Flipping the cyclooxygenase (Ptgs) genes reveals isoform-specific compensatory functions

Pharmacological profiling of a berbamine derivative for lymphoma treatment

ABSTRACT

Ca2+/calmodulin-dependent protein kinase II γ (CAMKIIγ) has been identified as a potential target for treating cancer. Based on our previous study of berbamine (BBM) as a CAMKIIγ inhibitor, we have synthesized a new BBM derivative termed PA4. Compared with BBM, PA4 showed improved potency and specificity and was more cytotoxic against lymphoma and leukemia than against other types of cancer. In addition to indirectly targeting c-Myc protein stability, we demonstrated that its cytotoxic effects were also mediated via increased reactive oxygen species production in lymphoma cells. PA4 significantly impeded tumor growth in vivo in a xenograft T-cell lymphoma mouse model. Pharmacokinetics studies demonstrated quick absorption into plasma after oral administration, with a maximum concentration of 1680 ± 479 ng/mL at 5.33 ± 2.31 hours. The calculated oral absolute bioavailability was 34.1%. Toxicity assessment of PA4 showed that the therapeutic window used in our experiments was safe for future development. Given its efficacy, safety, and favorable pharmacokinetic profile, PA4 is a potential lead candidate for treating lymphoma.

Modulation of the Immune Response to Severe Acute Respiratory Syndrome Coronavirus 2 Vaccination by Nonsteroidal Anti-Inflammatory Drugs

Evidence is scarce to guide the use of nonsteroidal anti-inflammatory drugs (NSAIDs) to mitigate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine-related adverse effects, given the possibility of blunting the desired immune response. In this pilot study, we deeply phenotyped a small number of volunteers who did or did not take NSAIDs concomitant with SARS-CoV-2 immunizations to seek initial information on the immune response. A SARS-CoV-2 vaccine-specific receptor binding domain (RBD) IgG antibody response and efficacy in the evoked neutralization titers were evident irrespective of concomitant NSAID consumption. Given the sample size, only a large and consistent signal of immunomodulation would have been detectable, and this was not apparent. However, the information gathered may inform the design of a definitive clinical trial. Here we report a series of divergent omics signals that invites additional hypotheses testing. SIGNIFICANCE STATEMENT: The impact of nonsteroidal anti-inflammatory drugs (NSAIDs) on the immune response elicited by repeat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunizations was profiled by immunophenotypic, proteomic, and metabolomic approaches in a clinical pilot study of small sample size. A SARS-CoV-2 vaccine-specific immune response was evident irrespective of concomitant NSAID consumption. The information gathered may inform the design of a definitive clinical trial.

Increased COX-1 expression in benign prostate epithelial cells is triggered by mitochondrial dysfunction

BACKGROUND

Prostatic inflammation is closely linked to the development and progression of benign prostatic hyperplasia (BPH). Clinical studies of non-steroidal anti-inflammatory drugs, which inhibit cyclooxygenase-2 (COX-2), targeting prostate inflammation patients with symptomatic BPH have demonstrated conflicting results, with some studies demonstrating symptom improvement and others showing no impact. Thus, understanding the role of the cyclooxygenases in BPH and prostatic inflammation is important.

METHODS

The expression of COX-1 was analyzed in a cohort of donors and BPH patients by immunohistochemistry and compared to previously determined characteristics for this same cohort. The impact of mitochondrial dysfunction on COX-1 and COX-2 was determined in experiments treating human benign prostate epithelial cell lines BPH-1 and RWPE-1 with rotenone and MitoQ. RWPE-1 cells were transfected with small interfering RNA specific to complex 1 gene NDUFS3.

RESULTS

COX-1 expression was increased in the epithelial cells of BPH specimens compared to young healthy organ donor and normal prostate adjacent to BPH and frequently co-occurred with COX-2 alteration in BPH patients. COX-1 immunostaining was associated with the presence of CD8+ cytotoxic T-cells, but was not associated with age, prostate size, COX-2 or the presence of CD4+, CD20+ or CD68+ inflammatory cells. In cell line studies, COX protein levels were elevated following treatment with inhibitors of mitochondrial function. MitoQ significantly decreased mitochondrial membrane potential in RWPE-1 cells. Knockdown of NDUFS3 stimulated COX-1 expression.

CONCLUSION

Our findings suggest COX-1 is elevated in BPH epithelial cells and is associated with increased presence of CD8+ cytotoxic T-cells. COX-1 can be induced in benign prostate epithelial cells in response to mitochondrial complex I inhibition, and knockdown of the complex 1 protein NDUFS3. COX-1 and mitochondrial dysfunction may play more of a role than previously recognized in the development of age-related benign prostatic disease.

Signaling Pathways Mediating Bradykinin-Induced Contraction in Murine and Human Detrusor Muscle

Bradykinin (BK) has been proposed to modulate urinary bladder functions and implicated in the pathophysiology of detrusor overactivity. The present study aims to elucidate the signaling pathways of BK-induced detrusor muscle contraction, with the goal of better understanding the molecular regulation of micturition and identifying potential novel therapeutic targets of its disorders. Experiments have been carried out on bladders isolated from wild-type or genetically modified [smooth muscle-specific knockout (KO): Gαq/11-KO, Gα12/13-KO and constitutive KO: thromboxane prostanoid (TP) receptor-KO, cyclooxygenase-1 (COX-1)-KO] mice and on human bladder samples. Contractions of detrusor strips were measured by myography. Bradykinin induced concentration-dependent contractions in both murine and human bladders, which were independent of secondary release of acetylcholine, ATP, or prostanoid mediators. B2 receptor antagonist HOE-140 markedly diminished contractile responses in both species, whereas B1 receptor antagonist R-715 did not alter BK's effect. Consistently with these findings, pharmacological stimulation of B2 but not B1 receptors resembled the effect of BK. Interestingly, both Gαq/11- and Gα12/13-KO murine bladders showed reduced response to BK, indicating that simultaneous activation of both pathways is required for the contraction. Furthermore, the Rho-kinase (ROCK) inhibitor Y-27632 markedly decreased contractions in both murine and human bladders. Our results indicate that BK evokes contractions in murine and human bladders, acting primarily on B2 receptors. Gαq/11-coupled and Gα12/13-RhoA-ROCK signaling appear to mediate these contractions simultaneously. Inhibition of ROCK enzyme reduces the contractions in both species, identifying this enzyme, together with B2 receptor, as potential targets for treating voiding disorders.

Network pharmacology combined with metabolomics approach to investigate the protective role and detoxification mechanism of Yunnan Baiyao formulation

BACKGROUND

Yunnan Baiyao (YNBY) is a traditional Chinese medicine formulae, which has the functions of hemostasis, activating blood circulation and removing blood stasis, anti-inflammation, etc. Although the presence of Caowu (CW, Aconiti Kusnezoffii Radix), the detoxification mechanism of YNBY is still unclear.

PURPOSE

In current study, network pharmacology, toxicological methods and metabolomics technique were applied to explore YNBY in attenuating toxicity of CW.

METHODS

Prediction of targets and pathways of CW were carried out by commonly used network pharmacological method. Simultaneously, SD rats were orally administrated with CW, processed CW (ZCW), YNBY, and YNBY which lack of CW (QCW) for 15 days. Tissue samples were observed with histopathology. Urine samples were analyzed with ultra-performance liquid chromatography-mass spectrometry to screen differential metabolites and related metabolic pathways associated with toxicity of CW. Furthermore, by comparing the changes of the metabolite contents, focused the attenuated metabolic pathway. Finally, the network pharmacological and experimental data were integrated to investigate detoxification mechanism of YNBY.

RESULTS

A total of 44 potential toxicity biomarkers were identified and 14 related pathways were involved in the toxicity of CW. Furthermore, 5 core toxicity biomarkers (2-keto-6-acetamidocaproate, γ-glutamylleucine, prostaglandin E₃, 4-hydroxy-5-(3'-hydroxyphenyl)-valeric acid-3'-O-sulphate, and 3,4-dihydroxy- phenylglycol O-sulfate) were regulated to normal condition in YNBY group. Lysine degradation was locked as the core metabolic pathway of detoxification of YNBY. Integrating the predicted results of network pharmacology, ACHE, SLC6A3, SLC6A4 might be the target of protective role of other herbs in YNBY.

CONCLUSION

Network pharmacology combined with metabolomics exhibited a powerful mean to investigate the herbal toxicity and probed into the detoxification mechanism of formulae, which contributes to its safety evaluation.

The enzymology of the human prostanoid pathway

Prostanoids are short-lived autocrine and paracrine signaling molecules involved in a wide range of biological functions. They have been shown to be intimately involved in many different disease states when their regulation becomes dysfunctional. In order to fully understand the progression of any disease state or the biological functions of the well state, a complete evaluation of the genomics, proteomics, and metabolomics of the system is necessary. This review is focused on the enzymology for the enzymes involved in the synthesis of the prostanoids (prostaglandins, prostacyclins and thromboxanes). In particular, the isolation and purification of the enzymes, their enzymatic parameters and catalytic mechanisms are presented.

Synthesis and Different Effects of Biotinylated PAMAM G3 Dendrimer Substituted with Nimesulide in Human Normal Fibroblasts and Squamous Carcinoma Cells

Squamous cell carcinoma (SCC) remains a main cause of mortality in patients with neck and head cancers, with poor prognosis and increased prevalence despite of available therapies. Recent studies have identified a role of cyclooxygenases, particularly inducible isoform cyclooxygenase-2 (COX-2) and its metabolite prostaglandin E2 (PGE₂) in cancer cell proliferation, and its inhibition become a target for control of cancer development, particularly in the view of recognized additive or synergic action of COX-2 inhibitors with other forms of therapy. Nimesulide (N), the selective COX-2 inhibitor, inhibits growth and proliferation of various types of cancer cells by COX-2 dependent and independent mechanisms. In the presented study, the conjugates of biotinylated third generation poly(amidoamine) dendrimer (PAMAM) with covalently linked 18 (G3^B18N) and 31 (G3^B31N) nimesulide residues were synthesized and characterized by NMR spectroscopy. Biological properties of conjugates were evaluated, including cytotoxicity, proliferation, and caspase 3/7 activities in relation to COX-2/PGE₂ axis signaling in human normal fibroblast (BJ) and squamous cell carcinoma (SCC-15). Both conjugates exerted a selective cytotoxicity against SCC-15 as compared with BJ cells at low 1.25-10 µM concentration range and their action in cancer cells was over 250-fold stronger than nimesulide alone. Conjugates overcome apoptosis resistance and sensitized SCC-15 cells to the apoptotic death independently of COX-2/PGE₂ axis. In normal human fibroblasts the same concentrations of G3^B31N conjugate were less effective in inhibition of proliferation and induction of apoptosis, as measured by caspase 3/7 activity in a manner depending on increase of PGE₂ production by either COX-1/COX-2.

Perivascular adipose tissue-derived extracellular vesicle miR-221-3p mediates vascular remodeling

Adipose tissue-secreted extracellular vesicles (EVs) containing microRNAs (miRNAs) convey intercellular message signaling. The biogenesis of EV-miRNAs from perivascular adipose tissue (PVAT) and their roles in intercellular communication in response to obesity-associated inflammation have not yet been fully explored. By feeding mice a high-fat diet for 16 wk, we established obesity-associated, chronic low-grade inflammation in PVAT, characterized as hypertrophy of perivascular adipocytes, decreased adipogenesis, and proinflammatory macrophage infiltration. We show that PVAT-derived EVs and their encapsulated miRNAs can be taken up into vascular smooth muscle cells (VSMCs) in vivo and in vitro. miR-221-3p is one of the highly enriched miRNAs in obese PVAT and PVAT-derived EVs. Transfer and direct overexpression of miR-221-3p dramatically enhances VSMC proliferation and migration. Peroxisome proliferator-activated receptor γ coactivator 1α is identified as a miR-221-3p target in VSMC phenotypic modulation. Obese mice secrete abundant miRNA-containing EVs, evoking inflammatory responses in PVAT and vascular phenotypic switching in abdominal aorta of lean mice. Local delivery of miR-221-3p mimic in femoral artery causes vascular dysfunction by suppressing the contractile genes in the arterial wall. Our findings provide an EV-miR-221-3p-mediated mechanism by which PVAT triggers an early-stage vascular remodeling in the context of obesity-associated inflammation.-Li, X., Ballantyne, L. L., Yu, Y., Funk, C. D. Perivascular adipose tissue-derived extracellular vesicle miR-221-3p mediates vascular remodeling.

Interactions of fatty acids, nonsteroidal anti-inflammatory drugs, and coxibs with the catalytic and allosteric subunits of cyclooxygenases-1 and -2

Prostaglandin endoperoxide H synthases-1 and -2, commonly called cyclooxygenases-1 and -2 (COX-1 and -2), catalyze the committed step in prostaglandin biosynthesis-the conversion of arachidonic acid to prostaglandin endoperoxide H₂ Both COX isoforms are sequence homodimers that function as conformational heterodimers having allosteric (Eallo) and catalytic (Ecat) subunits. At least in the case of COX-2, the enzyme becomes folded into a stable Eallo/Ecat pair. Some COX inhibitors (i.e. nonsteroidal anti-inflammatory drugs and coxibs) and common fatty acids (FAs) modulate Ecat activity by binding Eallo. However, the interactions and outcomes often differ between isoforms. For example, naproxen directly and completely inhibits COX-1 by binding Ecat but indirectly and incompletely inhibits COX-2 by binding Eallo. Additionally, COX-1 is allosterically inhibited up to 50% by common FAs like palmitic acid, whereas COX-2 is allosterically activated 2-fold by palmitic acid. FA binding to Eallo also affects responses to COX inhibitors. Thus, COXs are physiologically and pharmacologically regulated by the FA tone of the milieu in which each operates-COX-1 in the endoplasmic reticulum and COX-2 in the Golgi apparatus. Cross-talk between Eallo and Ecat involves a loop in Eallo immediately downstream of Arg-120. Mutational studies suggest that allosteric modulation requires a direct interaction between the carboxyl group of allosteric effectors and Arg-120 of Eallo; however, structural studies show some allosterically active FAs positioned in COX-2 in a conformation lacking an interaction with Arg-120. Thus, many details about the biological consequences of COX allosterism and how ligand binding to Eallo modulates Ecat remain to be resolved.

Isoform-Specific Compensation of Cyclooxygenase (Ptgs) Genes during Implantation and Late-Stage Pregnancy

The participation of cyclooxygenase (COX) in embryo implantation and parturition has been studied extensively. However, the distinct role of the two COX isoforms in these processes still remains unclear. Using three characterized mouse lines where the Ptgs1 and Ptgs2 genes substitute for one another, this study focused on the reproductive significance of their distinct roles and potential biological substitution. In both non-gravid and gravid uteri, the knock-in COX-2 is expressed constitutively, whereas the knock-in COX-1 is slightly induced in early implantation. The delayed onset of parturition previously found in COX-1 null mice was corrected by COX-2 exchange in COX-2>COX-1 mice, with normal term pregnancy, gestation length and litter size. In contrast, loss of native COX-2 in COX-1>COX-2 mice resulted in severely impaired reproductive functions. Knock-in COX-1 failed to substitute for the loss of COX-2 in COX-1>COX-2 mice during implantation, indicating that COX-1 may be replaced by COX-2, but not vice versa. A panel of prostaglandins detected in uterus and ovary demonstrates that prostaglandin biosynthesis preferentially depends on native COX-1, but not COX-2. More interestingly, preferential compensations by the COX isoforms were sustained despite weak dependency on their role in prostaglandin biosynthesis in the uterus and ovary.

Differential compensation of two cyclooxygenases in renal homeostasis is independent of prostaglandin-synthetic capacity under basal conditions

The distinct functions of each cyclooxygenase (COX) isoform in renal homeostasis have been the subject of intense investigation for many years. We took the novel approach of using 3 characterized mouse lines, where the prostaglandin (PG)-endoperoxide synthase genes 1 and 2 ( Ptgs1 and Ptgs2) substitute for one another to delineate distinct roles and the potential for COX isoform substitution. Flipped Ptgs genes generate a reversed COX-expression pattern in the kidney, where the knockin COX-2 is highly expressed. Normal nephrogenesis was sustained in all 3 strains at the postnatal stage d 8 (P8). Knockin COX-1 can temporally restore renal function and delay but not prevent renal pathology consequent to COX-2 deletion. Loss of COX-2 in adult COX-1 > COX-2 mice results in severe nephropathy, which leads to impaired renal function. These defects are partially rescued by the knockin COX-2 in Reversa mice, whereas COX-2 can compensate for the loss of COX-1 in COX-2 > COX-1 mice. Intriguingly, the highly expressed knockin COX-2 enzyme barely makes any PGs or thromboxane in neonatal P8 or adult mice, demonstrating that prostanoid biosynthesis requires native COX-1 and cannot be rescued by the knockin COX-2. In summary, the 2 COX isoforms can preferentially compensate for some renal functions, which appears to be independent of the PG-synthetic capacity.-Li, X., Mazaleuskaya, L. L., Ballantyne, L. L., Meng, H., FitzGerald, G. A., Funk, C. D. Differential compensation of two cyclooxygenases in renal homeostasis is independent of prostaglandin-synthetic capacity under basal conditions.

Genomic and lipidomic analyses differentiate the compensatory roles of two COX isoforms during systemic inflammation in mice

Both cyclooxygenase (COX)-1 and COX-2, encoded by Ptgs1 and Ptgs2, function coordinately during inflammation. But the relative contributions and compensations of COX-1 and COX-2 to inflammatory responses remain unanswered. We used three engineered mouse lines where the Ptgs1 and Ptgs2 genes substitute for one another to discriminate the distinct roles and interchangeability of COX isoforms during systemic inflammation. In macrophages, kidneys, and lungs, "flipped" Ptgs genes generate a "reversed" COX expression pattern, where the knock-in COX-2 is expressed constitutively and the knock-in COX-1 is lipopolysaccharide inducible. A panel of eicosanoids detected in serum and kidney demonstrates that prostaglandin (PG) biosynthesis requires native COX-1 and cannot be rescued by the knock-in COX-2. Our data further reveal preferential compensation of COX isoforms for prostanoid production in macrophages and throughout the body, as reflected by urinary PG metabolites. NanoString analysis indicates that inflammatory networks can be maintained by isoform substitution in inflamed macrophages. However, COX-1>COX-2 macrophages show reduced activation of inflammatory signaling pathways, indicating that COX-1 may be replaced by COX-2 within this complex milieu, but not vice versa. Collectively, each COX isoform plays a distinct role subject to subcellular environment and tissue/cell-specific conditions, leading to subtle compensatory differences during systemic inflammation.