Low Nutritional Conditions Research Articles

RfaH contributes to maximal colonization and full virulence of hypervirulent Klebsiella pneumoniae.

Hypervirulent K. pneumoniae (hvKp) have emerged as clinically important pathogens, posing a serious threat to human health. RfaH, a transcriptional elongation factor, has been regarded as implicated in facilitating the transcription of long virulence operons in certain bacterial species. In K. pneumoniae, RfaH plays a vital role in promoting CPS synthesis and hypermucoviscosity, as well as mediating bacterial fitness during lung infection. In this study, we aim to conduct a systematic investigation of the roles of rfaH in the survival, dissemination, and colonization of hvKp through in vitro and in vivo assays. We found that bacterial cells and colonies displayed capsule -deficient phenotypes subsequent to the deletion of rfaH in K. pneumoniae NTUH-K2044. We confirmed that rfaH is required for the synthesis of capsule and lipopolysaccharide (LPS) by positively regulating the expression of CPS and LPS gene clusters. We found that the ΔrfaH mutant led to a significantly decreased mortality of K. pneumoniae in a mouse intraperitoneal infection model. We further demonstrated that the absence of rfaH was associated with slower bacterial growth under conditions of low nutrition or iron limitation. ΔrfaH displayed reduced survival rates in the presence of human serum. Besides, the engulfment of the ΔrfaH mutant was significantly higher than that of NTUH-K2044 by macrophages in vivo, indicating an indispensable role of RfaH in the phagocytosis resistance of hvKp in mice. Both mouse intranasal and intraperitoneal infection models revealed a higher bacterial clearance rate of ΔrfaH in lungs, livers, and spleens of mice compared to its wild type, suggesting an important role of RfaH in the bacterial survival, dissemination, and colonization of hvKp in vivo. Histopathological results supported that RfaH contributes to the pathogenicity of hvKp in mice. In conclusion, our study demonstrates crucial roles of RfaH in the survival, colonization and full virulence of hvKp, which provides several implications for the development of RfaH as an antibacterial target.

Relationship between nutritional condition and causes of death in beluga whales Delphinapterus leucas from the St. Lawrence estuary, Quebec, Canada.

Carcasses of endangered beluga whales Delphinapterus leucas from the St. Lawrence Estuary, Canada, have been examined consistently since 1983 to determine causes of death. The objective of this study is to compare the nutritional condition of belugas that died of different causes. Previously published categories of death were refined to discriminate acute from chronic pathological processes. Bayesian linear models were used to predict cause of death from the scaled mass index (SMI). Causes of death were as follows: 'bacterial diseases', 'verminous pneumonia', 'toxoplasmosis', 'other parasitic diseases', 'other infectious diseases', 'trauma-entrapment', 'other noninfectious diseases', 'dystocia-postpartum complications', 'neonatal mortality', 'cancer', 'primary starvation' and 'undetermined'. The models predicted a lower nutritional condition for the 'neonatal mortality' in belugas <290 cm in length and for 'primary starvation' and 'verminous pneumonia' categories for belugas ≥290 cm. Belugas that died from 'dystocia-postpartum complications' or from 'undetermined causes' had a higher-than-average SMI. Animals in the 'trauma-entrapment' category did not exhibit the highest nutritional condition, which was unexpected since individuals that died from trauma or entrapment are often used as references for optimal nutritional condition in other cetacean populations. Females that died from dystocia and postpartum complications were in similar nutritional condition as females dead from other causes during, or shortly after, pregnancy. This suggests that these females are not obese, ruling out a possible cause of dystocia. Although studying dead animals biases results toward low nutritional condition, our findings support the link between chronic pathological processes and poorer nutritional condition in belugas.

Screening of Poly(3-Hydroxybutyrate) P(3HB) Producing Bacteria from Mackerel Fish (Rastrelliger sp.)

Bioplastic P(3HB) is a plastic that can be decomposed by decomposing microorganisms. Bacteria can produce P(3HB) in conditions of low nutrition and high carbon sources accumulated in cells as energy reserves. Isolation of bacteria-producing bioplastic P(3HB) was carried out in mackerel fish's gills and intestines, allowing direct contact with polluted waters. This research aimed to determine the presence of P(3HB) bioplastic-producing bacteria in mackerel fish samples and to screen for P(3HB) bioplastic-producing bacteria. The stages of the research were the isolation of P(3HB) producing bacteria from the gills and intestines of mackerel fish, screening of P(3HB) bioplastic-producing bacteria by using Nile Blue A staining, and molecular identification of bioplastic-producing bacteria using 16S rRNA gene. The results of bacterial isolation in the gills and intestines of mackerel obtained 10 bacterial isolates. P(3HB) screening found 1 bacterium showing orange fluorescence, namely IKE-1 isolate which was isolated from the gills of mackerel fish and included in the Gram-negative group with a monobacilli cell shape. Molecular identification of bacteria by using the 16S rRNA gene that isolate IKE-1 is Enterobacter roggenkampii. These results indicate that Enterobacter roggenkampii can produce P(3HB) which was confirmed by the screening results

The exception to the rule? TORC1 triggers growth under low nutrient environments

Eukaryotic cells' proliferation and growth are controlled by the target of rapamycin kinase (TOR). TOR usually activates in favorable energy and nutritional circumstances. This is challenged by recent research, suggesting that plant cells optimized for nutrient absorption in low nutritional conditions may activate the TOR pathway in a polarized manner.

Inter-organ Wingless/Ror/Akt signaling regulates nutrient-dependent hyperarborization of somatosensory neurons.

Nutrition in early life has profound effects on an organism, altering processes such as organogenesis. However, little is known about how specific nutrients affect neuronal development. Dendrites of class IV dendritic arborization neurons in Drosophila larvae become more complex when the larvae are reared on a low-yeast diet compared to a high-yeast diet. Our systematic search for key nutrients revealed that the neurons increase their dendritic terminal densities in response to a combined deficiency in vitamins, metal ions, and cholesterol. The deficiency of these nutrients upregulates Wingless in a closely located tissue, body wall muscle. Muscle-derived Wingless activates Akt in the neurons through the receptor tyrosine kinase Ror, which promotes the dendrite branching. In larval muscles, the expression of wingless is regulated not only in this key nutrient-dependent manner, but also by the JAK/STAT signaling pathway. Additionally, the low-yeast diet blunts neuronal light responsiveness and light avoidance behavior, which may help larvae optimize their survival strategies under low-nutritional conditions. Together, our studies illustrate how the availability of specific nutrients affects neuronal development through inter-organ signaling.

Assessment on the cumulative effect of pollutants and the evolution of micro-ecosystems in bioretention systems with different media

Bioretention system is one of the most used green stormwater infrastructures (GSI), and its media is a key factor in reducing runoff water volume and purifying water quality. Many studies have investigated media improvement to enhance the pollutant removal capacity. However, the long-term cumulative effect and microbial effect of pollutants in the modified-media bioretention system is less known. This study investigated the cumulative effect of pollutants and their influence on microbial characteristics in conventional and modified media bioretention system. The addition of modifiers increased the background content of pollutants in the media, and the accumulation of pollutants in planting soil (PS) and bioretention soil mixing + water treatment residuals (BSM+WTR) was relatively higher after the simulated rainfall experiment. The accumulation of pollutants led to a decrease in dehydrogenase activity, and an increase in urease and invertase activities. Ten dominant bacterial species at the phylum level were found in all bioretention systems. The relative abundances of the bacteria with good viability under low nutritional conditions decreased, while the species which could live in the pollutant-rich environment increased. The accumulation of pollutants in the bioretention system led to the extinction of some functional microorganisms. The better the effects of modified media on pollutant removal showed, the more obvious effect on the media micro-ecosystem was. To ensure the long-term efficient and stable operation of the modified-media bioretention system, we recommend balancing the pollutant removal efficiency and cumulative effect in modified-media bioretention systems.

Enumeration of Viable Non-Culturable Vibrio cholerae Using Droplet Digital PCR Combined With Propidium Monoazide Treatment.

Many bacterial species, including Vibrio cholerae (the pathogen that causes cholera), enter a physiologically viable but non-culturable (VBNC) state at low temperature or in conditions of low nutrition; this is a survival strategy to resist environmental stress. Identification, detection, and differentiation of VBNC cells and nonviable cells are essential for both microbiological study and disease surveillance/control. Enumeration of VBNC cells requires an accurate method. Traditional counting methods do not allow quantification of VBNC cells because they are not culturable. Morphology-based counting cannot distinguish between live and dead cells. A bacterial cell possesses one copy of the chromosome. Hence, counting single-copy genes on the chromosome is a suitable approach to count bacterial cells. In this study, we developed quantitative PCR-based methods, including real-time quantitative PCR (qPCR) and droplet digital PCR (ddPCR), to enumerate VBNC V. cholerae cells by counting the numbers of single-copy genes in samples during VBNC-state development. Propidium monoazide (PMA) treatment was incorporated to distinguish dead cells from viable cells. Both PCR methods could be used to quantify the number of DNA copies/mL and determine the proportion of dead cells (when PMA was used). The methods produced comparable counts using three single-copy genes (VC1376, thyA, and recA). However, ddPCR showed greater accuracy and sensitivity than qPCR. ddPCR also allows direct counting without the need to establish a standard curve. Our study develops a PMA-ddPCR method as a new tool to quantify VBNC cells of V. cholerae. The method can be extended to other bacterial species.

Methods and Nutritional Interventions to Improve the Nutritional Status of Dialysis Patients in JAPAN-A Narrative Review.

Patients receiving dialysis therapy often have frailty, protein energy wasting, and sarcopenia. However, medical staff in Japan, except for registered dietitians, do not receive training in nutritional management at school or on the job. Moreover, registered dietitians work separately from patients and medical staff even inside a hospital, and there are many medical institutions that do not have registered dietitians. In such institutions, medical staff are required to manage patients’ nutritional disorders without assistance from a specialist. Recent studies have shown that salt intake should not be restricted under conditions of low nutrition in frail subjects or those undergoing dialysis, and protein consumption should be targeted at 0.9 to 1.2 g/kg/day. The Japanese Society of Dialysis Therapy suggests that the Nutritional Risk Index-Japanese Hemodialysis (NRI-JH) is a useful tool to screen for older patients with malnutrition.

Bone Formation: Rolled‐Up Metal Oxide Microscaffolds to Study Early Bone Formation at Single Cell Resolution (Small 12/2021)

Transparent Ti-45Nb 3D microstructures offer an elegant way to study single bone cell-implant material interactions and pore size effects in vitro. In article number 2005527, Mariana Medina-Sánchez and co-workers present this technology as an excellent tool to live monitor cell migration and adhesion behavior changes deriving from highly constricted microenvironments, while also providing deeper insights on cell death related bone mineralization processes in low nutrition conditions.

Quorum sensing regulation confronts the development of a viable but non-culturable state in Vibrio cholerae.

Vibrio cholerae can enter a viable but non-culturable (VBNC) state when it encounters unfavourable environments; VBNC cells serve as important reservoirs and still pose threats to public health. The genetic regulation of V. cholerae entering its VBNC state is not well understood. Here, we show a confrontation strategy adapted by V. cholerae O1 in which it utilizes a quorum sensing (QS) system to prevent transition into a VBNC state under low nutrition and temperature conditions. The upregulation of hapR resulted in a prolonged culturable state of V. cholerae in artificial sea water at 4°C, whereas the mutation of hapR led to fast entry into the VBNC state. We also observed that different V. cholerae O1 natural isolates with distinct QS functions present a variety of abilities to maintain culturability during the transition to a VBNC state. The strain groups with higher or constitutive expression of QS genes exhibit a greater tendency to maintain the culturable state during VBNC induction than those lacking QS functional groups. In summary, HapR-mediated QS regulation is associated with the transition to the VBNC state in V. cholerae. HapR expression causes V. cholerae to resist VBNC induction and become dominant over competitors in changing environments.

Downregulation of the circadian rhythm regulator HLF promotes multiple-organ distant metastases in non-small cell lung cancer through PPAR/NF-κb signaling.

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death due to its early recurrence and widespread metastatic potential. Accumulating studies have reported that dysregulation of circadian rhythms-associated regulators is implicated in the recurrence and metastasis of NSCLC. Therefore, identification of metastasis-associated circadian rhythm genes is clinically necessary. Here we report that the circadian gene hepatic leukemia factor (HLF), which was dramatically reduced in early-relapsed NSCLC tissues, was significantly correlated with early progression and distant metastasis in NSCLC patients. Upregulating HLF inhibited, while silencing HLF promoted lung colonization, as well as metastasis of NSCLC cells to bone, liver and brain in vivo. Importantly, downexpression of HLF promoted anaerobic metabolism to support anchorage-independent growth of NSCLC cells under low nutritional condition by activating NF-κB/p65 signaling through disrupting translocation of PPARα and PPARγ. Further investigations revealed that both genetic deletion and methylation contribute to downexpression of HLF in NSCLC tissues. In conclusion, our results shed light on a plausible mechanism by which HLF inhibits distant metastasis in NSCLC, suggesting that HLF may serve as a novel target for clinical intervention in NSCLC.

Bioprospection of indigenous flora grown in copper mining tailing area for phytoremediation of metals

The study evaluated plants with phytoremediation potential that occur spontaneously in an area of copper mining tailings in Southern of Brazil. Eleven plant species were investigated for heavy metal concentrations in its biomass. All species showed copper concentrations greater than 100 mg kg−1, and seven species highlighted for copper concentrations between 321 and 586 mg kg−1 and these species showed Cr concentrations between 25 and 440 mg kg−1. The species S. viarum Dunal and B. trimera Less were highlighted showing the highest concentrations of Cr (586 mg kg−1) and Cu (440 mg kg−1), respectively. Seven species showed Pb phytoextraction potential and four species showed Cu phytostabilization potential. It was concluded that the investigated species are adapted to low nutritional conditions and showed tolerance to heavy metals, mainly Cu, Pb and Cr in its biomass.

Dietary carotenoids affect the development of individual differences and behavioral plasticity

AbstractNutritional conditions experienced during development are expected to play a key role in shaping an individual’s behavioral phenotype. The long term, irreversible effects of nutritional conditions on behavioral variation among and within individuals remains largely unexplored. This study aimed to investigate how long-term carotenoid availability (representing low vs. high quality nutritional conditions) during both larval and adult life stages influences the expression of among-individual variation (animal personality) and within-individual variation (behavioral plasticity). We tested for personality and plasticity along the exploration/avoidance behavioral axis in the Southern Corroboree frog (Pseudophryne corroboree). We predicted that treatment groups receiving carotenoids during early development would be more exploratory and have greater among- and within-individual variation compared with individuals that did not receive carotenoids (i.e., silver spoon hypothesis). Superior nutritional conditions experienced during development are expected to provide individuals with resources needed to develop costly behaviors, giving them an advantage later in life irrespective of prevailing conditions. Unexpectedly, frogs that did not receive carotenoids as larvae expressed greater among-individual variance in exploration behavior. Additionally, frogs that did not receive carotenoids at either life stage displayed greater within-individual variance. Our findings provide no support for the silver spoon hypothesis but suggest that inconsistent nutritional conditions between life stages may adversely affect the development of behavioral phenotypes. Overall, our results indicate that early and late life nutritional conditions affect the development of personality and plasticity. They also highlight that nutritional effects on behavior may be more complex than previously theorized.

LINC00641 regulates autophagy and intervertebral disc degeneration by acting as a competitive endogenous RNA of miR-153-3p under nutrition deprivation stress.

Emerging evidence supports the involvement of autophagy in the pathogenesis of intervertebral disc degeneration (IDD). MicroRNAs (miRNAs) and long noncoding RNAs (lncRNAs) play fundamental roles in various cellular processes, including autophagy. However, it remains largely unknown as to how autophagy is regulated by miRNAs and lncRNAs in IDD. Biological functions of miR-153-3p and long intergenic nonprotein coding RNA 641 (LINC00641) were investigated. Luciferase reporter assays was done to validate miR-153-3p targets. To induce nutritional stress, nucleus pulposus (NP) cells were cultured in the normal nutritional condition and the low nutritional condition. Quantitative reverse-transcription polymerase chain reaction (RT-qPCR) was used to analyze miR-153-3p and LINC00641 in response to nutrient deprivation. Autophagic activity was assessed by transmission electron microscopy, western blot analysis and green fluorescent protein-light chain 3 puncta. Pull-down assay and RNA fluorescent in situ hybridization were performed to validate LINC00641 target and the location. MiR-153-3p is downregulated in NP tissues from IDD patients. Further, LINC00641 can affect collagen II and matrix metalloproteinase-3 expressions. Upregulation of LINC00641 and downregulation of miR-153-3p are detected in NP cells under nutritional stress. LINC00641 can regulate autophagic cell death by targeting miR-153-3p and autophagy-related gene 5 (ATG5). MiR-153-3p inhibits autophagy and IDD by targeting ATG5. More important, LINC00641 targets miR-153-3p, and thus affects ATG5 expression, autophagic cell death and IDD. These findings uncover a novel regulatory pathway that is composed of LINC00641, miR-153-3p, and ATG5 in IDD. This mechanism may stimulate to a more understanding of IDD pathogenesis and provide new sights for the treatment of this disorder.

Molecular Ontogeny of First-Feeding European Eel Larvae.

Digestive system functionality of fish larvae relies on the onset of genetically pre-programmed and extrinsically influenced digestive functions. This study explored how algal supplementation (green-water) until 14 days post hatch (dph) and the ingestion of food [enriched rotifer (Brachionus plicatilis) paste] from 15 dph onward affects molecular maturation and functionality of European eel larval ingestion and digestion mechanisms. For this, we linked larval biometrics to expression of genes relating to appetite [ghrelin (ghrl), cholecystokinin (cck)], food intake [proopiomelanocortin (pomc)], digestion [trypsin (try), triglyceride lipase (tgl), amylase (amyl)], energy metabolism [ATP synthase F0 subunit 6 (atp6), cytochrome-c-oxidase 1 (cox1)], growth [insulin-like growth factor (igf1)] and thyroid metabolism [thyroid hormone receptors (thrαA, thrβB)]. Additionally, we estimated larval nutritional status via nucleic acid analysis during transition from endogenous and throughout the exogenous feeding stage. Results showed increased expression of ghrl and cck on 12 dph, marking the beginning of the first-feeding window, but no benefit of larviculture in green-water was observed. Moreover, expression of genes relating to protein (try) and lipid (tgl) hydrolysis revealed essential digestive processes occurring from 14 to 20 dph. On 16 dph, a molecular response to initiation of exogenous feeding was observed in the expression patterns of pomc, atp6, cox1, igf1, thrαA and thrβB. Additionally, we detected increased DNA contents, which coincided with increased RNA contents and greater body area, reflecting growth in feeding compared to non-feeding larvae. Thus, the here applied nutritional regime facilitated a short-term benefit, where feeding larvae were able to sustain growth and better condition than their non-feeding conspecifics. However, RNA:DNA ratios decreased from 12 dph onward, indicating a generally low larval nutritional condition, probably leading to the point-of-no-return and subsequent irreversible mortality due to unsuccessful utilization of exogenous feeding. In conclusion, this study molecularly identified the first-feeding window in European eel and revealed that exogenous feeding success occurs concurrently with the onset of a broad array of enzymes and hormones, which are known to regulate molecular processes in feeding physiology. This knowledge constitutes essential information to develop efficient larval feeding strategies and will hopefully provide a promising step toward sustainable aquaculture of European eel.

Zebra finch nestlings, rather than parents, suffer from raising broods under low nutritional conditions

In sexually reproducing species, parents and offspring have different optima in terms of the amount of parental investment. For offspring, higher investment than the parental optimum generally increases their fitness. However, such higher investment will, in theory, result in net parental fitness loss because increased benefits from current offspring will be more than offset by a potential decrease in parental survival or future reproduction. Whether and how parents respond to a shortfall in resources might therefore have important fitness consequences. Here, we manipulate the nutritional condition of captive zebra finch families to investigate how variation in environmental conditions influences parental resource allocation between themselves and their offspring. By allowing the same zebra finch pairs to raise one brood under high and another brood under low nutritional conditions, we found that parents lost more body mass and their offspring grew at slower rates under low nutritional conditions. Therefore, both parents and their offspring were affected by the nutritional treatments. Offspring incurred greater costs, because slower growth rates under low nutritional conditions resulted in an overall lower body mass of nestlings after reaching independence. Nutritional treatments had sex-specific effects on parental body mass, because, in contrast to fathers, only mothers recouped their losses under high nutritional conditions. Furthermore, both parents spent less time brooding their nestlings under low nutritional conditions. Parental strategies hence vary with the nutritional quality of their food, even in captivity, supporting the idea that parental resource allocation may be driven by the expected costs and benefits from current offspring. Parental care is among the most influential traits affecting fitness in many sexually reproducing animals. The more care offspring receive, the higher their chances of survival and reproduction. However, caring for their young does not only provide benefits for parents: all costs of parental care are paid by them. Parental resource allocation is therefore expected to be optimised. But how should parents respond to changing environmental conditions when they are already breeding? By manipulating nutritional conditions in a captive population of zebra finches Taeniopygia guttata, we show that both parents and their offspring lose body mass under low nutritional conditions. The effect on offspring was more pronounced and long lasting, and parents also decreased their parental effort. Our results show plasticity in parental investment of zebra finches in response to nutritional conditions and reproductive value of their offspring.

Severity of phytophthora root rot and pre‐emergence damping‐off in subterranean clover influenced by moisture, temperature, nutrition, soil type, cultivar and their interactions

Studies were carried out in controlled environment rooms reflecting field situations. In the presence of the devastating soilborne pathogen Phytophthora clandestina, subterranean clover (Trifolium subterraneum) seedling emergence was significantly affected by moisture, soil type, temperature and cultivar. The level of rotting of tap and lateral roots was significantly affected by nutrition, soil type, temperature and cultivar. There were significant interactions involving temperature, moisture, soil type and cultivar; cultivar resistance, high moisture, high or medium temperature, high nutrition and sand soil all contributed towards less pre‐emergence damping‐off and tap and lateral root disease and to greater clover productivity. Host resistance of subterranean clover cultivars was critical for reducing disease severity and increasing productivity, even when favourable environmental conditions for severe disease occurred. In the presence of P. clandestina, the most resistant cultivar, Seaton Park, performed best under a high temperature, high nutrition and high moisture combination, but showed lower productivity under conditions of low nutrition or lower temperature, even when moisture level was high. In contrast, less resistant cultivars Riverina and Meteora had less disease and greater productivity under low moisture conditions. Findings reflect field observations that pre‐emergence damping‐off and root disease from P. clandestina in subterranean clover is particularly severe under colder conditions and in nutritionally impoverished sandy soils, and demonstrate how variations in soil type, nutrition, moisture, temperature and cultivar have profound effects on the expression and severity of phytophthora pre‐emergence damping‐off and root disease and the productivity of subterranean clover forages.

VEGF expression is regulated by HIF-1α and ARNT in 3D KYSE-70, esophageal cancer cell spheroids.

In 3D cultured cell systems, the cells form 3D spheroids that mimic cancer cell spheroids in vivo. Cancer cells form cell spheroids as they grow. The in vivo spheroids do not contain a vascular network; therefore, oxygen and nutrition supplies are insufficient. Specifically, the cells in the core region of the cluster are exposed to higher stress levels than the cells in the outer spheroid layer. As a result, the cells in the spheroid are exposed to low nutrition and hypoxia conditions. To overcome these shortages, angiogenesis is induced in cancer spheroids in vivo. Vascular endothelial growth factor (VEGF) is an important molecule involved in angiogenesis. VEGF is secreted by cancer cells in vivo in response to stress conditions such as hypoxia. VEGF expression in cancer cells is mediated by hypoxia-inducible factor 1α (HIF1α), which accumulates in cancer cells during hypoxia. In this report, we show that VEGF expression is regulated by HIF1α and that VEGF is secreted to the outside of the spheroid in vitro. Several investigators have reported that HIF1α forms a protein-protein complex with aryl hydrocarbon receptor translocator (ARNT). We report here that not only HIF1α but also ARNT regulates VEGF expression in 3D cancer spheroids. Our results suggest the utility of the in vitro 3D cancer spheroid model for investigating angiogenesis in cancerous tissues.

Recombinant human SIRT1 protects against nutrient deprivation-induced mitochondrial apoptosis through autophagy induction in human intervertebral disc nucleus pulposus cells.

IntroductionNutrient deprivation is a likely contributor to intervertebral disc (IVD) degeneration. Silent mating type information regulator 2 homolog 1 (SIRT1) protects cells against limited nutrition by modulation of apoptosis and autophagy. However, little evidence exists regarding the extent to which SIRT1 affects IVD cells. Therefore, we conducted an in vitro study using human IVD nucleus pulposus (NP) cells.MethodsThirty-two IVD specimens were obtained from patients who underwent surgical intervention and were categorized based on Pfirrmann IVD degeneration grades. Cells were isolated from the NP and cultured in the presence of recombinant human SIRT1 (rhSIRT1) under different serum conditions, including 10 % (v/v) fetal bovine serum (FBS) as normal nutrition (N) and 1 % (v/v) FBS as low nutrition (LN). 3-Methyladenine (3-MA) was used to inhibit autophagy. Autophagic activity was assessed by measuring the absorbance of monodansylcadaverine and immunostaining and Western blotting for light chain 3 and p62/SQSTM1. Apoptosis and pathway analyses were performed by flow cytometry and Western blotting.ResultsCells cultured under LN conditions decreased in number and exhibited enhanced autophagy compared with the N condition. Medium supplementation with rhSIRT1 inhibited this decrease in cell number and induced an additional increase in autophagic activity (P < 0.05), whereas the combined use of rhSIRT1 and 3-MA resulted in drastic decreases in cell number and autophagy (P < 0.05). The incidence of apoptotic cell death increased under the LN condition, which was decreased by rhSIRT1 (P < 0.05) but increased further by a combination of rhSIRT1 and 3-MA (P < 0.05). Under LN conditions, NP cells showed a decrease in antiapoptotic Bcl-2 and an increase in proapoptotic Bax, cleaved caspase 3, and cleaved caspase 9, indicating apoptosis induction via the mitochondrial pathway. These changes were suppressed by rhSIRT1 but elevated further by rhSIRT1 with 3-MA, suggesting an effect of rhSIRT1-induced autophagy on apoptosis inhibition. Furthermore, the observed autophagy and apoptosis were more remarkable in cells from IVDs of Pfirrmann grade IV than in those from IVDs of Pfirrmann grade II.ConclusionsSIRT1 protects against nutrient deprivation-induced mitochondrial apoptosis through autophagy induction in human IVD NP cells, suggesting that rhSIRT1 may be a potent treatment agent for human degenerative IVD disease.

Eastern Baltic cod in distress: biological changes and challenges for stock assessment

AbstractThe eastern Baltic (EB) cod (Gadus morhua) stock was depleted and overexploited for decades until the mid-2000s, when fishing mortality rapidly declined and biomass started to increase, as shown by stock assessments. These positive developments were partly assigned to effective management measures, and the EB cod was considered one of the most successful stock recoveries in recent times. In contrast to this optimistic view, the analytical stock assessment failed in 2014, leaving the present stock status unclear. Deteriorated quality of some basic input data for stock assessment in combination with changes in environmental and ecological conditions has led to an unusual situation for cod in the Baltic Sea, which poses new challenges for stock assessment and management advice. A number of adverse developments such as low nutritional condition and disappearance of larger individuals indicate that the stock is in distress. In this study, we (i) summarize the knowledge of recent changes in cod biology and ecosystem conditions, (ii) describe the subsequent challenges for stock assessment, and (iii) highlight the key questions where answers are urgently needed to understand the present stock status and provide scientifically solid support for cod management in the Baltic Sea.