Metabolic and enzymatic engineering approach for the production of 2-phenylethanol in engineered Escherichia coli.

2-Phenylethanol, known for its rose-like odor and antibacterial activity, is synthesized via exogenous phenylpyruvate by the sequential reaction of phenylpyruvate decarboxylase (PDC) and aldehyde reductase. We first targeted ARO10, a phenylpyruvate decarboxylase gene from Saccharomyces cerevisiae, and identified a suitable aldehyde reductase gene. Co-expression of ARO10 and yahK in E. coli transformants yielded 1.1 g/L of 2-phenylethanol in batch culture. We hypothesized that there might be a bottleneck in PDC activity. The computer-based enzyme evolution was utilized to enhance production. The introduction of an amino acid substitution in ARO10 (ARO10 I544W) stabilized the aromatic ring of the phenylpyruvate substrate, increasing 2-phenylethanol yield 4.1-fold compared to wild-type ARO10. Cultivation of ARO10 I544W-expressing E. coli produced 2.5 g/L of 2-phenylethanol with a yield from glucose of 0.16 g/g after 72 h. This approach represents a significant advancement, achieving the highest yield of 2-phenylethanol from glucose using microbes to date.

Persistent iatrogenic muscular ventricular septal lead perforation after pacemaker implantation using delivery sheath system.

Ventricular septal perforation is a rare complication of pacemaker implantation. Here, we describe the case of a 69-year-old man with complete atrioventricular block and heart failure. The right ventricular pacemaker was implanted with a long pre-shaped delivery sheath. A new systolic murmur appeared after the procedure. Transthoracic echocardiography revealed a ventricular septal perforation, with a Qp/Qs of 1.09, which was a small shunt rate and required no intervention. The persistent ventricular septal perforation was observed, and the shunt rate remained at 8-month follow-up. Learning objective: Ventricular septal lead perforation (VSP) is a rare complication of pacemaker implantation. Although iatrogenic VSP generally close spontaneously without adverse clinical outcomes, clinicians should pay attention to the possibility of its persistence.

Styrene Production in Genetically Engineered Escherichia coli in a Two-Phase Culture.

Styrene is an important industrial chemical. Although several studies have reported microbial styrene production, the amount of styrene produced in batch cultures can be increased. In this study, styrene was produced using genetically engineered Escherichia coli. First, we evaluated five types of phenylalanine ammonia lyases (PALs) from Arabidopsis thaliana (AtPAL) and Brachypodium distachyon (BdPAL) for their ability to produce trans-cinnamic acid (Cin), a styrene precursor. AtPAL2-expressing E. coli produced approximately 700 mg/L of Cin and we found that BdPALs could convert Cin into styrene. To assess styrene production, we constructed an E. coli strain that co-expressed AtPAL2 and ferulic acid decarboxylase from Saccharomyces cerevisiae. After a biphasic culture with oleyl alcohol, styrene production and yield from glucose were 3.1 g/L and 26.7% (mol/mol), respectively, which, to the best of our knowledge, are the highest values obtained in batch cultivation. Thus, this strain can be applied to the large-scale industrial production of styrene.

[Relapsed/refractory Philadelphia chromosome-positive acute lymphoblastic leukemia responding to retreatment with inotuzumab ozogamicin].

A 72-year-old man with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL) was treated with dasatinib (week1: 50 mg/day, week2: 70 mg/day, week3-: 100 mg/day) and prednisolone from June 2017. However, in January 2018, it relapsed with the T315I mutation. Although the treatment was changed to ponatinib 30 mg/day, he experienced a second relapse in June 2018. Following confirmation of CD22 positivity, he was treated with three cycles of inotuzumab ozogamicin (InO), resulting in CR. He was CR for 2.9 years before relapsing for the third time in May 2021. Because the patient was still CD22-positive, InO was given again, and the patient achieved CR at the end of the second cycle. We had a case where re-administering InO was effective as a salvage therapy for relapsed/refractory Ph+ALL (r/r Ph+ALL) in an elderly patient.

The E/e' ratio on echocardiography as an independent predictor of the improvement of left ventricular contraction in patients with heart failure with reduced ejection fraction.

OBJECTIVE: Clinical feature of heart failure with improved ejection fraction (HFimpEF) remains to be fully elucidated. The present study investigated the association of clinical and echocardiographic parameters with the subsequent improvement of left ventricular ejection fraction (LVEF) in heart failure with reduced ejection fraction (HFrEF). METHODS: From outpatients with a history of hospitalized for heart failure, 128 subjects diagnosed as HFrEF (LVEF <40%) on heart failure hospitalization were enrolled and longitudinally surveyed. During follow-up periods more than 1 year, 58 and 42 patients were identified as HFimpEF (improved LVEF to ≥40% and its increase of ≥10 points) and persistent HFrEF, respectively. RESULTS: There was no difference in age or sex between the two groups with HFimpEF and persistent HFrEF. The rate of ischemic heart disease was lower and that of tachyarrhythmia was higher in the HFimpEF group than in the persistent HFrEF group. At baseline (i.e., on heart failure hospitalization), LVEF did not differ between the two groups, but left ventricular systolic and diastolic diameters were already smaller and the ratio of early diastolic transmitral velocity to early diastolic tissue velocity (E/e') was lower in the HFimpEF group. A multiple logistic regression analysis revealed that lower baseline E/e' was a significant determinant of HFimpEF, independently of confounding factors such as ischemic heart disease, tachyarrhythmia, and baseline left ventricular dimension. CONCLUSION: Our findings indicate that the lower ratio of E/e' in the acute phase of heart failure onset is an independent predictor of the subsequent improvement of LVEF in HFrEF patients.

Caffeic acid production from glucose using metabolically engineered Escherichia coli.

Caffeic acid (3,4-dihydroxycinnamic acid) is a precursor for high-valued compounds with anticancer, antiviral activities, and anti-inflammatory making it an important substance in the food additive, cosmetics, and pharmaceutical industries. Here, we developed an engineered Escherichia coli strain capable of directly producing high levels of caffeic acid from glucose. Tyrosine ammonia-lyase from Rhodotorula glutinis (RgTAL) and p-coumaric acid 3-hydroxylase from Saccharothrix espanaensis (SeC3H) were expressed. Next, feedback-resistant chorismate mutase/prephenate dehydrogenase, was introduced to promote l-tyrosine synthesis. This engineered strain CA3 produced 1.58 g/L of caffeic acid from glucose without tyrosine supplemented to the medium. Furthermore, to reduce p-coumaric acid accumulation, 4-hydroxyphenylacetate 3-hydroxylase from Pseudomonas aeruginosa (PaHpaBC) was introduced. Finally, an engineered strain CA8 directly produced 6.17 g/L of caffeic acid from glucose using a jar fermenter. The E. coli developed in this study would be helpful as a chassis strain to produce value-added caffeic acid-derivatives.

Clinical predictors of cardiac syncope in patients with unexplained syncope after the implantation of an insertable cardiac monitor.

Syncope prognosis is related to both its etiology and comorbidities, with cardiac syncope (CS) having higher risks for mortality and cardiovascular events than syncope of non-cardiac causes. Although a novel insertable cardiac monitor (ICM) is an effective diagnostic tool for unexplained syncope, decision regarding ICM implantation with a high pre-test likelihood of CS should contribute to economic cost reduction and avoidance of unnecessary complications. This study aimed to investigate clinical factors associated with CS after ICM implantation in patients with unexplained syncope. This retrospective observational study included 31 consecutive patients with ICM implantation for syncope between September 2016 and August 2021. The initial examinations for syncope included a detailed history, physical examination, blood tests, 12-lead electrocardiograms, and transthoracic echocardiography. Of the 31 patients, 13 (41.9%) experienced recurrent CS during follow-up (676 ± 469 days). Among several clinical factors, syncope-related minor injuries (p = 0.017) and higher brain natriuretic peptide (BNP; p = 0.043) levels were significantly associated with CS. Moreover, multivariable analysis showed that both syncope-related minor injuries (odds ratio, 11.2; 95% confidence interval, 1.4-88.4; p = 0.022) and BNP higher than 64.0 pg/mL (odds ratio, 7.0; 95% confidence interval, 1.1-44.2; p = 0.038) were independent predictors of CS after ICM implantation. In conclusion, a history of minor injury secondary to syncope and higher BNP levels were independent CS predictors in patients receiving ICM for syncope. These results emphasized the utility of ICM implantation early in the diagnostic journey of patients presenting with CS predictors requiring specific treatments.

Renoprotective effect of chronic treatment with sodium-glucose cotransporter 2 inhibitors and its associated factors in Japanese patients with chronic heart failure and diabetes.

Background: Recent clinical trials have shown that sodium-glucose cotransporter 2 (SGLT2) inhibitors have beneficial effects on renal function in heart failure patients. This study confirmed the renoprotective effect of treatment with SGLT2 inhibitors in Japanese patients with chronic heart failure and diabetes and further investigated what cardiac/hemodynamic and noncardiac factors are involved in its effect. Methods: Eligible 50 outpatients with chronic heart failure and type-2 diabetes mellitus chronically taking SGLT2 inhibitors were enrolled. Annual changing rates of estimated glomerular filtration rate (eGFR) were compered before and after treatment with SGLT2 inhibitors and the associations of the change in eGFR slope after SGLT2 inhibitor administration with changes in various clinical and echocardiographic parameters were evaluated. Results: The mean follow-up periods before and after SGLT2 inhibitor administration were 2.6 and 1.9 years, respectively. Changing rates of eGFR per year were significantly improved after treatment with SGLT2 inhibitors (-5.78 ± 7.67 to -0.43 ± 10.81 mL/min/1.73 m2/year, p = 0.006). The daily doses of loop diuretics were not altered after SGLT2 inhibitor administration. Neither decreased body weight nor increased hematocrit was associated with the change in eGFR slope before and after SGLT2 inhibitor administration. While, the decrease in inferior vena cava diameter and the increase in its respiratory collapsibility were significantly correlated with the improvement of eGFR decline slope after SGLT2 inhibitor administration. Conclusions: Our findings indicated that chronic treatment with SGLT2 inhibitors ameliorated annual decline in eGFR in Japanese patients with chronic heart failure, suggesting the possibility that the improvement of venous congestion was involved in its renoprotective effect.

Chlorpromazine cooperatively induces apoptosis with tyrosine kinase inhibitors in EGFR-mutated lung cancer cell lines and restores the sensitivity to gefitinib in T790M-harboring resistant cells.

We previously reported that the antipsychotic drug chlorpromazine (CPZ), which inhibits the formation of clathrin-coated vesicles (CCVs) essential for endocytosis and intracellular transport of receptor tyrosine kinase (RTK), inhibits the growth/survival of acute myeloid leukemia cells with mutated RTK (KIT D816V or FLT3-ITD) by perturbing the intracellular localization of these molecules. Here, we examined whether these findings are applicable to epidermal growth factor receptor (EGFR). CPZ dose-dependently inhibited the growth/survival of the non-small cell lung cancer (NSCLC) cell line, PC9 harboring an EGFR-activating (EGFR exon 19 deletion). In addition, CPZ not only suppressed the growth/survival of gefitinib (GEF)-resistant PC9ZD cells harboring T790 M, but also restored their sensitivities to GEF. Furthermore, CPZ overcame GEF resistance caused by Met amplification in HCC827GR cells. As for the mechanism of CPZ-induced growth suppression, we found that although CPZ hardly influenced the phosphorylation of EGFR, it effectively reduced the phosphorylation of ERK and AKT. When utilized in combination with trametinib (a MEK inhibitor), dabrafenib (an RAF inhibitor), and everolimus (an mTOR inhibitor), CPZ suppressed the growth of PC9ZD cells cooperatively with everolimus but not with trametinib or dabrafenib. Immunofluorescent staining revealed that EGFR shows a perinuclear pattern and was intensely colocalized with the late endosome marker, Rab11. However, after CPZ treatment, EGFR was unevenly distributed in the cells, and colocalization with the early endosome marker Rab5 and EEA1 became more apparent, indicating that CPZ disrupted the intracellular transport of EGFR. These results suggest that CPZ has therapeutic potential for NSCLC with mutated EGFR by a novel mechanism different from conventional TKIs alone or in combination with other agents.

G6P-capturing molecules in the periplasm of Escherichia coli accelerate the shikimate pathway.

Escherichia coli, the most studied prokaryote, is an excellent host for producing valuable chemicals from renewable resources as it is easy to manipulate genetically. Since the periplasmic environment can be easily controlled externally, elucidating how the localization of specific proteins or small molecules in the periplasm affects metabolism may lead to bioproduction development using E. coli. We investigated metabolic changes and its mechanisms occurring when specific proteins are localized to the E. coli periplasm. We found that the periplasmic localization of ß-glucosidase promoted the shikimate pathway involved in the synthesis of aromatic chemicals. The periplasmic localization of other proteins with an affinity for glucose-6-phosphate (G6P), such as inactivated mutants of Pgi, Zwf, and PhoA, similarly accelerated the shikimate pathway. Our results indicate that G6P is transported from the cytoplasm to the periplasm by the glucose transporter protein EIICBGlc, and then captured by ß-glucosidase.

C-type lectin-like receptor 2 specifies a functionally distinct subpopulation within phenotypically defined hematopoietic stem cell population that contribute to emergent megakaryopoiesis.

C-type lectin-like receptor 2 (CLEC-2) expressed on megakaryocytes plays important roles in megakaryopoiesis. We found that CLEC-2 was expressed in about 20% of phenotypical long-term hematopoietic stem cells (LT-HSCs), which expressed lower levels of HSC-specific genes and produced larger amounts of megakaryocyte-related molecules than CLEC-2low LT-HSCs. Although CLEC-2high LT-HSCs had immature clonogenic activity, cultured CLEC-2high LT-HSCs preferentially differentiated into megakaryocytes. CLEC-2high HSCs yielded 6.8 times more megakaryocyte progenitors (MkPs) and 6.0 times more platelets 2 weeks and 1 week after transplantation compared with CLEC-2low LT-HSCs. However, platelet yield from CLEC-2high HSCs gradually declined with the loss of MkPs, while CLEC-2low HSCs self-renewed long-term, indicating that CLEC-2high LT-HSCs mainly contribute to early megakaryopoiesis. Treatment with pI:C and LPS increased the proportion of CLEC-2high LT-HSCs within LT-HSCs. Almost all CLEC-2low LT-HSCs were in the G0 phase and barely responded to pI:C. In contrast, 54% of CLEC-2high LT-HSCs were in G0, and pI:C treatment obliged CLEC-2high LT-HSCs to enter the cell cycle and differentiate into megakaryocytes, indicating that CLEC-2high LT-HSCs are primed for cell cycle entry and rapidly yield platelets in response to inflammatory stress. In conclusion, CLEC-2high LT-HSCs appear to act as a reserve for emergent platelet production under stress conditions.

Achilles tendon thickness is associated with coronary lesion severity in acute coronary syndrome patients without familial hypercholesterolemia.

BACKGROUND: Thickening of Achilles tendon (≥9 mm on radiography) is one of the diagnostic criteria for familial hypercholesterolemia (FH). Since FH is associated with premature coronary artery disease (CAD) including acute coronary syndrome (ACS), measurement of Achilles tendon thickness (ATT) is important for early diagnosis of FH. However, clinical significance of mild thickening of Achilles tendon in non-FH patients with CAD is unclear. The present study investigated the association of ATT with coronary lesion severity in early-onset ACS without clinically diagnosed FH. METHODS: From outpatients who had a history of ACS under 60 years old, 76 clinically non-FH subjects (71 men and 5 women; mean age at the onset of ACS, 50.5 years) with maximum ATT of <9 mm were enrolled in this study. The severity of coronary lesions was assessed by SYNTAX score derived from coronary angiography at the onset of ACS. RESULTS: ATT levels were not significantly different among patients with ST-elevation myocardial infarction (STEMI, n=47), non-STEMI (n=12), and unstable angina (n=17). Whereas, both average and maximum ATT were significantly larger in patients with multivessel lesions (n=25) than in those with single-vessel disease (n=51). Furthermore, SYNTAX score was positively correlated with average ATT (r=0.368, p=0.0011) and maximum ATT (r=0.388, p=0.0005). As for the relation to clinical parameters, maximum ATT had positive correlations with body mass index and C-reactive protein. A multiple regression analysis revealed that average and maximum ATT were significantly associated with SYNTAX score, independently of various confounding factors. CONCLUSIONS: Our findings demonstrated that ATT, even though its level was <9 mm, was associated with coronary lesion severity in clinically non-FH patients with early-onset ACS. Apart from diagnosing FH, ATT may be a predictor of the progression of CAD.

Reprogramming Escherichia coli pyruvate-forming reaction towards chorismate derivatives production.

Microbial metabolic pathway engineering is a potent strategy used worldwide to produce aromatic compounds. We drastically rewired the primary metabolic pathway of Escherichia coli to produce aromatics and their derivatives. The metabolic pathway of E. coli was compartmentalized into the production and energy modules. We focused on the pyruvate-forming reaction in the biosynthesis pathway of some compounds as the reaction connecting those modules. E. coli strains were engineered to show no growth unless pyruvate was synthesized along with the compounds of interest production. Production of salicylate and maleate was demonstrated to confirm our strategy's versatility. In maleate production, the production, yield against the theoretical yield, and production rate reached 12.0 g L-1, 67%, and up to fourfold compared to that in previous reports, respectively; these are the highest values of maleate production in microbes to our knowledge. The results reveal that our strategy strongly promotes the production of aromatics and their derivatives.

Metabolic engineering of 1,2-propanediol production from cellobiose using beta-glucosidase-expressing E. coli.

Microbial 1,2-propanediol production using renewable feedstock is a promising method for the sustainable production of value-added fuels and chemicals. We demonstrated the metabolically engineered Escherichia coli for improvement of 1,2-propanediol production using glucose and cellobiose. The deletion of competing pathways improved 1,2-propanediol production. To reduce carbon flux toward downstream glycolysis, the phosphotransferase system (PTS) was inactivated by ptsG gene deletion. The resultant strain, GL3/PD, produced 1.48 ± 0.01 g/L of 1,2-propanediol from 20 g/L of glucose. A sugar supply was engineered by coexpression of ß-glucosidase (BGL). The strain expressing BGL produced 1,2-propanediol from cellobiose at a concentration of 0.90 ± 0.11 g/L with a yield of 0.15 ± 0.01 g/g glucose (cellobiose 1 g is equal to glucose 1.1 g). As cellobiose or cellooligosaccharides a carbon source, the feasibility of producing 1,2-propanediol using an E. coli strain engineered for ß-glucosidase expression are demonstrated.

Long-term administration of tolvaptan ameliorates annual decline in estimated glomerular filtration rate in outpatients with chronic heart failure.

Protective effects of tolvaptan against worsening renal function in acute heart failure have been shown. However, long-term effects of its agent on renal function remain to be elucidated. The present study investigated retrospectively whether long-term treatment with tolvaptan exerts renoprotective effects in patients with chronic heart failure, by comparing serial changes in estimated glomerular filtration rate (eGFR) for years before and after tolvaptan administration. From 63 outpatients with chronic heart failure taking diuretics including tolvaptan, 34 patients whose eGFR levels were continuously measured for more than 6 months both before and after administration of tolvaptan (average dose, 7.8 mg/day at the end of the follow-up period) were selected as eligible for the present analyses. All eGFR values were separately plotted before and after the initiation of treatment with tolvaptan (except hospitalization periods) along the time course axis and the slope of the linear regression curve was calculated as an annual change in eGFR. The mean follow-up periods before and after tolvaptan administration were 1197 and 784 days (3.3 and 2.1 years), respectively. Changing rates of eGFR per year were significantly ameliorated after treatment with tolvaptan (mean ± SD, - 8.02 ± 9.35 to - 1.62 ± 5.09 mL/min/1.73m2 /year, P = 0.001). In echocardiographic parameters, inferior vena cava (IVC) diameter significantly decreased after tolvaptan administration, and the decrease in IVC diameter was correlated with the improvement of eGFR decline slope after administration of tolvaptan (P = 0.0075). This longitudinal observational study indicated that long-term treatment with tolvaptan ameliorated annual decline in eGFR in outpatients with chronic heart failure. Our findings suggest that tolvaptan has a protective effect against chronically worsening renal function in heart failure patients.

Metabolic engineering of E. coli for improving mevalonate production to promote NADPH regeneration and enhance acetyl-CoA supply.

Microbial production of mevalonate from renewable feedstock is a promising and sustainable approach for the production of value-added chemicals. We describe the metabolic engineering of Escherichia coli to enhance mevalonate production from glucose and cellobiose. First, the mevalonate-producing pathway was introduced into E. coli and the expression of the gene atoB, which encodes the gene for acetoacetyl-CoA synthetase, was increased. Then, the deletion of the pgi gene, which encodes phosphoglucose isomerase, increased the NADPH/NADP+ ratio in the cells but did not improve mevalonate production. Alternatively, to reduce flux toward the tricarboxylic acid cycle, gltA, which encodes citrate synthetase, was disrupted. The resultant strain, MGΔgltA-MV, increased levels of intracellular acetyl-CoA up to sevenfold higher than the wild-type strain. This strain produced 8.0 g/L of mevalonate from 20 g/L of glucose. We also engineered the sugar supply by displaying ß-glucosidase (BGL) on the cell surface. When cellobiose was used as carbon source, the strain lacking gnd displaying BGL efficiently consumed cellobiose and produced mevalonate at 5.7 g/L. The yield of mevalonate was 0.25 g/g glucose (1 g of cellobiose corresponds to 1.1 g of glucose). These results demonstrate the feasibility of producing mevalonate from cellobiose or cellooligosaccharides using an engineered E. coli strain.

Publisher Correction: Metabolic engineering of Escherichia coli for shikimate pathway derivative production from glucose-xylose co-substrate.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Metabolic engineering of Escherichia coli for shikimate pathway derivative production from glucose-xylose co-substrate.

Glucose and xylose are the major components of lignocellulose. Effective utilization of both sugars can improve the efficiency of bioproduction. Here, we report a method termed parallel metabolic pathway engineering (PMPE) for producing shikimate pathway derivatives from glucose-xylose co-substrate. In this method, we seek to use glucose mainly for target chemical production, and xylose for supplying essential metabolites for cell growth. Glycolysis and the pentose phosphate pathway are completely separated from the tricarboxylic acid (TCA) cycle. To recover cell growth, we introduce a xylose catabolic pathway that directly flows into the TCA cycle. As a result, we can produce 4.09 g L-1 cis,cis-muconic acid using the PMPE Escherichia coli strain with high yield (0.31 g g-1 of glucose) and produce L-tyrosine with 64% of the theoretical yield. The PMPE strategy can contribute to the development of clean processes for producing various valuable chemicals from lignocellulosic resources.

Excessive Reactive Iron Impairs Hematopoiesis by Affecting Both Immature Hematopoietic Cells and Stromal Cells.

Iron overload is the accumulation of excess iron in the body that may occur as a result of various genetic disorders or as a consequence of repeated blood transfusions. The surplus iron is then stored in the liver, pancreas, heart and other organs, which may lead to chronic liver disease or cirrhosis, diabetes and heart disease, respectively. In addition, excessive iron may impair hematopoiesis, although the mechanisms of this deleterious effect is not entirely known. In this study, we found that ferrous ammonium sulfate (FeAS), induced growth arrest and apoptosis in immature hematopoietic cells, which was mediated via reactive oxygen species (ROS) activation of p38MAPK and JNK pathways. In in vitro hematopoiesis derived from embryonic stem cells (ES cells), FeAS enhanced the development of dysplastic erythroblasts but inhibited their terminal differentiation; in contrast, it had little effect on the development of granulocytes, megakaryocytes, and B lymphocytes. In addition to its directs effects on hematopoietic cells, iron overload altered the expression of several adhesion molecules on stromal cells and impaired the cytokine production profile of these cells. Therefore, excessive iron would affect whole hematopoiesis by inflicting vicious effects on both immature hematopoietic cells and stromal cells.