Integrative systems biology of wheat susceptibility to Fusarium graminearum uncovers a conserved gene regulatory network and identifies master regulators targeted by fungal core effectors

BACKGROUND

Plant diseases are driven by an intricate set of defense mechanisms counterbalanced by the expression of host susceptibility factors promoted through the action of pathogen effectors. In spite of their central role in the establishment of the pathology, the primary components of plant susceptibility are still poorly understood and challenging to trace especially in plant-fungal interactions such as in Fusarium head blight (FHB) of bread wheat. Designing a system-level transcriptomics approach, we leveraged the analysis of wheat responses from a susceptible cultivar facing Fusarium graminearum strains of different aggressiveness and examined their constancy in four other wheat cultivars also developing FHB.

RESULTS

In this study, we describe unexpected differential expression of a conserved set of transcription factors and an original subset of master regulators were evidenced using a regulation network approach. The dual-integration with the expression data of pathogen effector genes combined with database mining, demonstrated robust connections with the plant molecular regulators and identified relevant candidate genes involved in plant susceptibility, mostly able to suppress plant defense mechanisms. Furthermore, taking advantage of wheat cultivars of contrasting susceptibility levels, a refined list of 142 conserved susceptibility gene candidates was proposed to be necessary host's determinants for the establishment of a compatible interaction.

CONCLUSIONS

Our findings emphasized major FHB determinants potentially controlling a set of conserved responses associated with susceptibility in bread wheat. They provide new clues for improving FHB control in wheat and also could conceivably leverage further original researches dealing with a broader spectrum of plant pathogens.

Fusarium graminearum Infection Strategy in Wheat Involves a Highly Conserved Genetic Program That Controls the Expression of a Core Effectome

Fusarium graminearum, the main causal agent of Fusarium Head Blight (FHB), is one of the most damaging pathogens in wheat. Because of the complex organization of wheat resistance to FHB, this pathosystem represents a relevant model to elucidate the molecular mechanisms underlying plant susceptibility and to identify their main drivers, the pathogen’s effectors. Although the F. graminearum catalog of effectors has been well characterized at the genome scale, in planta studies are needed to confirm their effective accumulation in host tissues and to identify their role during the infection process. Taking advantage of the genetic variability from both species, a RNAseq-based profiling of gene expression was performed during an infection time course using an aggressive F. graminearum strain facing five wheat cultivars of contrasting susceptibility as well as using three strains of contrasting aggressiveness infecting a single susceptible host. Genes coding for secreted proteins and exhibiting significant expression changes along infection progress were selected to identify the effector gene candidates. During its interaction with the five wheat cultivars, 476 effector genes were expressed by the aggressive strain, among which 91% were found in all the infected hosts. Considering three different strains infecting a single susceptible host, 761 effector genes were identified, among which 90% were systematically expressed in the three strains. We revealed a robust F. graminearum core effectome of 357 genes expressed in all the hosts and by all the strains that exhibited conserved expression patterns over time. Several wheat compartments were predicted to be targeted by these putative effectors including apoplast, nucleus, chloroplast and mitochondria. Taken together, our results shed light on a highly conserved parasite strategy. They led to the identification of reliable key fungal genes putatively involved in wheat susceptibility to F. graminearum, and provided valuable information about their putative targets.

Eye amputation following lifitegrast treatment for ocular graft-versus-host disease: First case report

Graft-versus-host disease (GVHD) is a common complication in patients undergoing allogeneic stem cell transplantation for acute myeloblastic leukemia that could be very difficult to treat. Lifitegrast 5% (Xiidra@, Novartis), a new immunosuppressive eye drop, was recently approved by the FDA for the treatment of severe dry eye and is currently under review by the European Medicines Agency. In France, lifitegrast has been approved by the French authorities for temporary use in refractory dry eye syndrome resistant to tear substitutes and topical cyclosporine. To date, serious complications have been reported only exceptionally. In this article, we report the case of a 65-year-old patient with a medical history of acute myeloid leukemia (AML) diagnosed in 2015 who received a first matched related donor transplant. In 2019, this patient developed chronic GVH involving the skin, oral mucosa and eye. Despite taking topical and systemic medications for 3 months, the patient did not report relief of ocular symptoms. Therefore, lifitegrast was prescribed. To our knowledge, we report the first case of corneal perforation in which evisceration was required following treatment with topical lifitegrast for chronic GVH. In the case presented here, it can be assumed that the underlying mechanisms leading to corneal perforation are multifactorial. Using drug accountability criteria, lifitegrast appears to be strongly associated with the development of bacterial keratitis and corneal perforation.

Searching for FHB Resistances in Bread Wheat: Susceptibility at the Crossroad

Fusarium head blight (FHB), primarily caused by Fusarium graminearum, is one of the most devastating fungal wheat diseases. During the past decades, many efforts have been deployed to dissect FHB resistance, investigating both the wheat responses to infection and, more recently, the fungal determinants of pathogenicity. Although no total resistance has been identified so far, they demonstrated that some plant functions and the expression of specific genes are needed to promote FHB. Associated with the increasing list of F. graminearum effectors able to divert plant molecular processes, this fact strongly argues for a functional link between susceptibility-related factors and the fate of this disease in wheat. In this review, we gather more recent data concerning the involvement of plant and fungal genes and the functions and mechanisms in the development of FHB susceptibility, and we discuss the possibility to use them to diversify the current sources of FHB resistance.

Multiple immune disorders after natalizumab discontinuation: After the CIRIS, the SIRIS?

Natalizumab (NTZ) is an effective treatment for patients with highly active relapsing remitting multiple sclerosis (MS). However, when the therapy must be interrupted, it is important to anticipate the withdrawal to avoid reactivation or disease rebound. Described here is the case of a 35-year-old woman, with a past history of beta thalassemia, bulimia and asthma, who was diagnosed with MS at age 26. She was treated initially with first-line subcutaneous (sc) immunomodulatory treatments. However, due to liver toxicity, interferon beta-1a sc was interrupted and replaced by glatiramer acetate treatment, which was well tolerated and used for several years. Unfortunately, disease progression with numerous relapses and contrast enhancement on brain MRI led to initiation of NTZ treatment. After more than 2 years of treatment, NTZ was interrupted because of pregnancy, and the patient was again put on glatiramer acetate. Eight weeks after interruption of NTZ therapy, the first signs of diabetes were observed, together with an increase in blood levels of hepatic enzymes, skin reactions such as angioedema and giant urticaria, and hypothyroidism requiring hormone supplementation. The patient delivered her baby without complications, and NTZ was reintroduced several months later. At the present time, the patient's hypothyroidism, diabetes and increased blood levels of hepatic enzymes persist, although no new skin reactions have been observed. Withdrawal of NTZ can not only lead to reactivation of the disease or its rebound, but also to autoimmune manifestations within the framework of immune reconstitution inflammatory syndrome (IRIS). This risk needs to be considered when therapy has to be interrupted, especially when a personal and/or familial past history of autoimmune disease is present.

Efficiency of auricular acupuncture in climacteric symptoms after cancer treatments

OBJECTIVES

This paper aims to highlight the efficiency of auriculotherapy in the treatment of hot flushes, especially in cancer-related menopausal transition.

METHODS

We used systematically collected data from patients in 2014 in a medical oncology practice. The treatment was made according to the guidelines of The Inter-University Diploma and the cartography of the World Health Organization; data on satisfaction were collected orally.

RESULTS

In 2014, 49 patients, among whom 41 had cancer, were treated for hot flushes. Although it is not recommended to treat several symptoms during the same session, we dealt with 1.7 symptoms per session on average. Sixty-nine percent of the patients were satisfied. We lacked data for nine patients, who did not come to the minimal recommended number of treatments (three). Only one patient among those who did not observe any improvement received three treatments.

CONCLUSIONS

Auricular acupuncture is a safe and cheap method to treat hot flushes. It has been effective in numerous and various cases, among which were patients who presented cancer-related menopausal symptoms. It may be applied for a large variety of other symptoms.

[Topiramate and acute myopia with angle-closure glaucoma: case report and literature review]

Topiramate, an antiepileptic medication, has been widely used since its recent indication for migraine prophylaxis. We report a case of bilateral angle-closure glaucoma and acute myopia in a 44-year-old woman on oral topiramate therapy initiation for migraine prophylaxis. Intraocular pressure was 31 mmHg right and 32 mmHg left, myopia was 4 diopters. Topiramate was interrupted and general and local hypotensive treatment begun and rapidly stopped after improvement. Iridotomy was also performed. Fifteen days later, complete resolution was observed on ophthalmologic examination: anterior chambers were deep, myopia fully regressed, intraocular pressure returned to normal, and the visual field was complete. This new case prompts discussion on current reports in the literature and French drug monitoring database cases in this context.

Syndrome de Möbius : manifestations ophtalmologiques et cliniques

PURPOSE

To assess ocular and clinical manifestations in patients with Möbius syndrome.

METHODS

Twenty-seven patients (26 infants and 1 adult) underwent prospective ophthalmic, clinical, neurological, otorhinological, orthopedic and electrophysiological assessment. Twenty-three patients underwent MRI and 20 patients genetic examination with karyotype.

RESULTS

Three of 27 patients with cranial nerve palsies did not satisfy the criteria for Möbius syndrome. All 24 patients with Möbius syndrome had facial palsy. Nineteen patients (79.2%) had limited abduction. Eleven patients (45.9%) presented with esotropia, five patients (20.8%) presented with exotropia or hypertropia. Cranial nerve impairment of the Vth, IXth, XIth, and XIIth nerves was noted in 20 patients (83.4%). Other signs were general motor disability in 14 patients (58.2%), orthopedic abnormalities in eight patients (33.3%), and otorhinological abnormalities in six patients (25%). Electromyographic studies of facial muscles revealed neuromuscular changes in all cases. MRI findings showed hypoplasia of facial nerves in two patients (8.3%). Chromosomal abnormalities were not found. One patient presented an inherited inversion of the sixth chromosome.

CONCLUSION

The diagnosis of Möbius syndrome may be difficult in some patients with atypical signs of facial diplegia and other cranial nerve palsies. When diagnosing Möbius syndrome, all ophthalmologic and clinical signs must be applied. Möbius syndrome is more than a cranial nerve or nuclear disorder. It is a syndrome of more complex lower brainstem involvement.

Maladie de Kikuchi et atteinte ophtalmologique

PURPOSE

Report a case of oculomotor palsy with papillary edema in a child showing signs of Kikuchi's disease and review the literature.

MATERIALS AND METHODS

A 10-year-old girl presented with diplopia with right ptosis, right exophthalmia, headache, generalized weakness, and fever. The assessment consisted of an ocular and neurological examination, imagery by cerebral magnetic resonance, a biological and immunological assessment, and a biopsy.

RESULTS

The ophthalmologic examination found right exophthalmia with absence of right abduction and adduction, and right ptosis. The ocular fundus showed a bilateral papillary edema. Magnetic resonance revealed a bilateral intraconic attack of the orbital apex. The biopsy of cervical adenopathy showed a histiocytic necrotizing lymphadenitis. Infection assessment was negative and immunologic tests were normal.

DISCUSSION

Kikuchi's disease, or histiocytic necrotizing lymphadenitis, is a rare disease in young patients that is characterized by adenopathy, fever, and neutropenia. The diagnosis was confirmed histologically. The etiology of Kikuchi's disease remains unknown, although a viral or autoimmune hypothesis has been suggested. The course of the disease is spontaneously favorable and recurrence is rare. Association with systemic lupus erythematous had been described. The differential diagnosis of Kikuchi's disease includes infectious necrotizing lymphadenitis, systemic lupus erythematous, and lymphoma. Ocular manifestation is exceptionally described (uveitis).

CONCLUSION

Kikuchi's disease should be considered in children revealing ocular manifestations with lymphadenopathy and fever of unknown origin.

Comparison of the capsular response to the Biocell RTV and Mentor 1600 Siltex breast implant surface texturing: a scanning electron microscopic study

The utility of mammary prosthesis texturing in the prevention of capsular contracture was established some 20 years ago. Various models of implant texturing are currently on the market. We decided to study two of the most popular implants with two different surface texturings: the Biocell RTV and the Mentor 1600 Siltex. An observation at the electron microscopic level of the implants' surfaces was achieved. At the time of a prospective survey on 10 patients, the capsule fragments corresponding to these two prostheses have been analyzed at the electron microscopic level. All prostheses were removed from the patients because of asymmetry or bad positioning. The aim of our study was to establish a correlation between these two frequent texturing surfaces and their corresponding capsules. Our results showed that only the Biocell's capsules present a mirror image with correspondence of the depressions on the prosthesis and contacts on the capsule. This phenomenon seems linked to the existence of a critical size of the pores constituting the implant surface. This observation leads us to the hypothesis of an adhesive effect between the prosthesis and its capsule. If this last is not directly linked to the prevention of capsular contracture, it can have an effect on implant stabilization in the primary mammary reconstruction and in the secondary corrections of asymmetry or bad position.

Carrier-mediated uptake and phloem systemy of a 350-Dalton chlorinated xenobiotic with an alpha-amino acid function

In a previous paper we have shown that epsilon-(phenoxyalkanecarboxylyl)-L-Lys conjugates are potent inhibitors of amino acid transport systems and that it is possible to modulate the uptake inhibition by hydrophobic or hydrophilic additions in the 4-position of the aromatic ring (J.F. Chollet, C. Delétage, M. Faucher, L. Miginiac, J.L. Bonnemain [1997] Biochem Biophys Acta 1336: 331-341). In this report we demonstrate that epsilon-(2,4-dichlorophenoxyacetyl)-L-Lys (2,4D-Lys), one of the largest molecules of the series and one of the most potent inhibitors, is a highly permeant conjugate. Uptake of 2,4D-Lys by broad bean (Vicia faba) leaf discs is mediated by an active carrier system (Km1 = 0.2 mM; Vmax1 = 2.4 nmol x cm(-2) x h(-1) at pH 5.0) complemented by an important diffusive component. Among the compounds tested (neutral, basic, and acidic amino acids, auxin, glutathione, and sugars), only the aromatic amino acids clearly compete with 2,4D-Lys. The conjugate accumulates in the vein network, is exported toward the growing organs, and exhibits a distribution pattern different from that of the herbicide moiety. However, over time 2,4D-Lys progressively splits into 2,4D and lysine. Analyses by high-performance liquid chromatography and liquid scintillation spectrometry of the phloem sap collected from the castor bean system, used as a systemy test, indicate decreasing capacities of 2,4D, 2,4D-Lys, and glyphosate, respectively, to move from the epidermis cell wall to the sieve element. Our results show that it is possible to design synthesis of large-size xenobiotics (approximately 350 D) with a lipophilic pole, exhibiting high mobility within the vascular system.

[A scanning electron microscopy study of the surface of porous-textured breast implants and their capsules. Description of the "velcro" effect of porous-textured breast prostheses]

The efficacy of breast prosthesis texturing in the prevention of capsular contracture has been established for about 20 years. This successful procedure has led to the development and marketing of a number of different models. In the present study, four porous-textured breast prostheses have been examined: the Arion monoblock implant, the CUI (McGahn), the Biocell (Mcgahn), and the Sebbin LS21. Scanning electron microscopic (SEM) investigation of the implant surfaces of the different prostheses was carried out on new samples received from the manufacturers. During a prospective study on eight patients, capsule samples corresponding to the four above-mentioned prostheses were taken to determine whether a secondary intervention was necessary for correction of asymmetry or malpositioning. These samples were analyzed by SEM to investigate whether there could be a correlation between prosthesis texturing and the aspect of the corresponding capsules. Significant ultrastructural differences were found between the various prostheses examined: the results showed that only the CUI and Biocell prostheses presented a mirror image of the capsule texturing, with a correspondence between the depressions on the prosthesis and the contacts on the capsule. This finding seems to be linked to the existence of a critical size for the pores that constitute the implant surface. This observation led to the hypothesis of an adhesive "velcro" effect between the prosthesis and its capsule. Although the latter may not be directly linked to the prevention of capsular contracture it can, however, have a major effect on implant stabilization in cases of primary breast reconstruction and in possible secondary adjustments of asymmetry and malpositioning.

Prognostic factors in chordoma: role of postoperative radiotherapy

We have investigated prognostic factors for survival in a series of 26 patients with chordoma treated in Lyon, France, between 1979 and 1993. In this series, the median progression-free (PFS) and overall survival (OS) were 10 and 90 months, respectively. In univariate analysis, PFS, but not OS, was found significantly longer in males as compared to females (median: 19 versus 7 months, P = 0.05); and patients under 60 years of age had a longer PFS (median: 18 versus 6 months; P = 0.06) and OS (median: 108 versus 47+, P = 0.05) than older patients. A favourable prognostic subgroup including male patients under 60 years and a poor prognostic group including female patients and male over 60 years were thus defined (median PFS: 36 versus 6 months, P = 0.001; median OS: 108 versus 55+, P = 0.15). Primary treatment combining surgery and postoperative radiotherapy was associated with a longer PFS than surgery only (median: 36 versus 7 months, P = 0.002) in the whole series and in both prognostic subgroups.

In vivo activation of alveolar macrophages in ovine lentivirus infection

Sheep infected by visna-maedi virus, a lentivirus related to the human immunodeficiency virus, develop a chronic interstitial lung disease. Since monocyte/macrophages are known to be specifically infected by visna-maedi virus, we investigated the role of macrophages in the appearance of pulmonary lesions in animals with naturally occurring disease. Alveolitis in maedi leads to a doubling in bronchoalveolar lavage total cell counts and of macrophages as compared to normal sheep. A significant increase in the relative percentage of neutrophils was also observed, accompanied by an increased spontaneous release of neutrophil chemotactic activity by alveolar macrophages of diseased animals, suggesting that they may be activated. Macrophage activation is also demonstrated by the observation of a significant (x3) increase of spontaneous fibronectin release by alveolar macrophages from maedi lungs, and furthermore by the high level expression of major histocompatibility complex class II antigens on most of these cells. Thus viral infection, although restricted to a small population of macrophages, is able to modulate extensive activation of macrophages in the lung. Activated macrophages release mediators likely to play a role in the development of the alveolitis and the parenchymal desorganization. These findings may be relevant to our understanding of the mechanisms by which human immunodeficiency virus infection leads to pulmonary disease other than that caused by opportunistic infections.

Scintigraphy of the salivary glands in Sjögen's syndrome

Scintigraphy of the salivary glands with technetium-sodium pertechnetate (99mTc) was undertaken on 320 patients with oral dryness or connective tissue disease using a computer assisted method that gave quantitative results about the major salivary gland function. Compared with clinical and histological data, scintigraphy provides a sensitive method, even though it is not specific, for detecting minimal injuries to salivary glands in patients suspected of having Sjögen's syndrome. Moreover, it might differentiate between the Sjögen-like syndrome and the sequelae of radiotherapy in patients with bone marrow graft. Scintigraphy of the major salivary glands could therefore form part of the routine investigation of patients with Sjögen's syndrome.

[Gougerot-Sjögren syndrome. Functional study of the salivary glands by scintigraphy]

One-hundred and twenty patients with sicca syndrome, connective tissue disease or chronic graft-versus-host disease were investigated in the Saint-Louis Hospital Department of Nuclear Medicine. Technetium scanning of the salivary glands was performed in all patients. The results of the scintigraphic study were closely correlated with clinical and histological data in patients with Sjögren's syndrome. This method, which accurately quantifies the salivary function without danger nor discomfort to the patients, has a number of advantages: (a) it is sensitive enough to detect minimal salivary gland dysfunction; (b) it differentiates between parotid gland and submandibular gland involvement and demonstrates asymmetry in pathological processes; (c) it helps in following up patients with Sjögren's disease and in assessing the results of immunosuppressive or anti-inflammatory treatment.