Ventral posteromedial nucleus of the thalamus gates the spread of trigeminal neuropathic pain.

BACKGROUND: Widespread neuropathic pain usually affects a wide range of body areas and inflicts huge suffering on patients. However, little is known about how it happens and effective therapeutic interventions are lacking. METHODS: Widespread neuropathic pain was induced by partial infraorbital nerve transection (p-IONX) and evaluated by measuring nociceptive thresholds. In vivo/vitro electrophysiology were used to evaluate neuronal activity. Virus tracing strategies, combined with optogenetics and chemogenetics, were used to clarify the role of remodeling circuit in widespread neuropathic pain. RESULTS: We found that in mice receiving p-IONX, along with pain sensitization spreading from the orofacial area to distal body parts, glutamatergic neurons in the ventral posteromedial nucleus of the thalamus (VPMGlu) were hyperactive and more responsive to stimulations applied to the hind paw or tail. Tracing experiments revealed that a remodeling was induced by p-IONX in the afferent circuitry of VPMGlu, notably evidenced by more projections from glutamatergic neurons in the dorsal column nuclei (DCNGlu). Moreover, VPMGlu receiving afferents from the DCN extended projections further to glutamatergic neurons in the posterior insular cortex (pIC). Selective inhibition of the terminals of DCNGlu in the VPM, the soma of VPMGlu or the terminals of VPMGlu in the pIC all alleviated trigeminal and widespread neuropathic pain. CONCLUSION: These results demonstrate that hyperactive VPMGlu recruit new afferents from the DCN and relay the extra-cephalic input to the pIC after p-IONX, thus hold a key position in trigeminal neuropathic pain and its spreading. This study provides novel insights into the circuit mechanism and preclinical evidence for potential therapeutic targets of widespread neuropathic pain.

Glutamatergic and GABAergic neurons in the vLGN mediate the nociceptive effects of green and red light on neuropathic pain.

Phototherapy is an emerging non-pharmacological treatment for depression, circadian rhythm disruptions, and neurodegeneration, as well as pain conditions including migraine and fibromyalgia. However, the mechanism of phototherapy-induced antinociception is not well understood. Here, using fiber photometry recordings of population-level neural activity combined with chemogenetics, we found that phototherapy elicits antinociception via regulation of the ventral lateral geniculate body (vLGN) located in the visual system. Specifically, both green and red lights caused an increase of c-fos in vLGN, with red light increased more. In vLGN, green light causes a large increase in glutamatergic neurons, whereas red light causes a large increase in GABAergic neurons. Green light preconditioning increases the sensitivity of glutamatergic neurons to noxious stimuli in vLGN of PSL mice. Green light produces antinociception by activating glutamatergic neurons in vLGN, and red light promotes nociception by activating GABAergic neurons in vLGN. Together, these results demonstrate that different colors of light exert different pain modulation effects by regulating glutamatergic and GABAergic subpopulations in the vLGN. This may provide potential new therapeutic strategies and new therapeutic targets for the precise clinical treatment of neuropathic pain.

Prognostic factors for the efficacy of infliximab in patients with luminal fistulizing Crohn's disease.

BACKGROUND: Enteric fistula is one of the penetrating features in Crohn's disease (CD). This study aimed to clarify the prognostic factors for the efficacy of infliximab (IFX) treatment in luminal fistulizing CD patients. METHODS: We retrospectively included 26 cases diagnosed with luminal fistulizing CD hospitalized in our medical center from 2013 to 2021. The primary outcome of our research was defined as death from all causes and undergoing of any relevant abdominal surgery. Kaplan-Meier survival curves were used to describe overall survival. Univariate and multivariate analyses were used to identify prognostic factors. A predictive model was constructed using Cox proportional hazard model. RESULTS: The median follow-up time was 17.5 months (range 6-124 months). The 1- and 2-year surgery-free survival rates were 68.1% and 63.2%, respectively. In the univariate analysis, the efficacy of IFX treatment at 6 months after initiation (P < 0.001, HR 0.23, 95% CI 0.01-0.72) and the existence of complex fistula (P = 0.047, HR 4.11, 95% CI 1.01-16.71) was found significantly related to the overall surgery-free survival, while disease activity at baseline (P = 0.099) also showed predictive potential. The multivariate analysis showed that efficacy at 6 months (P = 0.010) was an independent prognostic factor. The C-index of the model for surgery-free survival was 0.923 (P < 0.001), indicating an acceptable predictive effect. CONCLUSION: Prognostic model including the existence of complex fistula, disease activity at baseline and efficacy of IFX at 6 months may be useful to predict long-term outcome of luminal fistulizing CD patients.

(+)-Borneol enantiomer ameliorates epileptic seizure via decreasing the excitability of glutamatergic transmission.

Epilepsy is one common brain disorder, which is not well controlled by current pharmacotherapy. In this study we characterized the therapeutic potential of borneol, a plant-derived bicyclic monoterpene compound, in the treatment of epilepsy and elucidated the underlying mechanisms. The anti-seizure potency and properties of borneol were assessed in both acute and chronic mouse epilepsy models. Administration of (+)-borneol (10, 30, 100 mg/kg, i.p.) dose-dependently attenuated acute epileptic seizure in maximal-electroshock seizure (MES) and pentylenetetrazol (PTZ)-induced seizure models without obvious side-effect on motor function. Meanwhile, (+)-borneol administration retarded kindling-induced epileptogenesis and relieved fully kindled seizures. Importantly, (+)-borneol administration also showed therapeutic potential in kainic acid-induced chronic spontaneous seizure model, which was considered as a drug-resistant model. We compared the anti-seizure efficacy of 3 borneol enantiomers in the acute seizure models, and found (+)-borneol being the most satisfying one with long-term anti-seizure effect. In electrophysiological study conducted in mouse brain slices containing the subiculum region, we revealed that borneol enantiomers displayed different anti-seizure mechanisms, (+)-borneol (10 µM) markedly suppressed the high frequency burst firing of subicular neurons and decreased glutamatergic synaptic transmission. In vivo calcium fiber photometry analysis further verified that administration of (+)-borneol (100 mg/kg) inhibited the enhanced glutamatergic synaptic transmission in epilepsy mice. We conclude that (+)-borneol displays broad-spectrum anti-seizure potential in different experimental models via decreasing the glutamatergic synaptic transmission without obvious side-effect, suggesting (+)-borneol as a promising anti-seizure compound for pharmacotherapy in epilepsy.

Risk of malignancy in patients with inflammatory bowel disease: A population-based cohort study from China.

Carcinogenesis is one of the major complications for patients with inflammatory bowel disease (IBD) and causes poor prognosis. We aimed to describe cancer incidence in the Chinese IBD cohort compared to general population-based cancer registration data and further explore associated risk factors for cancer occurrence in IBD patients. IBD inpatients from January 1998 to January 2018 in Peking Union Medical College Hospital (PUMCH) were included in our study. Patients were followed-up from the date of IBD diagnosis until either the date of first cancer diagnosis or January 2019. Standardized incidence ratios (SIRs) of overall cancer and site-specific cancers were calculated. A total of 869 Ulcerative Colitis (UC) and 516 Crohn's disease (CD) patients were finally included with median follow-up time of 7 and 5 years, respectively. Fifty-three cases developed malignancies. After standardization by age and gender, SIR of total cancer occurrence in IBD patients was 1.77 (95% CI, 1.33-2.32). As for UC, digestive cancers (SIR 3.75; 95% CI, 2.29-5.80), thyroid cancer (SIR 10.34; 95% CI, 4.72-19.64) and hematological malignancies (SIR 6.25; 95% CI, 1.68-16.00) had the highest incidence, which were prominent in young and middle-aged patients. Use of steroids, immunosuppressants or infliximab did not present higher risk of malignancies in UC patients. There was no significant difference in cancer risk between CD patients and general population. In conclusion, the increased risks of multiple cancers are particularly prominent in Chinese UC patients and these findings can provide more targeted guidance for cancer monitoring in Chinese IBD patients.

Subicular Caspase-1 Contributes to Pharmacoresistance in Temporal Lobe Epilepsy.

OBJECTIVE: Unidentified mechanisms largely restrict the viability of effective therapies in pharmacoresistant epilepsy. Our previous study revealed that hyperactivity of the subiculum is crucial for the genesis of pharmacoresistance in temporal lobe epilepsy (TLE), but the underlying molecular mechanism is not clear. METHODS: Here, we examined the role of subicular caspase-1, a key neural pro-inflammatory enzyme, in pharmacoresistant TLE. RESULTS: We found that the expression of activated caspase-1 in the subiculum, but not the CA1, was upregulated in pharmacoresistant amygdaloid-kindled rats. Early overexpression of caspase-1 in the subiculum was sufficient to induce pharmacoresistant TLE in rats, whereas genetic ablation of caspase-1 interfered with the genesis of pharmacoresistant TLE in both kindled rats and kainic acid-treated mice. The pro-pharmacoresistance effect of subicular caspase-1 was mediated by its downstream inflammasome-dependent interleukin-1ß. Further electrophysiological results showed that inhibiting caspase-1 decreased the excitability of subicular pyramidal neurons through influencing the excitation/inhibition balance of presynaptic input. Importantly, a small molecular caspase-1 inhibitor CZL80 attenuated seizures in pharmacoresistant TLE models, and decreased the neuronal excitability in the brain slices obtained from patients with pharmacoresistant TLE. INTERPRETATION: These results support the subicular caspase-1-interleukin-1ß inflammatory pathway as a novel alternative mechanism hypothesis for pharmacoresistant TLE, and present caspase-1 as a potential target. ANN NEUROL 2021;90:377-390.

The role of cytomegalovirus colitis on short- and long-term outcomes for patients with ulcerative colitis.

BACKGROUND AND AIM: Cytomegalovirus (CMV) colitis brings great obstacles for treatment of ulcerative colitis (UC). We aimed to assess the impact of CMV colitis on prognostic outcomes and associated risk factors for UC patients. METHODS: A consecutive 77 inpatients diagnosed as UC were collected retrospectively from January 2012 to December 2015. About 33 patients were defined with CMV colitis by histological tests of colon mucosa. Clinical characteristics and outcomes were compared between patients with CMV colitis or those without. The primary outcomes were UC-related colectomy or the first time of disease relapse after discharge. RESULTS: 33 CMV colitis patients had higher frequency of recent steroid treatment (81.8% vs. 31.8%, p < .001), older age of onset (45.3 ± 13.0 vs. 44.5 ± 15.7 years, p = .028) and more severe colitis (p < .001) characterized by lower hemoglobin (99.0 ± 23.2 vs. 114.6 ± 22.6 g/L, p = .004), albumin (29.7 ± 4.6 vs. 35.4 ± 6.5 g/L, p < .001), immunoglobulin G [8.8 (5.9-10.6) vs. 12.3 (9.3-16.2) g/L, p = .003] and higher C reactive protein [48.5 (21.6-73.8) vs. 9.1 (3.6-35.0) mg/L, p < .001]. The occurrence of UC-related colectomy in patients with CMV colitis was more frequent (48.5% vs 20.5%, p<.01) and CMV colitis was proved to be one of risk factors of colectomy with a hazard ratio of 3.15 (95%CI 1.387-7.171, p = .006), mainly in a short term period. UC-related complications almost occurred within 1 year since CMV colitis diagnosis. And UC patients with CMV colitis always experienced early relapse. CONCLUSIONS: CMV colitis increases the colectomy risk mainly in a short term due to severe inflammatory response, early-onset complications or medication treatment failure. There is also potential correlation between CMV colitis and early relapse. Short-term therapy for UC patients with CMV colitis should be more concerned on controlling systemic inflammation and reducing complications whereas long-term maintenance therapy may not require more aggressive intervention.

Recurrent spontaneous pneumoperitoneum secondary to intestinal dilatation caused by allied disorders of Hirschsprung's disease: a case report.

BACKGROUND: Allied disorders of Hirschsprung's disease (ADHD) mainly present with bowel obstruction, intestinal dilatation, and chronic constipation, while recurrent spontaneous pneumoperitoneum was rarely reported. We aimed to report a case of recurrent spontaneous pneumoperitoneum caused by ADHD. CASE PRESENTATION: A 59-year-old female patient presented with progressive and severe constipation in the past 30 years. She suffered from abdominal discomfort, which was described as 'gurgling' during the last three years. Radiography showed free-air and intestinal dilatation, without any other diseases, and she was identified with recurrent spontaneous pneumoperitoneum. Gastrointestinal transit test indicated gastrointestinal motility disorder, and anorectal manometry confirmed the presence of rectal anus-suppressing reflex. Subtotal colectomy was performed to relieve apparent constipation, and the postoperative pathological examination of the colon demonstrated proliferation of nerve fibers and hyperplasia of myenteric plexuses, as well as a relatively scarcity of ganglion cells in the myenteric plexus. Based on the presentations and the postoperative pathology, she was diagnosed with ADHD. The recurrent spontaneous pneumoperitoneum was regarded as the gas escape from dilated intestines, which was in high pressure. All the symptoms and her mental state were improved after the treatment with gastrointestinal decompression and enteral nutrition. However, during follow-up visits, she had intestinal infection, and suffered from severe diarrhea and water-electrolyte imbalance, and the patient eventually died at 17 months after the diagnosis. CONCLUSION: ADHD could be a rare cause of recurrent spontaneous pneumoperitoneum, and are mainly undiagnosed or misdiagnosed. A full-thickness biopsy of the gastrointestinal tract (especially the small intestine and sigmoid colon) and differential diagnosis are recommended for the definitive diagnosis. While the ADHD have shown a poor prognosis, timely and long-term treatment with intestinal decompression and nutritional therapy could help relieve symptoms and provide a better quality of life for such patients.

The efficacy and safety of anti-tumor necrosis factor agents in the treatment of intestinal Behcet's disease, a systematic review and meta-analysis.

BACKGROUND AND AIM: Behcet's disease is a systemic vasculitis that can involve gastrointestinal tract. This is a systematic review and meta-analysis evaluating the efficacy and safety of anti-tumor necrosis factor (TNF) agents in treating patients with intestinal Behcet's disease. METHODS: We conducted searches on PubMed, Embase, and Cochrane. Data from eligible studies were used to calculate the pooled estimate of proportions of clinical remission, mucosal healing at Months 3, 6, 12, and 24 as well as the pooled incidence of adverse drug reactions. And subgroup analysis based on the specific type of anti-TNF agents was performed. RESULTS: Of the 828 studies initially identified, 13 were included finally, all of which were single-arm cohort studies. The pooled proportions of clinical remission at Months 3, 6, 12, and 24 were 0.61 (95%CI 0.48-0.78), 0.51 (95%CI 0.40-0.66), 0.57 (95%CI 0.48-0.67), and 0.38 (95%CI 0.16-0.88), respectively. The pooled proportions of mucosal healing at Months 3, 6, 12, and 24 were 0.66 (95%CI 0.50-0.86), 0.82 (95%CI 0.48-0.98), 0.65 (95%CI 0.51-0.81), and 0.69 (95%CI 0.39-1.00), respectively. The pooled estimate of proportion of overall adverse drug reactions for infliximab was 0.22 (95%CI 0.07-0.69). CONCLUSIONS: Anti-TNF agents, including infliximab and adalimumab, were an efficient therapy for intestinal Behcet's disease. The safety of anti-TNF agents used in the treatment of intestinal Behcet's disease was acceptable.

Update: Innate Lymphoid Cells in Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD) is a chronic and nonspecific intestinal inflammatory condition with high relapse rate. Its pathogenesis has been linked to dysbacteriosis, genetic and environmental factors. In recent years, a new type of lymphocytes, termed innate lymphoid cells, has been described and classified into three subtypes of innate lymphoid cells-group 1, group 2 and group 3. An imbalance among these subsets' interaction with gut microbiome, and other immune cells affects intestinal mucosal homeostasis. Understanding the role of innate lymphoid cells may provide ideas for developing novel and targeted approaches for treatment of IBD.

The Role of Saponins in the Treatment of Neuropathic Pain.

Neuropathic pain is a chronic pain caused by tissue injury or disease involving the somatosensory nervous system, which seriously affects the patient's body function and quality of life. At present, most clinical medications for the treatment of neuropathic pain, including antidepressants, antiepileptic drugs, or analgesics, often have limited efficacy and non-negligible side effects. As a bioactive and therapeutic component extracted from Chinese herbal medicine, the role of the effective compounds in the prevention and treatment of neuropathic pain have gradually become a research focus to explore new analgesics. Notably, saponins have shown analgesic effects in a large number of animal models. In this review, we summarized the most updated information of saponins, related to their analgesic effects in neuropathic pain, and the recent progress on the research of therapeutic targets and the potential mechanisms. Furthermore, we put up with some perspectives on future investigation to reveal the precise role of saponins in neuropathic pain.

Research progress on mechanism of Chinese Kaiqiao herbs in management of neuropathic pain.

The Chinese herbal medicine for Kaiqiao, such as borneol, musk, grassleaf sweetflag rhizome, storax and camphor, have been prescribed in traditional Chinese medicine for thousands of years and now are widely used for neuropathic pain, the main components of which are annular compounds. Studies have shown that their analgesic mechanisms include regulating the expression of γ-aminobutyric acid, N-methyl- D-aspartic acid and other receptors; regulating ion channel function; inhibiting inflammatory response, oxidative stress and apoptosis; regulating neurotransmission and neuronal excitability; and participating in neuroprotection and neurological repair. It is suggested that the mechanisms of action of Kaiqiao herbs in central nervous system analgesia should be further explored; high-quality rapid screening of drug targets may be used, and the targeted agents using the characteristics of Kaiqiao herbs would be developed. This article reviews the research progress on the effect mechanism of traditional Kaiqiao herbs in the treatment of neuropathic pain to provide further research directions.

Tryptophan Pathway-Targeted Metabolomics Study on the Mechanism and Intervention of Cisplatin-Induced Acute Kidney Injury in Rats.

Cisplatin is a chemotherapeutic agent widely employed in the treatment of various solid tumors. However, its use is often restricted by acute kidney injury (AKI) which is the dose-limiting adverse effect of cisplatin. While numerous studies aiming to alleviate the AKI have been conducted, there are no effective remedies in clinical practice. In this paper, a targeted metabolomics study was performed to reveal the potential relationship between tryptophan metabolism and cisplatin-induced AKI. A chemical derivatization integrated liquid chromatography coupled tandem mass spectrometry (LC-MS/MS) approach was utilized to quantify 29 metabolites in the tryptophan pathway in rat kidney medulla and cortex after cisplatin administration. Results showed that tryptophan metabolism was remarkably disturbed both in the medulla and cortex after cisplatin administration. We also found that the tryptophan pathway in the medulla was more sensitive to cisplatin exposure compared with the cortex. Among these metabolites, indoxyl sulfate was focused for further study because it accumulated most significantly in the kidney cortex and medulla in a dose-dependent manner. A function verification study proved that chlormethiazole, a widely used CYP2E1 inhibitor, could reduce the production of indoxyl sulfate in the liver and attenuate cisplatin-induced AKI in rats. In conclusion, our study depicted the tryptophan pathway in cisplatin-induced AKI for the first time and demonstrated tryptophan metabolism is closely associated with the renal toxicity caused by cisplatin, which can be of great use for the discovery of renal toxicity attenuating remedies.

Cholinergic Signaling, Neural Excitability, and Epilepsy.

Epilepsy is a common brain disorder characterized by recurrent epileptic seizures with neuronal hyperexcitability. Apart from the classical imbalance between excitatory glutamatergic transmission and inhibitory γ-aminobutyric acidergic transmission, cumulative evidence suggest that cholinergic signaling is crucially involved in the modulation of neural excitability and epilepsy. In this review, we briefly describe the distribution of cholinergic neurons, muscarinic, and nicotinic receptors in the central nervous system and their relationship with neural excitability. Then, we summarize the findings from experimental and clinical research on the role of cholinergic signaling in epilepsy. Furthermore, we provide some perspectives on future investigation to reveal the precise role of the cholinergic system in epilepsy.

Effects of dietary yeast culture on shrimp growth, immune response, intestinal health and disease resistance against Vibrio harveyi.

The current study was conducted to evaluate the effects of different levels of yeast culture (YC) supplementation at 0% (YC 0%), 1% (YC 1%), and 2% (YC 2%) on growth, feed conversion ratio, body composition, intestinal morphology, microflora, immune response, and resistance to Vibrio harveyi infection in Litopenaeus vannamei. After 8-weeks feeding trial, the results showed significant improvement (p < .05) in the final weight, weight gain rate, specific growth rate, survival rate and low feed conversion ratio in YC groups than the control. Serum total protein, superoxide dismutase, catalase, alkaline phosphatase, acid phosphatase, lysozyme, and phenol oxidase in shrimps fed diet YC (2%) were significantly higher (p < .05), whereas significantly decreased trend in serum cholesterol, triglyceride, aspartate aminotransferase, and alanine aminotransferase (p < .05) were observed in YC (2%) diet. Proteobacteria, Bacteroidetes, Actinobacteria, and Firmicutes were the core phylum bacteria found in the shrimp intestines. At the genus level, opportunistic pathogenic bacteria, Vibrio was significantly decreased (p < .05) while beneficial bacteria Pseudoalteromonas was increased in YC (2%) group. Intestinal villus height and width in shrimps fed YC diets were significantly improved than the control diet (p < .05). YC groups challenged test significantly showed (p < .05) improved shrimps immune response against V. harveyi infections with YC (2%) recording the highest percentage survival rate (70%). The present study demonstrated that supplementing YC (2%) can improve growth, intestinal microbiota, intestinal morphology, and immune response against V. harveyi infections in L. vannamei.

Influence of different oil sources on growth, disease resistance, immune response and immune-related gene expression on the hybrid grouper (♀ Epinephelus fuscoguttatus × â™‚ E. lanceolatu), to Vibrio parahaemolyticus challenge.

The aim of this study was to investigate the effects of feeding alternative dietary oils to hybrid grouper fish (♀Epinephelus fuscoguttatus × â™‚E. lanceolatu) on their growth, histological morphology of hepatocytes, disease resistance, immune response, and expression of immune-related genes. Seven experimental fish meal-based isonitrogenous and isolipidic diets were formulated containing 5% fish oil (FO; acting as controls) and various vegetable oils (VOs): corn oil (CO), sunflower oil (SO), tea oil (TO), olive oil (OO), rice oil (RO), and mixed oil (MO); comprising equal amounts of these oils). Each diet was fed to triplicate groups of 40 fish (initial mean body weight ± standard error = 15.09 ± 0.01 g) for eight weeks. The results show that 1) alternative dietary oils had no significant effects on weight gain rate, specific growth rate, protein efficiency ratio, and survival rate compared with controls (P > 0.05). The weight gain rate (WGR) and specific growth rate (SGR) of the SO group were lower than in the CO and OO groups. 2) These were no differences in morphological indexes among groups; except for the CO group, in which the condition factor and hepatosomatic index were lower than those in other groups. 3) Compared with controls, the whole-body moisture and crude protein contents in the VO groups were higher, while their crude lipid contents were lower. 4) The fatty acid contents in liver and muscle were affected by lipid type, and the contents of eicosapentaenoic acid and docosahexaenoic acid in liver and muscle in the VO groups were markedly lower than in controls. 5) Compared with control group, VO groups damaged the histological morphology of hepatocytes. 6) After a challenge with the Vibrio parahaemolyticus bacterium, there were no differences in mortality among groups. However, VO enhanced the activity of non-specific immune enzymes while down-regulating the expression of Nrf2 and inducing the expression of pro-inflammatory factors (IL1ß, TNFα, TLR22, and MyD88) in the kidney. It can be concluded that dietary VO substitution does not affect the growth of fish but damaged the histological morphology of hepatocytes and induced the expression of pro-inflammatory factors in tissues. Finally, OO and CO were recommended as the appropriate lipid replacement for FO.

Dietary biotin deficiency decreased growth performance and impaired the immune function of the head kidney, spleen and skin in on-growing grass carp (Ctenopharyngodon idella).

The aim of this study was to investigate the effects of dietary biotin deficiency on the growth performance and immune function of the head kidney, spleen and skin in on-growing grass carp (Ctenopharyngodon idella). A total of 540 on-growing grass carp (117.11 ± 0.48 g) were fed six diets containing increasing levels of biotin (0.012, 0.110, 0.214, 0.311, 0.427 and 0.518 mg/kg diet) for 70 days. Subsequently, a challenge experiment was performed by infecting them with Aeromonas hydrophila for six days. Our results showed that compared with the appropriate biotin level, (1) biotin deficiency (0.012 mg/kg diet) reduced the activities of lysozyme (LZ) and acid phosphatase (ACP), decreased the contents of complement 3 (C3), C4 and immunoglobulin M (IgM), as well as reduced the mRNA levels of antimicrobial peptides in the head kidney, spleen and skin of on-growing grass carp; (2) biotin deficiency reduced the mRNA levels of anti-microbial substances: liver-expressed antimicrobial peptide (LEAP) -2A, LEAP-2B, hepcidin, ß-defensin-1 and mucin 2 in the head kidney, spleen and skin of on-growing grass carp; (3) biotin deficiency increased the mRNA levels of pro-inflammatory cytokines interleukin 1ß (IL-1ß), IL-6, IL-8, IL-12p40, IL-15, IL-17D, tumour necrosis factor α (TNF-α) and interferon γ2 (IFN-γ2) partially in association with nuclear factor-kappa B (NF-κB) signalling and reduced anti-inflammatory IL-4/13A, IL-10, IL-11 and transforming growth factor ß1 (TGF-ß1) mRNA levels partially in association with target of rapamycin (TOR) signalling in the head kidney, spleen and skin of on-growing grass carp. Interestingly, biotin deficiency had no effect on the expression of IL-12p35, IL-4/13B, TGF-ß2, 4E-BP1 (skin only) or IKKα in the head kidney, spleen and skin of on-growing grass carp. In conclusion, the results indicated that biotin deficiency impaired the immune function of the head kidney, spleen and skin in fish. Finally, based on the percent weight gain (PWG), the ability to prevent skin haemorrhages and lesions, the LZ activity in the head kidney and the C4 content in the spleen, the optimal dietary biotin levels for on-growing grass carp (117-534 g) were estimated as 0.210, 0.230, 0.245 and 0.238 mg/kg diet, respectively.

The dynamic process of dietary soybean ß-conglycinin in digestion, absorption, and metabolism among different intestinal segments in grass carp (Ctenopharyngodon idella).

The present study aimed to investigate the dynamic process of soybean ß-conglycinin in digestion, absorption, and metabolism in the intestine of grass carp (Ctenopharyngodon idella). Fish fed with 80 g ß-conglycinin/kg diet for 7 weeks, the intestinal digestive enzyme was extracted to hydrolyze ß-conglycinin in vitro, the free amino acid and its metabolism product contents in intestinal segments were analyzed. The present study first found that ß-conglycinin cannot be thoroughly digested by fish intestine digestive enzyme and produces new products (about 60- and 55-kDa polypeptides). The indigestible ß-conglycinin further caused the free amino acid imbalance, especially caused free essential amino acid deficiency in the proximal intestine but excess in the distal intestine. Moreover, these results might be partly associated with the effect of ß-conglycinin in amino acid transporters and tight junction-regulated paracellular pathway. Finally, dietary ß-conglycinin increased the content of amino acid catabolism by-product ammonia while decreased the amino acid anabolism product carnosine content in the proximal intestine and distal intestine. Thus, the current study first and systemically explored the dynamic process of ß-conglycinin in digestion, absorption, and metabolism, which further supported our previous study that dietary ß-conglycinin suppressed fish growth and caused intestine injure.

Effects of different dietary carbohydrate-to-lipid ratios on growth, plasma biochemical indexes, digestive, and immune enzymes activities of sub-adult orange-spotted grouper Epinephelus coioides.

A 10-week feeding trial was conducted to investigate the effects of dietary carbohydrate-to-lipid (CHO:L) ratios on glycogen content, hematological indices, liver, and intestinal enzyme activity of sub-adult grouper Epinephelus coioides. Five iso-nitrogenous (496.0 g kg-1 protein) and iso-energetic (21.6 KJ g-1 gross energy) diets with varying CHO: L ratios of 0.65 (D1), 1.31 (D2), 2.33 (D3), 4.24 (D4), and 8.51 (D5), respectively, were fed to triplicate groups of 20 fish (average 275.1 ± 1.86 g). Results showed that the weight gain rate (WGR), specific growth rate (SGR), and protein efficiency ratio (PER) of sub-adult grouper increased and then stable when dietary CHO:L ratios reach D4 (CHO:L = 4.24). The trend of feed conversion ratio (FCR) was opposite to PER. Along with the dietary CHO:L ratios, the liver and muscle glycogen level increased gradually. Plasma triglycerides (TG) and glucose (GLU) were all maximized at D5 (CHO:L = 8.51) group, cholesterol (CHOL) at D4 (CHO:L = 4.24) group. Digestive enzyme activities were significantly affected by dietary CHO:L ratios. Liver hexokinase (HK), alkaline phosphatase (AKP), and glucose-6-phosphate dehydrogenase (G6PDH) activity increased significantly as CHO:L ratios increased. Liver lysozyme (LYZ) and superoxide dismutase (SOD) activity of sub-adult grouper fed the D4 diet was significantly higher than that of the D2 (CHO:L = 1.31) diet. The trend of acid phosphatase (ACP) is opposite to AKP. The regression model analysis showed that the most suitable dietary CHO:L ratio to reach the highest SGR is 6.06.