New studies with stable gastric pentadecapeptide protecting gastrointestinal tract. significance of counteraction of vascular and multiorgan failure of occlusion/occlusion-like syndrome in cytoprotection/organoprotection.

Since the early 1990s, when Robert's and Szabo's cytoprotection concept had already been more than one decade old, but still not implemented in therapy, we suggest the stable gastric pentadecapeptide BPC 157 as the most relevant mediator of the cytoprotection concept. Consequently, it can translate stomach and gastrointestinal mucosal maintenance, epithelium, and endothelium cell protection to the therapy of other tissue healing (organoprotection), easily applicable, as native and stable in human gastric juice for more than 24 h. These overwhelm current clinical evidence (i.e., ulcerative colitis, phase II, no side effects, and no lethal dose (LD1) in toxicology studies), as BPC 157 therapy effectively combined various tissue healing and lesions counteraction. BPC 157 cytoprotection relevance and vascular recovery, activation of collateral pathways, membrane stabilizer, eye therapy, wound healing capability, brain-gut and gut-brain functioning, tumor cachexia counteraction, muscle, tendon, ligament, and bone disturbances counteraction, and the heart disturbances, myocardial infarction, heart failure, pulmonary hypertension, arrhythmias, and thrombosis counteraction appeared in the recent reviews. Here, as concept resolution, we review the counteraction of advanced Virchow triad circumstances by activation of the collateral rescuing pathways, depending on injury, activated azygos vein direct blood flow delivery, to counteract occlusion/occlusion-like syndromes starting with the context of alcohol-stomach lesions. Counteraction of major vessel failure (congested inferior caval vein and superior mesenteric vein, collapsed azygos vein, collapsed abdominal aorta) includes counteraction of the brain (intracerebral and intraventricular hemorrhage), heart (congestion, severe arrhythmias), lung (hemorrhage), and congestion and lesions in the liver, kidney, and gastrointestinal tract, intracranial (superior sagittal sinus), portal and caval hypertension, aortal hypotension, and thrombosis, peripherally and centrally.

The relation between stress-induced dopamine release in the ventromedial prefrontal cortex, fronto-striatal functional connectivity, and negative urgency: A multimodal investigation using [18F]Fallypride PET, MRI and experience sampling.

Negative urgency (NU), or the tendency to act rashly when stress of negative affect is high, could be the result of an insufficient control of the ventromedial prefrontal cortex (vmPFC) over the striatum, through an impaired dopamine (DA) transmission. Therefore, we investigated in vivo human stress-induced DA release in the vmPFC, its relation with fronto-striatal functional connectivity (FC), and NU in daily life. In total, 12 female healthy participants performed a simultaneous [18 F]fallypride PET and fMRI scan during which stress was induced. Regions displaying stress-induced DA release were identified and used to investigate stress-induced changes in fronto-striatal FC. Additionally, participants enrolled in an experience sampling study, reporting on daily life stress and rash actions over a 12-month-long period. Mixed models explored whether stress-induced DA release and FC moderated NU in daily life. Stress led to a lower FC between the vmPFC and dorsal striatum, but a higher FC between the vmPFC and contralateral ventral striatum. Participants with a higher FC between the vmPFC and dorsal striatum displayed more NU in daily life. A higher stress-induced DA release in the vmPFC was related to a higher stress-induced change in FC between the vmPFC and striatum. Participants with a higher DA release in the vmPFC displayed more NU in daily life. In conclusion, stress could differentially impact fronto-striatal FC whereby the connectivity with the dorsal striatum is especially important for NU in daily life. This could be mediated by a higher, but not a lower, stress-induced DA release in the vmPFC.

Effects of buccal acupuncture on postoperative analgesia in elderly patients undergoing laparoscopic radical gastrectomy: a randomized controlled trial.

Objective: This study aimed to evaluate the efficacy and safety of buccal acupuncture on postoperative analgesia, perioperative stress response and adverse events in elderly patients undergoing laparoscopic radical gastrectomy. Methods: It was a prospective, outcome assessor-blinded, randomized controlled trial, involving 90 patients aged 65-80 years who were treated with an elective laparoscopic radical gastrectomy. They were randomly assigned to buccal acupuncture group (Group B) and control group (Group C). Buccal acupuncture was applied to patients of Group B before the induction of general anesthesia, while no additional application was given to those in Group C. Patient-controlled intravenous analgesia (PCIA) with sufentanil was postoperatively performed in both groups. Sufentanil consumption and the Visual Analog Scale (VAS) score within 48 h postoperatively were assessed as primary outcomes. Secondary outcomes included peripheral levels of stress markers, intraoperative consumptions of anesthetic drugs and postoperative recovery. Results: Patients in Group B presented significantly lower VAS scores within 24 h and less consumption of sufentanil within 48 h postoperatively (both p < 0.01). The awaking time, time to extubation and length of stay were significantly shorter in Group B than in Group C (p = 0.005, 0.001 and 0.028, respectively). Compared with Group C, stress response and inflammatory response within 24 h postoperatively were also significantly milder in Group B. Conclusion: The use of buccal acupuncture before general anesthesia induction favors the postoperative analgesic effect and recovery in elderly patients undergoing laparoscopic radical gastrectomy, the mechanism of which involves relieving postoperative stress response and inflammatory response. Clinical trial registration: This study was registered in the Chinese Clinical Trial Registry (www.chictr.org.cn) on 15/06/2023 (ChiCTR2300072500).

Proteome profiling of cutaneous leishmaniasis lesions due to dermotropic Leishmania donovani in Sri Lanka.

BACKGROUND: Characterization of the host response in cutaneous leishmaniasis (CL) through proteome profiling has gained limited insights into leishmaniasis research compared to that of the parasite. The primary objective of this study was to comprehensively analyze the proteomic profile of the skin lesions tissues in patients with CL, by mass spectrometry, and subsequent validation of these findings through immunohistochemical methods. METHODS: Eight lesion specimens from leishmaniasis-confirmed patients and eight control skin biopsies were processed for proteomic profiling by mass spectrometry. Formalin-fixed paraffin-embedded lesion specimens from thirty patients and six control skin specimens were used for Immunohistochemistry (IHC) staining. Statistical analyses were carried out using SPSS software. The chi-square test was used to assess the association between the degree of staining for each marker and the clinical and pathological features. RESULTS: Sixty-seven proteins exhibited significant differential expression between tissues of CL lesions and healthy controls (p < 0.01), representing numerous enriched biological processes within the lesion tissue, as evident by both the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Reactome databases. Among these, the integrated endoplasmic reticulum stress response (IERSR) emerges as a pathway characterized by the up-regulated proteins in CL tissues compared to healthy skin. Expression of endoplasmic reticulum (ER) stress sensors, inositol-requiring enzyme-1 (IRE1), protein kinase RNA-like ER kinase (PERK) and activating transcription factor 6 (ATF6) in lesion tissue was validated by immunohistochemistry. CONCLUSIONS: In conclusion, proteomic profiling of skin lesions carried out as a discovery phase study revealed a multitude of probable immunological and pathological mechanisms operating in patients with CL in Sri Lanka, which needs to be further elaborated using more in-depth and targeted investigations. Further research exploring the intricate interplay between ER stress and CL pathophysiology may offer promising avenues for the development of novel diagnostic tools and therapeutic strategies in combating this disease.

Amino-modified polystyrene nanoplastics induced multiple response of Artemia hemocytes.

Polystyrene polymers cause severe toxicity to aquatic animals. However, the process and mechanisms of innate immunity of invertebrates living at the bottom of the food chain to these pollutants remain unclear. In this study, the blood system responses of zooplankton Artemia were assessed through in vivo and in vitro exposure to amino-modified polystyrene nanoplastics (PS-NH2 NPs). The results indicated that the LC50 values of PS-NH2 NPs were 1.09 µg·mL-1 over 48 h and 0.42 µg·mL-1 over 7 d. Based on the five hemocyte subpopulations identified in Artemia, in vitro exposure assays revealed that phagocytosis was performed by plasmocytes and granulocytes with phagocytic rate of 22.64 %. TEM analysis further showed that PS-NH2 NPs caused cytoplasm vacuolization, swollen mitochondria, and lipid processing disorder. Gene expression pattern results demonstrated that Spatzle, Tollip, Hsp70, Hsp90, Casp8, API5and Pxn were significantly upregulated upon acute and chronic exposure (p < 0.05), while chronic exposure could induce significantly upregulation of ProPO (p < 0.05). Moreover, PS-NH2 NPs exposure remarkably varied the hemolymph microbiota and hemogram, particularly by increasing the proportion of adipohemocytes and phagocytes (p < 0.05). Our findings suggest that PS-NH2 NPs induce different responses in Artemia hemocyte, as primarily reflected by phagocytic processes, expression of immune and apoptosis relating genes, cell fates, hemogram and hemolymph microbiota variations. These findings support the possibility of using Artemia hemocytes as bioindicator to estimate nanoplastics pollution, thus contributing to hematological toxicity research in response to nanoplastics.

Zinc Deficiency in Critically Ill Patients: Impact on Clinical Outcome.

Background Zinc is a trace element essential for the normal functioning of many vital enzymes and organ systems. Studies examining the rates and degrees of zinc deficiency and its consequences in patients with critical illnesses remain scarce. Materials and methods This is a prospective observational study assessing zinc deficiency in critically ill adult patients admitted to a tertiary care intensive care unit (ICU) and its impact on clinical outcomes. Patients were divided into those with normal (≥ 71 µg/dl) and low (≤ 70 µg/dl) zinc levels. Zinc-deficient patients were further divided into mild, moderate, and severe zinc deficiency groups based on zinc levels of 61-70 µg/dl, 51-60 µg/dl, and below 51 µg/dl, respectively. The primary outcome assessed was ICU mortality, and the secondary outcomes were ICU length of stay (LOS), duration of invasive mechanical ventilation (IMV), acute kidney injury (AKI) at admission, need for non-invasive ventilation (NIV), renal replacement therapy (RRT), or vasopressors during the course of the ICU. Other parameters compared included APACHE (Acute Physiology and Chronic Health Evaluation) II, SOFA (Sequential Organ Failure Assessment) score on day 1, and levels of lactate, procalcitonin, calcium, magnesium, phosphate, and serum albumin. The study also compared the mean zinc levels in patients with low and high SOFA scores (scores up to 7 vs. 8 and above) and low and high APACHE II values (scores up to 15 vs. 16 and above). Results A total of 50 patients were included, of whom 43 (86%) were zinc deficient. Mortality in zinc-deficient and normal zinc-level patients was 33% and 43%, respectively (p = 0.602). Patients with zinc deficiency were also older (mean age 69 vs. 49 years, p = 0.02). There was no difference in secondary outcome parameters, except for more zinc-deficient patients needing RRT. Twenty-six of the zinc-deficient patients had severe zinc deficiency, ten moderate, and seven mild (p = 0.663). ICU mortality was approximately 42%, 10%, and 29% in the severe, moderate, and mild deficiency groups, respectively (p = 0.092). Zinc levels were similar between those with low and high APACHE II scores (mean 47.9 vs. 45.5 µg/dl, p = 0.606) as well as between low and high SOFA scores (mean 47.8 vs. 45.7 µg/dl, p = 0.054). Conclusion The present study suggests that zinc deficiency is very common in critically ill patients but does not correlate with their severity of illness, nor does it lead to a poorer outcome in these patients. However, further studies with a larger cohort of patients would be required to make definitive conclusions.

Response of Fusarium oxysporum soil isolate to amphotericin B and fluconazole at the proteomic level.

Fusarium oxysporum is a cross-kingdom pathogen that infects humans, animals, and plants. The primary concern regarding this genus revolves around its resistance profile to multiple classes of antifungals, particularly azoles. However, the resistance mechanism employed by Fusarium spp. is not fully understood, thus necessitating further studies to enhance our understanding and to guide future research towards identifying new drug targets. Here, we employed an untargeted proteomic approach to assess the differentially expressed proteins in a soil isolate of Fusarium oxysporum URM7401 cultivated in the presence of amphotericin B and fluconazole. In response to antifungals, URM7401 activated diverse interconnected pathways, such as proteins involved in oxidative stress response, proteolysis, and lipid metabolism. Efflux proteins, antioxidative enzymes and M35 metallopeptidase were highly expressed under amphotericin B exposure. Antioxidant proteins acting on toxic lipids, along with proteins involved in lipid metabolism, were expressed during fluconazole exposure. In summary, this work describes the protein profile of a resistant Fusarium oxysporum soil isolate exposed to medical antifungals, paving the way for further targeted research and discovering new drug targets.

Multigenerational inheritance drives symbiotic interactions of the bacterium Bacillus subtilis with its plant host.

Bacillus subtilis is a beneficial bacterium that supports plant growth and protects plants from bacterial, fungal, and viral infections. Using a simplified system of B. subtilis and Arabidopsis thaliana interactions, we studied the fitness and transcriptome of bacteria detached from the root over generations of growth in LB medium. We found that bacteria previously associated with the root or exposed to its secretions had greater stress tolerance and were more competitive in root colonization than bacteria not previously exposed to the root. Furthermore, our transcriptome results provide evidence that plant secretions induce a microbial stress response and fundamentally alter signaling by the cyclic nucleotide c-di-AMP, a signature maintained by their descendants. The changes in cellular physiology due to exposure to plant exudates were multigenerational, as they allowed not only the bacterial cells that colonized a new plant but also their descendants to have an advance over naive competitors of the same species, while the overall plasticity of gene expression and rapid adaptation were maintained. These changes were hereditary but not permanent. Our work demonstrates a bacterial memory manifested by multigenerational reversible adaptation to plant hosts in the form of activation of the stressosome, which confers an advantage to symbiotic bacteria during competition.

TDP-43 in nuclear condensates: where, how, and why.

TDP-43 is an abundant and ubiquitously expressed nuclear protein that becomes dysfunctional in a spectrum of neurodegenerative diseases. TDP-43's ability to phase separate and form/enter biomolecular condensates of varying size and composition is critical for its functionality. Despite the high density of phase-separated assemblies in the nucleus and the nuclear abundance of TDP-43, our understanding of the condensate-TDP-43 relationship in this cellular compartment is only emerging. Recent studies have also suggested that misregulation of nuclear TDP-43 condensation is an early event in the neurodegenerative disease amyotrophic lateral sclerosis. This review aims to draw attention to the nuclear facet of functional and aberrant TDP-43 condensation. We will summarise the current knowledge on how TDP-43 containing nuclear condensates form and function and how their homeostasis is affected in disease.

Mesenchymal stem cells-extracellular vesicles alleviate pulmonary fibrosis by regulating immunomodulators.

BACKGROUND: Pulmonary fibrosis (PF) is a chronic interstitial lung disease characterized by fibroblast proliferation and extracellular matrix formation, causing structural damage and lung failure. Stem cell therapy and mesenchymal stem cells-extracellular vesicles (MSC-EVs) offer new hope for PF treatment. AIM: To investigate the therapeutic potential of MSC-EVs in alleviating fibrosis, oxidative stress, and immune inflammation in A549 cells and bleomycin (BLM)-induced mouse model. METHODS: The effect of MSC-EVs on A549 cells was assessed by fibrosis markers [collagen I and α-smooth muscle actin (α-SMA), oxidative stress regulators [nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1), and inflammatory regulators [nuclear factor-kappaB (NF-κB) p65, interleukin (IL)-1ß, and IL-2]. Similarly, they were assessed in the lungs of mice where PF was induced by BLM after MSC-EV transfection. MSC-EVs ion PF mice were detected by pathological staining and western blot. Single-cell RNA sequencing was performed to investigate the effects of the MSC-EVs on gene expression profiles of macrophages after modeling in mice. RESULTS: Transforming growth factor (TGF)-ß1 enhanced fibrosis in A549 cells, significantly increasing collagen I and α-SMA levels. Notably, treatment with MSC-EVs demonstrated a remarkable alleviation of these effects. Similarly, the expression of oxidative stress regulators, such as Nrf2 and HO-1, along with inflammatory regulators, including NF-κB p65 and IL-1ß, were mitigated by MSC-EV treatment. Furthermore, in a parallel manner, MSC-EVs exhibited a downregulatory impact on collagen deposition, oxidative stress injuries, and inflammatory-related cytokines in the lungs of mice with PF. Additionally, the mRNA sequencing results suggested that BLM may induce PF in mice by upregulating pulmonary collagen fiber deposition and triggering an immune inflammatory response. The findings collectively highlight the potential therapeutic efficacy of MSC-EVs in ameliorating fibrotic processes, oxidative stress, and inflammatory responses associated with PF. CONCLUSION: MSC-EVs could ameliorate fibrosis in vitro and in vivo by downregulating collagen deposition, oxidative stress, and immune-inflammatory responses.

Interplay between mistranslation and oxidative stress in Escherichia coli.

Mistakes in translation are mostly associated with toxic effects in the cell due to the production of functionally aberrant and misfolded proteins. However, under certain circumstances mistranslation can have beneficial effects and enable cells to preadapt to other stress conditions. Mistranslation may be caused by mistakes made by aminoacyl-tRNA synthetases, essential enzymes that link amino acids to cognate tRNAs. There is an Escherichia coli strain expressing isoleucyl-tRNA synthetase mutant variant with inactivated editing domain which produces mistranslated proteomes where valine (Val) and norvaline (Nva) are misincorporated into proteins instead of isoleucine. We compared this strain with the wild-type to determine the effects of such mistranslation on bacterial growth in oxidative stress conditions. When the cells were pre-incubated with 0.75 mmol/L Nva or 1.5 mmol/L Val or Nva and exposed to hydrogen peroxide, no beneficial effect of mistranslation was observed. However, when the editing-deficient strain was cultivated in medium supplemented with 0.75 mmol/L Val up to the early or mid-exponential phase of growth and then exposed to oxidative stress, it slightly outgrew the wild-type grown in the same conditions. Our results therefore show a modest adaptive effect of isoleucine mistranslation on bacterial growth in oxidative stress, but only in specific conditions. This points to a delicate balance between deleterious and beneficial effects of mistranslation.

Dissection of transcriptional events in graft incompatible reactions of "Bearss" lemon (Citrus limon) and "Valencia" sweet orange (C. sinensis) on a novel citrandarin (C. reticulata × Poncirus trifoliata) rootstock.

Citrus is commercially propagated via grafting, which ensures trees have consistent fruit traits combined with favorable traits from the rootstock such as soil adaptability, vigor, and resistance to soil pathogens. Graft incompatibility can occur when the scion and rootstock are not able to form a permanent, healthy union. Understanding and preventing graft incompatibility is of great importance in the breeding of new fruit cultivars and in the choice of scion and rootstock by growers. The rootstock US-1283, a citrandarin generated from a cross of "Ninkat" mandarin (Citrus reticulata) and "Gotha Road" #6 trifoliate orange (Poncirus trifoliata), was released after years of field evaluation because of its superior productivity and good fruit quality on "Hamlin" sweet orange (C. sinensis) under Florida's growing conditions. Subsequently, it was observed that trees of "Bearss" lemon (C. limon) and "Valencia" sweet orange (C. sinensis) grafted onto US-1283 exhibited unhealthy growth near the graft union. The incompatibility manifested as stem grooving and necrosis underneath the bark on the rootstock side of the graft. Another citrandarin rootstock, US-812 (C. reticulata "Sunki" × P. trifoliata "Benecke"), is fully graft compatible with the same scions. Transcriptome analysis was performed on the vascular tissues above and below the graft union of US-812 and US-1283 graft combinations with "Bearss" and "Valencia" to identify expression networks associated with incompatibility and help understand the processes and potential causes of incompatibility. Transcriptional reprogramming was stronger in the incompatible rootstock than in the grafted scions. Differentially expressed genes (DEGs) in US-1283, but not the scions, were associated with oxidative stress and plant defense, among others, similar to a pathogen-induced immune response localized to the rootstock; however, no pathogen infection was detected. Therefore, it is hypothesized that this response could have been triggered by signaling miscommunications between rootstock and scion either through (1) unknown molecules from the scion that were perceived as danger signals by the rootstock, (2) missing signals from the scion or missing receptors in the rootstock necessary for the formation of a healthy graft union, (3) the overall perception of the scion by the rootstock as non-self, or (4) a combination of the above.

Transcriptome- and genome-wide systematic identification of expansin gene family and their expression in tuberous root development and stress responses in sweetpotato (Ipomoea batatas).

Introduction: Expansins (EXPs) are essential components of the plant cell wall that function as relaxation factors to directly promote turgor-driven expansion of the cell wall, thereby controlling plant growth and development and diverse environmental stress responses. EXPs genes have been identified and characterized in numerous plant species, but not in sweetpotato. Results and methods: In the present study, a total of 59 EXP genes unevenly distributed across 14 of 15 chromosomes were identified in the sweetpotato genome, and segmental and tandem duplications were found to make a dominant contribution to the diversity of functions of the IbEXP family. Phylogenetic analysis showed that IbEXP members could be clustered into four subfamilies based on the EXPs from Arabidopsis and rice, and the regularity of protein motif, domain, and gene structures was consistent with this subfamily classification. Collinearity analysis between IbEXP genes and related homologous sequences in nine plants provided further phylogenetic insights into the EXP gene family. Cis-element analysis further revealed the potential roles of IbEXP genes in sweetpotato development and stress responses. RNA-seq and qRT-PCR analysis of eight selected IbEXPs genes provided evidence of their specificity in different tissues and showed that their transcripts were variously induced or suppressed under different hormone treatments (abscisic acid, salicylic acid, jasmonic acid, and 1-aminocyclopropane-1-carboxylic acid) and abiotic stresses (low and high temperature). Discussion: These results provide a foundation for further comprehensive investigation of the functions of IbEXP genes and indicate that several members of this family have potential applications as regulators to control plant development and enhance stress resistance in plants.

Effect of pericapsular nerve group block and suprainguinal fascia iliaca block on postoperative analgesia and stress response in elderly patients undergoing hip arthroplasty: a prospective randomized controlled double-blind trial.

BACKGROUND: As a novel regional analgesic technique, ultrasound-guided pericapsular nerve group (PENG) block has some potential advantages, and we designed a randomized clinical trial (RCT) to investigate whether the ultrasound-guided PENG block combined with general anesthesia can better reduce stress response, maintain intraoperative hemodynamic stability, and reduce postoperative analgesia in elderly hip arthroplasty compared with ultrasound-guided suprainguinal fascia iliaca block (SIFIB) combined with general anesthesia. METHODS: Seventy-four subjects were enrolled over an 8-month period (20 April 2023 to 31 December 2023). All patients were divided into the test group (group P) and the control group (group S) using the envelope as the randomization method. The test group was treated with preoperative ultrasound-guided PENG block analgesia combined with general anesthesia and the control group was treated with preoperative ultrasound-guided SIFIB analgesia combined with general anesthesia. The primary outcome selected was the patient Visual Analogue Scale (VAS) score at 12 h postoperatively. RESULTS: After generalized estimating equations (GEE) analysis, there was a statistically significant difference in the main effect of postoperative VAS score in group P compared with group S (P = 0.009), the time effect of VAS score in each group was significantly different (P < 0.001), and there was no statistically significant difference in the group-time interaction effect (P = 0.069). There was no statistically significant difference in the main effect of intraoperative mean arterial pressure (MAP) change (P = 0.911), there were statistically significant differences in the time effect of MAP in each group (P < 0.001), and there were statistically significant differences in the interaction effect (P < 0.001). CONCLUSIONS: In summary, we can conclude that in elderly patients undergoing hip fracture surgery, postoperative analgesia is more pronounced, intraoperative hemodynamic parameters are more stable, and intraoperative stress is less induced in patients receiving SIFIB than in patients receiving PENG block.

Molecular insights into the initiation step of the Rcs signaling pathway.

The Rcs pathway is repressed by the inner membrane protein IgaA under non-stressed conditions. This repression is hypothesized to be relieved by the binding of the outer membrane-anchored RcsF to IgaA. However, the precise mechanism by which RcsF binding triggers the signaling remains unclear. Here, we present the 1.8 Å resolution crystal structure capturing the interaction between IgaA and RcsF. Our comparative structural analysis, examining both the bound and unbound states of the periplasmic domain of IgaA (IgaAp), highlights rotational flexibility within IgaAp. Conversely, the conformation of RcsF remains unchanged upon binding. Our in vivo and in vitro studies do not support the model of a stable complex involving RcsF, IgaAp, and RcsDp. Instead, we demonstrate that the elements beyond IgaAp play a role in the interaction between IgaA and RcsD. These findings collectively allow us to propose a potential mechanism for the signaling across the inner membrane through IgaA.

The transcription factor ERF110 promotes cold tolerance by directly regulating sugar and sterol biosynthesis in citrus.

ERFs (ethylene-responsive factors) are known to play a key role in orchestrating cold stress signal transduction. However, the regulatory mechanisms and target genes of most ERFs are far from being well deciphered. In this study, we identified a cold-induced ERF, designated as PtrERF110, from trifoliate orange (Poncirus trifoliata L. Raf., also known as Citrus trifoliata L.), an elite cold-hardy plant. PtrERF110 is a nuclear protein with transcriptional activation activity. Overexpression of PtrERF110 remarkably enhanced cold tolerance in lemon (Citrus limon) and tobacco (Nicotiana tabacum), whereas VIGS (virus-induced gene silencing)-mediated knockdown of PtrERF110 drastically impaired the cold tolerance. RNA sequence analysis revealed that PtrERF110 overexpression resulted in global transcriptional reprogramming of a range of stress-responsive genes. Three of the genes, including PtrERD6L16 (early responsive dehydration 6-like transporters), PtrSPS4 (sucrose phosphate synthase 4), and PtrUGT80B1 (UDP-glucose: sterol glycosyltransferases 80B1), were confirmed as direct targets of PtrERF110. Consistently, PtrERF110-overexpressing plants exhibited higher levels of sugars and sterols compared to their wild type counterparts, whereas the VIGS plants had an opposite trend. Exogenous supply of sucrose restored the cold tolerance of PtrERF110-silencing plants. In addition, knockdown of PtrSPS4, PtrERD6L16, and PtrUGT80B1 substantially impaired the cold tolerance of P. trifoliata. Taken together, our findings indicate that PtrERF110 positively modulates cold tolerance by directly regulating sugar and sterol synthesis through transcriptionally activating PtrERD6L16, PtrSPS4, and PtrUGT80B1. The regulatory modules (ERF110-ERD6L16/SPS4/UGT80B1) unraveled in this study advance our understanding of the molecular mechanisms underlying sugar and sterol accumulation in plants subjected to cold stress.

The germline coordinates mitokine signaling.

The ability of mitochondria to coordinate stress responses across tissues is critical for health. In C. elegans, neurons experiencing mitochondrial stress elicit an inter-tissue signaling pathway through the release of mitokine signals, such as serotonin or the Wnt ligand EGL-20, which activate the mitochondrial unfolded protein response (UPRMT) in the periphery to promote organismal health and lifespan. We find that germline mitochondria play a surprising role in neuron-to-periphery UPRMT signaling. Specifically, we find that germline mitochondria signal downstream of neuronal mitokines, Wnt and serotonin, and upstream of lipid metabolic pathways in the periphery to regulate UPRMT activation. We also find that the germline tissue itself is essential for UPRMT signaling. We propose that the germline has a central signaling role in coordinating mitochondrial stress responses across tissues, and germline mitochondria play a defining role in this coordination because of their inherent roles in germline integrity and inter-tissue signaling.

Histone H3.3 chaperone HIRA renders stress-responsive genes poised for prospective lethal stresses in acquired tolerance.

Appropriate responses to environmental challenges are imperative for the survival of all living organisms. Exposure to low-dose stresses is recognized to yield increased cellular fitness, a phenomenon termed hormesis. However, our molecular understanding of how cells respond to low-dose stress remains profoundly limited. Here we report that histone variant H3.3-specific chaperone, HIRA, is required for acquired tolerance, where low-dose heat stress exposure confers resistance to subsequent lethal heat stress. We found that human HIRA activates stress-responsive genes, including HSP70, by depositing histone H3.3 following low-dose stresses. These genes are also marked with histone H3 Lys-4 trimethylation and H3 Lys-9 acetylation, both active chromatin markers. Moreover, depletion of HIRA greatly diminished acquired tolerance, both in normal diploid fibroblasts and in HeLa cells. Collectively, our study revealed that HIRA is required for eliciting adaptive stress responses under environmental fluctuations and is a master regulator of stress tolerance.

Metabolic model guided CRISPRi identifies a central role for phosphoglycerate mutase in Chlamydia trachomatis persistence.

Upon nutrient starvation, Chlamydia trachomatis serovar L2 (CTL) shifts from its normal growth to a non-replicating form, termed persistence. It is unclear if persistence reflects an adaptive response or a lack thereof. To understand this, transcriptomics data were collected for CTL grown under nutrient-replete and nutrient-starved conditions. Applying K-means clustering on transcriptomics data revealed a global transcriptomic rewiring of CTL under stress conditions in the absence of any canonical global stress regulator. This is consistent with previous data that suggested that CTL's stress response is due to a lack of an adaptive response mechanism. To investigate the impact of this on CTL metabolism, we reconstructed a genome-scale metabolic model of CTL (iCTL278) and contextualized it with the collected transcriptomics data. Using the metabolic bottleneck analysis on contextualized iCTL278, we observed that phosphoglycerate mutase (pgm) regulates the entry of CTL to the persistence state. Our data indicate that pgm has the highest thermodynamics driving force and lowest enzymatic cost. Furthermore, CRISPRi-driven knockdown of pgm in the presence or absence of tryptophan revealed the importance of this gene in modulating persistence. Hence, this work, for the first time, introduces thermodynamics and enzyme cost as tools to gain a deeper understanding on CTL persistence. IMPORTANCE: This study uses a metabolic model to investigate factors that contribute to the persistence of Chlamydia trachomatis serovar L2 (CTL) under tryptophan and iron starvation conditions. As CTL lacks many canonical transcriptional regulators, the model was used to assess two prevailing hypotheses on persistence-that the chlamydial response to nutrient starvation represents a passive response due to the lack of regulators or that it is an active response by the bacterium. K-means clustering of stress-induced transcriptomics data revealed striking evidence in favor of the lack of adaptive (i.e., a passive) response. To find the metabolic signature of this, metabolic modeling pin-pointed pgm as a potential regulator of persistence. Thermodynamic driving force, enzyme cost, and CRISPRi knockdown of pgm supported this finding. Overall, this work introduces thermodynamic driving force and enzyme cost as a tool to understand chlamydial persistence, demonstrating how systems biology-guided CRISPRi can unravel complex bacterial phenomena.

Natural elicitors enhanced suberin polyphenolic accumulation in wounded potato tuber tissues.

Introduction: Unintended wounding or bruising during harvest or postharvest handling leads to significant tuber loss and imposes economic burden to potato industry. Therefore, finding effective strategies to mitigate wound-related tuber losses is very important from industry perspectives. Formation of protective barrier through accumulation of suberin polyphenolics (SPP) is a natural and initial response of potato tuber tissues to wounding. Materials and methods: In this study, efficacy of two natural elicitors, such as chitosan oligosaccharide (COS 0.125 g L-1) and cranberry pomace residue (Nutri-Cran 0.125 g L-1) was investigated using a mechanically wounded tuber tissue model and by histological determination of SPP formation in five agronomically relevant and red-skin potato cultivars (Chieftain, Dakota Rose, Dakota Ruby, Red LaSoda, Red Norland). Furthermore, the potential role of stress protective metabolic regulation involving phenolic metabolites, proline, and antioxidant enzymes in tuber WH processes were also investigated during 0-9 days after wounding. Results and discussion: Exogenous treatments of both COS and Nutri-Cran resulted into enhanced SPP formation in wounded surface, but the impact was more rapid with Nutri-Cran treatment in select cultivars. Greater contents of total soluble phenolic, ferulic acid, chlorogenic acid, total antioxidant activity, and superoxide dismutase activity were also observed in elicitor treated tuber tissues at different time points after wounding. Nutri-Cran treatment also reduced the activity of succinate dehydrogenase in Red Norland and Dakota Ruby at 3 d, indicating a suppression in respiration rate. Collectively, these results suggest that Nutri-Cran can be potentially utilized as an effective WH treatment to potato tubers for minimizing wound-related losses.