Possible cerebroprotective effect of citronellal: molecular docking, MD simulation and in vivo investigations.

This study focused on molecular docking, dynamic simulation, and in vivo approaches to examine the molecular interactions between citronellal (CT) and neurotoxic proteins. In silico studies of CT were performed using proteins involved in the pathophysiology of stroke, such as interleukin-6 (IL-6), interleukin-12 (IL-12), TNF-α, and nitric oxide synthase (NOS), to determine the binding affinity based on their interactions. The docking results of CT revealed that, among the targets, NOS had a better binding energy of -6.4 Kcal/mol. NOS showed good hydrophobic interactions: TYR A, 347; VAL A, 352; PRO A, 350; TYR A, 373 amino acids. Interactions with IL-6, TNF-α, and IL-12 resulted in lower binding affinities of -3.7, -3.9 and -3.1 Kcal/mol. Based on molecular dynamics simulations of 100 ns, the binding affinity of CT (-66.782 ± 7.309 kJ/mol) was well complemented, and NOS stability at the docked site was confirmed. In in vivo studies, cerebral stroke was induced by occlusion of the bilateral common carotid arteries for 30 min and reperfusion for 4 h. CT treatment protected the brain by decreasing cerebral infarction size, increasing GSH(p < 0.001***), decreasing MPO (p < 0.001***), MDA (p < 0.001***), NO production (p < 0.01**), and AChE (p < 0.001***) compared to stroke rats. Histopathological examination revealed that CT treatment reduced the severity of cerebral damage. The investigation concluded that CT strongly binds to NOS, as observed in molecular docking and dynamic simulation studies, which are involved in nitric oxide production, leading to cerebral damage, and CT treatment reduces NO production and oxidative stress parameters, and increases antioxidants via inhibition of NOS function.Communicated by Ramaswamy H. Sarma.

Acute decompensated heart failure (ADHF) during COVID-19 pandemic-insights from South India.

AIM: This retrospective study compares admissions and outcomes due to acute decompensated heart failure (ADHF) during the COVID-19 pandemic from 25 March to 25 July 2020 with the historical patient control who were admitted during the same period in 2019. METHODS AND RESULTS: Data of the participating hospitals was collected and analysed from the ICC NHFR (Indian College of Cardiology National Heart Failure Registry) for 2019 and 2020. Total number of ADHF admissions, demographics, aetiology, co-morbid conditions and in-hospital mortality was compared and analysed. A significant decrease in the number of hospital admissions due to ADHF from 2019 to 2020 (1056 vs. 526 respectively) was noted. Incidence of admissions with <40% ejection fraction (EF) reduced in 2020 (72.4% and 80.2% in2020 and 2019)and >40% (EF) increased (27.6% and 19.8% in 2019 and 2020 respectively, p = 0.0005). Ischemic heart disease (IHD) was the most common aetiology (78.59% in 2019 and 80.98% in 2020, p = 0.268). The in-hospital mortality was numerically higher in 2020 (10%) than in 2019 (8%), but not statistically significant (p = 0.161). CONCLUSION: This study from the registry shows that the incidence of ADHF admissions during COVID-19 lockdown significantly reduced compared to the previous year. Demographic patterns remained similar but patients presenting with de-novo HF increased; IHD was the most common cause. The in-hospital mortality was numerically higher during the lockdown. The impact of lockdown perhaps led to fewer hospitalisations and this is to be factored in future strategies to address health care delivery during such crises.

A new cerebral ischemic injury model in rats, preventive effect of gallic acid and in silico approaches.

Current study was designed multiple occlusions and reperfusion of bilateral carotid arteries induced cerebral injury model and evaluated the protective effect of gallic acid on it. In silico study was involved to study gallic acid binding affinity on cerebrotonic proteins compared with standard drugs using Autodoc vina tool. Cerebral ischemia was induced by occlusion of bilateral common carotid arteries for 10 mins followed by 10 reperfusions (1 cycle), cycle was continued to 3 cycles (MO/RCA), then pathological changes were observed by estimation of brain antioxidants as superoxide dismutase, glutathione, catalase, oxidants like malonaldehyde, cerebral infarction area, histopathology, and study gallic acid treatment against cerebral injury. Gallic acid exhibited a strong binding affinity on targeted cerebrotoxic proteins. MO/RCA rat brain antioxidant levels were significantly decreased and increased MDA levels (p < 0.0001), Infarction size compared to sham rats. Gallic acid treatment rat brain MDA levels significantly decreased (p < 0.4476) and increased SOD (p < 0.0001), CAT (p < 0.0001), GSH (p < 0.0001), cerebral infarction area when compared to MO/RCA group. Developed model showed significant cerebral ischemic injury in rats, injury was ameliorated by Gallic acid treatment and in silico approaches also inhibit the cerebrotoxic protein function by targeting on active sites.

Mapping of the Q-utilization site (qut) required for antitermination of late transcription in bacteriophage lambda.

To locate the site required for transcription antitermination by the gene Q product, we constructed a plasmid containing the p'R promoter, the t'R1 terminator, and gene galK. We measured the galK expression in response to the lambda Q product supplied in trans, while deleting various portions of lambda DNA adjacent to p'R. The presence of the lambda p'R promoter together with the downstream DNA coding for only a 34-bp segment of 5'-proximal 6S RNA permits antitermination to occur, whereas deletions removing this segment abolish antitermination, as measured by galK expression, but do not affect the p'R promoter. Thus the 34-bp segment must contain the p'R-distal (right) boundary of the Q-specific recognition site qut (Fig. 1). The Q-mediated antitermination appears to be p'R-qut specific but not t'R1 specific, since it does not operate with the pp-t'R1 assembly, but is also effective with terminators other than t'R1, e.g., with the combination of the p'R-qut-tL3 modules.

Antisense RNA does not significantly affect expression of the galK gene of Escherichia coli or the N gene of coliphage lambda.

The effect of antisense RNA on the expression of genes galK and N was studied in vivo. These two genes were either present in the Escherichia coli chromosome, as single copies, or were cloned on plasmid vectors. Antisense RNA was supplied from multicopy vectors where the entire galK or N gene, or only their N-proximal portions, were cloned in the antisense orientation downstream from the strong PL, PR or lacZp promoters. In all of the experiments there was no significant inhibition of the galK or N expression by up to a 50-fold excess of the specific antisense RNAs, for both the in cis and in trans experimental designs. The excess of the antisense RNA was calculated as based on respective copy numbers, but was not experimentally measured. The apparent five-fold regulatory effect observed in one of the experiments was found to be artifactually caused by unexpected creation of a terminator in one of our constructs. To avoid such artifacts, all our constructs were equipped with the nut-N antitermination system. We conclude that the reported antimessenger-mediated inhibition of gene expression is not a general phenomenon, but must require some special features which are not present in the galK and N systems.

Sequence changes in coliphage lambda mutants affecting the nutL antitermination site and termination by tL1 and tL2.

The 17-bp sequence designated nutL is required for the N-mediated antitermination of transcription in the major leftward operon of coliphage lambda. The single-stranded sequence can be folded into a hairpin structure. Ten independently isolated spontaneous lambda nutL- mutants have changes that affect the same nucleotide, located in the loop of the hairpin structure, changing the guanine to adenine, thymine or cytosine. Another mutant (lambda nutL3), selected by a different means, has a deletion of one GC base pair and thus eliminates one C in the stem of the hairpin structure, destabilizing it -11.2 to -2.2 kcal/mol. True reversions of the nutL point mutations restore the guanine. The second-site revertant lambda ninL99 was found to have a deletion of 417 bp between the tL1 terminator and the N gene, removing bases +523 to +939 (counted from SL = +1). This deletion include codons for the six carboxy-terminal amino acids of gene N product, but the fusion allows continuation of translation for 53 additional amino acid residues beyond the truncated N gene before reaching a nonsense codon. The fused N product is active.

The functional boundaries of the Q-utilization site required for antitermination of late transcription in bacteriophage lambda.

Expression of the late genes of bacteriophage lambda requires, in addition to the host functions, the lambda p'R promoter, the antiterminator sequence qut, and the product of gene Q which interacts with the Q utilization (qut) site. In the absence of the Q function or qut site, the p'R-initiated transcription is blocked by the t'R terminator at the 194th nucleotide downstream of the start point, s'R, producing a short 6 S mRNA. In this study the position and boundaries of the qut site were deduced by constructing plasmids containing various portions of the p'R-qut region, the t'R1 terminator, and the reporter gene galK. We measured galK gene expression in response to the gamma Q gene product supplied in trans by a prophage or Q-expression plasmid. We show that among the lambda proteins, the Q gene product alone is necessary and sufficient for complete qut-mediated transcription antitermination in vivo. These antitermination experiments, employing plasmids that contain different lengths of lambda p'R-qut sequence, identified the right boundary of the qut site, which is located between +4 and +18 (for s'R = +1). The functional left boundary of qut does not extend upstream from the -26th nucleotide of the p'R promoter, as based on the following experiments. The promoter function of the truncated (-26)p'R-s'R-(+18) sequence can be restored by fusion to the complete but qut-less p'R, pp, or PLac promoter; however, no antitermination was observed for such a p-(-26)p'R-s'R-(+18)-t'R-galK plasmid. Thus we conclude that the qut site partially overlaps with the p'R promoter sequence. However, promoters that contain the -10 region of p'R, s'R, and the +1 to +18 qut sequence did mediate Q-dependent antitermination when properly fused to the homologous or heterologous -35 promoter regions. Only those transcripts that start at s'R (+1 or very near to it) and also contain at least the first 18 nucleotides (actually greater than 4 and less than or equal to 18) of 6 S RNA appear to be a target for the Q-qut-mediated transcription antitermination, which acts not only at t'R but also at other Rho-independent or Rho-dependent terminators.

Expression and characterization of the tau subunit of phosphorylase kinase.

A cDNA encoding the entire tau subunit of rabbit skeletal muscle phosphorylase kinase was reconstructed and inserted into a plasmid containing the Escherichia coli ptac promoter and a constructed plasmid containing the ptac promoter and bacterial chloramphenicol acetyl transferase (CAT) gene, respectively. A significant phosphorylase kinase activity was found, in the first case. In the second case, a fused protein containing 73 amino acids from the CAT protein was obtained. After renaturation, the CAT-tau subunit protein shows enzymatic activity similar to the HPLC-purified and renatured tau subunit.