TRF1 uses a noncanonical function of TFIIH to promote telomere replication.

Telomeric DNA challenges the replisome and requires TRF1 for efficient duplication. TRF1 recruits the BLM helicase, but BLM loss does not explain the extensive telomere fragility, ATR signaling, and sister telomere associations (STAs) induced by TRF1 deletion. Here, we document that Helix2 of the TRFH domain and Helix1 of the Myb domain of TRF1 are required for efficient telomere replication. Mutation of both helices generated a TRF1 separation-of-function mutant (TRF1-E83K/LW-TI) that induced severe telomere replication defects but no ATR signaling or STAs. We identified the transcription and nucleotide excision repair (NER) factor TFIIH as a critical effector of TRF1. Loss of TFIIH subunits, but no other NER factors, caused the same telomere replication phenotypes as the TRF1-E83K/LW-TI mutant independent of the effects on TRF1 expression. TFIIH subunits coimmunoprecipitated with wild-type TRF1 but not with TRF1-E83K/LW-TI. These results establish that the major mechanism by which TRF1 ensures telomere replication involves a noncanonical function of TFIIH.

Cutaneous-immuno-neuro-endocrine (CINE) system: A complex enterprise transforming skin into a super organ.

Skin is now emerging as a complex realm of three chief systems viz. immune system, nervous system, and endocrine system. The cells involved in their intricate crosstalk, namely native skin cells, intra-cutaneous immune cells and cutaneous sensory neurons have diverse origin and distinct functions. However, recent studies have explored their role beyond their pre-defined functional boundaries, such that the cells shun their traditional functions and adopt unconventional roles. For example, the native skin cells, apart from providing for basic structural framework of skin, also perform special immune functions and participate in extensive neuro-endocrine circuitry, which were traditionally designated as functions of cutaneous resident immune cells and sensory neurons respectively. At the cellular level, this unique collaboration is brought out by special molecules called neuromediators including neurotransmitters, neuropeptides, neurotrophins, neurohormones and cytokines/chemokines. While this intricate crosstalk is essential for maintaining cutaneous homeostasis, its disruption is seen in various cutaneous diseases. Recent study models have led to a paradigm shift in our understanding of pathophysiology of many such disorders. In this review, we have described in detail the interaction of immune cells with neurons and native skin cells, role of neuromediators, the endocrine aspect in skin and current understanding of cutaneous neuro-immuno-endocrine loop in one of the commonest skin diseases, psoriasis. An accurate knowledge of this unique crosstalk can prove crucial in understanding the pathophysiology of different skin diseases and allow for generation of targeted therapeutic modalities.

Raman Spectroscopy on Free-Base Meso-tetra(4-pyridyl) Porphyrin under Conditions of Low Temperature and High Hydrostatic Pressure.

We present a Raman spectroscopy study of the vibrational properties of free-base meso-tetra(4-pyridyl) porphyrin polycrystals under various temperature and hydrostatic pressure conditions. The combination of experimental results and Density Functional Theory (DFT) calculations allows us to assign most of the observed Raman bands. The modifications in the Raman spectra when excited with 488 nm and 532 nm laser lights indicate that a resonance effect in the Qy band is taking place. The pressure-dependent results show that the resonance conditions change with increasing pressure, probably due to the shift of the electronic transitions. The temperature-dependent results show that the relative intensities of the Raman modes change at low temperatures, while no frequency shifts are observed. The experimental and theoretical analysis presented here suggest that these molecules are well represented by the C2v point symmetry group.

Intestinal Host Response to SARS-CoV-2 Infection and COVID-19 Outcomes in Patients With Gastrointestinal Symptoms.

BACKGROUND & AIMS: Given that gastrointestinal (GI) symptoms are a prominent extrapulmonary manifestation of COVID-19, we investigated intestinal infection with SARS-CoV-2, its effect on pathogenesis, and clinical significance. METHODS: Human intestinal biopsy tissues were obtained from patients with COVID-19 (n = 19) and uninfected control individuals (n = 10) for microscopic examination, cytometry by time of flight analyses, and RNA sequencing. Additionally, disease severity and mortality were examined in patients with and without GI symptoms in 2 large, independent cohorts of hospitalized patients in the United States (N = 634) and Europe (N = 287) using multivariate logistic regressions. RESULTS: COVID-19 case patients and control individuals in the biopsy cohort were comparable for age, sex, rates of hospitalization, and relevant comorbid conditions. SARS-CoV-2 was detected in small intestinal epithelial cells by immunofluorescence staining or electron microscopy in 15 of 17 patients studied. High-dimensional analyses of GI tissues showed low levels of inflammation, including down-regulation of key inflammatory genes including IFNG, CXCL8, CXCL2, and IL1B and reduced frequencies of proinflammatory dendritic cells compared with control individuals. Consistent with these findings, we found a significant reduction in disease severity and mortality in patients presenting with GI symptoms that was independent of sex, age, and comorbid illnesses and despite similar nasopharyngeal SARS-CoV-2 viral loads. Furthermore, there was reduced levels of key inflammatory proteins in circulation in patients with GI symptoms. CONCLUSIONS: These data highlight the absence of a proinflammatory response in the GI tract despite detection of SARS-CoV-2. In parallel, reduced mortality in patients with COVID-19 presenting with GI symptoms was observed. A potential role of the GI tract in attenuating SARS-CoV-2-associated inflammation needs to be further examined.

Erratum: Anharmonicity and Universal Response of Linear Carbon Chain Mechanical Properties under Hydrostatic Pressure [Phys. Rev. Lett. 125, 105501 (2020)].

This corrects the article DOI: 10.1103/PhysRevLett.125.105501.

Erratum: Anharmonicity and Universal Response of Linear Carbon Chain Mechanical Properties under Hydrostatic Pressure [Phys. Rev. Lett. 125, 105501 (2020)].

This corrects the article DOI: 10.1103/PhysRevLett.125.105501.

The heterologous expression of conserved Glycine max (soybean) mitogen activated protein kinase 3 (MAPK3) paralogs suppresses Meloidogyne incognita parasitism in Gossypium hirsutum (upland cotton).

Two conserved Glycine max (soybean) mitogen activated protein kinase 3 (MAPK3) paralogs function in defense to the parasitic soybean cyst nematode Heterodera glycines. Gene Ontology analyses of RNA seq data obtained from MAPK3-1-overexpressing (OE) and MAPK3-2-OE roots compared to their control, as well as MAPK3-1-RNA interference (RNAi) and MAPK3-2-RNAi compared to their control, hierarchically orders the induced and suppressed genes, strengthening the hypothesis that their heterologous expression in Gossypium hirsutum (upland cotton) would impair parasitism by the root knot nematode (RKN) Meloidogyne incognita. MAPK3-1 expression (E) in G. hirsutum suppresses the production of M. incognita root galls, egg masses, and second stage juveniles (J2s) by 80.32%, 82.37%, and 88.21%, respectfully. Unexpectedly, egg number increases by 28.99% but J2s are inviable. MAPK3-2-E effects are identical, statistically. MAPK3-1-E and MAPK3-2-E decreases root mass 1.49-fold and 1.55-fold, respectively, as compared to the pRAP15-ccdB-E control. The reproductive factor (RF) of M. incognita for G. hirsutum roots expressing MAPK3-1-E or MAPK3-2-E decreases 60.39% and 50.46%, respectively, compared to controls. The results are consistent with upstream pathogen activated molecular pattern (PAMP) triggered immunity (PTI) and effector triggered immunity (ETI) functioning in defense to H. glycines. The experiments showcase the feasibility of employing MAPK3, through heterologous expression, to combat M. incognita parasitism, possibly overcoming impediments otherwise making G. hirsutum's defense platform deficient. MAPK homologs are identified in other important crop species for future functional analyses.

Thermodynamics of Linear Carbon Chains.

Linear carbon chains (LCCs) are one-dimensional materials with unique properties, including high Debye temperatures and restricted selection rules for phonon interactions. Consequently, their Raman C-band frequency's temperature dependence is a probe to their thermal properties, which are well described within the Debye formalism even at room temperatures. Therefore, with the basis on a semiempirical approach we show how to use the C band to evaluate the LCCs' internal energy, heat capacity, coefficient of thermal expansion, thermal strain, and Grüneisen parameter, providing universal relations for these quantities in terms of the number of carbons atoms and the temperature.

Anharmonicity and Universal Response of Linear Carbon Chain Mechanical Properties under Hydrostatic Pressure.

Isolated linear carbon chains (LCCs) encapsulated by multiwalled carbon nanotubes are studied under hydrostatic pressure (P) via resonance Raman scattering. The LCCs' spectroscopic signature C band around 1850 cm^{-1} softens linearly with increasing P. A simple anharmonic force-constant model not only describes such softening but also shows that the LCCs' Young's modulus (E), Grüneisen parameter (γ), and strain (ϵ) follow universal P^{-1} and P^{2} laws, respectively. In particular, γ also presents a unified behavior for all LCCs. To the best of our knowledge, these are the first results reported on such isolated systems and the first work to explore universal P-dependent responses for LCCs' E, ϵ, and γ.

Syntaxin 31 functions in Glycine max resistance to the plant parasitic nematode Heterodera glycines.

A Glycine max syntaxin 31 homolog (Gm-SYP38) was identified as being expressed in nematode-induced feeding structures known as syncytia undergoing an incompatible interaction with the plant parasitic nematode Heterodera glycines. The observed Gm-SYP38 expression was consistent with prior gene expression analyses that identified the alpha soluble NSF attachment protein (Gm-α-SNAP) resistance gene because homologs of these genes physically interact and function together in other genetic systems. Syntaxin 31 is a protein that resides on the cis face of the Golgi apparatus and binds α-SNAP-like proteins, but has no known role in resistance. Experiments presented here show Gm-α-SNAP overexpression induces Gm-SYP38 transcription. Overexpression of Gm-SYP38 rescues G. max [Williams 82/PI 518671], genetically rhg1 (-/-), by suppressing H. glycines parasitism. In contrast, Gm-SYP38 RNAi in the rhg1 (+/+) genotype G. max [Peking/PI 548402] increases susceptibility. Gm-α-SNAP and Gm-SYP38 overexpression induce the transcriptional activity of the cytoplasmic receptor-like kinase BOTRYTIS INDUCED KINASE 1 (Gm-BIK1-6) which is a family of defense proteins known to anchor to membranes through a 5' MGXXXS/T(R) N-myristoylation sequence. Gm-BIK1-6 had been identified previously by RNA-seq experiments as expressed in syncytia undergoing an incompatible reaction. Gm-BIK1-6 overexpression rescues the resistant phenotype. In contrast, Gm-BIK1-6 RNAi increases parasitism. The analysis demonstrates a role for syntaxin 31-like genes in resistance that until now was not known.

Facile synthesis of Ag NPs@MgO nanosheets for quantitative SERS-based detection and removal of hazardous organic pollutants.

Surface-enhanced Raman spectroscopy (SERS) is a highly precise and non-invasive analytical method known for its ability to detect vibrational signatures of minute analytes with exceptional sensitivity. However, the efficacy of SERS is subject to substrate properties, and current methodologies face challenges in attaining consistent, replicable, and stable substrates to regulate plasma hot spots across a wide spectral range. This study introduces a straightforward and economical approach that incorporates monodispersed silver nanoparticles onto 2-D porous magnesium oxide nanosheets (Ag@MgO-NSs) through an in-situ process. The resulting nanocomposite, Ag@MgO-NSs, demonstrates substantial SERS enhancement owing to its distinctive plasmonic resonance. The effectiveness of this nanocomposite is exemplified by depositing diverse environmental pollutants as analytes, such as antibiotic ciprofloxacin (CIP), organic dyes like rhodamine 6G (R6G) and methylene blue (MB), and nitrogen-rich pollutant like melamine (MLN), onto the proposed substrate. The proposed nanocomposite features a 2-D porous structure, resulting in a larger surface area and consequently providing numerous adsorption sites for analytes. Moreover, engineering the active sites of the nanocomposite results in a higher number of hotspots, leading to an enhanced performance. The nanocomposite outperforms, exhibiting superior detection capabilities for R6G, MB, and MLN at concentrations of 10-6 M and CIP at concentration of 10-5 M, with impressive uniformity, reproducibility, stability, and analytical enhancement factors (EF) of 6.3 x 104, 2 x 104, 2.73 x 104 and 1.8 x 104 respectively. This approach provides a direct and cost-effective method for the detection of a broad spectrum of environmental pollutants and food additives, presenting potential applications across diverse domains. The detected environmental pollutants and food additives are removed through both catalytic degradation (R6G and MB) and adsorption (CIP and MLN).

Well Defined Phosphine Free Ni-Catalyzed Dehydrogenation of Secondary Alcohols for the Synthesis of Ketones and Ketazines.

In this work, we unveil a novel synthesis of bench stable Ni (II) complexes supported by tetradentate Schiff-base ligands and the complexes were devoid of any phosphine or phosphine-based ligand. These Ni-complexes were successfully applied for the dehydrogenation of secondary alcohols for ketone and ketazine syntheses. Secondary alcohols with different functional groups were well tolerated during catalytic cycle. Moreover, we successfully extended this protocol for the synthesis of biologically significant ketones and ketazines. On the basis of various control experiments, probable reaction pathway was proposed and an acceptorless alcohol dehydrogenation mechanism was suggested.

A sustainable strategic approach for N-alkylation of amines with activation of alcohols triggered via a hydrogen auto-transfer reaction using a Pd(II) complex: evidence for metal-ligand cooperativity.

This work describes a new well-defined, air-stable, phosphine free palladium(II) [Pd(L)Cl] (1) catalyst. This catalyst was utilized for N-alkylation of amines and indole synthesis where H2O was found to be the by-product. A broad range of aromatic amines were alkylated using this homogeneous catalyst with a catalyst loading of 0.1 mol%. Greener aromatic and aliphatic primary alcohols were utilized and a hydrogen auto-transfer strategy via a metal-ligand cooperative approach was investigated. The precursor of the antihistamine-containing drug molecule tripelennamine was synthesized on a gram scale for large-scale applicability of the current synthetic methodology. A number of control experiments were performed to investigate the possible reaction pathway and the outcomes of these experiments indicated the azo-chromophore as a hydrogen reservoir during the catalytic cycle.

Gastrointestinal germinal center B cell depletion and reduction in IgA + plasma cells in HIV-1 infection.

Gastrointestinal (GI) B cells and plasma cells (PCs) are critical to mucosal homeostasis and the host response to HIV-1 infection. Here, high resolution mapping of human B cells and PCs sampled from the colon and ileum during both viremic and suppressed HIV-1 infection identified a reduction in germinal center (GC) B cells and follicular dendritic cells (FDCs) during HIV-1 viremia. IgA + PCs are the major cellular output of intestinal GCs and were significantly reduced during viremic HIV-1 infection. PC-associated transcriptional perturbations, including type I interferon signaling, persisted in antiretroviral therapy (ART)-treated individuals, suggesting ongoing disruption of the intestinal immune milieu during ART. GI humoral immune perturbations were associated with changes in the intestinal microbiome composition and systemic inflammation. These findings highlight a key immune defect in the GI mucosa due to HIV-1 viremia. One Sentence Summary: Intestinal germinal center B cell reduction in HIV-1 infection linked to reduced IgA + plasma cells and systemic inflammation.

Gastrointestinal germinal center B cell depletion and reduction in IgA+ plasma cells in HIV-1 infection.

Gastrointestinal (GI) B cells and plasma cells (PCs) are critical to mucosal homeostasis and the host response to HIV-1 infection. Here, high-resolution mapping of human B cells and PCs sampled from the colon and ileum during both viremic and suppressed HIV-1 infection identified a reduction in germinal center (GC) B cells and follicular dendritic cells (FDCs) during HIV-1 viremia. Immunoglobulin A-positive (IgA+) PCs are the major cellular output of intestinal GCs and were significantly reduced during viremic HIV-1 infection. PC-associated transcriptional perturbations, including type I interferon signaling, persisted in antiretroviral therapy (ART)-treated individuals, suggesting ongoing disruption of the intestinal immune milieu during ART. GI humoral immune perturbations were associated with changes in the intestinal microbiome composition and systemic inflammation. These findings highlight a key immune defect in the GI mucosa due to HIV-1 viremia.

Gut-associated lymphoid tissue attrition associates with response to anti-α4ß7 therapy in ulcerative colitis.

Vedolizumab (VDZ) is a first-line treatment in ulcerative colitis (UC) that targets the α4ß7- mucosal vascular addressin cell adhesion molecule 1 (MAdCAM-1) axis. To determine the mechanisms of action of VDZ, we examined five distinct cohorts of patients with UC. A decrease in naïve B and T cells in the intestines and gut-homing (ß7+) plasmablasts in circulation of VDZ-treated patients suggested that VDZ targets gut-associated lymphoid tissue (GALT). Anti-α4ß7 blockade in wild-type and photoconvertible (KikGR) mice confirmed a loss of GALT size and cellularity because of impaired cellular entry. In VDZ-treated patients with UC, treatment responders demonstrated reduced intestinal lymphoid aggregate size and follicle organization and a reduction of ß7+IgG+ plasmablasts in circulation, as well as IgG+ plasma cells and FcγR-dependent signaling in the intestine. GALT targeting represents a previously unappreciated mechanism of action of α4ß7-targeted therapies, with major implications for this therapeutic paradigm in UC.

High frequency of ofloxacin resistance patterns of Mycobacterium leprae from India: An indication to revisit second line anti-leprosy treatment regimen.

OBJECTIVES: Drug resistance in leprosy is an emerging concern, leading to treatment failures, recurrences, and potential spread of resistant Mycobacterium leprae in the community. In this study, we aimed to assess drug resistance prevalence and patterns amongst leprosy patients at a tertiary care referral hospital in India. METHODS: Mutations in drug resistance determining regions for dapsone, rifampicin, and ofloxacin of the M. leprae genome in DNA extracted from skin biopsies of 136 leprosy patients (treatment-naive = 67, with persistent skin lesions = 35, with recurrence = 34) were analysed by polymerase chain reaction followed by Sanger sequencing. Wild-type strain (Thai-53) was used as a reference strain. RESULTS: Resistance mutations were identified in a total of 23 patients, constituting 16.9% of the cohort. Within this subset of 23 cases, resistance to ofloxacin was observed in 17 individuals (12.5%), while resistance to both dapsone and rifampicin was detected in three patients each (2.2% for both). The occurrence of ofloxacin resistance showed minimal disparity between recurrent and treatment-naive cases, at 17.6% and 16.4%, respectively. Dapsone resistance emerged in two treatment-naive cases and one case with persistent skin lesions. Notably, none of the treatment-naive cases or those with recurrence/relapse exhibited rifampicin resistance. Subsequently, no statistically significant correlation was identified between other clinical variables and the presence of antimicrobial resistance. CONCLUSIONS: The occurrence of resistance to the current multidrug therapy regimen (specifically dapsone and rifampicin) and to ofloxacin, a secondary antileprosy medication in M. leprae, represents a concerning scenario. This calls for an expansion towards bactericidal drug options and the establishment of robust surveillance for drug resistance in countries burdened with high leprosy rates. Moreover, the introduction of stringent antimicrobial stewardship initiatives is imperative. As a single centre study, it represents a limited, cross-sectional view of the real situation in the field.

Single amino acid change alters specificity of the multi-allelic wheat stem rust resistance locus SR9.

Most rust resistance genes thus far isolated from wheat have a very limited number of functional alleles. Here, we report the isolation of most of the alleles at wheat stem rust resistance gene locus SR9. The seven previously reported resistance alleles (Sr9a, Sr9b, Sr9d, Sr9e, Sr9f, Sr9g, and Sr9h) are characterised using a synergistic strategy. Loss-of-function mutants and/or transgenic complementation are used to confirm Sr9b, two haplotypes of Sr9e (Sr9e_h1 and Sr9e_h2), Sr9g, and Sr9h. Each allele encodes a highly related nucleotide-binding site leucine-rich repeat (NB-LRR) type immune receptor, containing an unusual long LRR domain, that confers resistance to a unique spectrum of isolates of the wheat stem rust pathogen. The only SR9 protein effective against stem rust pathogen race TTKSK (Ug99), SR9H, differs from SR9B by a single amino acid. SR9B and SR9G resistance proteins are also distinguished by only a single amino acid. The SR9 allelic series found in the B subgenome are orthologs of wheat stem rust resistance gene Sr21 located in the A subgenome with around 85% identity in protein sequences. Together, our results show that functional diversification of allelic variants at the SR9 locus involves single and multiple amino acid changes that recognize isolates of wheat stem rust.