates.A total of 179 OC patients were studied by molecular testing for BRCA1/2 through next-generation sequencing and multiplex ligation-dependent probe amplification. Recurrence-free survival (RFS) was estimated by the Kaplan–Meier method. BRCA mutation was detected in 33% of patients. A percentage of 66.1% were BRCA1 mutated and 33.9% were BRCA2 mutated. BRCA1 mutation carriers had a worst RFS compared with BRCA2 mutation carriers (37.6 [29–46.2] vs 72.7 [38.4–107.2]; P = 0.030). The most common mutation for BRCA1 was ex9-12del (28.2%) (Mexican founder mutation). The Mexican founder mutation had a better RFS than other BRCA1 mutations (86.1 [37.2–135.1] vs 34.5 [20.7–48.2]; P = 0.033). The presence of BRCA2 mutations in the ovarian cancer cluster region (OCCR) had a significantly better RFS than mutations in breast cancer cluster regions (BCCR) and not-related risk region (NRR) (NR vs 72.8 [39–106.6] vs 25.8 [8.3–43.2]; P = 0.013). These results demonstrate that the prevalence of BRCA1/2 positive patients in OC Mexican patients are the highest reported. Patients with mutations in BRCA2 have a better prognosis than those mutated in BRCA1. The Mexican founder mutation has an important role in clinical outcomes. These results highlight the importance to test all the HGSP (high-grade serous papillary) OC patients with or without cancer family history (CFH) in Mexican population.     

Non-Canonical Allostery in Cyclic Nucleotide Dependent Kinases

The cAMP- and cGMP-dependent protein kinases (PKA and PKG) are canonically activated by the corresponding cyclic nucleotides. However, both systems are also sensitive to a wide range of non-canonical allosteric effectors, such as reactive oxygen species, which induce the formation of regulatory inter- and intra-molecular disulfide bridges, and disease-related mutations (DRMs). Here, we present a combined analysis of representative non-canonical allosteric effectors for PKA and PKG, and we identify common molecular mechanisms underlying non-canonical allostery in these kinases, from shifts in dynamical regulatory equilibria to modulation of inter-protomer interactions. In addition, mutations may also drive oligomerization beyond dimerization, and possibly phase transitions, causing loss of kinase inhibitory function and amplifying the allosteric effects of DRMs. Hence non-canonical allosteric stimuli often result in constitutive kinase activation underlying either physiological control of downstream signaling pathways or pathological outcomes, from aortic aneurisms to cancer predisposition. Overall, PKA and PKG emerge as “pan-sensors” going well beyond canonical cyclic nucleotide activation, revealing their versatile roles as central signaling hubs.     

Phytochemical profiling and antioxidant potential of Daphne mucronata Royle and action against paracetamol-induced hepatotoxicity and nephrotoxicity in rabbits

The paracetamol-induced injuries of liver and kidneys in animals are mostly used to screen out the hepato and nephroprotective effect of extract or other therapeutic agents. In the present study total phenolic and flavonoid contents, in vitro antioxidant, and in vivo hepato/nephroprotective (on paracetamol-induced intoxication in experimental rabbits) potentials of the Daphne mucronata leaves methanolic extract were determined. For the identification of possible phytochemicals, HPLC (high performance liquid chromatography) analysis was carried out and a total of eight phenolic compounds; malic acid, gallic acid, chlorogenic acid, epigallocatechin gallate, quercetin, morin, ellagic acid, and rutin were identified. D. mucronata extract at doses of 250 and 500 mg/kg body weight were given for eight days to paracetamol intoxicated rabbits and the observed results were compared with standard Silymarin. The level of liver enzymes like aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, serum triglyceride, serum cholesterol, serum bilirubin, and kidneys biomarkers like serum urea, uric acid, and creatinine, as well as lipid peroxidation malondialdehyde contents were increased while the antioxidant enzymes like reduced glutathione and total antioxidant capacity were decreased. Furthermore, histopathological analysis of the liver and kidney tissues of control and treated groups also confirmed the hepatoprotective and nephroprotective effect of the D. mucronata which was most probably due to its high antioxidant phenolic and flavonoid phytoconstituents.     

Gut microbiome-derived glycine lipids are diet-dependent modulators of hepatic injury and atherosclerosis

Oral and gut Bacteroidetes produce unique classes of serine-glycine lipodipeptides and glycine aminolipids that signal through host Toll-like receptor 2. These glycine lipids have also been detected in human arteries, but their effects on atherosclerosis are unknown. Here, we sought to investigate the bioactivity of bacterial glycine lipids in mouse models of atherosclerosis. Lipid 654 (L654), a serine-glycine lipodipeptide species, was first tested in a high-fat diet (HFD)-fed Ldlr^?/? model of atherosclerosis. Intraperitoneal administration of L654 over 7 weeks to HFD-fed Ldlr^?/? mice resulted in hypocholesterolemic effects and significantly attenuated the progression of atherosclerosis. We found that L654 also reduced liver inflammatory and extracellular matrix gene expression, which may be related to inhibition of macrophage activation as demonstrated in vivo by lower major histocompatibility complex class II gene expression and confirmed in cell experiments. In addition, L654 and other bacterial glycine lipids in feces, liver, and serum were markedly reduced alongside changes in Bacteroidetes relative abundance in HFD-fed mice. Finally, we tested the bioactivities of L654 and related lipid 567 in chow-fed Apoe^?/? mice, which displayed much higher fecal glycine lipids relative to HFD-fed Ldlr^?/? mice. Administration of L654 or lipid 567 for 7 weeks to these mice reduced the liver injury marker alanine aminotransferase, but other effects seen in Ldlr^?/? were not observed. Therefore, we conclude that conditions in which gut microbiome-derived glycine lipids are lost, such as HFD, may exacerbate the development of atherosclerosis and liver injury, whereas correction of such depletion may protect from these disorders.