Strain dependent rat iNOS promoter activity--correlation to identified WT1 transcription factor binding site

Construction and characterization of a promoter library with varying strengths to enhance acetoin production from xylose in Serratia marcescens

Serratia marcescens is utilized as a significant enterobacteria in the production of various high-value secondary metabolites. Acetoin serves as a crucial foundational compound of development and finds application in a broad range of fields. Furthermore, S. marcescens HBQA-7 is capable of utilizing xylose as its exclusive carbon source for acetoin production. The objective of this study was to utilize a constitutive promoter screening strategy to enhance both xylose utilization and acetoin production in S. marcescens HBQA-7. By utilizing RNA-seq, we identified the endogenous constitutive promoter P6 that is the most robust, which facilitated the overexpression of the sugar transporter protein GlfL445I, α-acetyl lactate synthase, and α-acetyl lactate decarboxylase, respectively. The resultant recombinant strains exhibited enhanced xylose utilization rates and acetoin yields. Subsequently, a recombinant plasmid, denoted as pBBR1MCS-P6-glfL445IalsSalsD, was constructed, simultaneously expressing the aforementioned three genes. The resulting recombinant strain, designated as S3, demonstrated a 1.89-fold boost in xylose consumption rate compared with the original strain during shake flask fermentation. resulting in the accumulation of 7.14 g/L acetoin in the final fermentation medium. Subsequently, in a 5 L fermenter setup, the acetoin yield reached 48.75 g/L, corresponding to a xylose-to-acetoin conversion yield of 0.375 g/g.

Central nervous system, peripheral and hemodynamic effects of nanoformulated anandamide in hypertension

PURPOSE

Hypertensive lesions induce alterations at hemodynamic, peripheral, and central levels. Anandamide (N-arachidonoylethanolamine; AEA) protects neurons from inflammatory damage, but its free administration may cause central adverse effects. AEA controlled release by nanoformulations could reduce/eliminate its side effects. The present study aimed to evaluate the effects of nanoformulated AEA (nf-AEA) on systolic blood pressure (SBP), behavior, and central/peripheral inflammatory, oxidative, and apoptotic state in spontaneously hypertensive rats (SHR).

MATERIALS/METHODS

Male rats were used, both Wistar Kyoto (WKY) and SHR (n ​= ​10 per group), with/without treatment with nf-AEA (obtained by electrospraying) at a weekly dose of 5 ​mg/kg IP for 4 weeks. SBP was measured and behavioral tests were performed. Inflammatory/oxidative markers were quantified at the central (brain cortex) and peripheral (serum) level.

RESULTS

SHR showed hyperactivity, low anxiety, and high concentrations of central/peripheral inflammatory/oxidative markers, also higher apoptosis of brain cortical cells compared to WKY. As opposed to this group, treatment with nf-AEA in SHR significantly reduced SBP, peripheral/central inflammatory/oxidative makers, and central apoptosis. Nf-AEA also increased neuroprotective mechanisms mediated by intracellular heat shock protein 70 (Hsp70), which were attenuated in untreated SHR. Additionally, nf-AEA reversed the abnormal behaviors observed in SHR without producing central adverse effects.

CONCLUSIONS

Our results suggest protective properties of nf-AEA, both peripherally and centrally, through a signaling pathway that would involve the type I angiotensin II receptor, Wilms tumor transcription factor 1, Hsp70, and iNOS. Considering non-nf-AEA limitations, this nanoformulation could contribute to the development of new antihypertensive and behavioral disorder treatments associated with neuroinflammation.

Alterations on a key nephrogenic/cardiogenic gene expression linked to hypertension development

The elevation of blood pressure produces specific organic lesions, including kidney and cardiac damage. On the other hand, cardiovascular disease usually leads to the development of hypertension. Thus, hypertension could be both a cause and a consequence of cardiovascular disease. Previous studies linked the lack of nitric oxide to cardiovascular abnormalities, including hypertension, arteriosclerosis, myocardial infarction, cardiac hypertrophy, diastolic heart failure, and reduced endothelium-derived hyperpolarizing factor responses, with shorter survival. The lack of this gas also leads to renal/cardiac abnormalities. It is widely known that nephrogenic deficiency is a risk factor for kidney disease. Besides, recent evidence suggests that alterations in WT-1, a key nephrogenic factor, could contribute to the development of hypertension. Moreover, some genes involved in the development of hypertension depend on WT-1. This knowledge makes it essential to investigate and understand the mechanisms regulating the expression of these genes during renal/cardiac development, and hypertension. As a consequence, the most in-depth knowledge of the complex aetiopathogenic mechanism responsible for the hypertensive disease will allow us to propose novel therapeutic tools.

Mediators and mechanisms of heat shock protein 70 based cytoprotection in obstructive nephropathy

Urinary heat shock protein 70 (Hsp70) is rapidly increased in patients with clinical acute kidney injury, indicating that it constitutes a component of the endogenous stress response to renal injury. Moreover, experimental models have demonstrated that Hsp70 activation is associated with the cytoprotective actions of several drugs following obstruction, including nitric oxide (NO) donors, geranylgeranylacetone, vitamin D, and rosuvastatin. Discrete and synergistic effects of the biological activities of Hsp70 may explain its cytoprotective role in obstructive nephropathy. Basic studies point to a combination of effects including inhibition of apoptosis and inflammation, repair of damaged proteins, prevention of unfolded protein aggregation, targeting of damaged protein for degradation, and cytoskeletal stabilization as primary effectors of Hsp70 action. This review summarizes our understanding of how the biological actions of Hsp70 may affect renal cytoprotection in the context of obstructive injury. The potential of Hsp70 to be of central importance to the mechanism of action of various drugs that modify the genesis of experimental obstructive nephropathy is considered.

Mechanisms of transcriptional regulation by WT1 (Wilms' tumour 1)

The WT1 (Wilms' tumour 1) gene encodes a zinc finger transcription factor and RNA-binding protein that direct the development of several organs and tissues. WT1 manifests both tumour suppressor and oncogenic activities, but the reasons behind these opposing functions are still not clear. As a transcriptional regulator, WT1 can either activate or repress numerous target genes resulting in disparate biological effects such as growth, differentiation and apoptosis. The complex nature of WT1 is exemplified by a plethora of isoforms, post-translational modifications and multiple binding partners. How WT1 achieves specificity to regulate a large number of target genes involved in diverse physiological processes is the focus of the present review. We discuss the wealth of the growing molecular information that defines our current understanding of the versatility and utility of WT1 as a master regulator of organ development, a tumour suppressor and an oncogene.

Wt-1 Expression Linked to Nitric Oxide Availability during Neonatal Obstructive Nephropathy

The wt-1 gene encodes a zinc finger DNA-binding protein that acts as a transcriptional activator or repressor depending on the cellular or chromosomal context. The wt-1 regulates the expression of a large number of genes that have a critical role in kidney development. Congenital obstructive nephropathy disrupts normal renal development and causes chronic progressive interstitial fibrosis, which contributes to renal growth arrest, ultimately leading to chronic renal failure. Wt-1 is downregulated during congenital obstructive nephropathy, leading to apoptosis. Of great interest, nitric oxide bioavailability associated with heat shock protein 70 (Hsp70) interaction may modulate wt-1 mRNA expression, preventing obstruction-induced cell death during neonatal unilateral ureteral obstruction. Moreover, recent genetic researches have allowed characterization of many of the complex interactions among the individual components cited, but the realization of new biochemical, molecular, and functional experiments as proposed in our and other research labs allows us to establish a deeper level of commitment among proteins involved and the potential pathogenic consequences of their imbalance.

Role of the mitochondria in immune-mediated apoptotic death of the human pancreatic β cell line βLox5

Mitochondria are indispensable in the life and death of many types of eukaryotic cells. In pancreatic beta cells, mitochondria play an essential role in the secretion of insulin, a hormone that regulates blood glucose levels. Unregulated blood glucose is a hallmark symptom of diabetes. The onset of Type 1 diabetes is preceded by autoimmune-mediated destruction of beta cells. However, the exact role of mitochondria has not been assessed in beta cell death. In this study, we examine the role of mitochondria in both Fas- and proinflammatory cytokine-mediated destruction of the human beta cell line, βLox5. IFNγ primed βLox5 cells for apoptosis by elevating cell surface Fas. Consequently, βLox5 cells were killed by caspase-dependent apoptosis by agonistic activation of Fas, but only after priming with IFNγ. This beta cell line undergoes both apoptotic and necrotic cell death after incubation with the combination of the proinflammatory cytokines IFNγ and TNFα. Additionally, both caspase-dependent and -independent mechanisms that require proper mitochondrial function are involved. Mitochondrial contributions to βLox5 cell death were analyzed using mitochondrial DNA (mtDNA) depleted βLox5 cells, or βLox5 ρ⁰ cells. βLox5 ρ⁰ cells are not sensitive to IFNγ and TNFα killing, indicating a direct role for the mitochondria in cytokine-induced cell death of the parental cell line. However, βLox5 ρ⁰ cells are susceptible to Fas killing, implicating caspase-dependent extrinsic apoptotic death is the mechanism by which these human beta cells die after Fas ligation. These data support the hypothesis that immune mediators kill βLox5 cells by both mitochondrial-dependent intrinsic and caspase-dependent extrinsic pathways.

Regulation of the expression of inducible nitric oxide synthase

The role of nitric oxide (NO) generated by the inducible isoform of nitric oxide synthase (iNOS) is very complex. Induction of iNOS expression and hence NO production has been described to have beneficial antiviral, antiparasital, microbicidal, immunomodulatory, and antitumoral effects. However, induced at the wrong place or at the wrong time, iNOS has detrimental consequences and seems to be involved in the pathophysiology of different human diseases. The pathways regulating iNOS expression seem to vary in different cells or different species. In general, activation of the transcription factors nuclear factor (NF)-kappaB and signal transducer and activator of transcription (STAT)-1alpha and thereby activation of the iNOS promoter seems to be an essential step in the regulation of iNOS expression in most cells. Also, post-transcriptional mechanisms are critically involved in the regulation of iNOS expression.