Explore the vast range of titles available.

Regeneration of complex multi-tissue structures, such as limbs, requires the coordinated effort of multiple cell types. In axolotl limb regeneration, the wound epidermis and blastema have been extensively studied via histology, grafting, and bulk-tissue RNA-sequencing. However, defining the contributions of these tissues is hindered due to limited information regarding the molecular identity of the cell types in regenerating limbs. Here we report unbiased single-cell RNA-sequencing on over 25,000 cells from axolotl limbs and identify a plethora of cellular diversity within epidermal, mesenchymal, and hematopoietic lineages in homeostatic and regenerating limbs. We identify regeneration-induced genes, develop putative trajectories for blastema cell differentiation, and propose the molecular identity of fibroblast-like blastema progenitor cells. This work will enable application of molecular techniques to assess the contribution of these populations to limb regeneration. Overall, these data allow for establishment of a putative framework for adult axolotl limb regeneration. Limb regeneration requires a blastema with progenitor cells, immune cells, and an overlying wound epidermis, but molecular identities of these populations are unclear. Here, the authors use single-cell RNA-sequencing to identify transcriptionally distinct cell populations in adult axolotl limb blastemas.

CRISPR–Cas13 systems have been developed for precise RNA editing, and can potentially be used therapeutically when temporary changes are desirable or when DNA editing is challenging. We have identified and characterized an ultrasmall family of Cas13b proteins—Cas13bt—that can mediate mammalian transcript knockdown. We have engineered compact variants of REPAIR and RESCUE RNA editors by functionalizing Cas13bt with adenosine and cytosine deaminase domains, and demonstrated packaging of the editors within a single adeno-associated virus. Compact Cas13 proteins are used to design RNA editors that fit into a single adeno-associated virus.

Axolotl salamanders are powerful models for understanding how regeneration of complex body parts can be achieved, whereas mammals are severely limited in this ability. Factors that promote normal axolotl regeneration can be examined in mammals to determine if they exhibit altered activity in this context. Furthermore, factors prohibiting axolotl regeneration can offer key insight into the mechanisms present in regeneration-incompetent species. We sought to determine if we could experimentally compromise the axolotl’s ability to regenerate limbs and, if so, discover the molecular changes that might underlie their inability to regenerate. We found that repeated limb amputation severely compromised axolotls’ ability to initiate limb regeneration. Using RNA-seq, we observed that a majority of differentially expressed transcripts were hyperactivated in limbs compromised by repeated amputation, suggesting that mis-regulation of these genes antagonizes regeneration. To confirm our findings, we additionally assayed the role of amphiregulin , an EGF-like ligand, which is aberrantly upregulated in compromised animals. During normal limb regeneration, amphiregulin is expressed by the early wound epidermis, and mis-expressing this factor lead to thickened wound epithelium, delayed initiation of regeneration, and severe regenerative defects. Collectively, our results suggest that repeatedly amputated limbs may undergo a persistent wound healing response, which interferes with their ability to initiate the regenerative program. These findings have important implications for human regenerative medicine. Persistent healing blocks salamander limb regeneration Understanding a roadblock to limb regeneration in salamanders could help develop suitable regenerative therapies for humans. Jessica Whited of the Harvard Stem Cell Institute and colleagues in the US found that repeatedly amputating a limb in Mexican salamanders compromised their normal ability to regenerate it. The team found high levels of a gene encoding a damage-protecting protein, called amphiregulin, at the wound site. Artificially inducing the expression of this gene in salamanders whose limbs were amputated just once also led to slow and poor regeneration. The findings suggest that high levels of amphiregulin induce a persistent wound-healing response that interferes with the salamanders’ ability to initiate regeneration. Pushing organisms with strong regenerative abilities into a non-regenerative state can help researchers understand the factors that limit human regenerative abilities and thus develop suitable therapies.

Tuberculosis (TB) is a disease caused by . Cessation of treatment before the recommended conclusion may lead to the emergence of multidrug-resistant strains. The aim of this study was to develop nanostructured lipid carriers (NLCs) for use in the treatment of . The NLCs comprised the following lipid phase: 2.07% polyoxyethylene 40 stearate, 2.05% caprylic/capric triglyceride, and 0.88% polyoxyl 40 hydrogenated castor oil; the following aqueous phase: 3.50% poloxamer 407 (F1-F6), and 0.50% cetyltrimethylammonium bromide (F7-F12); and incorporated the copper(II) complexes [CuCl (INH) ]·H O (1), [Cu(NCS) (INH) ]·5H O (2), and [Cu(NCO) (INH) ]·4H O (3) to form compounds F11.1, F11.2, and F11.3, respectively. The mean diameter of F11, F11.1, F11.2, and F11.3 ranged from 111.27±21.86 to 134.25±22.72 nm, 90.27±12.97 to 116.46±9.17 nm, 112.4±10.22 to 149.3±15.82 nm, and 78.65±6.00 to 122.00±8.70 nm, respectively. The polydispersity index values for the NLCs ranged from 0.13±0.01 to 0.30±0.09. The NLCs showed significant changes in zeta potential, except for F11.2, with F11, F11.1, F11.2, and F11.3 ranging from 18.87±4.04 to 23.25±1.13 mV, 17.03±1.77 to 21.42±1.87 mV, 20.51±1.88 to 22.60±3.44 mV, and 17.80±1.96 to 25.25±7.78 mV, respectively. Atomic force microscopy confirmed the formation of nanoscale spherical particle dispersions by the NLCs. Differential scanning calorimetry determined the melting points of the constituents of the NLCs. The in vitro activity of copper(II) complex-loaded NLCs against H R showed an improvement in the anti-TB activity of 55.4, 27.1, and 41.1 times the activity for complexes 1, 2, and 3, respectively. An in vivo acute toxicity study of complex-loaded NLCs demonstrated their reduced toxicity. The results suggest that NLCs may be a powerful tool to optimize the activity of copper(II) complexes against .

The commitment of differentiating cells to a specialized fate is fundamental to the correct assembly of tissues within a multicellular organism. Because commitment is often irreversible, entry into and progression through this phase of development must be tightly regulated. Under nitrogen-limiting conditions, the multicellular cyanobacterium Anabaena sp. strain PCC 7120 terminally commits ∼10% of its cells to become specialized nitrogen-fixing heterocysts. Although commitment is known to occur 9–14 h after the induction of differentiation, the factors that regulate the initiation and duration of this phase have yet to be elucidated. Here, we report the identification of four genes that share a functional domain and modulate heterocyst commitment: hetP (alr2818), asl1930, alr2902, and alr3234. Epistatic relationships between all four genes relating to commitment were revealed by deleting them individually and in combination; asl1930 and alr3234 acted most upstream to delay commitment, alr2902 acted next in the pathway to inhibit development, and hetP acted most downstream to drive commitment forward. Possible protein–protein interactions between HetP, its homologs, and the heterocyst master regulator, HetR, were assessed, and interaction partners were defined. Finally, patterns of gene expression for each homolog, as determined by promoter fusions to gfp and reverse transcription–quantitative PCR, were distinct from that of hetP in both spatiotemporal organization and regulation. We posit that a dynamic succession of protein–protein interactions modulates the timing and efficiency of the commitment phase of development and note that this work highlights the utility of a multicellular cyanobacterium as a model for the study of developmental processes.

The COVID-19 pandemic, caused by the coronavirus SARS-CoV-2, has impacted health across all sectors of society. A cytokine-release syndrome, combined with an inefficient response of innate immune cells to directly combat the virus, characterizes the severe form of COVID-19. While immune factors involved in the development of severe COVID-19 in the general population are becoming clearer, identification of the immune mechanisms behind severe disease in oncologic patients remains uncertain. Here we evaluated the systemic immune response through the analysis of soluble blood immune factors and anti-SARS-CoV-2 antibodies within the early days of a positive SARS-CoV-2 diagnostic in oncologic patients. Individuals with hematologic malignancies that went on to die from COVID-19 displayed at diagnosis severe leukopenia, low antibody production against SARS-CoV-2 proteins, and elevated production of innate immune cell recruitment and activation factors. These patients also displayed correlation networks in which IL-2, IL-13, TNF-alpha, IFN-gamma, and FGF2 were the focal points. Hematologic cancer patients that showed highly networked and coordinated anti-SARS-CoV-2 antibody production, with central importance of IL-4, IL-5, IL-12A, IL-15, and IL-17A, presented only mild COVID-19. Conversely, solid tumor patients that had elevated levels of inflammatory cytokines IL-6, CXCL8, and lost the coordinate production of anti-virus antibodies developed severe COVID-19 and died. Patients that displayed positive correlation networks between anti-virus antibodies, and a regulatory axis involving IL-10 and inflammatory cytokines recovered from the disease. We also provided evidence that CXCL8 is a strong predictor of death for oncologic patients and could be an indicator of poor prognosis within days of the positive diagnostic of SARS-CoV-2 infection. Our findings defined distinct systemic immune profiles associated with COVID-19 clinical outcome of patients with cancer and COVID-19. These systemic immune networks shed light on potential immune mechanisms involved in disease outcome, as well as identify potential clinically useful biomarkers.

Abstract Background: Factors at birth and infancy may increase risk of being overweight in childhood. The aim of this study was to examine the relationship of birth size and infant growth (2–24 months) with BMI at age 5 years in a multiethnic population. Methods: This was a retrospective study (using electronic medical records of a health maintenance organization in Hawaii) of singleton children born in 2004–2005, with linked maternal and birth information, infant weights (n = 597) and lengths (n = 473) in the first 2 years, and BMI measures at age 5 years (n = 894). Multiple regression models were used to estimate the association of BMI at age 5 years with birth size and infant growth. Results: Birth weight was positively associated with BMI at age 5 years, adjusting for gestational age, sex, race/ethnicity, and maternal prepregnancy weight, age, education, and smoking. A greater change in infant weight was associated with a higher BMI at age 5 years, though the effect of birth weight on BMI was neither mediated nor modified by infant growth rate. Birth weight, change in infant weight, and BMI at age 5 years varied by race/ethnicity. Change in infant BMI in the first 2 years was higher in other Pacific Islanders and whites (Δ = 0.966; confidence interval [CI] = 0.249–1.684; p = 0.02) than in Asian, other, and part Native Hawaiian race/ethnic groups. Conclusions: Early biological measures of birth weight and infant weight gain varied by race/ethnicity and positively predicted BMI at age 5 years.

Abstract Background: Pacific Islander, Asian, and mixed-ethnicity children are not described in national nutrition and health surveys. Methods: Data on BMI values of 4608 5- to 8-year-old children available from Kaiser Permanente Hawaii electronic medical records in 2010 were analyzed for prevalence of overweight and obesity and for ethnic differences in BMI and risk for overweight and obesity, controlling for age, sex, neighborhood education level, and on a subset (n=2169) that further controlled for maternal education and maternal age. Kaiser Permanente data allow for reporting of multiple ethnicities. Results: Data revealed that 33% of this child population was of mixed ethnic ancestry. Prevalence of overweight and obesity was 32.6% (12.9% overweight and 19.7% obese). However, Samoan children and children of Native Hawaiian, Filipino, and mixed ethnic ancestries had higher levels of overweight and obesity than whites or Asians. Higher neighborhood education level, higher maternal education level, and older maternal age were associated with decreased risk of overweight and obesity, except for children whose mothers were between 21 and 30 years old, who had a higher risk for obesity than those whose mothers were under 20 years of age (odds ratio=1.34). Conclusions: Populations of mixed ethnicities in the Pacific region deserve further study related to healthy body size and acculturation to environment and lifestyle.

Tuberculosis (TB) is a disease caused by Mycobacterium tuberculosis. Cessation of treatment before the recommended conclusion may lead to the emergence of multidrug-resistant strains. The aim of this study was to develop nanostructured lipid carriers (NLCs) for use in the treatment of M. tuberculosis. The NLCs comprised the following lipid phase: 2.07% polyoxyethylene 40 stearate, 2.05% caprylic/capric triglyceride, and 0.88% polyoxyl 40 hydrogenated castor oil; the following aqueous phase: 3.50% poloxamer 407 (F1-F6), and 0.50% cetyltrimethylammonium bromide (F7-F12); and incorporated the copper(II) complexes [Cu[Cl.sub.2][(INH).sub.2][H.sub.2]O (1), [Cu[(NCS).sub.2][(INH).sub.2]-5[H.sub.2]O (2), and [Cu[(NCO).sub.2][(INH).sub.2]]-4[H.sub.2]O (3) to form compounds F11.1, F11.2, and F11.3, respectively. The mean diameter of F11, F11.1, F11.2, and F11.3 ranged from 111.27[+ or -]21.86 to 134.25[+ or -]22.72 nm, 90.27[+ or -]12.97 to 116.46[+ or -]9.17 nm, 112.4[+ or -]10.22 to 149.3[+ or -]15.82 nm, and 78.65[+ or -]6.00 to 122.00[+ or -]8.70 nm, respectively. The polydispersity index values for the NLCs ranged from 0.13[+ or -]0.01 to 0.30[+ or -]0.09. The NLCs showed significant changes in zeta potential, except for F11.2, with F11, F11.1, F11.2, and F11.3 ranging from 18.87[+ or -]4.04 to 23.25[+ or -]1.13 mV, 17.03[+ or -]1.77 to 21.42[+ or -]1.87 mV, 20.51[+ or -]1.88 to 22.60[+ or -]3.44 mV, and 17.80[+ or -]1.96 to 25.25[+ or -]7.78 mV, respectively. Atomic force microscopy confirmed the formation of nanoscale spherical particle dispersions by the NLCs. Differential scanning calorimetry determined the melting points of the constituents of the NLCs. The in vitro activity of copper(II) complex-loaded NLCs against M. tuberculosis [H.sub.37][R.sub.v] showed an improvement in the anti-TB activity of 55.4, 27.1, and 41.1 times the activity for complexes 1, 2, and 3, respectively. An in vivo acute toxicity study of complex-loaded NLCs demonstrated their reduced toxicity. The results suggest that NLCs may be a powerful tool to optimize the activity of copper(II) complexes against M. tuberculosis. Keywords: tuberculosis, M. tuberculosis, nanostructured lipid carriers, copper(II) complex, in vitro activity, in vivo acute toxicity assay

Tuberculosis (TB) is a disease caused by Mycobacterium tuberculosis. Cessation of treatment before the recommended conclusion may lead to the emergence of multidrug-resistant strains. The aim of this study was to develop nanostructured lipid carriers (NLCs) for use in the treatment of M. tuberculosis. The NLCs comprised the following lipid phase: 2.07% polyoxyethylene 40 stearate, 2.05% caprylic/capric triglyceride, and 0.88% polyoxyl 40 hydrogenated castor oil; the following aqueous phase: 3.50% poloxamer 407 (F1-F6), and 0.50% cetyltrimethylammonium bromide (F7-F12); and incorporated the copper(II) complexes [Cu[Cl.sub.2][(INH).sub.2][H.sub.2]O (1), [Cu[(NCS).sub.2][(INH).sub.2]-5[H.sub.2]O (2), and [Cu[(NCO).sub.2][(INH).sub.2]]-4[H.sub.2]O (3) to form compounds F11.1, F11.2, and F11.3, respectively. The mean diameter of F11, F11.1, F11.2, and F11.3 ranged from 111.27[+ or -]21.86 to 134.25[+ or -]22.72 nm, 90.27[+ or -]12.97 to 116.46[+ or -]9.17 nm, 112.4[+ or -]10.22 to 149.3[+ or -]15.82 nm, and 78.65[+ or -]6.00 to 122.00[+ or -]8.70 nm, respectively. The polydispersity index values for the NLCs ranged from 0.13[+ or -]0.01 to 0.30[+ or -]0.09. The NLCs showed significant changes in zeta potential, except for F11.2, with F11, F11.1, F11.2, and F11.3 ranging from 18.87[+ or -]4.04 to 23.25[+ or -]1.13 mV, 17.03[+ or -]1.77 to 21.42[+ or -]1.87 mV, 20.51[+ or -]1.88 to 22.60[+ or -]3.44 mV, and 17.80[+ or -]1.96 to 25.25[+ or -]7.78 mV, respectively. Atomic force microscopy confirmed the formation of nanoscale spherical particle dispersions by the NLCs. Differential scanning calorimetry determined the melting points of the constituents of the NLCs. The in vitro activity of copper(II) complex-loaded NLCs against M. tuberculosis [H.sub.37][R.sub.v] showed an improvement in the anti-TB activity of 55.4, 27.1, and 41.1 times the activity for complexes 1, 2, and 3, respectively. An in vivo acute toxicity study of complex-loaded NLCs demonstrated their reduced toxicity. The results suggest that NLCs may be a powerful tool to optimize the activity of copper(II) complexes against M. tuberculosis. Keywords: tuberculosis, M. tuberculosis, nanostructured lipid carriers, copper(II) complex, in vitro activity, in vivo acute toxicity assay