Multilayered synergistic regulation of phytoalexin biosynthesis by ethylene, jasmonate, and MAPK signaling pathways in Arabidopsis.

Camalexin, an indolic antimicrobial metabolite, is the major phytoalexin in Arabidopsis thaliana, and plays a crucial role in pathogen resistance. Our previous studies revealed that the Arabidopsis mitogen-activated protein kinases MPK3 and MPK6 positively regulate pathogen-induced camalexin biosynthesis via phosphoactivating the transcription factor WRKY33. Here, we report that the ethylene and jasmonate (JA) pathways act synergistically with the MPK3/MPK6-WRKY33 module at multiple levels to induce camalexin biosynthesis in Arabidopsis upon pathogen infection. The ETHYLENE RESPONSE FACTOR1 (ERF1) transcription factor integrates the ethylene and JA pathways to induce camalexin biosynthesis via directly upregulating camalexin biosynthetic genes. ERF1 also interacts with and depends on WRKY33 to upregulate camalexin biosynthetic genes, indicating that ERF1 and WRKY33 form transcriptional complexes to cooperatively activate camalexin biosynthetic genes, thereby mediating the synergy of ethylene/JA and MPK3/MPK6 signaling pathways to induce camalexin biosynthesis. Moreover, as an integrator of the ethylene and JA pathways, ERF1 also acts as a substrate of MPK3/MPK6, which phosphorylate ERF1 to increase its transactivation activity and therefore further cooperate with the ethylene/JA pathways to induce camalexin biosynthesis. Taken together, our data reveal the multilayered synergistic regulation of camalexin biosynthesis by ethylene, JA, and MPK3/MPK6 signaling pathways via ERF1 and WRKY33 transcription factors in Arabidopsis.

Treatment patterns and survival in metastatic castration-sensitive prostate cancer in the US Veterans Health Administration.

BACKGROUND: Limited real-world data exist on treatment patterns and outcomes in patients with metastatic castration-sensitive prostate cancer (mCSPC). METHODS: A retrospective cohort study was conducted, using the Veterans Health Administration claims database (April 2013-March 2018). Among 369,734 prostate cancer patients, we selected all men who developed metastases within 90 days before or after medical/surgical castration and who received androgen deprivation therapy (ADT). Patients were categorized into four cohorts: ADT-only (± <90-day nonsteroidal anti-androgen [NSAA] use), ADT + NSAA, ADT + docetaxel, and ADT + abiraterone. Main outcomes were treatment patterns, time-to-progression to metastatic castration-resistant disease, and overall survival. Multivariable analysis and sensitivity analysis were conducted. RESULTS: Of 1395 patients, 874 (63%) received ADT-only, 338 (24%) received ADT + NSAA, 108 (8%) received ADT + docetaxel, and 75 (5%) received ADT + abiraterone. Proportions on ADT-only and ADT + NSAA declined (from 66% to 60% and from 31% to 17%, respectively) over the study period, while proportions prescribed ADT + docetaxel or abiraterone increased from 3% to 9% and from 1% to 15%, respectively. Patients treated with ADT + NSAA had similar risks of castration-resistant disease (hazard ratio [HR] 1.05; 95% confidence interval [CI]: 0.87, 1.26) and overall mortality (HR 1.22; 95% CI: 0.97, 1.54) as ADT-only. CONCLUSIONS: Most patients with mCSPC initiating ADT received ADT-only or ADT + NSAA, despite the emergence of docetaxel and novel hormonal therapies. Even in the most recent period (2017 to early 2018), only 24% of men received intensified therapy with agents known to prolong survival versus ADT-only. These data in real-world clinical practice suggest substantial room for improved outcomes in patients with mCSPC.

Comparative Clinical and Economic Outcomes Associated with Warfarin Versus Apixaban in the Treatment of Patients with Venous Thromboembolism in a Large U.S. Commercial Claims Database.

BACKGROUND: Venous thromboembolism (VTE), constituting deep vein thrombosis (DVT) and pulmonary embolism (PE), is a common cause of vascular-related morbidity and mortality, resulting in a significant clinical and economic burden in the United States each year. Clinical guidelines recommend that patients with DVT and PE without cancer should be initiated on anticoagulation therapy with a direct oral anticoagulant over a vitamin K antagonist. Yet there is limited real-world evidence comparing the economic burden of warfarin and apixaban in treating VTE patients in a large commercially insured population. OBJECTIVE: To compare safety and effectiveness of warfarin and apixaban and evaluate associated economic burden in treating VTE patients in a large U.S. commercial health care claims database. METHODS: The PharMetrics Plus database was used to identify oral anticoagulant (OAC)-naive patients aged ≥ 18 years who initiated apixaban or warfarin within 30 days of a qualifying VTE encounter and had continuous health plan enrollment with medical and pharmacy benefits for 6 months before treatment initiation. Apixaban initiators and warfarin initiators were matched using the propensity score matching (PSM) technique. Cox proportional hazard models were used to assess and compare the risk of major bleeding (MB), clinically relevant nonmajor (CRNM) bleeding, and recurrent VTE. Generalized linear models were used to assess and compare the all-cause health care costs. A 2-part model with bootstrapping was used to evaluate MB- and recurrent VTE-related medical costs. RESULTS: Among 25,193 prematched patients, 13,421 (53.3%) were prescribed warfarin and 11,772 (46.7%) were prescribed apixaban. After 1:1 PSM, 8,858 matched warfarin-apixaban pairs were selected with a mean follow-up of 109 days and 103 days, respectively. Warfarin was associated with a significantly higher risk of MB (HR = 1.52, 95% CI = 1.14-2.04), CRNM bleeding (HR = 1.27, 95% CI = 1017.15-1.40), and recurrent VTE (HR = 1.50, 95% CI = 1.24-1.82) compared with apixaban. Warfarin patients had significantly higher all-cause medical costs per patient per month (PPPM; $2,333 vs. $1,992; P = 0.001), MB-related costs PPPM ($112 vs. $65; P = 0.020), and recurrent VTE-related costs PPPM ($287 vs. $206; P = 0.014) compared with apixaban patients. Warfarin patients had similar all-cause total health care costs PPPM ($2,630 vs. $2,420; P = 0.051) compared with apixaban patients. CONCLUSIONS: Warfarin use was associated with a higher risk of MB, CRNM bleeding, and recurrent VTE compared with apixaban. Warfarin use was also associated with higher all-cause medical costs, MB-related medical costs, and recurrent VTE-related costs PPPM compared with apixaban. DISCLOSURES: This study was funded by Bristol Myers Squibb and Pfizer, which were also involved in the study design, as well as writing and revising of the manuscript. Guo, Rajpura, Okano, and Rosenblatt are employees of Bristol Myers Squibb. Hlavacek, Mardekian, and Russ are employees of Pfizer. Keshishian, Sah, Delinger, and Mu are employees of SIMR, LLC, which received funding from the study sponsors to conduct this study.

Genome-Wide Identification of Klebsiella pneumoniae Fitness Genes during Lung Infection.

UNLABELLED: Klebsiella pneumoniae is an urgent public health threat because of resistance to carbapenems, antibiotics of last resort against Gram-negative bacterial infections. Despite the fact that K. pneumoniae is a leading cause of pneumonia in hospitalized patients, the bacterial factors required to cause disease are poorly understood. Insertion site sequencing combines transposon mutagenesis with high-throughput sequencing to simultaneously screen thousands of insertion mutants for fitness defects during infection. Using the recently sequenced K. pneumoniae strain KPPR1 in a well-established mouse model of pneumonia, insertion site sequencing was performed on a pool of >25,000 transposon mutants. The relative fitness requirement of each gene was ranked based on the ratio of lung to inoculum read counts and concordance between insertions in the same gene. This analysis revealed over 300 mutants with at least a 2-fold fitness defect and 69 with defects ranging from 10- to >2,000-fold. Construction of 6 isogenic mutants for use in competitive infections with the wild type confirmed their requirement for lung fitness. Critical fitness genes included those for the synthesis of branched-chain and aromatic amino acids that are essential in mice and humans, the transcriptional elongation factor RfaH, and the copper efflux pump CopA. The majority of fitness genes were conserved among reference strains representative of diverse pathotypes. These results indicate that regulation of outer membrane components and synthesis of amino acids that are essential to its host are critical for K. pneumoniae fitness in the lung. IMPORTANCE: Klebsiella pneumoniae is a bacterium that commonly causes pneumonia in patients after they are admitted to the hospital. K. pneumoniae is becoming resistant to all available antibiotics, and when these infections spread to the bloodstream, over half of patients die. Since currently available antibiotics are failing, we must discover new ways to treat these infections. In this study, we asked what genes the bacterium needs to cause an infection, since the proteins encoded by these genes could be targets for new antibiotics. We identified over 300 genes that K. pneumoniae requires to grow in a mouse model of pneumonia. Many of the genes that we identified are found in K. pneumoniae isolates from throughout the world, including antibiotic-resistant forms. If new antibiotics could be made against the proteins that these genes encode, they may be broadly effective against K. pneumoniae.