The dimer effect: A refinement approach towards skin sensitization assessment in-chemico using Amino acid Derivative Reactivity Assay.

Skin sensitization is a key endpoint for safety assessment, especially for cosmetics and personal care products. The adverse outcome pathway for skin sensitization and the chemical and biological events driving the induction of human skin sensitization are now well understood. Several non-animal test methods have been developed to predict sensitizer potential by measuring the impact of chemical sensitizers on these key events. In this work, we have focused on Key Event 1 (the molecular initiating step), which is based on formation of a covalent adduct between skin sensitizers and endogenous proteins and/or peptides in the skin. There exists three in-chemico assays approved by the Organization for Economic Co-operation and Development-(1) Direct Peptide Reactivity Assay (DPRA), (2) Amino Acid Derivative Reactivity Assay (ADRA), and (3) Kinetic Direct Peptide Reactivity Assay (kDPRA) to quantify peptide/amino acid derivative depletion after incubation with test chemicals. However, overestimated depletion of the cysteine-based peptide/amino acid derivatives is known in such assays because of the dimerization of the thiol group. In this present work, we report the synthesis and structural confirmation of the dimer of N-(2-[1-naphthyl]acetyl)-L-cysteine (NAC) from the ADRA assay to allow simultaneous determination of (a) peptide depletion by quantifying NAC monomer and (b) peptide dimerization by quantifying NAC dimer thereby eliminating the overestimation. We present a case study with three chemicals to demonstrate the importance of this approach. Thus, this simultaneous assay gives a more informed view of the peptide reactivity of chemicals to better identify skin sensitizers.

Fading and Color Reproducibility of Nipple-Areola Tattoos in Asian Patients.

Background The purpose of this study was to clarify fading, red, green, and blue values (RGB) change, and color reproducibility for nipple-areola complex (NAC) tattoos. Methods NAC tattooing was performed on 60 sites in 59 Japanese patients prospectively. The evaluation was assessed using digital photo, Casmatch standardization, and RGB and luminance values preoperatively, immediately after, 1 week, 1, 3, 6, and 12 months after tattooing. RGB and luminance values changes over time, time-adjusted fading rate, and the rate of luminance at 12 months were calculated. In color reproducibility study ( n = 34), RGB values after 12 months were compared with the color sample about dark/reddish and light/less reddish pigments. Results RGB varied widely from immediately after to 1 month after tattooing. For RGB and luminance, significant differences were seen between pre and immediate after, 1 and 3 months, 3 and 6 months, and 6 and 12 months. In G values, significant differences were seen between all neighboring points. The fading rate tended to decrease as time progresses, but was not significant, that is, fading continued even between 6 and 12 months. Luminance was 9% brighter than contralateral NAC at 12 months. Color reproducibility tended to be higher with dark/reddish pigments, despite no significant differences. Conclusion The fading rate of tattooed NACs tended to decrease as time progresses, but fading still occurs between 6 and 12 months. Luminance was 9% brighter than contralateral NAC at 12 months after.

Anti-Inflammatory and Anti-Oxidant Properties of N-Acetylcysteine: A Fresh Perspective.

N-acetyl-L-cysteine (NAC) was initially introduced as a treatment for mucus reduction and widely used for chronic respiratory conditions associated with mucus overproduction. However, the mechanism of action for NAC extends beyond its mucolytic activity and is complex and multifaceted. Contrary to other mucoactive drugs, NAC has been found to exhibit antioxidant, anti-infective, and anti-inflammatory activity in pre-clinical and clinical reports. These properties have sparked interest in its potential for treating chronic lung diseases, including chronic obstructive pulmonary disease (COPD), bronchiectasis (BE), cystic fibrosis (CF), and idiopathic pulmonary fibrosis (IPF), which are associated with oxidative stress, increased levels of glutathione and inflammation. NAC's anti-inflammatory activity is noteworthy, and it is not solely secondary to its antioxidant capabilities. In ex vivo models of COPD exacerbation, the anti-inflammatory effects have been observed even at very low doses, especially with prolonged treatment. The mechanism involves the inhibition of the activation of NF-kB and neurokinin A production, resulting in a reduction in interleukin-6 production, a cytokine abundantly present in the sputum and breath condensate of patients with COPD and correlates with the number of exacerbations. The unique combination of mucolytic, antioxidant, anti-infective, and anti-inflammatory properties positions NAC as a safe, cost-effective, and efficacious therapy for a plethora of respiratory conditions.

Journey from lab to clinic: Design, preclinical, and clinical development of systemic, targeted dendrimer-N-acetylcysteine (D-NAC) nanomedicines.

Drug discovery is challenging task with numerous obstacles in translating drug candidates into clinical products. Dendrimers are highly adaptable nanostructured polymers with significant potential to improve the chances of clinical success for drugs. Yet, dendrimer-based drug products are still in their infancy. However, Hydroxyl polyamidoamine (PAMAM) dendrimers showed significant promise in drug discovery efforts, owning their remarkable potential to selectively target and deliver drugs specifically to activated microglia and astrocytes at the site of brain injury in several preclinical models. After a decade's worth of academic research and pre-clinical efforts, the hydroxyl PAMAM dendrimer-N-acetyl cysteine conjugate (OP-101) nanomedicine has made a significant advancement in the field of nanomedicine and targeted delivery. The OP-101 conjugate, primarily developed and validated in academic labs, has now entered clinical trials as a potential treatment for hyperinflammation in hospitalized adults with severe COVID-19 through Ashvattha Therapeutics. This chapter, we delve into the journey of the hydroxyl PAMAM dendrimer-N-acetylcysteine (NAC) OP-101 formulation from the laboratory to the clinic. It will specifically focus on the design, synthesis, preclinical, and clinical development of OP-101, highlighting the potential it holds for the future of medicine and the positive Phase 2a results for treating severe COVID-19.

Prognostic significance of the neutrophil to lymphocyte ratio in locally advanced breast cancer.

The present study aimed to clarify the prognostic role of the pre-treatment neutrophil-to-lymphocyte ratio (NLR) for the response to neoadjuvant chemotherapy (NAC) in locally advanced breast cancer (LABC). Due to conflicting results in currently available data, the specific focus of the present study was on evaluating the associations between the pre-treatment NLR and the rate of achieving a pathological complete response (pCR) and survival outcomes. For the present study, data from a cohort of 465 consecutive patients with LABC who underwent NAC at King Feisal Specialist Hospital and Research Center (Riyadh, Saudi Arabia) between 2005 and 2014 were obtained from a prospective BC database and analyzed. Patients were stratified into two groups based on an optimal NLR cut-off determined using the receiver operating characteristic curve. Logistic regression analyses were conducted to assess variables associated with pCR, and Cox regression analyses were used to assess variables associated with survival outcomes. The low pre-treatment NLR group (≤2.2) was found to exhibit a higher likelihood of achieving a pCR (odds ratio, 2.59; 95% CI, 1.52-4.38; P<0.001), along with higher 5-year disease-free survival (DFS) [75.8 vs. 64.9%; hazard ratio (HR), 0.69; 95% CI, 0.50-0.94; P=0.02] and 5-year overall survival (OS; 90.3 vs. 81.9; HR, 0.62; 95% CI, 0.39-0.98; P=0.04) rates compared with those in the high NLR group (>2.2). Sub-group analysis revealed that the observed significance in survival outcomes was driven by the triple-negative BC (TNBC) subgroup. Patients with residual TNBC disease and a high pre-treatment NLR were observed to have lower 5-year DFS (44.4 vs. 75.0%; P=0.02) and 5-year OS (55.9 vs. 84.5%; P=0.055) rates compared with those with residual TNBC disease and a low NLR. To conclude, data from the present study suggest that the pre-treatment NLR can serve as a viable independent prognostic factor for pCR following NAC in patients with LABC and for survival outcomes, particularly for patients with TNBC.

Eggplant NAC domain transcription factor SmNST1 as an activator promotes secondary cell wall thickening.

NAC-domain transcription factors (TFs) are plant-specific transcriptional regulators playing crucial roles in plant secondary cell wall (SCW) biosynthesis. SCW is important for plant growth and development, maintaining plant morphology, providing rigid support, ensuring material transportation and participating in plant stress responses as a protective barrier. However, the molecular mechanisms underlying SCW in eggplant have not been thoroughly explored. In this study, the NAC domain TFs SmNST1 and SmNST2 were cloned from the eggplant line 'Sanyue qie'. SmNST1 and SmNST2 expression levels were the highest in the roots and stems. Subcellular localization analysis showed that they were localized in the cell membrane and nucleus. Their overexpression in transgenic tobacco showed that SmNST1 promotes SCW thickening. The expression of a set of SCW biosynthetic genes for cellulose, xylan and lignin, which regulate SCW formation, was increased in transgenic tobacco. Bimolecular fluorescence and luciferase complementation assays showed that SmNST1 interacted with SmNST2 in vivo. Yeast one-hybrid, electrophoretic mobility shift assay (EMSA) and Dual-luciferase reporter assays showed that SmMYB26 directly bound to the SmNST1 promoter and acted as an activator. SmNST1 and SmNST2 interact with the SmMYB108 promoter and repress SmMYB108 expression. Altogether, we showed that SmNST1 positively regulates SCW formation, improving our understanding of SCW biosynthesis transcriptional regulation.

N-acetyl Cysteine Overdose Induced Acute Toxicity and Hepatic Microvesicular Steatosis by Disrupting GSH and Interfering Lipid Metabolisms in Normal Mice.

N-acetyl cysteine (NAC) is a versatile drug used in various conditions, but the limitations and toxicities are not clear. The acute toxicity and toxicological mechanisms of an intraperitoneal injection of NAC in normal mice were deciphered. The LD50 for male and female BALB/cByJNarl mice were 800 mg/kg and 933 mg/kg. The toxicological mechanisms of 800 mg/kg NAC (N800) were investigated. The serum biomarkers of hepatic and renal indices dramatically increased, followed by hepatic microvesicular steatosis, renal tubular injury and necrosis, and splenic red pulp atrophy and loss. Thus, N800 resulted in mouse mortality mainly due to acute liver, kidney, and spleen damages. The safe dose (275 mg/kg) of NAC (N275) increased hepatic antioxidant capacity by increasing glutathione levels and catalase activity. N275 elevated the hepatic gene expressions of lipid transporter, lipid synthesis, ß-oxidation, and ketogenesis, suggesting a balance between lipid production and consumption, and finally, increased ATP production. In contrast, N800 increased hepatic oxidative stress by decreasing glutathione levels through suppressing Gclc, and reducing catalase activity. N800 decreased the hepatic gene expressions of lipid transporter, lipid synthesis, and interferred ß-oxidation, leading to lipid accumulation and increasing Cyp2E1 expression, and finally, decreased ATP production. Therefore, NAC doses are limited for normal individuals, especially via intraperitoneal injection or similar means.

Understanding Public Perceptions of Nipple and Scar Characteristics After Chest Wall Masculinization Surgery.

BACKGROUND: Surgical chest masculinization procedures, especially gender-affirming top surgery (GATS), are becoming increasingly prevalent in the USA. While a variety of surgical techniques have been established as both safe and effective, there is limited research examining ideal aesthetic nipple appearance and incision scar pattern. This study employs patient images to understand the public's perception on top surgery outcomes when adjusting for BMI ranges and Fitzpatrick skin types. METHODS: Images from RealSelf modified via Adobe Photoshop depicted various scar types and nipple-areolar complex (NAC) sizes/positions. A Qualtrics survey was distributed utilizing Amazon Mechanical Turk. Statistical analysis was performed through JMP Pro 17 for ordinal and categorical values, with a p value less than or equal to 0.05 statistically significant. RESULTS: A moderately sized and laterally placed NAC was preferred. A transverse scar that resembles the pectoral border between the level of the inframammary fold and pectoral insertion was deemed most masculine and aesthetic. Majority of results demonstrated that this is unaffected by Fitzpatrick skin types. Increased BMI images impacted public preferences, as a nipple placed farther from the transverse incision (p = 0.04) and a transverse scar position closer to the IMF was preferred in higher BMI patients. CONCLUSIONS: An understanding of the most popular NAC and scar choices, as well as how these factors may differ when considering a Fitzpatrick skin type or BMI categorization was attained. This validates the importance of patient-centered approach when employing surgical techniques in GATS. Future studies intend to obtain reports from actual patients considering GATS. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable.

Pathogen resistance was negatively regulated by the NAC transcription factor ScATAF1 in sugarcane.

The NAC (NAM, ATAF, and CUC) is one of the largest transcription factor gene families in plants. In this study, 180, 141, and 131 NAC family members were identified from Saccharum complex, including S. officinarum, S. spontaneum, and Erianthus rufipilus. The Ka/Ks ratio of ATAF subfamily was all less than 1. Besides, 52 ATAF members from 12 representative plants were divided into three clades and there was only a significant expansion in maize. Surprisingly, ABA and JA cis-elements were abundant in hormonal response factor, followed by transcriptional regulator and abiotic stressor. The ATAF subfamily was differentially expressed in various tissues, under low temperature and smut pathogen treatments. Further, the ScATAF1 gene, with high expression in leaves, stem epidermis, and buds, was isolated. The encoded protein, lack of self-activation activity, was situated in the cell nucleus. Moreover, SA and JA stresses down-regulated the expression of this gene, while ABA, NaCl, and 4°C treatments led to its up-regulation. Interestingly, its expression in the smut susceptible sugarcane cultivars was much higher than the smut resistant ones. Notably, the colors presented slight brown in tobacco transiently overexpressing ScATAF1 at 1 d after DAB staining, while the symptoms were more obvious at 3 d after inoculation with Ralstonia solanacearum, with ROS, JA, and SA signaling pathway genes significantly up-regulated. We thus speculated ScATAF1 gene could negatively mediate hypersensitive reactions and produce ROS by JA and SA signaling pathways. These findings lay the groundwork for in-depth investigation on the biological roles of ATAF subfamily in sugarcane.

Breast Cancer: Multi-b-Value Diffusion Weighted Habitat Imaging in Predicting Pathologic Complete Response to Neoadjuvant Chemotherapy.

RATIONALE AND OBJECTIVES: The aim of this study was to ascertain whether the utilization of multiple b-value diffusion-weighted habitat imaging, a technique that depicts tumor heterogeneity, could aid in identifying breast cancer patients who would derive substantial benefit from neoadjuvant chemotherapy (NAC). MATERIALS AND METHODS: This prospective study enrolled 143 women (II-III breast cancer), who underwent multi-b-value diffusion-weighted imaging (DWI) in 3-T magnetic resonance (MR) before NAC. The patient cohort was partitioned into a training set (consisting of 100 patients, of which 36 demonstrated a pathologic complete response [pCR]) and a test set (featuring 43 patients, 16 of whom exhibited pCR). Utilizing the training set, predictive models for pCR, were constructed using different parameters: whole-tumor radiomics (ModelWH), diffusion-weighted habitat-imaging (ModelHabitats), conventional MRI features (ModelCF), along with combined models ModelHabitats+CF. The performance of these models was assessed based on the area under the receiver operating characteristic curve (AUC) and calibration slope. RESULTS: In the prediction of pCR, ModelWH, ModelHabitats, ModelCF, and ModelHabitats+CF achieved AUCs of 0.733, 0.722, 0.705, and 0.756 respectively, within the training set. These scores corresponded to AUCs of 0.625, 0.801, 0.700, and 0.824 respectively in the test set. The DeLong test revealed no significant difference between ModelWH and ModelHabitats (P = 0.182), between ModelHabitats and ModelHabitats+CF (P = 0.113). CONCLUSION: The habitat model we developed, incorporating first-order features along with conventional MRI features, has demonstrated accurate predication of pCR prior to NAC. This model holds the potential to augment decision-making processes in personalized treatment strategies for breast cancer.

Polysubstance-Induced Hepatotoxicity and the Role of Supportive Management.

With the continued rise of polysubstance use throughout the country, it has been shown to affect a multitude of organ systems. Drug-induced liver injury (DILI) has been widely documented in its association with salicylates or acetaminophen and the utility of using N-acetylcysteine (NAC) for its hepatoprotective effects. However, DILI caused by illicit drug use and guideline-directed management has had little research. We present the case of a 29-year-old female who presented with altered mental status. She was found to have a concomitant liver injury and was treated supportively without the use of NAC, with gradual improvement.

Differential Roles of Key Brain Regions: Ventral Tegmental Area, Locus Coeruleus, Dorsal Raphe, Nucleus Accumbens, Caudate Nucleus, and Prefrontal Cortex in Regulating Response to Methylphenidate: Insights from Neuronal and Behavioral Studies in Freely Behaving Rats.

A total of 3102 neurons were recorded before and following acute and chronic methylphenidate (MPD) administration. Acute MPD exposure elicits mainly increases in neuronal and behavioral activity in dose-response characteristics. The response to chronic MPD exposure, as compared to acute 0.6, 2.5, or 10.0 mg/kg MPD administration, elicits electrophysiological and behavioral sensitization in some animals and electrophysiological and behavioral tolerance in others when the neuronal recording evaluations were performed based on the animals' behavioral responses, or amount of locomotor activity, to chronic MPD exposure. The majority of neurons recorded from those expressing behavioral sensitization responded to chronic MPD with further increases in firing rate as compared to the initial MPD responses. The majority of neurons recorded from animals expressing behavioral tolerance responded to chronic MPD with decreases in their firing rate as compared to the initial MPD exposures. Each of the six brain areas studied-the ventral tegmental area, locus coeruleus, dorsal raphe, nucleus accumbens, prefrontal cortex, and caudate nucleus (VTA, LC, DR, NAc, PFC, and CN)-responds significantly (p < 0.001) differently to MPD, suggesting that each one of the above brain areas exhibits different roles in the response to MPD. Moreover, this study demonstrates that it is essential to evaluate neuronal activity responses to psychostimulants based on the animals' behavioral responses to acute and chronic effects of the drug from several brain areas simultaneously to obtain accurate information on each area's role in response to the drug.

IDD10-NAC079 transcription factor complex regulates sheath blight resistance by inhibiting ethylene signaling in rice.

INTRODUCTION: Rhizoctonia solani Kühn is a pathogen causing rice sheath blight (ShB). Ammonium transporter 1 (AMT1) promotes resistance of rice to ShB by activating ethylene signaling. However, how AMT1 activates ethylene signaling remains unclear. OBJECTIVE: In this study, the indeterminate domain 10 (IDD10)-NAC079 interaction model was used to investigate whether ethylene signaling is modulated downstream of ammonium signaling and modulates ammonium-mediated ShB resistance. METHODS: RT-qPCR assay was used to identify the relative expression levels of nitrogen and ethylene related genes. Yeast two-hybrid assays, Bimolecular fluorescence complementation (BiFC) and Co-immunoprecipitation (Co-IP) assay were conducted to verify the IDD10-NAC079-calcineurin B-like interacting protein kinase 31 (CIPK31) transcriptional complex. Yeast one-hybrid assay, Chromatin immunoprecipitation (ChIP) assay, and Electrophoretic mobility shift assay (EMSA) were used to verify whether ETR2 was activated by IDD10 and NAC079. Ethylene quantification assay was used to verify ethylene content in IDD10 transgenic plants. Genetic analysis is used to detect the response of IDD10, NAC079 and CIPK31 to ShB infestation. RESULTS: IDD10-NAC079 forms a transcription complex that activates ETR2 to inhibit the ethylene signaling pathway to negatively regulating ShB resistance. CIPK31 interacts and phosphorylates NAC079 to enhance its transcriptional activation activity. In addition, AMT1-mediated ammonium absorption and subsequent N assimilation inhibit the expression of IDD10 and CIPK31 to activate the ethylene signaling pathway, which positively regulates ShB resistance. CONCLUSION: The study identified the link between ammonium and ethylene signaling and improved the understanding of the rice resistance mechanism.

The Role of Circulating MicroRNAs in the Prediction of Response to Neoadjuvant Chemotherapy in Locally Advanced Breast Cancer in the Indian Population.

INTRODUCTION: MicroRNAs (miRNAs) are known to play an important role in cancer cell proliferation, susceptibility of cancer cells to chemotherapy, and patient survival. Identifying miRNAs that can predict response to chemotherapy in locally advanced breast cancer (LABC), the most common variant, can help to choose appropriate drug regimens to suit the epigenetic profile of individual patients. OBJECTIVE: To investigate the expression of the differentially expressed miRNAs identified by next-generation sequencing from a pilot study involving cases and controls, in peripheral blood mononuclear cells (PBMC) of patients with LABC during the course of neoadjuvant chemotherapy (NAC) and determine their role in response to chemotherapy. METHODS: This study included 30 newly diagnosed LABC patients. Peripheral blood from every participant was collected before the start of chemotherapy, at the end of the third cycle, and at the end of the seventh cycle of NAC. Based on the results of a pilot study in a similar population with suitable controls, four differentially expressed miRNAs namely miR-24-2, miR-192-5p, miR-3609, and miR-664b-3p were considered to be validated in this study. The expression of these four miRNAs was examined by qRT-PCR, and their association with response to chemotherapy was analyzed. RESULT:  A significant change in the expression of miR-192-5p was found in responders (p = 0.001) over a period of seven cycles and the difference between the expression of miR-24-2 from baseline to the seventh cycle of NAC was higher in responders while compared to the non-responders (p < 0.05). CONCLUSION: miR-192-5p and miR-24-2 were identified as predictive biomarkers for response to NAC in south Indian patients with LABC.

LpNAC5 positively regulates drought, salt and alkalinity tolerance of Lilium pumilum.

NACs (NAM、ATAF1/2、CUC1/2), as a large family of plant transcription factors, are widely involved in abiotic stress responses. This study aimed to isolate and clone a novel stress-responsive transcription factor LpNAC5 from Lilium pumilum bulbs. Drought, salt, alkali, and ABA stresses induced the expression of LpNAC5. Transgenic tobacco plants overexpressing LpNAC5 were generated using the Agrobacterium-mediated method to understand the role of this factor in stress response. These plants exhibited increased tolerance to drought, salt, and alkali stresses. The tobacco plants overexpressing LpNAC5 showed strong drought, salt, and alkaline tolerance. Under the three abiotic stresses, the activities of antioxidant enzymes were enhanced, the contents of proline and chlorophyll increased, and the contents of malondialdehyde decreased. The functional analysis revealed that LpNAC5 enabled plants to positively regulate drought and salt stresses. These findings not only provided valuable insights into stress tolerance mechanisms in L. pumilum but also offered a potential genetic resource for breedi.

Unburned Tobacco Smoke Affects Neuroinflammation-Related Pathways in the Rat Mesolimbic System.

Tobacco use disorder represents a significant public health challenge due to its association with various diseases. Despite awareness efforts, smoking rates remain high, partly due to ineffective cessation methods and the spread of new electronic devices. This study investigated the impact of prolonged nicotine exposure via a heat-not-burn (HnB) device on selected genes and signaling proteins involved in inflammatory processes in the rat ventral tegmental area (VTA) and nucleus accumbens (NAc), two brain regions associated with addiction to different drugs, including nicotine. The results showed a reduction in mRNA levels for PPARα and PPARγ, two nuclear receptors and anti-inflammatory transcription factors, along with the dysregulation of gene expression of the epigenetic modulator KDM6s, in both investigated brain areas. Moreover, decreased PTEN mRNA levels and higher AKT phosphorylation were detected in the VTA of HnB-exposed rats with respect to their control counterparts. Finally, significant alterations in ERK 1/2 phosphorylation were observed in both mesolimbic areas, with VTA decrease and NAc increase, respectively. Overall, the results suggest that HnB aerosol exposure disrupts intracellular pathways potentially involved in the development and maintenance of the neuroinflammatory state. Moreover, these data highlight that, similar to conventional cigarettes, HnB devices use affects specific signaling pathways shaping neuroinflammatory process in the VTA and NAc, thus triggering mechanisms that are currently considered as potentially relevant for the development of addictive behavior.

A functional study reveals CsNAC086 regulated the biosynthesis of flavonols in Camellia sinensis.

MAIN CONCLUSION: CsNAC086 was found to promote the expression of CsFLS, thus promoting the accumulation of flavonols in Camellia sinensis. Flavonols, the main flavonoids in tea plants, play an important role in the taste and quality of tea. In this study, a NAC TF gene CsNAC086 was isolated from tea plants and confirmed its regulatory role in the expression of flavonol synthase which is a key gene involved in the biosynthesis of flavonols in tea plant. Yeast transcription-activity assays showed that CsNAC086 has self-activation activity. The transcriptional activator domain of CsNAC086 is located in the non-conserved C-terminal region (positions 171-550), while the conserved NAC domain (positions 1-170) does not have self-activation activity. Silencing the CsNAC086 gene using antisense oligonucleotides significantly decreased the expression of CsFLS. As a result, the concentration of flavonols decreased significantly. In overexpressing CsNAC086 tobacco leaves, the expression of NtFLS was significantly increased. Compared with wild-type tobacco, the flavonols concentration increased. Yeast one-hybrid assays showed CsNAC086 did not directly regulate the gene expression of CsFLS. These findings indicate that CsNAC086 plays a role in regulating flavonols biosynthesis in tea plants, which has important implications for selecting and breeding of high-flavonols-concentration containing tea-plant cultivars.

SlNAC3 suppresses cold tolerance in tomatoes by enhancing ethylene biosynthesis.

Low temperature stress poses a significant challenge to the productivity of horticultural crops. The dynamic expression of cold-responsive genes plays a crucial role in plant cold tolerance. While NAC transcription factors have been extensively studied in plant growth and development, their involvement in regulating plant cold tolerance remains poorly understood. In this study, we focused on the identification and characterisation of SlNAC3 as the most rapid and robust responsive gene in tomato under low temperature conditions. Manipulating SlNAC3 through overexpression or silencing resulted in reduced or enhanced cold tolerance, respectively. Surprisingly, we discovered a negative correlation between the expression of CBF and cold tolerance in the SlNAC3 transgenic lines. These findings suggest that SlNAC3 regulates tomato cold tolerance likely through a CBF-independent pathway. Furthermore, we conducted additional investigations to identify the molecular mechanisms underlying SINAC3-mediated cold tolerance in tomatoes. Our results revealed that SlNAC3 controls the transcription of ethylene biosynthetic genes, thereby bursting ethylene release in response to cold stress. Indeed, the silencing of these genes led to an augmentation in cold tolerance. This discovery provides valuable insights into the regulatory pathways involved in ethylene-mediated cold tolerance in tomatoes, offering potential strategies for developing innovative approaches to enhance cold stress resilience in this economically important crop species.

Breast surgery after neoadjuvant systemic therapy.

For patients with operable breast cancer, neoadjuvant systemic therapy (NST) can be used to downstage the primary tumor in the breast and to facilitate breast-conserving surgery (BCS) in patients with large tumors who desire breast conservation. Rates of breast pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) are highest in patients with triple-negative and human epidermal growth factor receptor 2 (HER2) positive (HER2+) disease; however, achieving pCR is not necessary for successful downstaging and avoidance of mastectomy, and rates of conversion to BCS-eligibility are high across all receptor subtypes. Neoadjuvant endocrine therapy (NET) can be used instead of NAC in postmenopausal patients with hormone receptor positive (HR+)/HER2 negative (HER2-) breast cancer to downstage the breast, particularly when the patient has no clear indication for systemic chemotherapy, but desires breast conservation. In patients treated with NET, rates of conversion to BCS-eligibility are similar to rates observed with NAC. The oncologic safety of BCS after NAC and NET has been established in prospective trials, and local recurrence (LR) rates are acceptably low provided negative surgical margins can be obtained. Investigation is under way to determine the feasibility and safety of omitting breast surgery in patients with responsive subtypes who have no residual invasive or in situ disease identified on post-treatment tumor bed biopsies; however, the significant risk of missing residual disease-which may impact selection of adjuvant systemic therapy-may preclude future adoption of this approach.

Ethylene induced AcNAC3 and AcNAC4 take part in ethylene synthesis through mediating AcACO1 during kiwifruit (Actinidia chinensis) ripening.

BACKGROUND: Ethylene plays a vital role in the ripening process of kiwifruit. A terrific amount of transcription factors (TFs) have been shown to regulate ethylene synthesis in various fruits. RESULTS: In this research, two new NAC TFs, named AcNAC3 and AcNAC4, were isolated from kiwifruit, which belonged to NAM subfamily. Bioinformatics analysis showed that both AcNAC3 and AcNAC4 were hydrophilic proteins with similar three-dimensional structures. The expression levels of AcNAC3, AcNAC4 and AcACO1 increased during kiwifruit ripening, as well as were induced by ethylene and repressed by 1-methylcyclopropene (1-MCP). Correlation analysis exhibited that ethylene production was positively correlated with the expression levels of AcNAC3, AcNAC4 and AcACO1. Moreover, both AcNAC3 and AcNAC4 acted as transcriptional activators and could bind to and activate AcACO1 promoter. CONCLUSION: All results unveiled that the ethylene-induced AcNAC3 and AcNAC4 were transcriptional activators, and might participate in kiwifruit ripening and ethylene biosynthesis through activating AcACO1, providing a new insight of ethylene synthetic regulation during kiwifruit ripening. © 2024 Society of Chemical Industry.