Heterologous reporter expression in the planarian Schmidtea mediterranea through somatic mRNA transfection

Planarians have long been studied for their regenerative abilities. Moving forward, tools for ectopic expression of non-native proteins will be of substantial value. Using a luminescent reporter to overcome the strong autofluorescence of planarian tissues, we demonstrate heterologous protein expression in planarian cells and live animals. Our approach is based on the introduction of mRNA through several nanotechnological and chemical transfection methods. We improve reporter expression by altering untranslated region (UTR) sequences and codon bias, facilitating the measurement of expression kinetics in both isolated cells and whole planarians using luminescence imaging. We also examine protein expression as a function of variations in the UTRs of delivered mRNA, demonstrating a framework to investigate gene regulation at the post-transcriptional level. Together, these advances expand the toolbox for the mechanistic analysis of planarian biology and establish a foundation for the development and expansion of transgenic techniques in this unique model system

The rs738409 (I148M) Variant of the PNPLA3 Gene and Type 2 Diabetes in Yakutia

The purpose of our research was to study the association of the PNPLA3 SNP rs738409 (C>G) with type 2 diabetes (T2D) in the Yakuts. The frequency distribution of alleles and genotypes of the PNPLA3 rs738409 SNP was in accordance with HWE. There were no statistically significant differences in the distribution of alleles and genotypes of the PNPLA3 SNP rs738409 (C>G) between T2D patients and non-T2D patients (P>0.05); the G allele and homozygous GG genotype prevailed in both groups. In T2D patients, a high frequency of the G allele (74.1%) was found, with a predominance of the GG genotype (58.5%). We also found that the mutant allele frequency is higher than in the studied populations of the world. Further studies with larger sample size are required to achieve sufficient statistical power to detect the association of the PNPLA3 SNP (rs738409 with the development of T2D in Yakut patients

Nanoengineered Osteoinductive and Elastomeric Scaffolds for Bone Tissue Engineering

Synthesis and fabrication of porous and elastomeric nanocomposite scaffolds from biodegradable poly(glycerol sebacate) (PGS) and osteoinductive nanosilicates is reported. Nanosilicates are mineral-based two-dimensional (2D) nanomaterials with high surface area which reinforced PGS network. The addition of nanosilicates to PGS resulted in mechanically stiff and elastomeric nanocomposites. The degradation rate and mechanical stiffness of nanocomposite network could be modulated by addition of nanosilicates. Nanocomposite scaffolds supported cell adhesion, spreading, and proliferation and promoted osteogenic differentiation of preosteoblasts. The addition of nanosilicates to PGS scaffolds increased alkaline phosphatase (ALP) activity and production of matrix mineralization. In vivo studies demonstrated biocompatibility and biodegradability of nanocomposite scaffolds. Overall, the combination of elasticity and tailorable stiffness, tunable degradation profiles, and the osteoinductive capability of the scaffolds offer a promising approach for bone tissue engineering

Mechanically resolved imaging of bacteria using expansion microscopy.

Imaging dense and diverse microbial communities has broad applications in basic microbiology and medicine, but remains a grand challenge due to the fact that many species adopt similar morphologies. While prior studies have relied on techniques involving spectral labeling, we have developed an expansion microscopy method (μExM) in which bacterial cells are physically expanded prior to imaging. We find that expansion patterns depend on the structural and mechanical properties of the cell wall, which vary across species and conditions. We use this phenomenon as a quantitative and sensitive phenotypic imaging contrast orthogonal to spectral separation to resolve bacterial cells of different species or in distinct physiological states. Focusing on host-microbe interactions that are difficult to quantify through fluorescence alone, we demonstrate the ability of μExM to distinguish species through an in vitro defined community of human gut commensals and in vivo imaging of a model gut microbiota, and to sensitively detect cell-envelope damage caused by antibiotics or previously unrecognized cell-to-cell phenotypic heterogeneity among pathogenic bacteria as they infect macrophages

Heterogeneity of health status treatment response with sacubitril/valsartan: insights from the CHAMP-HF registry.

AimsThe aim of our study was to investigate heterogeneity of health status treatment response of sacubitril/valsartan in patients with heart failure with reduced ejection fraction (HFrEF).Methods and resultsWe leveraged data from CHAMP-HF, an observational registry of 140 US clinics and 5026 outpatients with chronic HFrEF, where health status was serially assessed using the Kansas City Cardiomyopathy Questionnaire (KCCQ)-12 Overall Summary Scale (range from 0 to 100; ≥20-point improvement is a very large improvement). In 334 patients newly initiated on sacubitril/valsartan, we used hierarchical multivariable logistic regression (13 patient-level characteristics as well as baseline KCCQ-12 score) to calculate the odds ratio (OR) of any characteristic being associated with a very large health status improvement. A total of 104/334 (31.1%) of patients achieved the primary endpoint, where only worse baseline health status [KCCQ-12 score of 0-60 points had an OR = 0.86/5-point higher score (CI 0.79, 0.93)], and those with a KCCQ-12 score of 60-80 points had an OR = 0.61/5-point higher score (0.45-0.82), which was associated with a very large benefit. No other patient characteristic was associated with a very large health status improvement (P > 0.05).ConclusionsWe found that, after initiation of sacubitril/valsartan, only worse baseline health status was associated with very large health status improvement. Accordingly, a trial of therapy-particularly in those with worse symptoms, function, and quality of life-and assessing treatment response are likely to be the best prospective strategy

Alleviating Cell Lysate-Induced Inhibition to Enable RT-PCR from Single Cells in Picoliter-Volume Double Emulsion Droplets

Microfluidic droplet assays enable single-cell polymerase chain reaction (PCR) and sequencing analyses at unprecedented scales, with most methods encapsulating cells within nanoliter-sized single emulsion droplets (water-in-oil). Encapsulating cells within picoliter double emulsion (DE) (water-in-oil-in-water) allows sorting droplets with commercially available fluorescence-activated cell sorter (FACS) machines, making it possible to isolate single cells based on phenotypes of interest for downstream analyses. However, sorting DE droplets with standard cytometers requires small droplets that can pass FACS nozzles. This poses challenges for molecular biology, as prior reports suggest that reverse transcription (RT) and PCR amplification cannot proceed efficiently at volumes below 1 nL due to cell lysate-induced inhibition. To overcome this limitation, we used a plate-based RT-PCR assay designed to mimic reactions in picoliter droplets to systematically quantify and ameliorate the inhibition. We find that RT-PCR is blocked by lysate-induced cleavage of nucleic acid probes and primers, which can be efficiently alleviated through heat lysis. We further show that the magnitude of inhibition depends on the cell type, but that RT-PCR can proceed in low-picoscale reaction volumes for most mouse and human cell lines tested. Finally, we demonstrate one-step RT-PCR from single cells in 20 pL DE droplets with fluorescence quantifiable via FACS. These results open up new avenues for improving picoscale droplet RT-PCR reactions and expanding microfluidic droplet-based single-cell analysis technologies